TREATMENT OF THE CRITICALLY ILL CHILD: HEMORRHAGIC SHOCK

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TREATMENT

OF

THE

CRITICALLY

ILL

CHILD:

HEMORRHAGIC

SHOCK

Robert L. Replogle, M.D.

Department of Surgery, Sections of Pediatric and Thoracic and Cardiovascular Surgery,

Pritzker School of Medicine, University of Chicago, Chicago

Supported by the Office of Naval Research Contract #N00014-67-A-0285-005.

ADDRESS FOR REPRINTS: 950 East 59th Street, Chicago, Illinois 60637.

DIAGNOSIS

AND

TREATMENT

S

HOCK in the child is nearly always

caused by blood

(

or fluid) loss, burns,

or infection. The goal of the physician is to

recognize which of these are causing shock

in his patient, and to treat both the

under-lying disorder and the shock as quickly as

possible. This review will touch only on the

clinical management of the patient in

hem-orrhagic shock.

The pathophysiology of hemorrhagic

shock is characterized by a decrease in

car-diac output resulting in inadequate tissue

perfusion, tissue hypoxia, and acidosis; and,

it is caused by an inadequate circulating

blood volume.

The patient often arrives in the

emer-gency room with multiple injuries, being

hypotensive, tachycardic, tachypneic, and

obtunded. First priority is given to

estab-lishing an adequate airway, stopping

mas-sive hemorrhage

(

application of manual

pressure or tourniquets

)

, and splinting

unstable fractures. Since many resuscitative

measures should be undertaken

simulta-neously, even the most experienced

physi-cian should call for assistance as soon as he

recognizes the seriousness of a patient’s

condition. The nurse should start a chart on

the patient, recording at frequent intervals

vital signs, pupil size and reaction, and

fluids and medications given. As quickly as

possible, one or more routes for the rapid

infusion of fluid should be established. In

the child this is best accomplished by

cut-down of the greater saphenous vein at the

ankle and insertion of a large bore

catheter.’

(

Efforts at introducing a needle

or catheter percutaneously into a collapsed

peripheral vein will usually waste valuable

time.

)

Vasopressor or cardiotonic drugs are

rarely used in the treatment of shock, but

there may he a specific need for them early

in resuscitation while blood volume is being

rapidly restored. If no blood pressure or

pulse can be obtained, but heart sounds can

be heard or an ECG shows electrical

activ-ity, it is better to use calcium gluconate

and/or epinephrine to temporarily sustain a

heart beat than to delay and risk cardiac

arrest. Sodium bicarbonate solution should

be used extensively to treat the acidosis;

and, until arterial samples can be obtained

for pH measurements, two or three

infu-sions of 1 mEq/kg should be given

empiri-cally.

While blood is being set up for

transfu-sion, replacement of the volume deficit

should be undertaken with some type of

plasma expander. There are differing

opin-ions about the type of fluid to be used

mi-tially while compatible whole blood is

being prepared, but all agree that some

type of volume replacement should be

started immediately. Blalock2 observed that

it is the restoration of intravascular volume

that is of primary importance in

hemor-rhagic shock; replacement of the red cell

volume is of secondary importance. There

may even be some hemodynamic benefit of

moderate hemodilution in shock.3 Colloid

plasma expanding agents appear to be

preferable, since it is possible to predict the

degree of volume expansion from the

amount of fluid infused. Among these, a

commercially available plasma-like material

consisting principally of 5% serum

albu-men is quite satisfactory. Despite the

wide-spread enthusiasm for low molecular

weight dextran, there is little solid evidence

that its usefulness extends beyond a volume

replacement effect; furthermore, low

molec-ular weight dextran leaves the vascular

space rapidly: as much as 50% of the

in-fused volume may be lost extravascularly

(2)

DIAGNOSIS AND TREATMENT 1047

within two hours. ‘ The so-called “clinical

dextran”

(

molecular weight 70,000

)

is an

effective plasma expander; but, if it is given

in large quantities

(

over 1,000 ml in an

adult

)

, it may exert a deleterious effect on

the coagulation mechanism.6 As soon as

blood is available it should be used unless

there is evidence of hemoconcentration

(

hematocrit greater than 40%

),

in which

case a non-sanguinous material is

prefera-ble.

If the Iatient is bleeding massively, it is

not wise to wait until the hypotension has

been completely overcome by fluid infusion

l)efOre initiating efforts to control the

source of hemorrhage. Rapid infusion of

fluid can be continued while the operating

room is being prepared and the patient is

taken to surgery. The suspicion of major

in-tra-abdominal or intrathoracic hemorrhage

can be confirmed by a diagnostic tap, for

which an 18 gauge needle and 10 ml

sy-ringe is used to aspirate the four quadrants

of the peritonea! cavity and both pleural

cavities. The presence of large amounts of

blood in the peritoneal cavity is an

indica-tion for early surgical exploration.

Hemo-thorax, on the other hand, can usually be

managed by the insertion of a chest tube

p05-teriorly through the seventh intercostal space

on the affected side and attaching it to

chest suction bottles. Continued recovery of

large amounts of blood from the chest tube

is reason for thoracotomy to control

bleed-ing.

When it is apparent that immediate

sur-gery is not indicated, and while adequate

volume replacement is underway, the

pa-tient can be evaluated more thoroughly.

Chest and abdominal x-rays, urinalysis, and

a hematocrit are the basic laboratory

stud-ies. Physical examination should focus

par-ticularly Ott abdominal tenderness to deep

palpation

(

especially over the spleen

),

a

good neurological evaluation, and careful

as-sessment of the extremities and ribs for

pos-sible fractures. Special studies may include

intravenous pyelography or cystography if

kidney or bladder injury is suspected, and

skull and extremity x-rays; selective

angiog-raphy may be very useful in certain

circum-stances to delineate specific arterial injuries.

The patients can generally be separated

into two distinct groups rather quickly. One

group includes those without evidence of

major organ damage, neurological

impair-ment, or displaced fractures, in whom the

vital signs stabilize quickly following

moderate transfusion. The others

consti-tute the more severely injured; they

fre-quently require emergency surgery and

represent complex problems in resuscitation

and management.

For all patients the constant attendance

of a good nurse and frequent visits by an

interested physician are imperative to

per-mit early recognition of an unfavorable

change in condition. The standard methods

for evaluating the adequacy of the

circula-tion are satisfactory to monitor the patients

less severly injured, i.e., blood pressure by

cuff, heart rate, temperature and color of

the extremities, time required for capillary

refilling of the fingers and toes, and so on.

However, the massively injured patient

may present some very difficult problems,

and the physician is well advised to obtain

all the physiological information possible.

Since an accurate l)lood pressure may he

difficult to obtain by auscultatory methods,7

and frequent arterial blood samples may he

required to measure pH, pCO2, and pO, it

is very helpful to have an indwelling

arte-rial catheter. This is most easily done by

cut-ting down over the radial artery at the

wrist and inserting a small catheter

(

PE 50

is large enough

)

under direct vision. With

care and frequent irrigations with

heparin-ized saline, patency’ can be maintained for

prolonged periods even in the smallest

in-fant.

The central venous pressure

(

CVP

)

mea-surement has become virtually a necessity

to evaluate properly the adequacy of

vol-ume replacement in hemorrhagic shock.8

This is particularly true in children since

cardiac “pump failure” secondary to

coro-nary artery occlusive disease is not a

con-sideration. The resuscitative effort in

hemor-rhagic shock is directed toward restoring

cardiac output, and since the contractile

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1048 HEMORRHAGIC SHOCK

the diastolic filling pressure (or volume),

increasing this pressure by raising the

cen-tra! venous pressure

(

through volume

infu-sion

)

will increase myocardial contractility

and cardiac output. This is predicated on

the knowledge that central venous pressure

and left atrial pressure are equivalent

(which is nearly always true) and that the

left ventricle is not failing (which is

un-likely in the otherwise healthy child

)

. The

CVP is usually measured by means of a

catheter threaded into the superior vena

cava, either percutaneously or by cutdown.

It is often imprudent to be specific about

levels of pressure to be maintained; but, as

a rough although useful gauge, fluid or

blood may be infused safely without need

for concern about pulmonary edema as long

as the CVP remains below 20 cm H,O. It

would he very unusual for the child in

shock secondary to blood loss to be

hypo-tensive with a CVP of 15 to 20 cm H2O

un-less there were some complicating issue

such as hemopericardium, septicemia, or an

unrecognized cardiac lesion. Like many

useful techniques, there is a tendency

to-ward a ritual-in this case the ritualistic

order would read, “infuse volume until the

CVP goes above 15 cm H20.” If the patient

is clinically doing well, has a good blood

pressure and full pulse, a good urine

out-put, and so on, there is no need to maintain

the CVP above a level at which he is

ob-viously hemodynamically sound, be it 1 cm

1120 or 15 cm H2O.

A Foley catheter inserted aseptically into

the bladder is a very useful adjunct to help

gauge the adequacy of volume replacement

on an hour-to-hour basis. The patient with

a satisfactory cardiac output

(

thus renal

perfusion

)

will continue to make urine at a

steady rate. In the child this volume can be

as little as 5 ml per hour temporarily.

How-ever, the presence of a urinary osmolality of

300 to 400 mosm per liter and a urinary

so-dium concentration greater than 50 to 60

mEq per liter in an oliguric patient give

cause for grave concern that the oliguria is

secondary to acute renal failure. In some

instances, the infusion of a test quantity of

hypertonic mannitol

(

20% concentration)

may help separate the patient oliguric from

hypovolemia or water deficit from the

pa-tient oliguric because of renal failure, since

the first group of patients will respond to

the mannitol infusion with a brisk diuresis.

This author is not convinced that many

pa-tients have been spared the onset of acute

renal failure by the sustained infusion of

hypertonic mannitol during the period of

resuscitation from hemorrhagic shock, and

the obligatory diuresis that often does occur

when mannitol is given eliminates an

other-wise useful measurement for the evaluation

of an adequate volume replacement, i.e.,

the level of urinary output.

Used in conjunction with the clinical

evaluation, the arterial blood pressure,

cen-tral venous pressure, and urinary output are

the most valuable guides to adequacy of

volume replacement in hemorrhagic shock,

and it is volume replacement that is the

name of the game for the treatment of

hem-orrhagic shock.

REFERENCES

1. Randolph, J.: Technique for insertion of a

plas-tic catheter into the saphenous vein. PEDIAT-RICS, 24:631, 1959.

2. Blalock, A.: Principles of Surgical Care. Shock

and Other Problems. St. Louis: C. V. Mosby Company, p. 158, 1940.

3. Replogle, R. L., and Merrill, E. W. :

Flemodilu-tion: rheologic, hemodvnamic and metabolic consequences in shock. Surg. Forum, 18:157, 1967.

4. Replogle, R. L., Meiselman, J. J., and Merrill,

E. W. : Clinical implications of blood

rheol-ogy studies. Circulation, 36: 148, 1967.

5. Replogle, R. L., Kundler, H., and Cross, R. E.:

Studies on the hemodynamic importance of blood viscosity. J. Thor. Cardiovas. Surg., 50:658, 1965.

6. Jacobeus, U. : Studies on the effect of dextran on

the coagulation of the blood. Acta Med.

Scand. (Suppi. 322), 1957.

7. Cohn, J. N. : Blood pressure measurement in

shock. Mechanism of inaccuracy in

ausculta-tory and palpatory methods. J.A.M.A.,

199:118, 1967.

8. Wilson, J. N., Grow, J. B., Demong, C. V., Prevedel, A. E., and Owens, J. C. : Central

venous pressure in optimal blood volume

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1969;43;1046

Pediatrics

Robert L. Replogle