Sarah, Ninan (2009) Instillation of Lignocaine through the Endotracheal Tube to Attenuate the Extubation Response. Masters thesis, Christian Medical College, Vellore.
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Abstract
INTRODUCTION: Extubation is often associated with varying degrees of problems. The appropriate time to remove an endotracheal tube is part of the art of anaesthesia that develops with experience. Both intubation and extubation are associated with rise in heart rate and blood pressure, yet often there has been less emphasis on avoiding hemodynamic changes at extubation. These cardiovascular changes occur due to release of catecholamines at extubation, in addition to pain from the surgical site and irritation of the tracheal mucosa by the endotracheal tube. Coughing is another very common problem encountered at extubation. The mechanism of cough is presumed to be irritant or stretch stimuli in the trachea caused by the endotracheal tube and its cuff. Coughing and the hemodynamic response at extubation can result in potentially dangerous patient movements, hypertension, tachycardia, or other arrhythmias, myocardial ischemia, surgical bleeding, bronchospasm and increase in intracranial pressure and intraocular pressure. In patients coming for neurosurgical procedures, it is important to avoid factors such as coughing and hypertension at emergence, which are likely to cause raised intracranial pressure and intracranial bleeding. Any increase in intracranial pressure can adversely affect the postoperative outcome. Awakening and extubation after anaesthesia are associated with hemodynamic arousal lasting 10 to 25 minutes, partially mediated by elevations in catecholamine levels and partially by nociceptive stimuli. Thus both anti-sympathetic (betablockers) and antinociceptive (narcotics, lignocaine) treatment strategies are appropriate to decrease extubation response. Lignocaine has long been used to modulate the unwanted airway and circulatory reflexes seen in response to emergence and extubation. The administration of lignocaine has been through several routes such as intravenous (IV) injection, endotracheal cuff, or intratracheal (IT) instillation. In this study we have compared the efficacy of lignocaine administered via the endotracheal tube to lignocaine administered intravenously , and to placebo, in suppressing the extubation response. As a smooth extubation at the end of surgery is vital for a good outcome in neurosurgery, we have done this study in patients undergoing craniotomies. AIMS AND OBJECTIVES: 1. To determine whether intratracheal instillation of lignocaine is effective in attenuating airway & circulatory response to extubation. 2. To determine if the effect of intratracheal route is by absorption from the mucosa or if it has any local mucosal anaesthetizing effect. 3. To determine if awakening from anaesthesia is delayed with the use of lignocaine and to compare the time taken for extubation between the groups where lignocaine is used. MATERIAL AND METHODS: After obtaining approval from the institutional ethics committee, this study was carried out on 114 neurosurgical patients undergoing craniotomies. Inclusion criteria: 1. Patients undergoing elective craniotomies in the supine and lateral position with GCS 15/15. 2. Age 18 -65 years inclusive. 3. ASA (American Society of Anaesthesiologist) class 1 & 2. Exclusion criteria: Patients with 1. Sore throat or active URI. 2. History of laryngeal or tracheal pathology/surgery. 3. History of asthma or COPD. 4. Requirement for postoperative ventilation. Study Design: Prospective Randomized Double Blinded Clinical Trial. Location: The study was carried out in the Department of Anaesthesia in Christian Medical College and Hospital, Vellore. Sample size determination: The sample size was based on the study done by Daelim Jee and SoYoung Park where 3 groups of patients were assessed similarly. The means and standard deviation of number of coughs in the three groups were 10.2 +/-6.0, 4.5 +/-3.7, 7.8+/-4.6. With an alpha error of 5% and power of 80%, the sample size for each group was calculated to be 38. Therefore the total sample size would be 114. Sample size was determined, assuming that the anticipated analysis will be done using analysis of variance (ANOVA). Patient allocation: The patients were randomly allocated into one of the 3 groups by block randomization using computer assignment. The study drug was allocated to patients by the pharmacy according to the block randomization done and the nature of the drug was concealed by the pharmacy. Patients in group 1 received intratracheal lignocaine and intravenous placebo. Patients in group 2 received intravenous lignocaine and intratracheal placebo. Patients in group 3 received intravenous and intratracheal placebo (control group). CONCLUSIONS: 1. Lignocaine in the dose of 1 mg/kg given intratracheally does not prevent cough or hemodynamic response at emergence if given 20-30 min prior to extubation. Lignocaine in this dose provides poor local anaesthetic effect after tracheal instillation. 2. There was no increase in sedation with the use of lignocaine at a dose of 1 mg/kg when administered 20-30 min before extubation. 3. When volatile agents such as isoflurane and sevoflurane are continued till pin removal with an adequate dose of fentanyl, cough and haemodynamic response to extubation can be suppressed but with higher sedation in neurosurgical patients. 4. Plasma level of 0.8 μgm/ml was not sufficient to suppress cough at extubation.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Instillation ; Lignocaine ; Endotracheal Tube ; Attenuate ; Extubation Response. |
| Subjects: | MEDICAL > Anaesthesiology |
| Depositing User: | Subramani R |
| Date Deposited: | 30 Apr 2018 02:53 |
| Last Modified: | 30 Apr 2018 02:53 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/7319 |
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