Severe low cerebral oximetry in difficult cardiopulmonary bypass weaning of low body-weight infant: a case report and literature review

Background: For infants undergoing complex cardiac surgery, hemodynamic management after cardiopulmonary bypass (CPB) is challenging because of severe myocardial edema, vasomotor dysfunction and weak tolerance to a change in blood volume. More importantly, the lack of availability of equipment for advanced monitoring, such as transesophageal echocardiography or transthoracic echocardiography, restricts the accurate assessment of hemodynamics.

Case presentation: This is a case of severe hypotension and non-detectable pulse oxygen saturation (SpO₂) after CPB in a low-weight infant who had normal blood pressure and oxygen saturation before surgery. Epinephrine and milrinone were administered with cerebral oximetry monitoring rather than blood pressure measurements because cerebral oximetry was more responsive to treatment than blood pressure. Under the guidance of cerebral oximetry, the infant was successfully weaned from CPB and recovered after surgery without adverse neurological events.

Conclusions: For infants who develop refractory hypotension and failure in SpO₂ monitoring during the CPB weaning period, cerebral oximetry provides an index for assessing brain perfusion and valuable guidance for appropriate inotropic treatment.