Hemodynamic effects of lateral tilt before and after spinal anesthesia during cesarean delivery: an observational study.

BACKGROUND: Post-spinal hypotension is a common maternal complication during cesarean delivery. Aortocaval compression by the gravid uterus has been assumed as a precipitating factor for post-spinal hypotension. The role of left lateral tilting position in improving maternal cardiac output after subarachnoid block (SAB) is unclear. The aim of this work is to investigate the effect of left lateral tilting on maternal hemodynamics after SAB. METHODS: A prospective observational study was conducted including 105 full term pregnant women scheduled for cesarean delivery. Mean arterial pressure, heart rate, cardiac output (measured by electrical cardiometry), stroke volume, and systemic vascular resistance were recorded in three positions (supine, 150, and 300 left lateral positions) before SAB, after SAB, and after delivery of the fetus. RESULTS: Before SAB, no significant hemodynamic changes were reported with left lateral tilting. A significant decrease was reported in mean arterial pressure, cardiac output, stroke volume, and systemic vascular resistance after SAB (in supine position). When performing left lateral tilting, there was an increase in cardiac output, heart rate, and mean arterial pressure. No difference was reported between the two tilt angles (150 and 300). CONCLUSIONS: Changing position of full term pregnant woman after SAB from supine to left lateral tilted position results increased cardiac output and mean arterial pressure. There is no difference between the two tilt angles (150 and 300). TRIAL REGISTRATION: clinicaltrials.gov ( NCT02828176 ) retrospectively registered.

Vertebrobasilar Insufficiency Caused by Lateral Head Tilting

Vertebrobasilar insufficiency (VBI) in rotatory vertebral artery occlusion syndrome can be caused by voluntary head turning in the yaw plane. We report a case of VBI for head tilting in the roll plane. Transcranial Doppler on left head tilting resulted in decreased blood flow in both vertebral arteries. A CT angiogram revealed that the stenotic left vertebral artery was very close to an enlarged thyroid gland, suggesting mechanical compression of the vertebral artery during head tilt.