Initial evaluation and management of neonatal shock

O₂: oxygen; HR: heart rate; BP: blood pressure; BUN: blood urea nitrogen; LFTs: liver function tests; CBC: complete blood count; HSV: herpes simplex virus; ECG: electrocardiogram; ID: infectious disease; RBC: red blood cell; PGE1: prostaglandin E1; CSF: cerebrospinal fluid.
* The amount and rate of infusion may vary depending on the gestational age of the neonate and the suspected type of shock (eg, hypovolemic, distributive, or cardiogenic). An initial fluid bolus of 10 to 20 mL/kg isotonic crystalloid is appropriate for most neonates presenting in shock. However, fluid boluses should be administered cautiously in extremely preterm infants (gestational age <28 weeks) or if there is suspicion for a cardiac etiology of shock. Refer to UpToDate's topic on management of neonatal shock for additional details.
¶ In neonates presenting with shock, HSV infection should be suspected as a possible etiology if the neonate had perinatal exposure to HSV, has examination findings consistent with HSV (mucocutaneous vesicles), and/or has CSF pleocytosis. In addition, the diagnosis should be considered in neonates with concerning findings that are otherwise unexplained. These may include seizures, focal neurologic signs, abnormal neuroimaging, sepsis-like illness (fever or hypothermia, irritability, lethargy, respiratory distress, apnea, abdominal distension, hepatomegaly, ascites), thrombocytopenia, or elevated liver transaminases. Refer to separate UpToDate content on neonatal HSV infection for additional details on evaluation and treatment of neonatal HSV infection.
Δ Empiric antibiotic therapy is provided to all neonates with shock because sepsis is the leading cause of neonatal shock. Antimicrobial coverage should include agents active against organisms that most commonly cause neonatal sepsis (ie, group B streptococcus and Escherichia coli). The combination of ampicillin and gentamicin provides adequate coverage for these organisms until culture results are available. Local antibiotic resistance patterns should also be considered. If there is clinical suspicion for HSV infection, the empiric antimicrobial regimen should include acyclovir. For additional details on choice of empiric regimen and duration of therapy, refer to separate UpToDate content on evaluation and treatment of neonatal sepsis and HSV.
◊ An adequate response to therapy is signaled by improvement in pulses, skin perfusion (capillary refill <4 seconds), and vital signs (including rise in BP if initially hypotensive, decrease in HR if initially tachycardic, or rise in HR if initially bradycardic), and resolution of acidosis. For additional details on the goals of therapy and monitoring response, refer to UpToDate's topic on evaluation and management of neonatal shock.
§ Vasoactive agents commonly used in the management of neonatal shock include dopamine, epinephrine, dobutamine, and milrinone. The choice is based in part on the type of shock (eg, distributive versus cardiogenic). Dopamine is both a vasopressor and inotrope, and it is the most commonly used agent in neonates. Dobutamine is predominantly an inotrope, and it is commonly used for management of neonatal cardiogenic shock. For additional details, refer to UpToDate's topic on evaluation and management of neonatal shock.
¥ Cardiac disease may be suspected based upon the presence of a murmur or gallop, cyanosis, irregular heart rate, weak or absent femoral pulses, a differential in pre- and post-ductal oxygen saturation, and/or chest radiograph findings (eg, cardiomegaly, pulmonary edema).
‡ Primary adrenal insufficiency (eg, congenital adrenal hypoplasia) may be suspected based on physical examination findings (ambiguous genitalia) and laboratory findings (hyperkalemia, hyponatremia, hypoglycemia). Secondary or relative adrenal insufficiency may be suspected on the basis of shock that is refractory to fluid boluses and vasoactive therapy. Refer to separate UpToDate content on adrenal insufficiency and neonatal shock for additional details.
† See separate UpToDate topics for additional details of the initial evaluation and management of neonatal shock, evaluation and management of neonatal sepsis, management of suspected cyanotic heart disease, and management of arrhythmias in infants.
** In some cases, the source of bleeding may be evident based on the history and physical examination (eg, history of intrapartum hemorrhage, obvious bleeding source on examination such as a subgaleal hematoma). In cases where the source is unclear, additional evaluation may include cranial ultrasound to evaluate for intracranial hemorrhage and testing for fetal cells in a maternal blood sample (Kleihauer-Betke assay) to assess for fetomaternal hemorrhage.