A Comparative Study of Induction, Maintenance and Recovery Characteristics of Halothane and Sevoflurane in Pediatric Patients

Introduction: Methods for induction of general anaesthesia in children include inhalational agents as well as intravenous agents. Children are reluctant to have a needle to put them into sleep. So inhalational induction becomes preferable and is used more commonly in children as compared to adults. Desflurane, sevoflurane, isoflurane, enflurane, halothane, nitrous oxide are amongst the most popular inhalational agents used. Of these sevoflurane and halothane are used for induction owing to their non pungent nature. However, all of these products are airway irritants to varying degree and can cause laryngospasm, breath holding, coughing, and salivation in children. Halothane has a high solubility in tissues and is therefore associated with a slow onset and termination of effect and recovery. Patients receiving halothane have an increased risk of arrhythmias and hepatotoxicity. Sevoflurane has low blood gas partition coefficient and low issue solubility. In addition, sevoflurane appears to have fewer hemodynamic effects than halothane. Purpose of this study is to compare sevoflurane and halothane for induction, maintenance and recovery in general anaesthesia in pediatric patients. Our primary aim is to compare the induction time produced by halothane and sevoflurane in pediatric patients. Materials and Methods: After approval from proforma review board this comparative study of halothane and sevoflurane for induction, maintenance and recovery in pediatric patients was carried out in general operation theatre, S.N. Medical College, Agra. Using computer generated random number table patients were randomly allocated into two groups of 30 patients each according to the volatile anaesthetic to be used: Group-H: Included children who received halothane + nitrous oxide + Oxygen. Group-S: Included children who received sevoflurane + nitrous oxide+ Oxygen. Time gap between cessation of the inhalational agent and when child first open his/her eyes was recorded as recovery time 1. Respective time gap till child showed purposeful movements or obeyed commands were taken as recovery time 2. Statistical analysis: It was done using SPSS 20.0 version for windows. A study population of 30 patients for each group was determined to have 90% power at a =0.05. Data were presented as mean (+­­­SD). After the study, analysis of data was done by chi square test and t- test for parametric data and Mann-whitney for nonparametric data. P value<0.05 was considered as statistically significant. Results: In the comparative study we compared the induction, maintenance and recovery characteristics of halothane and sevoflurane in pediatric patient of 1 to 10 years of age undergoing elective surgeries of approximately 1 hour duration (ASA grade 1 & 2). In present study, the time to loss of eyelash reflex (induction time) was significantly shorter in the sevoflurane group, p<0.05 (88.23+19.129 sec) compared to halothane group (165.63+40.372 sec). This can be explained by low blood gas solubility of sevoflurane as compared to halothane. In our study we compared the two groups for intraoperative complications like cough, bucking, breath holding and oxygen desaturation on the basis of airway hyperreactivity score and found that there was no statistically significant difference (p-value is>0.05). It was because both sevoflurane and halothane are non-irritant and provide smooth induction with minimal secretions. sevoflurane is least airway irritant among all inhalational agents and halothane is most potent bronchodilator among these. In our study emergence phenomenon were compared among two groups on the basis of emergence agitation score and it was found that children who received sevoflurane were more agitated and restless at the time of emergence than the children who received halothane. The most likely explanation is that patients experienced rapid emergence as sevoflurane is eliminated rapidly while chidren who received halothane appeared sedated and calm due to slow elimination as compared to sevoflurane. Limitations of this study include lack of blinding due to study design and inability to assess arrhythmogenic properties of both the agents and high cost of sevoflurane. We conclude that induction with sevoflurane and oxygen leads to faster loss of consciousness, provides ideal conditions for managing airway with haemodynamic stability and rapid recovery from anaesthesia. Therefore, it can be a reasonable alternative to halothane for pediatric patients aged 1-10 years. Conclusion: Time to loss of eyelash reflex (induction time) was compared between two groups and it was significantly shorter in children. Baseline pulse rate was comparable between two groups. There was decline in pulse rate in both groups but this decline was more with children who received halothane anaesthesia than the children who received sevoflurane anaesthesia and difference was statistically significant ,p value<0.05. Mean arterial blood pressure was comparable between two groups. There was decline in mean arterial blood pressure in both groups but this decline was more with children who received halothane anaesthesia than the children who received sevoflurane anaesthesia and difference was statistically significant, p value <0.05.Time to open eyes and time to follow commands was shorter in sevoflurane group than halothane group and on comparison the difference was statistically significant, p value <0.05. In our study emergence phenomenon were compared among two groups on the basis of emergence agitation score and it was found that children who received sevoflurane were more agitated and restless at the time of emergence than the children who received halothane. So, we conclude that the anaesthesia with sevoflurane provided rapid induction and rapid recovery with more stable hemodynamics than halothane in pediatric patients of age group 1-10 years. However, more frequent emergent phenomenon and higher cost may be factors limiting its popularity.