Published experience is likely to be more favorable than experience in general, since smaller centers and those with high rates of complications are less likely to publish their experience. The unique aspects of pediatric physiology and anatomy that place children at greater risk for hemorrhagic shock have recently been reviewed. 20 Children have a relatively small total blood volume and lower hematocrit level than adults. The high ratio of body surface area to mass increases the risk for hypothermia and subsequent pulmonary hypertension, hypoxemia, and metabolic acidosis. Limited thermoregulation in infants due to inadequate subcutaneous fat and shivering mechanisms increases the risk for hypothermia and its consequences.
Vital signs are age-related, and early detection requires familiarity with normal values.
Tachycardia is the primary response to hypovolemia in children, and children receiving beta-blocking medications may be at greater risk for shock in the event of hemorrhage. In addition, gaining access to the peripheral venous system can be technically difficult. The subtlety of early clinical signs of hypovolemic shock in infants and young children may contribute to delayed recognition and intervention in comparison with the management of adult patients. Children who are uncooperative or unable to accurately report symptoms are particularly difficult to assess for early signs of shock or other complications. Cardiovascular collapse may ensue more rapidly than anticipated.