Association of elevated preoperative blood pressure with preincision hypotension in pediatric surgical patients

INTRODUCTION: High blood pressure (BP) in childhood is associated with left ventricular hypertrophy and abnormal vascular reactivity even in apparently healthy children. This study examined the prevalence of high BP in children undergoing elective noncardiac operations. We also determined the association of preoperative high BP with preincision hypotension (PIH). METHODS: This was a retrospective cohort study that used clinical and anthropometric data on children aged 3-17 years who underwent elective, noncardiac operations from January 2006 to January 2014. Preoperative blood pressure (BP) was used to stratify children into three categories: normal BP (systolic and diastolic BP below the 90th percentile), prehypertension (systolic and/or diastolic BP ≥90th percentile but <95th percentile or if the BP exceeds 120/80 mmHg even if it is below the 90th percentile), and hypertension (systolic and/or diastolic BP ≥95th percentile). Multivariable logistic regression analysis was used to calculate adjusted odds ratios for PIH using age, gender, body mass index (BMI), and BP categories as covariates. RESULTS: Among 35832 children, the overall prevalence of prehypertension, hypertension, and hypertension by adult standards were 16.4%, 6.8%, and 3.3%, respectively. Overweight and obese children had higher rates of elevated BP. Presence of elevated baseline BP, high BMI category, and presence of OSA diagnosis were independent predictors of multiple episodes of PIH in a logistic regression model. CONCLUSION: In children, preoperative high BP is an independent predictor of PIH. Although the longtime consequences of high BP are well known, this report provides the first intraoperative evidence of adverse event associated with preoperative high BP in children. Mechanisms underlying this hypotensive response are unclear.