Carotid Artery Corrected Flow Time and Respiratory Variations of Peak Blood Flow Velocity for Prediction of Hypotension After Induction of General Anesthesia in Adult Patients Undergoing Elective Surgery: A Prospective Observational Study

Abstract

Objectives Hypotension is common after induction of general anesthesia, and intraoperative hypotension is associated with postoperative end‐organ injury such as acute kidney injury and myocardial ischemia. This study was designed to determine the utility of the carotid corrected flow time (cFT) and carotid artery peak blood flow velocity variation (ðVpeak) for prediction of hypotension after induction of general anesthesia. Methods Adult patients (n = 112) undergoing any elective surgery under general anesthesia who fasted for at least 6 to 8 hours were recruited in this prospective observational study. The common carotid artery cFT and ðVpeak were measured with ultrasound 10 minutes before induction of general anesthesia. After that, general anesthesia with propofol was used, and hemodynamic data were collected until 3 minutes after induction of anesthesia. Results The carotid cFT was significantly correlated with percentages of the fall in the systolic blood pressure at 2 minutes (P < .0001) and 3 minutes (P < .0001) and percentages of the fall in the mean arterial pressure at 1 minute (P = .0006), 2 minutes (P < .0001), and 3 minutes (P < .0001). The cFT was a predictor of hypotension after induction of general anesthesia, with an area under the receiver operating characteristic curve of 0.91. The best cutoff value obtained from this study was 330.2 milliseconds or less, which predicted postinduction hypotension with sensitivity and specificity of 85.7% and 96.8%, respectively. The ðVpeak was an inferior predictor of postinduction hypotension, with an area under the receiver operating characteristic curve of 0.68. The optimum cutoff value was 18.8%, with sensitivity and specificity of 61.9% and 67.4%. Conclusions The cFT measured in the common carotid artery is a reasonable predictor of hypotension after induction of general anesthesia in American Society of Anesthesiologists physical status I and II patients. Further studies are required to identify its role in high‐risk patients such as older groups and patients with cardiovascular diseases and also to identify interobserver and intraobserver variability of cFT and ðVpeak measurements.

Assessment of role of inferior vena cava collapsibility index and variations in carotid artery peak systolic velocity in prediction of post-spinal anaesthesia hypotension in spontaneously breathing patients: An observational study

“…We have found that CAPVV is also a poor predictor of PSH. Our result agrees with the results of Maitra et al ,[ 22 ] who reported CAPVV to be a poor predictor of post-induction hypotension in patients receiving general anaesthesia for elective surgeries. CAPVV >18.8% could predict hypotension with only 61.9% sensitivity and 67.4% specificity in their study.…”

A wireless ultrasound patch detects mild-to-moderate central hypovolemia during lower body negative pressure

“…Indeed, recent investigations have observed that common carotid artery FTc predicts postinduction hypotension. 20,21 Our study has limitations. First, we did not study actual hemorrhage; however, the LBNP model does correlate well with blood loss in nonhuman primate studies 14 and diminished thoracic blood volume.…”

“…Ostensibly, a patient deemed to have mild-to-moderate SV reduction by common carotid Doppler assessment would be at increased risk of hypotension following initiation of mechanical ventilation. Indeed, recent investigations have observed that common carotid artery FTc predicts postinduction hypotension 20,21 …”

Functional Hemodynamic Monitoring With a Wireless Ultrasound Patch

“…42 FTc also detects clinically significant gastrointestinal hemorrhage 43 and hypotension after induction. 44 Further, FTc anticipates SV changes during blood donation and in response to a PLR following blood donation. 45,46 Similar findings are noted in healthy individuals who fast.…”

“…When the cardiovascular stress is cyclical intrathoracic pressure change induced by passive, mechanical ventilation, common carotid artery peak systolic velocity variation is also an accurate functional hemodynamic measure. 39,44,[50][51][52][53] Importantly, however, when respiration is controlled (even partially) by the patient, peak velocity variation-such as pulse-pressure and stroke-volume variation-usually underperforms as a functional measure. Nevertheless, one group found that carotid artery peak velocity variation worked well in spontaneously breathing preoperative neurosurgery patients, 51 and another group could not replicate this finding in critically ill patients.…”