Pediatric Resident Physician Albany Medical Center, United States
Abstract: Introduction In infants with single ventricle defects, the postoperative course after stage II surgical repair is often characterized by systemic hypertension. Factors such as increased cerebral venous pressure, postoperative physiological changes in the single ventricle, hormonal changes such as increased cortisol and aldosterone, and postoperative pain are hypothesized, but not well-described in the literature. The objective of our study was to explore potential etiologies, management, and outcomes of postoperative hypertension following stage II repair.
Methods This is a retrospective, observational study of all postoperative children less than 3 years of age who underwent bidirectional Glenn or Hemi-Fontan procedure at our facility. Exclusion criteria included prior history of hypertension or steroid therapy within 2 weeks prior to surgery. Data collected include congenital heart defect and type of stage II palliation, peak systolic, diastolic, and mean arterial blood pressures, duration of hypertension, type of antihypertensives, pre- and post-op creatinine, cardiopulmonary bypass and cross-clamp times, intraoperative and post-operative medications that affect blood pressure. Hypertension was defined as a systolic, diastolic, or mean arterial pressure >99th percentile for age for more than 4 consecutive hours. Descriptive data is represented by mean/standard deviation for normally distributed data and median/interquartile ranges for non-normal distribution.
Results A total of 29 patients were included in our study after the exclusion criteria. 26/29 (90%) developed hypertension. Seven of them (26%) did not respond to increased analgesia or sedation and required either nitroprusside or esmolol. Demographic characteristics of all patients are depicted in figures 1 and 2. The median total duration of hypertension was 32.5 hours [IQR 6.75-69.5]. Three patients developed hypertension in the operating room whereas 20/29 (69%) developed hypertension within 4 hours after surgery. Nitroprusside was the most common antihypertensive medication used. 20/26 (77%) of the patients received intraoperative steroids in the form of dexamethasone or methylprednisolone or hydrocortisone. The majority of the patients 23/26 (89%) received vasoactive medications such as dopamine, epinephrine, milrinone, or a combination. The mean (SD) pre- and post-operative creatinine was 0.28(0.06) mg/dL and 0.39(0.11) mg/dL respectively, indicating no acute kidney injury. Three patients were hypertensive (80th percentile) at discharge, which improved by the follow-up visit. One patient developed pulmonary hypertension, and one other patient died from sepsis.
Conclusion Our study confirms that postoperative hypertension is common in patients after stage II palliation but transient in nature. Potential causes, such as catecholamine use, intraoperative steroids, postoperative pain control, and sedation may play a treatable role. Elevated cerebral venous pressures with autoregulation response to maintain cerebral perfusion pressure could not be ruled out.
