TO COMPARE POSTOPERATIVE RECOVERY IN PATIENTS UNDERGOING TOTAL INTRAVENOUS ANAESTHESIA (Tiva) USING TARGET CONTROLLED INFUSION SYSTEM (TCI) AND CONVENTIONAL INTERMITTENT BOLUS TECHNIQUE

AIM

To compare time to recovery from anaesthesia in patients undergoing ‘Total Intravenous Anaesthesia’ using ‘Target Controlled Infusion’ system as compared to conventional ‘Intermittent bolus technique’.

OBJECTIVE

Primary objective*-* To compare time and quality of postoperative recovery in patients undergoing ‘Total Intravenous Anaesthesia’ using ‘Target Controlled Infusion’ system as compared to conventional ‘Intermittent bolus technique’.

Secondary objectives

• Total drug (Propofol) used intra operatively in either technique.
• Periods of apnea/ hypoxia in either technique

7.1 SOURCE OF DATA:

The proposed randomized controlled study will be conducted in the Department of Anaesthesia at Command Hospital (Air Force) Bengaluru after obtaining permission from the Institutional Ethical Committee.

A total of 100 patients who are willing to give the consent and also satisfy the inclusion/exclusion criteria will be included in the study during the 12 months period from approval of the study.

METHODS OF COLLECTION OF DATA:

A. INCLUSION CRITERIA:

1.   All patients undergoing short gynaecological procedures in ASA grade I,II

2.   Willing for valid consent.

B. EXCLUSION CRITERIA:

1.   Obese patients with BMI more than 30kg/m2

2.   Allergy to Propofol

C. SAMPLE SIZE: 52

Required sample for the group A = 26

Required sample for the group B= 26

METHOD OF COLLECTION OF DATA:

 All enrolled patients will be visited and explained in detail about the anaesthetic procedure and written and informed consent will be obtained from patient and NOK wherever applicable. Detailed Pre Anaesthetic evaluation will be carried out. Appropriate laboratory and radiological investigation will be requested for and evaluated.

 All the patients selected for the study will be advised to follow standard fasting guidelines.  Each day listed OT cases will be randomized into two groups A and B using computer generated random number tables. Group A will undergo Target Controlled Infusion [TCI]- Propofol Anesthesia while Group B will undergo Propofol intermittent bolus Anesthesia.

 In both groups, IV access (18G/20G) will be secured. All patients, irrespective of their randomization group will be administered Injection Fentanyl 2 mcg/kg IV and Injection Glycopyrolate 0.2 mg IV. Monitoring will be done as per ASA minimum monitoring guidelines. In addition,  all patients will be monitored using Bispectral Index (BIS) monitor to enable an objective measurement of depth of anesthesia prior to initiation of procedure. It correlates well with the level of sedation produced by Propofol and is shown to reliably assess the depth of anaesthesia. A BIS recording of 80 is commonly accepted as an indicator of light sedation and a recording of 40 indicates a deep hypnotic state. Procedure will only proceed in both groups when BIS ≤40.  A baseline value of BIS prior to initiation of anaesthetic agent will be recorded. In addition, intra procedural hemodynamic parameters (HR, BP, and SpO2) will be recorded at 5 min intervals. Guidelines for safe practice of TIVA will be adhered to TIVA will be administered via peripheral intravenous access with a three-way cannula.

 In the TCI group, patient parameters (height & weight) will be fed into the machine, which will be utilizing the modified Marsh’s Protocol for calculating appropriate dosing of Propofol. Time will be noted from initiation of Propofol to attainment of BIS≤40. Estimated plasma concentrations at this time will be displayed on TCI pump and will be noted.

 In the ‘Intermittent Bolus’ group, patients will be given Injection Propofol as intermittent bolus to achieve a BIS≤ 40.

 In both the groups, Infusion/ Bolus Injections will be stopped on completion of the procedure, and time taken for achieving BIS≥80 will be noted. This will be taken as the end point for recovery.

 Outcomes Measures: Post-operative recovery in the form of BIS value of more than 80 after stopping infusion/last bolus injection.

STATISTICAL ANALYSIS

Data collected will be entered in to MS Excel; tables and charts will be generated using MS Word. Qualitative variables and continuous variables will be presented using percentages and mean+/- SD. Mean differences in time will be compared using paired T -test P value <0.05 will be considered as statistically significant at 5% level of significance.