Comparison of Induction Characteristics of Propofol and Thiopentone in Ent Surgery in Children

Abstract

BACKGROUNDInduction of general anaesthesia in children (1) is accomplished by either intravenous or inhalations route or rarely by the rectal route. The choice will depend on the anaesthetist's preference, the ease of venous puncture and the child's level of co-operation, sedation and clinical condition. Intravenous agents (2) are used more commonly than inhalational agents to induce anaesthesia, as induction is more rapid and smoother. Inj. Propofol and Inj. Thiopentone sodium are common intravenous induction agents in our hospital. The aim of the study was to compare the induction characteristics of Inj. Thiopentone and Inj. Propofol in premedicated children namely, 1. Onset time of induction of general anaesthesia. 2. Haemodynamic changes (3) during induction. MATERIALS AND METHODSThis prospective clinical study was conducted at Government Vellore Medical College, Adukkamparai, Vellore in 50 patients aged between 6 to 10 yrs. undergoing tonsillectomy and adenoidectomy. They were divided into 2 groups of 25 each. Group P: children who received propofol 3 mg/kg gas induction agent. Group T: children who received thiopentone (4) 5 mg/kg as induction agent. Preinduction and post-induction parameters like onset of induction time, blood pressure, heart rate, incidence of apnoea, etc. were recorded. In analysing the data student's 'L' test, chi-squared test with Yates correction for small numbers were used where appropriate. P value ≤ 0.01 is considered statistically significant. RESULTSThe mean age, weights and sex of the patients were similar in both groups. The mean induction time in Group P was 36.8±7.90 seconds and in Group T was 29±3.44 seconds and the difference is not statistically significant. In Group T, mean systolic pressure increased from 112±4.8 mmHg to 117±4.2 mmHg during the second minute and 99±3.2 mmHg at 10th minute. In Group P, mean systolic pressure reduced from 112±4.8 mmHg to 102±4.4 mmHg during the second minute and 91±2.8 mmHg at 10th minute and the reduction is statistically significant. Following induction and intubation, the mean diastolic pressure in Group T increased from 73±4.7 mmHg to 79±4.3 mmHg in the second minute and 62±3.2 mmHg in the 10th minute. In Group P, the mean diastolic pressure fell from 70±4.6 mmHg to 66±4.8 mmHg in the second minute and 58±2.2 mmHg in the 10th minute. The fall in mean diastolic pressure was greater in Group P, statistically significant (p < 0.01). Mean arterial pressure in Group T increased from 86±4.7 mmHg to 91±4.6 mmHg in the second minute. In Group P, the mean arterial pressure fell from 84±4.6 mmHg to 77±5.2 mmHg in the second minute. The fall in mean systolic pressure in Group P is statistically significant (P=0.01). The pre-induction mean pulse rate Group T was 110±4.5 per minute, while pre-induction mean pulse rate Group P was 116±4.7 per minute. The mean pulse rate in Group P reduced to 108±4.6 per minute in the second minute and gradually reached 100±4.4 per minute in 10 minutes. The mean pulse rate in Group T increased to 118±4.4 pe...