IM Platinum, 2nd Edition (1)

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CHAPTER 1

BASIC INFORMATION

I.

Introduction to Internal Medicine

II.

Core Skills in Internal Medicine

1. Electrocardiography

2. Chest Radiograph Interpretation

3. Arterial Blood Gas Interpretation

4. Thoracentesis

5. Paracentesis

6. Foley Catheter Insertion

7. Intravenous Line Insertion

III.

Normal Laboratory Values and Conversion Factors

1. Complete Blood Count

2. Blood Chemistry

3. Urine Studies

4. Equivalent Values

IV.

Intravenous Fluids

1. Intravenous Fluids and Common Indications

V.

Commonly Used Drips

1. Formulation and Computation of Basic Drips

2. Other Commonly Used Drips

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SECTION 1

INTRODUCTION TO INTERNAL MEDICINE

Internal Medicine (IM) can be quite overwhelming because of the complexity of cases and long work hours. Despite these inherent toxicities, it remains one of the most rewarding fields in Medicine. Students and practitioners alike enjoy the intellectual stimulation and experience of translating theoretical knowledge into direct patient care. As basic IM principles cannot be dissociated from the cases we encounter, it is imperative for every practitioner to acquire the core competencies and skills of an internist. The approach to patient encounter and chart writing are discussed in the succeeding parts.

II. HISTORY AND PHYSICAL EXAMINATION

Complete history and physical examination are central to hypothetico-deductive reasoning in clinical medicine. Starting from the chief complaint, problems are elicited from the in chronological order. After completing the details for acute complaints, probe into the patient’s past medical history, including present medications and pre-morbid functional capacity. Diseases in the family such as hypertension, diabetes, heart disease, early cardiac death and other heredofamilial diseases should be elicited as part of the family medical history. History of allergic reactions to drugs and food should always be elicited. Dietary habits, smoking history, alcohol intake and illicit drug use should also be included in the personal and social history. Likewise, female patients should be asked about details on menstruation and pregnancy.

The comprehensive history is followed by the systematic physical examination (PE). This starts with a general survey followed by checking the patient’s vital signs. Permission should always be asked from the patient before doing any maneuver, especially the more intrusive ones. A complete PE is carried out with special focus on certain procedures pertinent to the identified problems of the patient.

III. WRITING THE ORDERS

With the information obtained from the history and PE, a prioritized problem list is then created, with the most urgent conditions listed first. Based on the problem list, the management list is then outlined.

The orders for the patient usually contain the following:

Diet  Dietary preparations (i.e., general liquids, soft diet, full diet) and specific dietary prescriptions (i.e., low-salt, low-fat, low-purine, DAT)

Fluids and Drips  Main IV lines (i.e., plain saline, D5-containing fluids) and side drips (i.e., vasopressors, electrolyte solutions)

Monitoring  BP, HR, RR, temperature, peripheral O2 saturation, neurologic vitals, etc.)

 Frequency by which these parameters are checked (i.e., q hourly, q4h, q shift)

Diagnostics  Prioritized list of diagnostic procedures such as imaging, blood tests and special procedures Therapeutics  Medications with corresponding doses, frequency of dosing, duration and side effects to

watch out for

Transfusions

 Blood products, the amount to be transfused, rate of transfusion and interval between transfusions

 Pre-medications and side effects to watch out for

 Anticipatory measures: diuretics for possible congestion, anti-pyretics for febrile transfusion reactions

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6/10/2015 7:30am

PHYSICIAN’S ORDER SHEET Gen Med

Diagnosis: Community acquired pneumonia, moderate risk Hypertension, stage I, controlled

Diet: Low salt, low fat diet; limit oral fluid intake <1.5L day IVF: PNSS 1L x 10 hours

Side drip1: MgSO4 2g in 250cc D5W x 24 hours

Dx: Chest X-Ray (PA and lateral views) Complete blood count

Tx:

1. Ceftriaxone 2g IV q24h

2. Azithromycin 500mg/tab 1 tab OD for 3 days 3. Losartan 50mg/tab 1 tab PO OD

Monitor VS q4 with temp and O2 sat Monitor I&O q shift and record

Refer to dietary for dietary prescription and advice Watch out for desaturation and BT reaction

Jaime Aherrera MD Lic. No. 123456 IV. PRESENTING THE CASE

A. General data – begin with the name, followed by the age, sex, chief complaint, reason for admission, and date of admission or referral

“Juan dela Cruz, 28 years old male, admitted yesterday morning for dyspnea.”

B. History of present illness – review of systems and pertinent information from the past medical, family medical, personal/social, and obstetric (if applicable) histories

C. Significant diagnostic findings and their interpretations, including pertinent normal findings to rule out the differentials being considered by the team

D. Hospital course – emphasize the developments or important events that happened to the patient E. Case summary – two or three sentences

F. Assessment/problem list

G. Plan – based on the assessment/problem list; detailed and specific. Orders for the patient should have their bases and the expected laboratory findings or trends should be known

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SECTION 2

CORE SKILLS IN INTERNAL MEDICINE

ELECTROCARDIOGRAPHY

I. THE STANDARD 12-LEAD ELECTROCARDIOGRAM (ECG) A. Limb leads

 Standard limb (Bipolar) leads: I, II, III

 Augmented limb (Unipolar) leads: aVF, aVR, aVL B. Chest leads

V1 4th _{ICS, right parameter border} V2 4th _{IC, left parasternal border}

V3 Between V2 and V4

V4 5th _{ICS, left midclavicular line} V5 5th _{ICS, left anterior axillary line} V6 5th _{ICS, left midaxillary line}

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Step 1: Determine rate Step 2: Determine rhythm Step 3: Measure intervals Step 4: Determine axis

Step 5: Look for chamber enlargements

Step 6: Check for arrhythmias and other abnormalities

STEP 1: DETERMINE HEART RATE

Regular Rhythm

1500_____________

Heart Rate = # of small squares from R to R

Irregular Rhythm

Heart Rate = # of QRS complexes within 30 large boxes x 10

STEP 1: DETERMINE RHYTHM

Regular Sinus Rhythm

 Rhythm is determined by the sinus node, which fires at 60-100 bpm

 P-wave is normally upright in lead II (and usually in leads I, aVL and aVF)

 Each p-wave is followed by a QRS complex, and each QRS complex is preceded by a p-wave

 The distances between the R-R intervals should be equal

Sinus Tachycardia and Bradycardia

 Tachycardia: HR >100bpm

 Bradycardia: HR <60bpm Sinus Arrhythmia

 SA node discharges irregularly (sinus node rate varies with the respiratory cycle)

 Rate: normal

 Rhythm: varies with respiration, variation in the P-P interval and R-R interval >120 msecs

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Normal Values

Wave/Interval Description Normal Values

P-wave Atrial depolarization < 0.12 sec or <120 msec (<3 small boxes) PR interval Conduction within the AV node 0.12-0.20 sec or 120-200 msec (3-5 small boxes) QRS duration Ventricular activation < 0.11-0.12 sec or <110-120 msec (<3 small boxes) QT interval (QTc) Ventricular activation and recovery 0.35-0.43* (males) and 0.45* (females)

*may vary depending on reference

*Source: Kasper DL, et al. Harrison’s Principle of Internal Medicine, 19th _edition

Corrected QT-interval (QTc) using the Bazett’s formula

 Done to adjust for abnormal heart rates (HR <60 or >100 bpm)

QT actual

Corrected QT interval =

R-R interval in sec

STEP 4: DETERMINE AXIS

Computation of Frontal Axis

 Deduct negative deflections form positive deflections in QRS complexes to derive the values for leads I and aVF.

 If lead I is a negative integer, subtract the computed axis from 180 to get the final axis.

 Note that the value for aVF in the denominator is the absolute value, while that in the numerator takes the sign (positive or negative) into consideration. This is why a predominantly negative deflection in aVF will make the axis negative.

____90 aVF____

Axis = | I | + | aVF

 Right Axis Deviation (RAD) 100o _{to 180}o

 Left Axis Deviation (LAD) -30o_{to -90}o

 Extreme Axis Deviation -90o _{to -180}o “Eyeballing” method – can be used to estimate axis

INTERPRETATION LEAD I LEAD aVF

Normal QRS pointing UP QRS pointing UP

Left Axis Deviation QRS pointing UP QRS pointing DOWN

Right Axis Deviation QRS pointing DOWN QRS pointing UP

Extreme Axis Deviation QRS pointing DOWN QRS pointing DOWN

STEP 5: LOOK FOR CHAMBER ENLARGEMENTS

A. Atrial Enlargement

Right Atrial Enlargement (RAE)

 Peaked P-wave with > 2.5mm amplitude (> 2.5 small boxes) in leads II, III or aVF

 “P-Pulmonale” or peaked P-wave from pulmonary causes

Left Atrial Enlargement (LAE)

 Broad P-wave (> 120ms or > 3 small boxes)

 Biphasic P wave in V1 with a broad negative component

 Often notched P-wave in one or more limb leads

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SOKOLOW-LYON CRITERIA CORNELL CRITERIA

[S in V1] + [R in V5 or v6] > 35 mm (>35 small boxes) OR R in aVL>11mm S in V3 + R in aVL:  Female > 20mm  Male > 28mm

C. Right Ventricular Hypertrophy (RVH)

 Relatively tall R wave in lead V1 (R > S wave) with right axis deviation

 R in V1 > 0.7mV

 R/S in V1 > 1 with R > 0.5 mV

 R/S in V5 or V6 < 1 IV. ARRYTHMIAS

JUNCTIONAL AND IDIOVENTRICULAR RHYTHMS

A. Junctional (Atrioventricular) Rhythm

 Pacemaker: AV junction with a ventricular rate of 40 to 60 bpm

 P wave: may appear before, after, or buried within the QRS complex

 Rhythm (RR-interval): regular

 QRS complex: narrow (<0.12 sec)

B. Idioventricular Rhythm

 Pacemaker: Hiis-Purkinje system (HPS) with a ventricular rate between 15 to 40 bpm

 P wave: absent

 Rhythm (RR interval): regular

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DISORDERS OF SINUS RHYTHM

A. Sinus Pause

 Temporary cessation of sinus node activity

 May be synonymous with sinus “arrest” – which pertains to a prolonged sinus pause (definition is arbitrary)

 Difference from sinus exit block: the supposed P-P interval of the dropped beat is not a multiple of the normal P-P interval

B. Sinus Exit Block

 Failure of impulse transmission

 No visible P-QRS-T complex for >1 cycle, wherein the P-P interval of the pause is a multiple of the normal P-P interval (differentiating it from sinus pause)

ATRIOVENTRICULAR (AV) BLOCKS

A. First Degree AV Block

 Prolonged PR interval (>0.20 sec or >5 small boxes)

 P-wave is followed by a QRS complex

B. Second Degree AV Block, Mobitz Type I (Wenckebach)

 PR interval progressively lengthens, then the impulse is blocked (P is not followed by QRS, resulting in a dropped beat)

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 PR intervals of

conducted beats are constant in length, however, beats are dropped with no warning

 PR intervals may be normal or prolonged D. High Grade AV Block

 2 out of every 3 or more impulses from the atria are blocked by the AV node and fail to reach the ventricles

 PR intervals are constant (in contrast to complete heart block)

E. Third Degree (Complete) AV Block

 P and QRS waves occur regularly but are independent of each other

 No consistent

relationship between atrial and ventricular activity (AV Dissociation)

 PP intervals and RR intervals are constant

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ATRIAL ARRHYTHMIAS

A. Premature Atrial Contractions (PAC)

 Premature P-waves (earlier than the next expected sinus P-wave)

 P-wave has a different morphology compared to the sinus P-wave since this P-wave is coming from a different atrial focus

 QRS is usually narrow B. Atrial Fibrillation (AF)

 Description: Rapid,

erratic electrical discharge from multiple atrial ectopic foci

 Rate: atrial rate >350

bpm; ventricular rate varies  Rhythm: irregularly irregular  P-waves: no discernable P-wave  QRS: usually normal C. Atrial Flutter  Description: Re-entrant

circuit within the atria, with variable conduction of impulses through the AV node to the ventricles

 Rate: atrial rate is

250-350 bpm; ventricular rate varies  Rhythm: variable (depending on conduction)  P-waves: saw-tooth appearance  QRS: usually normal D. Wandering Pacemaker  Description: impulses

originate from different foci in the atrium

 Rate: normal  Rhythm: irregular  P-waves:> 3 different forms  PR interval: variable  QRS: normal

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 Rate: Fast; Irregular

atrial rate (> 100)  Rhythm: irregular  P-wave: >

3 different

forms

SUPRAVENTRICULAR TACHYCARDIA (SVT)

fast rate that the P waves may not be seen

 Rate: 150-250 bpm

 Rhythm: regular

 P waves: frequently

buried in preceding T waves

 QRS: normal, but may

be wide if abnormally conducted through ventricles (aberrant conduction)

Atrioventricular Nodal Reentrant Tachycardia (AVNRT)

 Most common form of SVT

 Narrow QRS tachycardia with a short RP interval – P-waves buried in the QRS complex

 May have a “pseudo-S” wave (which is actually a retrogradely conducted P wave) in inferior leads or “pseudo-R prime” in V1

VENTRICULAR ARRHYTHMIAS

 Wide QRS tachycardias (>120 ms or 3 small squares): usually ventricular in origin

 Differentials for wide QRS tachycardia

o Ventricular tachycardia (VT): more common o Supraventricular tachycardia (SVT) with aberrancy

 When faced with a wide-complex tachycardia and the morphology is in question, it is safer to treat as ventricular tachycardia (the more life-threatening differential)

A. Premature Ventricular Contractions (PVC)

 Prematurely occurring QRS complex which is wide and bizarre-looking

 Usually no preceding P-wave

 T wave opposite in

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Trigeminy: PVC occurs after every 2 sinus beats

Couplet: two successive PVCs (if three successive PVCs, it is already considered unsustained VT)

B. Ventricular Tachycardia (VT) 1. VT According to Morphology a. Monomorphic Ventricular Tachycardia

 Rapid, bizarre wide QRS complex (appearance of all the beats match each other in each lead)

 No P-wave  Ventricular focus produces a rapid sequence of PVC-like wide ventricular complexes b. Polymorphic Ventricular Tachycardia (Torsades de Pointes)  Beat-to-beat variations in appearance  Baseline rhythm demonstrates long QT interval  Presents with an oscillating pattern mimicking the “turning of the points” stitching pattern

2. VT According to Duration

a. Sustained: ventricular tachycardia that lasts for more than 30 seconds

b. Non-sustained: ventricular tachycardia that self-terminates within 30 seconds (presence of at least >3 successive PVCs is considered VT)

3. VT Based on Symptoms

a. Pulseless VT: no effective cardiac output (no pulse, no BP)  defibrillate (treat as ventricular fibrillation) b. Unstable VT: with pulse, but unstable BP  cardioversion

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 Associated with coarse or fine chaotic undulations

 No P-wave

 No true QRS complexes

PACEMAKER RHYTHM

A. Ventricular Paced Rhythm

 RR interval is regular

 QRS complex is wide with an LBBB morphology

 Pacemaker spike (“blip”) is followed by a wide QRS complex (good capture)

B. Atrial Paced Rhythm

 Atrial pacing appears on the ECG as a single pacemaker stimulus followed by a P wave

 PR interval and configuration of the QRS complex are similar to those seen in a sinus rhythm

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ISCHEMIA

Findings suggestive of ischemia(should be in 2 or

more contiguous leads)

 ST segment depression > 1mm (> 1 small box)

 Deep T-wave inversions > 5 mm (> 5 small boxes)

 For example, if there are ST segment

depressions of >1mm in lead V5 and V6: then we can say that there is lateral wall ischemia. If ST segment depressions occur in V3 to V6: then we can say there is anterolateral wall ischemia.

The Contiguous Leads

II, III, aVF Inferior wall

I, aVL High lateral wall

V1, V2 Septal wall

V3, V4 Anterior wall

V5, V6 Lateral wall

V1 – V3 Anteroseptal wall

V3 – V6, I, aVL Anterolateral wall V5, V6, II, III, aVF Inferolateral wall Almost all leads Diffuse, massive V3R, V4R (right-sided

leads)

Right ventricular wall

INFARCTION

A. Findings suggestive of injury or infarction

Significant ST elevation:manifestation of myocardial necrosis; the earliest sign of acute infarction

 > 1 mm ST elevation in contiguous limb leads, or

 > 2 mm ST elevation in contiguous chest leads B. Pathologic Q-Waves

 Indicate myocardial necrosis

 Significant Q-wave: > 0.04 secs duration and > 25% of the R wave amplitude

 Ignored in lead V1 unless with abnormalities in other precordial leads

 Ignored in lead III unless with abnormalities in leads II and aVF C. Classification as to Timing of Myocardial Infarction

CLASSIFICATION TIMING ECG FINDINGS

(A) Normal

(B) Acute MI Minutes to hours ST elevation + peaked or inverted T-waves + Q waves (C) Recent MI Hours to days Q-waves +ST elevation + T-wave inversion

(D) Old MI Days to months Q-waves + Isoelectric ST-segment + T-wave inversion

D. Posterior LV wall involvement

 Posterior wall ischemia, which is usually associated with lateral or inferior involvement, may be indirectly recognized by reciprocal or “mirror-image” ST depressions in leads V1 to V3

 The posterior LV wall electrical activity is not represented in a typical standard surface ECG

 The anteroseptal leads (V1 to V3) are directed form the anterior precordium pointing towards the internal surface of the posterior myocardium

E. Reciprocal Changes

 Pertains to ST-depression in leads opposite those demonstrating ST-elevation

 “Ischemia at a distance”

 Anterior MI: reciprocal change in inferior wall

 Inferior MI: reciprocal change in I, aVL, or anterior wall

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PULMONARY EMBOLISM (PE)

 McGinn-White sign: S1Q3T3 pattern (large S-wave in lead I, Q-wave in lead III, and inverted T-wave in lead III) indicating acute right heart strain

 Sinus tachycardia: most commonly cited abnormality

 T wave inversion on leads V1-V4: another most commonly cited abnormality (due to RV strain)

 Right bundle branch block

 Low amplitude deflections

ELECTRICAL ALTERNANS

 Beat to beat variation in the QRS amplitude

 Seen in massive pericardial effusion and/or cardiac tamponade

BUNDLE BRANCH BLOCKS

V1 V6

Normal

RBBB

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 QRS duration >0.12 sec (complete LBBB)

 If <0.12 sec, then it is considered incomplete LBBB

 Broad, notched, or slurred R-waves in leads I, aVL, V5 and V6

 Small or absent initial R-waves in right precordial leads (V1 and V2) followed by deep S-waves

 Absent septal Q-waves in leads I, V5 and V6

B. Right Bundle Branch Block (RBBB)

 QRS duration >0.12 sec (complete RBBB)

 If <0.12 sec, then it is considered incomplete RBBB

 Slurred S-wave in leads I and V6

 RSR pattern in V1 (“bunny ears”)

PERICARDITIS

Acute Pericarditis

A. Stages of Pericarditis

 Stage 1: Widespread ST elevation and PR depression with reciprocal changes in aVR (first two weeks)

 Stage 2: Normalization of ST changes; generalized T wave flattening (1 to 3 weeks)

 Stage 3: Flattened T waves become inverted (3 to several weeks)

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PERICARDITIS MYOCARDIAL INFARCTION

ST elevation

Diffuse ST elevations which are concave upward ST elevations which are convex upward

T-waves T-wave usually not inverted unless ST is

isoelectric

T-waves may begin to invert before ST becomes isoelectric

Q-waves Usually absent Present

Reciprocal Change Unusual Common

PR depression Usually present Absent

WOLFF PARKINSON WHITE (WPW) PATTERN

ventricle earlier than would be expected if the impulse traveled by way of the normal AV conduction system

o Triad of WPW: PR interval <120 msec, QRS >120 msec, (+) delta wave (slurred upstroke or initial portion of QRS complex) o Secondary ST-T wave abnormalities

opposite that of the delta wave and QRS forces

ARRHYTHMOGENIC RV DYSPLASIA (ARVD)

buried at the end of the QRS complex, representing delay in depolarization of the right ventricular (RV) free wall and outflow tract

 Epsilon waves, found in 50% of patients with ARVD, are due to the slowed intraventricular conduction, hence the terminal notch in the last 1/3 segment of the QRS complex (which represents the right ventricular activation)

BRUGADA ECG PATTERN

Type 1  Prominent coved ST-elevation displaying J-point amplitude or ST-elevation >2mm, followed by a negative T-wave

Type 2  >2 mm J-point elevation, >1 mm ST-elevation and a saddleback appearance, followed by a positive or biphasic T-wave

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DEXTROCARDIA (“Right Sided Heart”)

 Absent R-wave progression in the chest leads (dominant S-waves throughout)

 Predominantly negative P-wave, QRS complex, and T-wave in lead I

 Low voltage in leads V3-V6 (because these leads are placed on the left side of the chest)

 Accidental reversal of the left and right arm electrodes may produce a similar ECG pattern in the limb leads but with normal QRS morphology in the precordial leads

OTHER ECG FINDINGS

Non-specific ST-T wave changes

 T-wave inversion, ST segment depression/elevation not fulfilling the criteria for ischemia or infarction (as outlined above): flattened or slightly inverted T-waves, ST segments slightly above or below the isoelectric line

Poor R wave progression  R-wave in leads V1-V3 is < 3 small boxes

 Normal R-wave in V4-V6 Low voltage complexes

 QRS complexes <5 small boxes in limb leads or < 10 small boxes in chest leads

 Example: COPD, anasarca, obesity, myocarditis, moderate-sized to massive pericardial effusions

Electrolyte abnormalities

Hypokalemia  Prominent U wave + flattened T wave Hyperkalemia  Peaked T-waves > 10 mm, wide QRS, sine

wave pattern

Hypocalcemia  Prolonged QT interval

Hypercalcemia  Shortened QT interval

CHEST RADIOGRAPH INTERPRETATION

I. BASIC STEPS IN READING CHEST X-RAYS (CXR)

Step 1: Identify general data

Step 2: Determine view (PA, AP, lateral, decubitus) Step 3: Assess quality of film

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 Patient name

 Date/Time CXR was taken

 Diagnosis of patient

 Indication for CXR

STEP 2: DETERMINING THE VIEW

Postero-Anterior View (PA) Antero-Posterior View (AP)

Scapula winged out, ribs and clavicles more angulated Scapula not winged out; clavicles more horizontal Arms at an angle with the body, with hands at waist Arms parallel to body

Mongolian hat sign appreciated

(formed by the C7 and T1 spinous + transverse processes)

Mongolian hat sign not appreciated

Heart not magnified Heart and other structures magnified

STEP 3: ASSESSING THE QUALITY OF THE FILM

Inclusion  Apices of the lungs to the costophrenic angles should be adequately visualized Inspiratory Effort  One should count >8 intercostal spaces, 6-8 anterior ribs, 9-11 posterior ribs

Exposure  Upper four thoracic vertebrae should be visualized Obliquity  Medial ends of both clavicles equidistant from midline

 The spinous process of the thoracic vertebra should be in the midline

STEP 4: ASSESSING ANATOMY AND ABNORMALITIES

A. General Structure

 Soft tissues and bones: soft tissue swellings, rib fractures, breast shadow, osteopenia/osteoporosis

 Trachea and mediastinum: carinal angle, tracheal position, mediastinal widening, masses

 Vessels: aortic knob and pulmonary arteries

 Diaphragm: right hemidiaphragm is usually higher than the left

B. The Heart

 Assess CT ratio: >0.50 in PA view suggests cardiomegaly

 Cardiomegaly cannot be definitively ascertained on AP films, due to the possibility of magnification effects

CHAMBER PA FILM LATERAL FILM

Left ventricular enlargement

 Apex displaced inferiorly and laterally (drooping apex)

 Obliteration of retrocardiac space

Right ventricular enlargement

 Apex displaced superiorly and laterally (uplifted apex)

 Obliteration of retrosternal space

Left atrial enlargement

 Prominence of left atrial appendage

 Loss of cardiac waistline

 Widening of carinal angle (>70o₎

 Double density sign on right cardiac border

 Posterior displacement of the left mainstem bronchus on lateral film

Right atrial enlargement

 Bulging right heart border (height >1/2 of right cardiac silhouette and width 1/3 of right hemithorax)

N/A

C. The Lungs

 CP angle: blunting suggests minimal pleural effusion

 Pleura: check for pneumothorax, lesions

 Parenchyma: check for opacities, densities, infiltrates

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o Left lung (2 lobes): Left upper lobe (LUL) + lingula + left lower lobe (LLL) II. COMMON CHEST X-RAY PATHOLOGIES

Aortic Aneurysm  Mediastinum >30% of thoracic diameter, or mediastinum >8-10 cm Atelectasis

 Density in the area of the collapsed lung

 Displacement of interlobular fissures (direct sign)

 Surrounding structures deviated to the side of the collapsed lung (ipsilateral mediastinal shift)

 Crowding of vessels/bronchi

 Ipsilateral diaphragmatic elevation

Bronchiectasis  Appears as “bunches of grapes” (ring shadows)

 Tram-track lines

Consolidation  Inhomogenous opacities

 Prominent air bronchogram sign COPD/Emphysema  Hyperaerated lungs  Flattened hemidiaphragms  Tubular heart  Occasionally, bullae Fibrosis

 Decreased lung volume

 Shift of mediastinum and surrounding structures towards fibrotic area

 Blurred heart border or diaphragm with indistinct vascular markings in the areas of fibrosis

Fungus Ball  Homogenous round opacity with a crescent sign

Hamartoma  Popcorn ball lesion

Pericardial Effusion  Generalized enlargement of the cardiac shadow (“water bottle sign”) with normal vascular markings

Pleural Effusion  Blunting of costophrenic angles

 Meniscus sign

Pneumomediastinum  Presence of gas between the mediastinal structures Pneumoperitoneum  Presence of gas underneath the diaphragm

Pneumothorax

 Hyperlucent pulmonary area

 Loss of vascular markings beyond the visceral pleural line

 Mediastinal structures deviated to contralateral side (tension pneumothorax) Pulmonary edema

 Prominent hilar vessels (hilar fullness) in a bat-wing distribution

 Cephalization of vessels

 Kerley B lines Pulmonary Metastasis  Cannon ball lesions

ARTERIAL BLOOD GAS (ABG) INTERPRETATION

I. BASIC STEPS IN ABG INTERPRETATION

Step 1: Determine the primary acid-base disorder and whether compensation is appropriate Step 2: Check for secondary acid-base disorders

Step 3: Compute for anion gap and / when needed Step 4: Check oxygenation status

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A. Check the pH, HCO3 and pCO2 levels

NORMAL VALUES IN ARTERIAL BLOOD GAS

Arterial pH 7.40 + 0.05

pCO2 40 +2

HCO3 24 + 2

Anion gap 12 + 2

B. Determine Primary Problem

 To assess whether primary problem is respiratory or metabolic in origin, compare changes of HCO3and pCO2 from baseline

 If the change in HCO3 from baseline is larger, then the problem is primarily metabolic and vice versa

Check pH Check HCO3& pCO2 PRIMARY DISTURBANCE

pH <7.4

CO2>HCO3 Respiratory acidosis

pH >7.4

CO2> HCO3 Respiratory acidosis

C. Assess for appropriateness of compensation using the following formulas

PRIMARY DISORDER COMPENSATION

Metabolic acidosis For every 1 meq/L FALL in HCO3,pCO2will DECREASE by 1.2 mmHg Metabolic alkalosis For every 1 meq/L RISE in HCO3,pCO2will INCREASE by 0.7 mmHg Respiratory acidosis For every 10 mmHg RISE in pCO2, HCO3will INCREASE by 1 meq/L Respiratory alkalosis For every 10 mmHg FALL in pCO2, HCO3will DECREASE by 2 meq/L

STEP 2: CHECK FOR SECONDARY ACID-BASE DISORDERS

A. In cases where there is inappropriate compensation, a secondary acid-base disorder should be considered

PRIMARY DISORDER COMPENSATION SECONDARY ACID-BASE DISORDER

Metabolic Acidosis

Actual reduction of pCO2 from baseline is

HIGHER than that of calculated compensation

Secondary RESPIRATORY ALKALOSIS is present

Actual reduction of pCO2 from baseline is LESS

than that of calculated compensation

Secondary RESPIRATORY ACIDOSIS is present

Metabolic Alkalosis

Actual increase of pCO2 from baseline is

HIGHER than that of calculated compensation

Secondary RESPIRATORY ACIDOSIS is present

Actual increase of pCO2 from baseline is LESS

than that of calculated compensation

Secondary RESPIRATORY ALKALOSIS is present

Respiratory Acidosis

Actual increase of HCO3 from baseline is

HIGHER than that of calculated compensation

Secondary METABOLIC ALKALOSIS is present

Actual increase of HCO3 baseline is LESS than

that of calculated compensation

Secondary METABOLIC ACIDOSIS is present

Respiratory Alkalosis

Actual decrease of HCO3 from baseline is

HIGHER than that of calculated compensation

Secondary METABOLIC ACIDOSIS is present

Actual decrease of HCO3 from baseline is LESS

than that of calculated compensation

Secondary METABOLIC ALKALOSIS is present

22

A. Formula for Anion Gap

Anion gap = Na – (HCO3 + Cl)

 High anion gap is >12 B. Usual Causes of Metabolic Acidosis are as follows:

HIGH-ANION GAP METABOLIC ACIDOSIS (HAGMA) NORMAL ANION GAP METABOLIC ACIDOSIS (NAGMA)

M: Methanol U: Uremia D: Diabetic ketoacidosis P: Paraldehyde I: Isoniazid, Iron L: Lactic acidosis

E: Ethylene glycol, Ethanol S: Salicylates

H: Hyperalimentation A: Acetazolamide R: Renal tubular acidosis D: Diarrhea

U: Uretero-pelvic shunt P: Post-hypocapnia C. Check for /

1. For High-Anion Gap Metabolic Acidosis (HAGMA)

Anion Gap

HCO

 If=1, there is pure HAGMA

 If <1, there is HAGMA + NAGMA

 If >1, there is HAGMA + metabolic alkalosis 2. For Normal-Anion Gap Metabolic Acidosis (NAGMA)

Chloride

HCO

 If=1, there is pure NAGMA

 If <1, there is NAGMA + HAGMA

 If >1, there is NAGMA + metabolic alkalosis D. Computing for Bicarbonate Deficit

HCO

deficit = (desired HCO

– actual HCO

) x weight x 0.4

STEP 4: CHECK FOR OXYGENATION STATUS

STATUS PO2 LEVEL ON ABG

Hyperoxemia (more than adequate) >100 mmHg

Normoxemia 80-100 mmHg

Mild hypoxemia 60-79 mmHg

Moderate hypoxemia 45-59 mmHg

23

THORACENTESIS

 Clean (non-sterile) gloves

 Sterile gloves  Cotton  Rubbing alcohol  Betadine  Sterile gauze  Micropore  Sterile specimen vials/bottles

1. Examine the patient and review available labs (CXR, CBC, blood chemistry,bleeding parameters)

2. Explain nature of procedure to patient and obtain consent

3. Extract simultaneous serum specimen for LDH, albumin, total protein and glucose 4. Position patient in sitting position with the mid-axillary line accessible for needle insertion 5. Confirm and mark topmost site of insertion by counting ribs based on CXR and percussing fluid level (usual site of insertion is at the 8th _{ICS posterior axillary line; alternatively, chest}

UTZ with markings can be done)

6. Observe sterile technique including sterile gloves, betadine prep and drapes

7. Anesthetize skin over insertion site with 2% Lidocaine, including superior surface of the rib and pleura

8. Insert thoracentesis needle perpendicularly through the anesthetized area to the same depth as the first needle and observe backflow of pleural fluid

9. Once with backflow, leave catheter in place, remove needle and attach three-way stopcock & tubing

10. Aspirate needed amount, then turn the stopcock and evacuate fluid through the tubing (do not remove more than 1.5L to avoid increased risk of re-expansionpulmonary edema or

hypotension)

11. Fill specimen tubes/containers and label properly

12. When draining of fluid is complete, have patient take a deep breath or ask patient to cough and gently remove needle

13. Cover insertion site with sterile occlusive dressing

14. Send specimen for qualitative studies (pH, specific gravity, cell count and differentials, protein, LDH, albumin, glucose), gram stain and culture, AFB smear and additional studies as necessary (i.e., cytology for malignancy, amylase for pancreatitis, triglycerides for

chylothorax)

15. Monitor patient closely and watch out for untoward reactions (chest pain, dyspnea, cough, infection)

16. Obtain upright CXR to evaluate lung expansion/fluid level and rule out pneumothorax 17. Provide post-procedural analgesics as necessary

18. Document procedure, patient response, side effects, nature of fluid drained and lab tests sent

PARACENTESIS

 Clean (non-sterile) gloves

 Sterile gloves  Cotton  Rubbing alcohol  Betadine  Sterile gauze  Micropore

 Sterile specimen vials/ bottles

1. Examine the patient and review available labs (CXR, CBC, blood chemistry,bleeding parameters)

2. Explain nature of procedure to patient and obtain consent 3. Have patient empty bladder prior to procedure

4. Extract simultaneous serum specimen for LDH, albumin, total protein and glucose 5. Assemble materials and prepare sterile field

6. Position patient in supine position with the trunk elevated 45 degrees

7. Confirm and mark the site of access (usually midline 3-4 cm below umbilicus, halfway between symphisis pubis and umbilicus)

8. Anesthetize skin over insertion site with 2% lidocaine, down to and including the peritoneum 9. Insert paracentesis needle perpendicularly through the anesthetized area to the same depth as the first needle and observe for backflow of fluid

10.Once with backflow, leave the catheter in place, remove needle and attach tubing draining into specimen needles

11.Remove the necessary amount of ascetic fluid

12. Monitor the patient for hypotension during the procedure

13. When draining of fluid is complete, remove needle and cover insertion site with sterile occlusive dressing

14. Fill specimen tubes/containers and label properly

15. Send specimens for qualitative studies (pH, specific gravity, cell count and differentials, LDH, protein, albumin, glucose), gram stain and culture, AFB smear and additional studies as necessary (i.e., cytology for malignancy)

16. Provide post-procedural analgesics as necessary

24

FOLEY CATHETER INSERTION

MATERIALS METHOD

 Foley catheter with urine bag

 Drapes

 10cc syringe

 1 vial syringe water

 Clean (non-sterile) gloves

 Sterile gloves

 Cotton

 Rubbing alcohol

 Betadine

 Lubricant (KY jelly)

 Micropore

 Sterile specimen bottles (if for urine collection)

1. Hand hygiene 2. Prepare materials

3. Identify patient by name and introduce self to patient 4. Explain nature of procedure

5. Provide as much privacy as possible 6. Position patient properly

7. Wash and rinse urethral area

8. Open foley catheter package, put aside but maintain sterile zone around foley catheter 9. Wear clean gloves

10.Clean urethral opening aseptically:

a. For male – in circular motions inside to out b. For female – follow a “7” figure then drop 11.Change to sterile gloves

12. Lubricate tip of catheter liberally

13. Attach drainage end of foley catheter to urine bag

14. Insert lubricated end of catheter into urinary meatus gently then push gently up until you are sure you are inside the bladder (usually up to the port where you inject water and there is urine backflow)

15. Observe for urine flow

16. Infuse 5-10ml of sterile water to inflate balloon 17. Pull foley catheter slowly until with some resistance 18. Secure foley catheter with tape

19. Dry patient’s perineum

20. Instruct patient on catheter care 21. Remove gloves 22. Hand hygiene

IV LINE INSERTION

 Clean (non-sterile) gloves

 Tourniquet  Cotton  Rubbing alcohol  Micropore  Splint (optional) 1. Hand hygiene 2. Prepare materials

3. Identify patient by name and introduce self to patient 4. Explain nature of procedure

5. Wear clean gloves

6. Select position/site of venipuncture

7. Swab puncture site with alcohol on concentric circles inside to out 8. Apply tourniquet

9. Stabilize the selected site 10.Insert needle bevel up 11.Observe for blood backflow

12. Remove needle while pushing cathula further into the vein

13. Attach infusion set quickly while pressing on vein to prevent excessive escape of blood 14. Release tourniquet

15. Try running the IV line to check that fluid infuses continuously and there is no bulging at the insertion site

16. Cover the insertion site with a 1x1 sterile gauze and tape securely 17. Loop tubing and secure with tape

18. Apply splint

19. Instruct the patient on care of IV site 20. Discard sharps properly

21. Remove gloves 22. Hand hygiene

25

SECTION 3

NORMAL LABORATORY VALUES AND CONVERSION FACTORS

COMPLETE BLOOD COUNT (CBC)

Monocytes: Neutrophils: 0.02-0.09 Hemoglobin: 0.50-0.70 120-180g/L Platelets: 12.0-18.0 g/dL WBC: 150-450 x 109_{/L 4-11 x 10}9_/L 150-450 x 103_/mm3 _{4-11 x 10}3_/mm3 Hematocrit: Eosinophils: 0.37-0.54 0.00-0.06 Lymphocytes: Basophils: 0.20-0.50 0.00-0.02 RBC MCV MCH MCHC RDW-CV Reticulocytes 4-6 x 1012_/L (106_/mm3₎ 80-100 fL 27-31 pg 320-360 g/L 11-16% 0.005-0.015

BLOOD CHEMISTRY

Chloride 100-108 mmol/L 100-108 mEq/L Calcium 2.12-2.52 mmol/L 8.7-10.2 mg/dL Magnesium 0.70-1.00 mmol/L 1.5-2.3 mg/dL Phosphorus 0.81-1.4 mmol/L 2.5-4.3 mg/dL Total protein 64-83 g/L 6.4-8.3 g/dL Albumin 34-50 g/L 3.4-5.0 g/dL Globulin 23-35 g/L 2.3-3.5 g/dL

AST (SGOT) 15-37 U/L 15-37 U/L

ALT (SGPT) 30-65 U/L 30-65 U/L

Alkaline phosphatase

36-92 umol/L 36-92 umol/L Total bilirubin 0-17.1 umol/L 0.3-1.3 mg/dL Direct bilirubin 0-5.00 umol/L 0.1-0.4 mg/dL

Indirect bilirubin 3.4-13.7 umol/L 0.2-0.9 mg/dL

Uric acid 0.13-0.44

umol/L

3.1-7.0 mg/dL

Ammonia 11-35 umol/L 19-60 ug/dL

Amylase 0.34-1.6 ukat/L 30-110 U/L

LABORATORY SI CONVENTIONAL Lipase 0.51-0.73 ukat/L 23-300 U/L LDH 2.0-3.8 ukat/L 100-190 U/L CRP 0.2-3.0 mg/L 0.2-3.0 mg/L RF < 30 kIU/L < 30 kIU/mL Free T4 10.3-21.9 pmol/L 0.8-1.7 ng/dL Free T3 3.7-6.5 pmol/L 2.4-4.2 pg/mL TSH 0.34-4.25 mIU/L 0.34-4.25 uIU/mL PSA < 40 y/o 0.0-2.0 ug/L 0.0-2.0 ng/mL PSA > 40 y/o 0.0-4.0 ug/L 0.0-4.0 ng/mL

AFP 0.0-8.5 ug/L 0.0-8.5 ng/mL CA 125 0-35 kU/L 0-35 U/mL CA 19-9 0-37 kU/L 0-37 U/mL CEA (nonsmokers) 0-3.0 ug/L 0-3.0 ng/mL CEA (smokers) 0-5.0 ug/L 0-5.0 ng/mL

CK-total 55-170 U/L 55-170 U/L

CK MB 0-16 U/L 0-16 U/L

CK MM 8-97 U/L 8-97 U/L

26

URINE STUDIES

URINALYSIS

Color Yellow, clear/hazy

Specific gravity 1.016-1.022 pH 4.6-6.5 Sugar, Albumin (-) RBC 0 / 0-2 / hpf WBC 0-2 / 0-5 / hpf

Casts Hyaline, coarse, fine, granular, waxy

Crystals Small amounts

Epithelial cells Small amounts

Bacteria (-)

Mucus thread Small amounts

24 HOUR URINE CHEMISTRY

Total volume 500-2000cc Creatinine 0.65-0.70 g/L or 8.8-14 mmol/d Total protein 0-0.1 g/24hr or < 100 mg/d Na+ 80-260 mmol/L K+ 25-100 mmol/L Cl- 80-340 mmol/L

Uric acid 4.42-5.9 mmol/24hr

CA2+ _{2.5-7.5 mmol/24hr}

Phosphorus 22.4-33.6 mmol/24hr

Amylase 64.75-490.25 U/L

Mucus thread Small amounts

Microalbumin N: 0.0-0.03 g/d Microalbuminuria: 0.03-0.30 g/d Clinical albuminuria: >0.3 g/d

EQUIVALENT VALUES

BUN (mmol/L) Multiply by 2.8

Creatinine (umol/L) Divide by 88.4

Calcium (mmol/L) Divide by 0.25

Magnesium (mmol/L) Divide by 0.411

Bilirubin (umol/L) Divide by 17.10

Uric acid (umol/L) Divide by 59.48

HDL or LDL (mmol/L) Divide by 0.0259

Triglycerides (mmol/L) Divide by 0.0113

Equivalent values of common interventions

INTERVENTION EQUIVALENT 1 cc 10% oral KCl 1.33 meqs K+ 15 cc 10% oral KCl 20 meqs K+ 30 cc 10% oral KCl 40 meqs K+ Kaliumdurule (750mg) 10 meqs K+ 1 medium sized banana Roughly 7-10 meqs K+ NaHCO3 50mL 45 meqs Na+ NaHCO3GrX tab (650 mg)

7.7 meqs Na+_{per tab}

NaCl tab (1g) 17 meqs Na+ _{per tab}

Normal saline solution (1L)

27

SECTION 4

INTRAVENOUS FLUIDS

INTRAVENOUS FLUIDS AND COMMON INDICATIONS

I. BASIC TYPES OF INTRAVENOUS FLUIDS

IV FLUIDS DESCRIPTIONS EXAMPLES

Crystalloids

 Balanced salt / electrolyte solutions which may be isotonic, hypertonic or hypotonic

 Normal saline (0.9% NaCl), lactated Ringer’s, hypertonic saline (3, 5, 7.5%), Ringer’s solution

Colloids

 High-molecular weight solutions which draw fluid into the intravascular component via oncotic pressure

 Effective plasma expanders

 Albumin, hetastarch, pentastarch, plasma and dextran

Free H2O solutions

 Provide water that is not bound by macromolecules or organelles, thus is free to pass through membranes

 D5W (5% dextrose in water), D10W, D20W, D50W, D50-50, dextrose/ crystalloid mixes

Blood products  Essentially are also considered colloids

 Whole blood, pRBC, FFP,

cryoprecipitate, platelet concentrate II. COMPOSITION OF INTRAVENOUS FLUIDS

IV FLUID Glucose Na+ _Cl- _K+ _CA2+ _HCO

3 COMMENTS

D5W 50 gm/L

 Useful in dehydrated states and hypernatremia

 Can be used as diluents

D10W 100 gm/L  Used to correct hypoglycemia

0.9 NSS 154 154  Fluid of choice for initial resuscitation

 Can be used as diluents D5 0.9 NSS 50 gm/L 154 154

 Same as 0.9 NSS but with additional glucose

 Useful for patients on NPO

LR 130 109 4 3 28  Useful for trauma, surgery and burn

patients

NR 140 98 5

D5NM 50 gm/L 40 40 13

 Routine fluid and electrolyte maintenance with minimal carbohydrate calories

D5NMK 50 gm/L 40 40 30  Same as D5NM but with additional

potassium content III. USUAL INDICATIONS FOR IV FLUID ADMINISTRATION

 Maintain normal blood pressure: normal or isotonic saline is the initial fluid of choice

 Return the intracellular (ICF) volume to normal

o In patients with acute hyponatremia, the ICF volume in the brain rises and could become dangerous high with more prominent decline in plasma sodium  hypertonic saline usually given to raise the plasma sodium

o When there is a large water deficit in the ICF compartment (e.g. severe hypernatremia), electrolyte-free water (D5W) is given

 Replace ongoing renal losses

 Give maintenance fluids to match insensible losses

28

1. Normal Saline (0,9% NaCl, pNSS)

 Least expensive and most commonly used resuscitative crystalloid

 High Cl content imposes on the kidneys an excess Cl load that cannot be rapidly excreted  risk of hyperchloremic acidosis

 The only solution that may be administered with blood products

 Does not provide free water or calories 2. Lactated Ringer’s (LR) Solution

 Lactate is converted readily to bicarbonate in the liver

 Minimal effects on normal body fluid composition and pH

 Most closely resembles the electrolyte composition of normal blood serum

 Does not provide calories 3. D5W or ¼ Normal Saline

 Provides 170 calories/L from 5% dextrose

 Provides free water for insensible losses and some sodium to promote renal function and excretion

 With added potassium, this is an excellent maintenance fluid in the immediate postoperative period

 Prevents excess catabolism and limits proteolysis 4. Hypertonic Saline (3% NaCl)

 1026 mOsm/L, 513 mEq/L Na+

 Increases plasma osmolality and thereby acts as a plasma expander, increasing circulatory volume via movement of intracellular and interstitial water into the intravascular space

 Due to high sodium content, poses high risk of hypernatremia

Before proceeding to the next section, here are some general terminologies using drips:

cc/hr

equal to

mL/hr

equal to

ugtt/min

ugtt/min

(microdrops/min) divided by

4

is EQUAL TO

gtt/min

(drops/min)

dose (mcg / kg / min) x BW in kg x 60 min

Infusion rate (cc / hr) = solution concentration (mcg / cc)

dose of drug (mcg)_

solution concentration (mcg / cc) = volume of diluent (cc)

29

SECTION 5

COMMONLY USED DRIPS

FORMULATION AND COMPUTATION OF BASIC DRIPS

I. DOPAMINE

 Generally used to augment BP and cardiac output in patients with cardiogenic shock

 Dopamine releases norepinephrine from nerve terminals, which itself stimulates A1 and B1 receptors

 Usually started at an infusion rate of 2-5 mcg/kg/min

 Dose is increased every 2-5 minutes to a maximum of 20-50 mcg/kg/min A. Things to know about Dopamine:

Preparation  One ampule contains 200 mg dopamine

Sample order  Dopamine drip: 200mg dopamine (1 ampule) + 250 cc D5W to run for ____ cc/hr

Dopamine factor

 For a formulation of 1 ampule (200mg) in 250 cc D5W factor, used is 13.3

 For a formulation of 2 ampules (400mg) in 250 cc D5W factor, used is 26.6

NOTE: A more concentrated dose is usually chosen for patients who cannot tolerate fluid overload (e.g. patients with CHF, CKD)

B. Dopamine demonstrates varying Hemodynamic Effects based on the dose

DOSE MECHANISM OF ACTION EFFECT

< 2 mcg/kg/min Activates DA1 and DA2 receptors

Renal Vasodilation:

Vasodilation of splanchnic and renal vasculature

2-10 mcg/kg/min Activates B1-receptors

Inotropic:

Increase in cardiac output with little or no change in HR or SVR

> 10 mcg/kg/min

Effects on A1-receptors overwhelm the dopaminergic

receptors

Vasoconstrictor:

Vasoconstriction, leading to increase in SVR, LV filling pressures, and HR

Source: Fauci, et.al, Harrison’s Principles of Internal Medicine 19th _{edition, 2015.}

C. Computation of Dopamine Drip Rate based on Desired Dose

mcg

Desired dose kg min x Body Weight (kg)

Dopamine drip rate (ugtt/min) = Dopamine factor

D. Sample computation

 55/F patient, 45kg, admitted for cardiogenic shock with BP of 80/50 mmHg

 If our desired dose is 10mcg/kg/min (chronotropic/inotropic dose) and we decide to give 400mg (2 amps) dopamine (factor is 26.6), the dopamine rate is computed as follows:

mcg

Dopamine drip rate (ugtt/min) =

10 kg min x 45 (kg) =

16.9 = 17 cc/hr = 17 ugtt/min

26.6

30

 Start dopamine drip: 400mg (2amps dopamine) + 250cc D5W x 17 cc/hr (dose of ~10 mcg/kg/min)

 Titrate by 2-3 cc/hr to maintain BP > 90/60

E. Reverse computation: computing for the DOSE of dopamine being administered

 Note that when reporting/endorsing a case, it is better to state the dose of dopamine that the patient is being given and not the drip rate. To compute for the specific dose, use the following formula

Dopamine drip rate ugtt x Dopamine factor

mcg min = min________________

Dopamine dose kg body weight (kg)

Example:

Patient is a 45-kg, 55/F, given 2 amps of Dopamine (200 mg/amp) in 250cc PNSS at a rate of 19 ugtts/min (or 19cc/hr). QUESTION: What is the dose of dopamine being given to the patient?

Dose given (in mcg/kg/min) = rate (in ugtt/min) x 26.6

= 19ugtt/min x 26.6 = 11.23mcg/kg.min

45 kg 45 kg

Answer: 11.23 mcg/kg/min is the dose being given to the patient at a rate of 19 ugtts/min (or 19cc/hr). Since

we are giving 11.23 mcg/kg/min, we have a vasoconstricting effect which is beneficial in a patient with septic

shock. If the patient is still hypotensive, we can increase the ugtt/min (titrate) up 34 ugtt/min (20mcg/kg/min)

for a 45-kg patient (“dopa max”). If still with no response to maximal dopamine dosing, we can start another

inotrope like norepinephrine.

In the computation, we used 26.6 because 2 ampules of dopamine were used for the patient.

1. Dopamine 200 mg + 250 cc D5W preparation Drip Rate (ugtt/min or cc/hr) Body Weight in Kg 40 kg 50 kg 60 kg 70 kg 80 kg 90 kg Dose (mcg/ kg/min) 2.5 7.5 cc/hr 9.4 cc/hr 11.3 cc/hr 13.1 cc/hr 15.0 cc/hr 16.9 cc/hr 5.0 15.0 cc/hr 18.8 cc/hr 22.5 cc/hr 26.3 cc/hr 30.0 cc/hr 33.8 cc/hr 7.5 22.5 cc/hr 28.1 cc/hr 33.8 cc/hr 39.4 cc/hr 45.0 cc/hr 50.6 cc/hr 10.0 30.0 cc/hr 37.5 cc/hr 45.0 cc/hr 52.5 cc/hr 60.0 cc/hr 67.5 cc/hr 15.0 45.0 cc/hr 56.3 cc/hr 67.5 cc/hr 78.8 cc/hr 90.0 cc/hr 101.3 cc/hr 20.0 60.0 cc/hr 75.0 cc/hr 90.0 cc/hr 105.0 cc/hr 120.0 cc/hr 135.0 cc/hr 2. Dopamine 400 mg + 250 cc D5W Preparation Drip Rate (ugtt/min or cc/hr) Body Weight in Kg 40 kg 50 kg 60 kg 70 kg 80 kg 90 kg Dose (mcg/ kg/min) 2.5 3.8 cc/hr 4.7 cc/hr 5.6 cc/hr 6.6 cc/hr 7.5 cc/hr 8.4 cc/hr 5.0 7.5 cc/hr 9.4 cc/hr 11.3 cc/hr 13.1 cc/hr 15.0 cc/hr 16.9 cc/hr 7.5 11.3 cc/hr 14.1 cc/hr 16.9 cc/hr 19.7 cc/hr 22.5 cc/hr 25.3 cc/hr 10.0 15.0 cc/hr 18.8 cc/hr 22.5 cc/hr 26.3 cc/hr 30.0 cc/hr 33.8 cc/hr 15.0 22.5 cc/hr 28.1 cc/hr 33.8 cc/hr 39.4 cc/hr 45.0 cc/hr 50.6 cc/hr 20.0 30.0 cc/hr 37.5 cc/hr 45.0 cc/hr 52.5 cc/hr 60.0 cc/hr 67.5 cc/hr

31

 A synthetic sympathomimetic amine with positive inotropic action

 Effects are due to selective stimulation of B1 adrenergic receptors A. Things to know about Dobutamine:

Preparation  One ampule contains 250 mg dobutamine

Sample order  Dobutamine drip: 250mg dobutamine (1 amp) + 250 cc D5W to run for ___ cc/hr

Dobutamine factor

 For a formulation of 1 ampule (250 mg) in 250 cc D5W, factor used is 16.6

 For a formulation of 2 ampules (500 mg) in 250 cc D5W,factor used is 33.2

NOTE: A more complicated dose is usually chosen for patients who cannot tolerate fluid overload (e.g. patients with CHF, CKD)

B. Effects of Dobutamine (dose-dependent)

 Minimal positive chronotropic activity at low doses(2.5 mcg/kg/min) and moderate chronotropic activity at

higher doses

 Usually given at 10 mcg/kg/min, however, its vasodilatory effect at this dose precludes its use in patients with decreased systemic vascular resistance

C. Computation of Dobutamine Drip Rate based on Desired Dose

Desired dose mcg min x Body weight (kg)

Dobutamine Drip Rate (ugtt/min) = kg_____________________

Dobutamine factor

D. Sample computation

 60/M patient, 50 kg, in cardiogenic shock from decompensated heart failure with BP of 80/50 mmHg

 If our desired dose is 5 mcg/kg/min and we decide to use 500 mg (2 amps) dobutamine (factor is 33.2)

5 mcg min x 50 (kg)

Dobutamine Drip Rate (ugtt/min) = kg_______________ = 7.5 = 8cc/hr = 8 ugtt/min

33.2

Sample chart order:

 Start dobutamine drip: 500 mg (2 amps dobutamine) + 250 cc D5W x 8 cc/hr (dose of 5 mcg/kg/min)

 Titrate by 2-3 cc/hr to maintain BP >90/60 until 15 cc/hr (~10 mcg/kg/min)

 The maximum dose of 15 cc/hr was computed using the dose 10 mcg/kg/min

 Note that when endorsing a case, it is better to state the dose of dobutamine that the patient is being given and not the drip rate

 To compute for the specific dose, use the following formula

Dobutamine drip rate ugtt x Dobutamine factor

Dobutamine Dose mcg min = min_____________________

kg body weight (kg)

32

1. Dobutamine 250 mg + 250 cc D5W Preparation Drip Rate (ugtt/min or cc/hr) Body Weight in Kg 40 kg 50 kg 60 kg 70 kg 80 kg 90 kg Dose (mcg/ kg/min) 2.5 6.0 cc/hr 7.5 cc/hr 9.0 cc/hr 10.5 cc/hr 12.0 cc/hr 13.5 cc/hr 5.0 12.0 cc/hr 15.0 cc/hr 18.0 cc/hr 21.0 cc/hr 24.0 cc/hr 27.0 cc/hr 7.5 18.0 cc/hr 22.5 cc/hr 27.0 cc/hr 31.5 cc/hr 36.0 cc/hr 40.5 cc/hr 10.0 24.0 cc/hr 30.0 cc/hr 36.0 cc/hr 42.0 cc/hr 48.0 cc/hr 54.0 cc/hr 15.0 36.0 cc/hr 45.0 cc/hr 54.0 cc/hr 63.0 cc/hr 72.0 cc/hr 81.0 cc/hr 20.0 48.0 cc/hr 60.0 cc/hr 72.0 cc/hr 84.0 cc/hr 96.0 cc/hr 108.0 cc/hr 2. Dobutamine 500 mg + 250 cc D5W Preparation Drip Rate (ugtt/min or cc/hr) Body Weight in Kg 40 kg 50 kg 60 kg 70 kg 80 kg 90 kg Dose (mcg/ kg/min) 2.5 3.0 cc/hr 3.8 cc/hr 4.5 cc/hr 5.3 cc/hr 6.0 cc/hr 6.8 cc/hr 5.0 6.0 cc/hr 7.5 cc/hr 9.0 cc/hr 10.5 cc/hr 12.0 cc/hr 13.5 cc/hr 7.5 9.0 cc/hr 11.3 cc/hr 13.5 cc/hr 15.8 cc/hr 18.0 cc/hr 20.3 cc/hr 10.0 12.0 cc/hr 15.0 cc/hr 18.0 cc/hr 21.0 cc/hr 24.0 cc/hr 27.0 cc/hr 15.0 18.0 cc/hr 22.5 cc/hr 27.0 cc/hr 31.5 cc/hr 36.0 cc/hr 40.5 cc/hr 20.0 24.0 cc/hr 30.0 cc/hr 36.0 cc/hr 42.0 cc/hr 48.0 cc/hr 54.0 cc/hr III. NORADRENALINE/NOREPINEPHRINE

 A potent vasoconstrictor and inotropic stimulant

 Despite non-significant improvement in survival compared to patients given dopamine, the relatively safer profile of norepinephrine makes it a good initial vasopressor therapy

 Usually started at a dose of 2 to 4 mcg/minand titrated upward as necessary

 If systematic perfusion or systolic pressure cannot be maintained at >90 mmHg with a dose of 15 mcg/min, it is unlikely that a further increase in dose will be beneficial

A. METHOD 1: Long Method

Step 1: Compute for concentration

stock (mg) x 1000 mcg Concentration = 250 cc IVF 1 mg

EXAMPLE: For 4 mg norepinephrine + 250 cc D5W

4 mg x 1000 mcg Concentration = 250 cc 1 mg

Step 2: Compute for infusion rate mcg / min

Infusion rate cc = dose kg x weight (kg) x 60 min/hr hr concentration (mcg/cc)

Sample chart order:

 To start norepinephrine drip as follows: 4 mg norepinephrine + 250 D5W x 38 cc/hr (0.2 mcg/kg/min or 10 mcg/min in a 50 kg patient)

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Dose mcg / min =Infusion rate (cc/hr) x concentration (mcg/cc)

kg weight (kg) 60 min/hr

B. METHOD 2: Short-Cut Method

Computation for Norepinephrine Drip Rate based on Desired Dose

Desired dose (mcg/min)____

Norepinephrine Drip Rate (ugtt/min) = Norepinephrine factor

Norepinephrine Factor

 Norepinephrine drip: 2 mg (1 amp) + 250cc D5W (factor used: 0.133)

 Norepinephrine drip: 4 mg (2 amps) + 250cc D5W (factor used: 0.266)

 Norepinephrine drip: 8 mg (4 amps) + 250cc D5W (factor used: 0.532)

*A more concentrated dose is usually chosen for patients who cannot tolerate fluid overload

C. For quick reference:

Drip rate (ugtt/min or cc/hr) Dose (mcg/min) Norepinephrine 2mg + 250 cc D5W Preparation Norepinephrine 4mg + 250 cc D5W Preparation 5 cc/hr 0.7 mcg/min 1.3 mcg/min 10 cc/hr 1.4 mcg/min 2.7 mcg/min 15 cc/hr 2.0 mcg/min 4.0 mcg/min 20 cc/hr 2.7 mcg/min 5.3 mcg/min 25 cc/hr 3.4 mcg/min 6.7 mcg/min 30 cc/hr 4.0 mcg/min 8.0 mcg/min 40 cc/hr 5.5 mcg/min 10.7 mcg/min 50 cc/hr 6.7 mcg/min 13.3 mcg/min 60 cc/hr 8.0 mcg/min 16.0 mcg/min 70 cc/hr 9.4 mcg/min 18.7 mcg/min 80 cc/hr 10.7 mcg/min 21.3 mcg/min 90 cc/hr 12.0 mcg/min 24.0 mcg/min 100 cc/hr 13.4 mcg/min 26.7 mcg/min

IV. UNFRACTIONED HEPARIN (UFH)

 A sulfated polysaccharide usually isolated from mammalian tissues rich in mast cells

 Acts as an anticoagulant by activating antithrombin (AT III) and accelerating the rate at which antithrombin inhibits clotting enzymes, particularly thrombin and factor Xa

A. Usual Formulation of Heparin Drip

 Heparin drip: 10,000 units of UFH in enough pNSS to make 100 cc in a soluset (concentration of 10,000

units/100 cc or 100 units/cc) B. Usual doses for Common Indications

Myocardial infarction = “60-12” 60 units/kg IV push as loading dose then start IV drip at 12 units/kg/hr Deep vein thrombosis or

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 PTT is ideally monitored every 6 hours (after a dose change) and IV drip adjusted accordingly to reach target PTT of 1.5-2.5 times the control (46-70 sec)

 Raschke’s Protocol

aPTT Heparin Adjustment

<1.2x control 80 u/kg IV bolus then add 4 u/kg/hr to infusion rate 1.2 to 1.5x control 40 u/kg IV bolus then add 2 u/kg/hr to infusion rate 1.5 to 2.3x control No change

2.3 to 3.0x control Decrease infusion rate by 2 u/kg/hr

>3.0x control Discontinue for 1 hour, then decrease infusion rate by 2 u/kg/hr

 Mayo Clinic Protocol

aPTT (seconds) Heparin Adjustment

<35 80 u/kg bolus then increase drip rate by 4 u/kg/hr 35-45 40 u/kg bolus then increase drip rate by 2 u/kg/hr

46-70 No change

71-90 Reduce drip rate by 2 u/kg/hr

>90 Withhold heparin for 1 hour then reduce drip rate by 3 u/kg/hr

*Order a PTT 6 hours after any dosage change and adjust accordingly until PTT is therapeutic (~46-70). When two consecutive PTTs are therapeutic, order PTT every 24 hours

V. INSULIN DRIP (Insulin regimen would depend on the indication) A. For Hyperkalemia

 Insulin causes K+ _{shift (extracellular potassium goes intracellularly)}

 Glucose-Insulin (GI) solution: 50 mL of 50% Dextrose in Water (D50-50) + 10 units Regular Insulin in 2-5 minutes

 Sample order: Mix 1 amp D50-50 + 10 units Humulin-R IV stat, then q6h x 4 doses B. For Hyperglycemia

1. Formulation of Insulin drip (depends on physician)

 Example (drip 1) 20 units of Insulin (HR) in 100cc pNSS = concentration of 0.2unit/cc (20units/100cc)

 Example (drip 2) 50 units of Insulin (HR) in 100cc pNSS = concentration of 0.5unit/cc (50units/100cc)

 Example (drip 3) 100 units of Insulin (HR) in 100cc pNSS = concentration of 1unit/cc (100units/100cc) 2. Examples

Example 1: If we decide to give our patient 2 units of insulin per hour (via insulin drip):

 For drip 1: give 10 cc per hour (10 cc/hr or 10 gtts/min)

 For drip 2: give 4 cc per hour (4 cc/hr or 4 ugtts/min)

 For drip 3: give 2 cc per hour (2 cc/hr or 2 ugtts/min)

Example 2: Start drip at 0.1 unit/kg/hr, titrate to desired blood glucose

 If the patient is 50kg, start Insulin drip at 5 units/hr. if we decide to use drip #3 form the example above, the order will be: Insulin drip 100 units HR + 100 cc pNSS at a rate of 5 cc/hr (to deliver 5 units/hr)

V. NICARDIPINE

 An intravenous calcium channel blocker used as a first-line agent in the management of hypertensive crises A. Things to know about Nicardipine:

Preparation One 10 mL ampule contains 10 mg Nicardipine Usual formulation

Drip: 10 mg Nicardipine + 90 mL D5W or pNSS in soluset

Concentration: 0.1 mg/mL of Nicardipine Dose Initial dose 5 mg/hr (ex. HPN emergency)

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0.1 mg/cc

Some would give an initial IV bolus prior to starting drip Titration Titrate by 2,5 mg/hr q15 minutes until target BP is reached

Maximum dose: 15 mg/hr B. Sample chart order:

 Start Nicardipine drip as follows: 10 mg Nicardipine + 90 cc D5W in a soluset x 50 cc/hr, titrate by 2.5 mg/hr every 15 minutes until target BP is reached

VI. NITROGLYCERIN (GLYCERYL TRINITRATE)

 Organic nitrate which causes systemic venodilation, decreasing preload and afterload and reducing myocardial oxygen demand

 Also improves coronary collateral circulation A. Things to know about Nitroglycerin

Preparation One ampule contains 10 mg nitroglycerin Usual formulation

Drip: 10 mg + 90 cc D5W in soluset

Concentration: 0.1 mg/cc of NTG 100 mcg/cc of NTG Dose

Initial dose 5 mcg/min or 300 mcg/hr 300 mcg/hr = 3 cc/hr (or 4 uggt/min) 100 mcg/cc

Titration Titrate by 5 mcg.min q5min until pain relief is achieved or BP is controlled B. Sample chart order:

 Start nitroglycerin drip: 10mg nitroglycerin + 90cc D5W in a soluset x 3cc/hr, titrate by 3 cc/hr until chest pain-free