|Year : 2021 | Volume
| Issue : 3 | Page : 175-178
Comparison of intravenous versus nebulised lignocaine for suppression of haemodynamic responses to tracheal intubation
Varun Bhaskar, Sumalatha R Shetty, Prabhu Rajaram, Murali Krishna Varmudy
Department of Anaesthesiology and Critical Care, KS Hegde Medical Academy, Mangalore, Karnataka, India
|Date of Submission||24-Mar-2021|
|Date of Acceptance||18-Jul-2021|
|Date of Web Publication||03-Sep-2021|
Dr. Prabhu Rajaram
Senior Resident, Department of Anaesthesiology, K S Hegde Medical Academy, Nitte University, Deralakatte, Mangalore - 575 018, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Laryngoscopy and tracheal intubation are noxious stimuli associated with transient haemodynamic changes which can be deleterious, especially in patients with cardiovascular or intracranial disease. Different pharmacological techniques are used to suppress this response. We designed this study to evaluate whether nebulised lignocaine can attenuate haemodynamic responses to intubation. Patients and Methods: Forty patients were enrolled for the study and randomly allocated into one of two groups, Group LN (nebulised lignocaine) and Group LI (intravenous [IV] lignocaine). Group LN and Group LI received nebulisation respectively with 5 mL of 2% lignocaine or 5 mL of normal saline 15 min before shifting the patient to the operation theatre. General anaesthesia with endotracheal intubation was provided as per institutional protocol. Participants in Group LN received 5 mL saline intravenously while Group LI received 5 mL of 2% lignocaine IV 90 s after muscle relaxant and were intubated 90 s later. Patients were monitored for the first 10 minutes postintubation without any additional drug or any surgical stimulus. Results: In our study, we found a statistically significant suppression of haemodynamic responses following intubation in the nebulised lignocaine group in comparison with the IV lignocaine group. Conclusion: Significant attenuation of haemodynamic responses to intubation was observed with nebulised lignocaine group as compared to IV lignocaine group. We believe that nebulisation of lignocaine is a simple, cost-effective and safe procedure to attenuate haemodynamic responses to intubation. This novel technique could replace the use of other pharmacological interventions for the same purpose, thereby avoiding polypharmacy.
Keywords: Attenuation of haemodynamic responses to intubation, intravenous lignocaine, nebulised lignocaine
|How to cite this article:|
Bhaskar V, Shetty SR, Rajaram P, Varmudy MK. Comparison of intravenous versus nebulised lignocaine for suppression of haemodynamic responses to tracheal intubation. Airway 2021;4:175-8
|How to cite this URL:|
Bhaskar V, Shetty SR, Rajaram P, Varmudy MK. Comparison of intravenous versus nebulised lignocaine for suppression of haemodynamic responses to tracheal intubation. Airway [serial online] 2021 [cited 2022 Aug 11];4:175-8. Available from: https://www.arwy.org/text.asp?2021/4/3/175/325564
| Introduction|| |
The induction of general anaesthesia and endotracheal intubation is stressful and is associated with significant haemodynamic changes. Laryngoscopy and intubation are noxious stimuli associated with a transient increase in autonomic response, leading to dysrhythmias and increase in blood pressure and heart rate (HR). King et al. described this response 70 years ago. In patients with coronary artery disease, hypertension, raised intracranial pressure or raised intraocular pressure, it may be associated with myocardial ischaemia, infarction, arrhythmias, cardiac failure, pulmonary oedema and cerebral haemorrhage.
Different methods such as topical lignocaine spray, intravenous (IV) lignocaine, opioids, volatile anaesthetics or β-blockers have been used to suppress this haemodynamic response to intubation. The precise mechanism of the intubation response is elusive, but it has been established to have both sympathetic and parasympathetic elements. The effect is transient, occurring 30 s after intubation and lasting for <10 min thereafter. Nebulisation of lignocaine is routinely practised in our department for providing topical airway anaesthesia during the management of a patient with a difficult airway. We planned this study to analyse whether nebulised lignocaine could be of use to suppress the haemodynamic responses to laryngoscopy and intubation.
| Patients and Methods|| |
This was a prospective study conducted to analyse whether nebulisation with lignocaine could attenuate haemodynamic responses to intubation. The sample was collected on a time-based manner (time-bound study), with the duration of the study being from August 2015 to October 2015. During this period, 20 participants were selected in each group. We used universal sampling for obtaining the sample.
The aim of this study was to analyse whether nebulised lignocaine can suppress haemodynamic responses to intubation. The primary objective was to compare the efficacy of nebulised versus IV lignocaine to suppress the haemodynamic responses to laryngoscopy and intubation.
All participants in this study were aged between 16 and 60 years and belonging to the American Society of Anesthesiologists Physical Status I. They were scheduled for elective surgery under general anaesthesia with endotracheal intubation. Pregnancy, obesity, anticipated difficult airway, airway-related surgeries and patients who refused to be enrolled for the study were excluded from the study. The aim of the study was to compare the relative efficacy of nebulised lignocaine and IV lignocaine to suppress the haemodynamic responses to laryngoscopy and intubation.
While 50 patients were screened, 10 refused to participate. The remaining forty patients were enrolled for the study and randomly allocated into one of two groups, Group LN (nebulised lignocaine) and Group LI (IV lignocaine). Informed consent to participate in the study was obtained, and preanaesthetic evaluation was done on the day before the surgery. All patients were kept nil per oral as per standard fasting guidelines. Premedication was given with tablet ranitidine 150 mg at night and 2 h before surgery and tablet diazepam 10 mg 2 h before surgery.
On the day of the surgery, 15 min before shifting the patient to the operation theatre, baseline readings of blood pressure and HR were recorded and patients in the LN group received 5 mL of 2% lignocaine nebulisation while LI group received normal saline nebulisation. Nebulisation was given in the preoperative holding area in the propped up position using a Philips Respironics InnoSpire Essence Nebulizer.
The patient was then shifted to the operation theatre and was monitored with a 5-electrode echocardiogram monitoring lead II and V5, noninvasive blood pressure and pulse oximetry. After preoxygenation, anaesthesia was induced with IV fentanyl 2 μg/kg and IV propofol 2 mg/kg. After confirming adequate mask ventilation, patients were paralysed with vecuronium 0.1 mg/kg. After 90 s, patients in the LN group received 5 mL of saline intravenously while patients in LI group received 5 mL of 2% lignocaine intravenously. Intubation was performed after 90 s with an appropriate-sized endotracheal tube and bilateral air entry confirmed. Anaesthesia was maintained with isoflurane in a gas:oxygen mixture. No additional agent/drug was given for the first 10 min postintubation nor was surgery allowed to start. The study period ended after 10 min, and further anaesthetic management was carried out as per the instructions of the consultant anaesthesiologist in that operation theatre.
Heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and arterial oxygen saturation were recorded at the following intervals – baseline, before nebulisation, before induction of anaesthesia, after induction of anaesthesia, immediately after intubation and every 1 min after intubation for the first 10 min.
Bradycardia, defined as a HR below 40/min, was treated with IV atropine 0.6 mg. Hypotension defined as mean arterial blood pressure below 60 mm Hg was managed with fluid therapy and 3–6 mg IV boluses of ephedrine. Hypertension defined as mean arterial blood pressure 20% above the baseline was managed with 0.5 mg/kg IV boluses of propofol.
| Results|| |
Increase in HR was observed at laryngoscopy in both groups as compared to the baseline (P = 0.009). This was considered statistically significant (Student's t-test) [Figure 1]. There was a statistically significant rise in SBP (P = 0.003), DBP (P = 0.004) and MAP (P = 0.004) postintubation in the IV lignocaine group as compared to the nebulised lignocaine group [Figure 2] and [Figure 3].
| Discussion|| |
In our study, we found a statistically significant suppression of blood pressure responses (SBP, DBP and MAP) to intubation with nebulised lignocaine in comparison with the IV lignocaine group. Even though increase in HR was observed at laryngoscopy in both groups as compared to the baseline, the rise in the HR was significantly higher in the IV lignocaine group compared to the nebulisation group (P = 0.009).
Chong et al. studied inhaled lignocaine treatment for cough suppression in patients with chronic obstructive pulmonary disease. They found lignocaine as effective as bronchodilator nebulisation but with mild side effects of oropharyngeal numbness and bitter taste. Our patients also had similar complaints, but it was evident for only a short duration as patients were anaesthetised soon after nebulisation.
Ganesan et al. evaluated nebulised versus IV lignocaine for attenuation of pressor response to laryngoscopy and intubation. The haemodynamic responses in our study were similar to that seen in their study with statistically significant increase in SBP, DBP and MAP, while HR increased in both groups after intubation. The authors recommended the use of nebulised lignocaine for effective suppression of haemodynamic responses to airway instrumentation.
The strength of this study is its simplicity in terms of medications, route of administration and the effectiveness of the procedure which can be easily replicated. One of the major drawbacks to soundly propose this technique for attenuation of intubation response is the small sample size. We also did not measure serum lignocaine levels after nebulisation to find a clinical relevance of plasma lignocaine levels. We believe that a study with a larger sample size will give a better insight into the effectiveness of nebulised lignocaine on attenuating haemodynamic responses to intubation.
| Conclusion|| |
Nebulisation of lignocaine is a simple, cost-effective and safe procedure. It has been used in the field of anaesthesia for suppression of cough and supplementation of airway blocks. Using this technique to attenuate haemodynamic responses to intubation is a novel workable idea. With the significant increases in haemodynamic variables observed in the IV lignocaine group compared with nebulisation group, we postulate that nebulisation of lignocaine is a better technique to attenuate haemodynamic responses than IV lignocaine. We believe that with the widespread use of nebulisation of lignocaine, these techniques could replace the use of other pharmacological interventions used for the same purpose, thereby avoiding polypharmacy.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]