When respiratory support and fluid resuscitation are insufficient, introduction of vasoactive substances is the next step. The choice of which agent to use depends on the type of shock present. Hypovolemic shock (when further volume is contraindicated) and distributive shock benefit from drugs that increase systemic vascular resistance (drugs with αagonist activity, such as epinephrine or norepinephrine). The treatment of cardiogenic shock is more complex. To improve cardiac output by increasing the heart rate, drugs with positive chronotropy are used (epinephrine, norepinephrine, and dopamine). Afterload reduction, using drugs such as dobutamine, nitroprusside, or milrinone, also may be needed. Measuring mixed venous oxygen saturation, central venous pressure, and regional oxygen saturations helps guide therapy.
The outcome of cardiopulmonary arrest in children is poor; survival to hospital discharge is about 6% for out-of-hospital arrest and about 27% for in-hospital arrest, with most survivors having permanent neurologic disability. The ability to anticipate or recognize pre–cardiopulmonary arrest conditions and initiate prompt and appropriate therapy not only is lifesaving, but also preserves the quality of life (see Table 38-2).
Children who need cardiopulmonary resuscitation (CPR) usually have a primary respiratory arrest. Hypoxia usually initiates the cascade leading to arrest and also produces organ dysfunction or damage (Table 38-3). The approach to cardiopulmonary arrest extends beyond CPR and includes efforts to preserve vital organ function. The goal in resuscitating a pediatric patient following a cardiopulmonary arrest should be to optimize cardiac output and tissue oxygen delivery, which may be accomplished by using artificial ventilation and chest compression and by the judicious administration of pharmacologic agents.
In 2010 the American Heart Association revised the recommendations for resuscitation for adults, children, and infants. The biggest change is the recommendation to start chest compressions immediately, rather than beginning with airway and breathing.
Chest compressions should be initiated if a pulse cannot be palpated or if the heart rate is less than 60 beats/min with signs of poor systemic perfusion. Chest compressions should be performed immediately by one person while a second person prepares to begin ventilation. Ventilation is extremely important in pediatric arrests because of the high likelihood of a primary respiratory cause; however, ventilation requires
Brain Seizures, cerebral edema, infarction, herniation, anoxic damage, SIADH, diabetes insipidus
Cardiovascular Heart failure, myocardial infarct
Lung and pulmonary Acute respiratory distress syndrome, vasculature pulmonary hypertension Liver Infarction, necrosis, cholestasis Kidney Acute tubular necrosis, acute cortical
Gastrointestinal Gastric ulceration, mucosal damage tract Hematologic Disseminated intravascular coagulation
SIADH, Syndrome of inappropriate secretion of antidiuretic hormone.
equipment and is, therefore, sometimes delayed. For this reason the recommendation is to start chest compressions first while preparing for ventilation.
For optimal chest compressions, the child should be supine on a flat, hard surface. Effective CPR requires a compression depth of one third to one half of the anterior-posterior diameter of the chest with complete recoil after each compression. The compression rate should be at least 100/min with breaths delivered 8 to 10 times per minute. If an advanced airway is in place, compressions should not pause for ventilation; both should continue simultaneously.
Ventilation requires a patent airway. In children, airway patency often is compromised by a loss of muscle tone, allowing the mandibular block of tissue, including the tongue, bony mandible, and the soft surrounding tissues, to rest against the posterior pharyngeal wall. The head tilt–chin lift maneuver should be used to open the airway in children with no sign of head or neck trauma. In children with signs of head or neck trauma, the jaw thrust maneuver should be used.