Evaluation of Perfusion Index-derived Parameters as Predictors of Hypotension After Induction of General Anaesthesia: a Prospective Cohort Study.
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Hypotension
- Sponsor
- Cairo University
- Enrollment
- 93
- Locations
- 1
- Primary Endpoint
- The area under receiver operating characteristic (AUROC) curve for perfusion index to predict hypotension after induction of anesthesia
- Status
- Completed
- Last Updated
- 5 years ago
Overview
Brief Summary
The perfusion index (PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow measured by a special pulse oximeter. PI represents the baseline sympathetic tone which is assumed one of the factors contributing for hypotension. Patients with low PI were reported by Mahendale and Rajasekhar to show greater hypotension after induction of anesthesia. This was explained by the high sympathetic tone in these patients which is suddenly masked by propofol administration leading to profound hypotension.
This study aims to evaluate the ability of preoperative plethysmographic variability index, perfusion index and the Dicrotic Plethysmography to predict post-induction hypotension.
Detailed Description
The perfusion index (PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow measured by a special pulse oximeter. PI represents the baseline sympathetic tone which is assumed one of the factors contributing for hypotension. Patients with low PI were reported by Mahendale and Rajasekhar to show greater hypotension after induction of anesthesia. This was explained by the high sympathetic tone in these patients which is suddenly masked by propofol administration leading to profound hypotension. Moreover, The PI has been described as a reliable tool for vascular tone assessment and monitoring. Dicrotic Plethysmography (Dicpleth): is easily derived from the photoplethysmographic signal. It represents the relative height of the dicrotic wave compared with the maximum peak of the waveform, has been described as the amount of reflected wave, dependent on the vascular tone. M.Coutrot et al quantified Dicpleth variations to detect arterial hypotension and mentioned that Dicpleth and PI are both related to vascular tone and are easily derived from the photoplethysmographic signal. Moreover, Chowienczyk PJ et. al. demonstrated that the reduction in Dicpleth is related to the reduction of vascular tone caused by vasodilator drugs, such as salbutamol or glyceryl trinitrate
Investigators
Bassant M. Abdelhamid
associate professor
Cairo University
Eligibility Criteria
Inclusion Criteria
- •• Adult patients (18-59 years)
- •Patients scheduled for elective surgeries under general anaesthesia
Exclusion Criteria
- •• Operations which will last for less than 15 minutes.
- •Patients with cardiac morbidities (impaired contractility with ejection fraction \< 40% and tight valvular lesions, unstable angina).
- •Patients with heart block and arrhythmia (atrial fibrillation and frequent ventricular or supraventricular premature beat).
- •Patient with decompansted respiratory disease (poor functional capacity, generalized wheezes, peripheral O2 saturation \< 90% on room air).
- •Patients with peripheral vascular disease or long standing DM affecting PVI readings.
- •Pregnancy.
Outcomes
Primary Outcomes
The area under receiver operating characteristic (AUROC) curve for perfusion index to predict hypotension after induction of anesthesia
Time Frame: 10 minutes
PI will be recorded in the supine position by an anaesthesiologist who was not involved in the further intraoperative monitoring of the patient using Masimo SET
Secondary Outcomes
- diastolic arterial blood pressure(5 minutes)
- Heart rate(5 minutes)
- Mean arterial blood pressure(15 minutes)
- Dicrotic Plethysmography(10 minutes)
- systolic arterial blood pressure(5 minutes)
- Incidence of post-induction hypotension(15 minutes after induction of anesthesia)
- Plethysmographic variability index(10 minutes)