BLOOD PRESSURE AND SHOCK
Stabilization of the Newborn 2021Peg Peterson, APRN
SHOCK
•
An acute, complex state of circulatory dysfunction resulting
in insufficient oxygen and nutrient delivery to satisfy tissue
requirements
SHOCK
Compensated Shock
•A complex series of responses are activated to maintain BP and preserve blood flow to vital organs
•Brain •Heart
•Adrenal Gland
•Blood is diverted away from non vital organs
•Skin •Muscle •GI Tract •Liver •Kidneys
REGULATION OF BP
•Involves•Neural and endocrine systems •Central and peripheral levels
•ABP is determined by the cardiac output and peripheral vascular resistance
BLOOD PRESSURE
•Defining normal versus hypotension is a complicated issue.
•Research is lacking that ID’s normal and what to treat.
•Common practice uses mean arterial pressure (MAP)
•Gestational Age
•Assessment of Neonates overall well-being and perfusion must be taken into consideration when making diagnosis of hypotension.
•CRT
•Mental state
•Poor cardiac output •Lab tests
PULSE PRESSURES
•
Systolic BP-Diastolic BP = Pulse Pressure
•
Normal: term: 25-35, preterm:15-25
•
Narrow PP: Peripheral vasoconstriction
•Heart Failure
•Compression of Heart
•Aortic stenosis
•Wide PP: Large aortic runoff lesion
•PDA
•AV malformation •Truncus
SHOCK
If shock is not quickly identified and reversed-•Metabolism converts to anaerobic
•Oxygen debt worsens
•Increased lactic acid
•Metabolic acidosis
•Cardiac output falls as heart muscle weakens
•The body compensates as long as it can
•Hypotension develops
•Uncompensated shock
CARDIAC OUTPUT
HR X SV = CO
Heart Rate x Stroke Volume = Cardiac Output
7TACHYCARDIA
•HR sustained >180 bpm•HR increases when trying to compensate for low cardiac output
•Neonatal myocardium has a poor capacity to increase SV unless augmented with BP meds and or volume
FACTORS THAT INFLUENCE CARDIAC OUTPUT
•Electrolyte Imbalance•Decreased Venous Return (preload)
•Increased Systemic Vascular Resistance (afterload)
•Decreased Myocardial Contractility
HYPOTENSION IN VLBW INFANTS
•Occurs in 30% of VLBW infants•16-25% treated with volume
•39% need vasopressor treatment
•VLBW infants have:
•Poor vasomotor tone •Immature myocardium
•Dysregulated NO production
•Recommend vasopressors over volume due to BPD risk
For cells to survive and function they need oxygen
11SHOCK
Failure to promptly recognize and treat shock may lead to
cellular dysfunction and multiple organ failure and even death.
EVALUATION FOR SHOCK
•Respiratory Effort •Color •Heart Rate •Blood Pressure •Pulses •Perfusion •Heart •Urine Output 13TYPES OF SHOCK
•Hypovolemic•Cardiogenic
•Septic
HYPOVOLEMIC
Acute Blood loss during intrapartum period
•Placenta abruption/previa•Umbilical cord injury
•Organ laceration
•Fetal to maternal hemorrhage
•Twin to twin
HYPOVOLEMIC
Postnatal Hemorrhage
•Brain •Lung •Adrenal •Scalp(subgaleal)HYPOVOLEMIC
Obstruction Etiology
•Pneumothorax •Pneumopericardium 17HYPOVOLEMIC
•Umbilical Cord Accidents•Nuchal cord •Cord prolapse •Cord knot
•Cord entanglement •Velamentous insertion
•Severe Capillary Leak-sepsis
•Dehydration
CYANOSIS
•Babies need 3-5gm of Hgb to be desaturated for cyanosis to appear.
•Also has influence on saturations.
•Hgb is 1/3 of Hct.
•Hct 30=Hgb10 •Hct 21=Hgb 7 •Hct 15=Hgb 5 19
CARDIOGENIC SHOCK
Heart muscle functions poorly
•Intrapartum/postpartum asphyxia •Hypoxia and or metabolic acidosis •Bacterial/viral infections
•Severe RDS
•Severe hypoglycemia
•Severe metabolic/electrolyte disturbances •Arrhythmia
•CHD
SEPTIC SHOCK-DISTRIBUTIVE
•Severe infections•Rapidly become critically ill
•Bacterial Infections
•Hypotension responds poorly to volume
•Capillary Leak=hypovolemic shock
•Poor cardiac function leads to poor tissue perfusion and decreased oxygenation
SHOCK
Infants can and may
have a combination of
all 3 types of shock
LABORATORY EVALUATION FOR SHOCK
•Blood gas •Lactate •CBC •Blood culture •Coagulation studies •Liver function 23OTHER TESTS
•EKG •ECHO •Urine output •Newborn ScreensTREATMENT OF SHOCK
•Identify the cause or causes•Identify and correct any related or underlying problems that may impair heart function
GOALS FOR TREATING
SHOCK
KARLSEN, 2013
TREATMENT OF HYPOVOLEMIC SHOCK
•Improve circulating blood volume
•No acute blood loss
•10cc/kg of NS
•Infuse over 10-20 min
•Improves preload(circulating blood volume)
•Acute blood loss
•PRBC’s-10cc/kg over 30-120min
TREATMENT OF CARDIOGENIC SHOCK
Evaluate the infant
•Heart rate •Blood pressure •Urine output •O2 sats •Blood gas •Blood sugar •CBC
Treatment is aimed at correcting the underlying problem
TREATMENT OF SEPTIC SHOCK
•Combination of therapies used to treat hypovolemic and cardiogenic shock
•Medications •Fluids
•Supportive cares 29
MEDICATIONS
•Normal Saline •Sodium Bicarbonate 4.2% •Dopamine •Dobutamine •Epinephrine •HydrocortisoneDOPAMINE
Dose: 5-20mcg/kg/min•0.5-2mcg-renal vasodilatation, little effect on BP
•2-10mcg-increased cardiac output and systolic BP
•>10mcg-vasoconstriction, increases systolic and diastolic BP
RULES FOR DOPAMINE INFUSION
•Never infuse in an art line•Never flush dopamine
•Always use a pump
•Monitor IV site closely
•Infiltrates can cause sloughing/necrosis
•Closely monitor BP’s
DOBUTAMINE
•
Increases cardiac output
•
No effect on HR
•
Decreases systemic vascular resistance
•
5-15mcg/kg/min
EPINEPHRINE
•Increases myocardial contractility
•Increases peripheral vascular resistance
•0.05-0.1mcg/kg/min
HYDROCORTISONE
•Maybe helpful in extreme preterm infants with hypotension
•Stabilizes BP
•Response usually happens in 2hrs after administration
•3mg/kg/day for 3-5 days
•Do not use in infants receiving Indocin
SCALP SWELLING
NEONATAL EXTRACRANIAL INJURIES
CAPUT VS CEPHALOHEMATOMA
SUBGALEAL HEMORRHAGE
•Rupture of emissary veins•Can occur during vacuum delivery
•Subaponeurotic space located above periosteum
•No barrier to stop bleeding
•Subgaleal space can hold up to 240-260ml of blood
•Entire blood volume of a 3kg infant
RISK FACTORS
•Nulliparous mother•Failed vacuum extraction
•Sequential use of vacuum and forceps
•Apgar score less then 8 at 5 minutes following vacuum assist delivery
MONITORING SUBGALEAL HEMORRHAGE
•Close monitoring of vital signs•Physical assessment of scalp, neck and face
•Head circumference
•Lab work
•CBC
•Blood gasses 41
TREATMENT
•Close monitoring•Treat hypotension
QUESTIONS
REFERENCES
•Eichenwald, E. C., Hansen, A. R., Martin, C. R., & Stark, A. R. (2016). Cloherty and
stark’s manual of neonatal care (8thed.). Philadelphia: Wolters Kluwer.
•Gomella, T. L., Cunningham, M. D., Eyal, F. G., & Zenk, K. E. (2004). Neonatology: Management, procedures, on-call problems, diseases, and drugs(5th ed.). New York: Lange Medical Books/McGraw-Hill Medical Pub. Division.
•Karlsen, K. (2013). Post-resuscitation / Pre-transport Stabilization care of sick infants: Guidelines for neonatal healthcare providers (5th ed). Salt Lake City, UT: S.T.A.B.L.E program.