Effect of hyperextension of the neck (rose position) on cerebral blood oxygenation in patients who underwent cleft palate reconstructive surgery: prospective cohort study using near-infrared spectroscopy.

OBJECTIVES: To facilitate the best approach during cleft palate surgery, children are positioned with hyperextension of the neck. Extensive head extension may induce intraoperative cerebral ischemia if collateral flow is insufficient. To evaluate and monitor the effect of cerebral blood flow on cerebral tissue oxygenation, near-infrared spectroscopy has proved to be a valuable method. The aim of this study was to evaluate and quantify whether hyperextension affects the cerebral tissue oxygenation in children during cleft palate surgery. MATERIALS AND METHODS: This prospective study included children (ASA 1 and 2) under the age of 3 years old who underwent cleft palate repair at the Wilhelmina Children's Hospital, in The Netherlands. Data were collected for date of birth, cleft type, date of cleft repair, and physiological parameters (MAP, saturation, heart rate, expiratory CO2 and O2, temperature, and cerebral blood oxygenation) during surgery. The cerebral blood oxygenation was measured with NIRS. RESULTS: Thirty-four children were included in this study. The majority of the population was male (61.8%, n = 21). The mixed model analyses showed a significant drop at time of Rose position of - 4.25 (69-74 95% CI; p < 0.001) and - 4.39 (69-74 95% CI; p < 0.001). Postoperatively, none of the children displayed any neurological disturbance. CONCLUSION: This study suggests that hyperextension of the head during cleft palate surgery leads to a significant decrease in cerebral oxygenation. Severe cerebral desaturation events during surgery were uncommon and do not seem to be of clinical relevance in ASA 1 and 2 children. CLINICAL RELEVANCE: There was a significant drop in cerebral oxygenation after positioning however it is not clear whether this drop is truly significant physiologically in ASA 1 and 2 patients.

Arrhythmogenicity of scuba diving: Holter monitoring in a hyperbaric environment.

INTRODUCTION: About 26% of diving-related fatalities are caused by cardiac disease, part of which might be associated with fatal arrhythmias. This raises the question as to whether fatal arrhythmias are being provoked by hyperbaric conditions themselves or if exercise or stress provokes the fatal arrhythmias in cases of underlying (ischemic) cardiac disease. OBJECTIVE: To measure the influence of hyperbaric conditions (50 msw) on cardiac conduction and arrhythmias in professional divers by means of ECG. METHODS: This is a prospective study on military divers in a hyperbaric chamber with continuous ECG monitoring using Holter registrations. Supraventricular and ventricular ectopy was registered during hyperbaric conditions. RR, PR, QRS, QT and QTc intervals were calculated at 50 msw and compared with ECGs at rest. RESULTS: Included were 17 male military divers who made 20 dives. A total of 10 PVCs, 45 PACs, four atrial runs and four atrial pairs were seen. Significant prolongation of the PR interval was seen and a decrease of in QRS duration at 50 msw. There was no significant change in the RR, QT and QTc intervals. CONCLUSION: In these divers, no clinically relevant arrhythmias were observed during wet dives in a recompression chamber at 50 msw. We observed a small prolongation of PR interval that is probably not clinically relevant in divers without any known conduction disorders.