European Journal of Cardiovascular Medicine

Rigid laryngoscopy and tracheal intubation continue to be the gold standards of airway care in contemporary anesthesia practice. It was discovered more than 50 years ago that airway manipulation affected blood pressure and heart rate. [1]. It is now commonly known that endotracheal intubation and laryngoscopy infringe against the patient's protective airway reflexes and always result in hemodynamic alterations, including elevated blood pressure, elevated heart rate, and sporadic irregularities in cardiac rhythm. These hemodynamic alterations result from the release of norepinephrine and, to a lesser extent, epinephrine, which is a type of sympathoadrenal reflex.[2]

These hemodynamic alterations are transient [3] and most likely not very significant in persons with normotension. On the other hand, individuals who have hypertension, ischemic heart disease, or cerebrovascular illness should be cautious when experiencing these hemodynamic changes. [4] Due to a rise in heart rate and blood pressure brought on by laryngoscopy and endotracheal intubation, patients with coronary artery disease may have myocardial ischemia. This is because these procedures may increase the demand for greater coronary flow and oxygen in the heart. These heightened reactions in hypertensive individuals can result in congestive heart failure, pulmonary edoema, and left ventricular failure. Increased systemic blood pressure in individuals with intracranial aneurysms or dissecting aortic aneurysms may result in vascular rupture that poses a serious risk to life. As laryngoscopy force and duration increase, so does the response's size. After a laryngoscopy, blood pressure and heart rate usually rise for 5 seconds, peak for 1 to 2 minutes, and then decline to baseline in 5 to 10 minutes.

Consequently, one of the main objectives of anesthesiology is to effectively reduce the sympathoadrenal stress response. A number of pharmacological and nonpharmacological techniques have been attempted to reduce the pressor reaction that occurs when the endotracheal tube is inserted [5]. Because every strategy has advantages and disadvantages of its own, the success rate varies depending on the method used.

Opioids, lidocaine, nitrates, calcium channel blockers, alpha-2 adrenergic agonists, beta blockers, magnesium, and other medications have been administered orally or parenterally to obstruct these sympathoadrenal reactions in a number of studies.

This prospective, randomized study was done after approval of the Ethical Committee of Ramakrishna Mission Seva Pratishthan, Vivekananda Institute of Medical Sciences, Kolkata. The study was carried out in the OT Complex and in the Department of Anaesthesiology of Ramakrishna Mission Seva Pratishthan, Vivekananda Institute of Medical Sciences during the period from January 2021 to January 2022.

This study was observational in nature. According to Padmawar et al.'s research [6], with 50 patients, the mean (±s.d.) heart rate of those treated with 2% lidocaine before and after premedication was 85.6±0.6.8 per minute and 79.8±7.1 per minute, respectively.

Thus, the required number of patients for each group were 30 with 89% power at 5% level of significance (i.e. α = 0.05). The number of patients in each group were is in the ratio 1:1. Thus the required sample size for the study was 120.

Inclusion Criteria

• Patients posted for abdominal surgeries under general anaesthesia.
• Age between 18-60 years
• Patients with ASA Grade I and II

Exclusion Criteria

• Age less than 18 years and more than 60 years
• Known allergy to anaesthetic agents
• History of a major psychiatric disorder
• History of substance abuse and current opioid use
• Compromised renal, hepatic, pulmonary, and cardiac status
• Diabetes (treated or untreated)
• Known Hypertensive
• Pregnancy

Table 1: Comparison between Two Groups in Heart Rate

Table 2: Comparison between Two Groups in Systolic Blood Pressure

Table 3: Comparison between Two Groups in Diastolic Blood Pressure

Table 4: Comparison between Two Groups in Adverse Effects

There was no statistically significant difference (p value>0.05) between the two groups' preoperative HR at baseline. A statistically significant decrease in heart rate (HR) was seen in Group-A vs to Group-B at 5, 10, and 15 minutes following the initiation of the study medication, as well as during intubation 1, 2, 4, 6, 8, and 10 minutes later (p value < 0.05). There was no statistically significant difference (p value>0.05) in the two groups' preoperative SBP at baseline or five minutes after the trial medication started. A statistically significant decrease in SBP was seen in Group-A relative to Group-B at induction, intubation, and 1, 2, 4, 6, 8, and 10 minutes following intubation, all occurring 10 minutes after the study medication was started (p value < 0.05). There was no statistically significant difference (p value>0.05) between the two groups' preoperative DBP at baseline. A statistically significant decrease in DBP was seen in Group-A relative to Group-B at induction, intubation, and 1, 2, 4, 6, 8, and 10 minutes after intubation (p value < 0.05), as well as five and ten minutes following the study drug's commencement. The statistical significance calculations showed that the negative effects were the same for all groups.

It’s a randomized, prospective study. It’s conducted in Ramakrishna Mission Seva Pratishthan Vivekananda Institute of Medical Sciences. Total of 120 samples have been included in this study.

In order to examine the efficacy of magnesium sulphate and lignocaine in reducing the hemodynamic response after laryngoscopy and endotracheal intubation, a randomized, prospective trial was conducted.

There have been reports of notable variations in hemodynamic responsiveness in elderly people. Consequently, patients who were within the ideal age range of 18 to 60 years old were chosen for this investigation. Even in individuals who are well-medicated, difficult intubation takes longer and is always linked with noticeable hemodynamic abnormalities. Therefore, participants with unexpectedly difficult airways and those with higher Mallampati classes (III and IV) were not allowed to participate in this study. The study excluded women who were in the reproductive age group and had a history of a positive pregnancy urine test.

Patients with cardiovascular diseases have also been excluded as these drugs can cause adverse cardiovascular complications.

Group A demonstrated a statistically significant reduction in heart rate, systolic blood pressure, mean arterial blood pressure, diastolic blood pressure, and rate pressure product compared to Group B 10 minutes after the study drug was started, at induction, during intubation, and at 1, 2, 4, 6, 8, and 10 minutes after intubation. At all times after intubation, the magnesium sulphate group's heart rate, systolic and diastolic blood pressure, mean arterial blood pressure, and rate pressure product were considerably lower than those of the lignocaine group (p<0.05). From the beginning of the medications until intubation, there was no discernible difference between the two groups (p>0.05).

Sachin Padmavar et al in 2016 [7] compared the effectiveness of magnesium sulphate over lignocaine in reducing stress reactions during laryngoscopy and endotracheal intubation. They came to the conclusion that magnesium sulfate is a superior substitute for lignocaine in terms of reducing the stress reactions caused by laryngoscopy and intubation. Five minutes after intubation, the HR and SBP in the lignocaine group did not return to baseline due to a significant increase throughout the post-intubation interval. The HR and SBP of the MgSO4 group increased initially upon medication administration and peaked one minute after intubation, however they did not return to baseline until five minutes later. This somewhat supports the findings of our investigation.

Bulle et al in 2017 [8] compared the effectiveness of magnesium sulphate over lignocaine in reducing stress reactions during laryngoscopy and endotracheal intubation. Both groups saw a notable increase in heart rate, although the lignocaine group's increase was greater than the magnesium group's. (p-value less than 0.01). When comparing group L to group M, the progressive climb was statistically significant (p value < 0.01). They came to the conclusion that, in comparison to lignocaine, magnesium sulphate offers pretty effective and prolonged control over rise in HR, SBP, and DBP during laryngoscopy and tracheal intubation in ASA grade I patients. Their results are consistent with those of our investigation.

Nooraei et al in 2013 [9] compared the effectiveness of magnesium sulfate over lignocaine. Systolic blood pressure rose in both groups as compared to the initial reading. There was a notable distinction between the two groups, nevertheless, as the magnesium sulfate group saw this rise within the first minute, whereas the lidocaine group experienced it during the first three minutes. There was no discernible rise in diastolic blood pressure. The mean arterial pressure increase did, however, differ significantly between the two groups because it happened in the first minute for the magnesium sulfate group and the first two minutes for the lidocaine group. Following intubation, there was no discernible difference in the heart rates of the two groups. Our results and the findings are somewhat corroborated.

Panda et al in 2013 [10] before being put under anesthesia, patients in Group IV (control group) got a 1.5 mg/kg lidocaine bolus, whereas patients in Group I, Group II, and Group III received a magnesium sulfate infusion at a dosage of 30, 40, or 50 mg/kg. They came to the conclusion that the best dose of magnesium sulfate for controlling blood pressure in hypertensive individuals during intubation is 30 mg/kg. Substantial hypotension can result from increasing the magnesium dosage any more. Consequently, the dosage of magnesium sulfate that we employed in our trial was 30 mg/kg.

Puri et al in 1998 [11] studied patients slated for elective coronary artery bypass grafting in order to compare the hemodynamic effects of lignocaine and magnesium on mitigating the endotracheal intubation reaction. Analysis of ST segments was done automatically over the duration of the investigation. The delivery of magnesium sulfate was linked to a considerable decrease in systemic vascular resistance (SVR) and mean arterial pressure (MAP) (P < 0.001), a small rise in heart rate, and an elevated cardiac index (P < 0.01). Compared to three patients in the control group, none of the magnesium group's patients experienced substantial ST depression. MAP (P < 0.05) and SVR (P < 0.01) increased considerably less in the magnesium group patients than in the control group, which consisted of patients who received lidocaine prior to endotracheal intubation. Magnesium is therefore a helpful adjuvant to reduce the reaction to endotracheal intubation in CAD patients. They came to the conclusion that endotracheal intubation has negative hemodynamic consequences, which may affect individuals with coronary artery disease more severely than those who are healthy. The current study demonstrates that magnesium, as opposed to lidocaine, can more effectively reduce this reaction when given prior to endotracheal intubation. Their results are consistent with ours.

Kindler CH et al in 1996 [12] studied Six groups were given lidocaine; the third and fourth groups got esmolol at doses of 1 mg/kg and 2 mg/kg, respectively; the fifth group received both esmolol and lidocaine at doses of 1.5 mg/kg and 2 mg/kg; the sixth group was given saline as a placebo. After intubation, only participants receiving a placebo showed higher HR values than baseline (p < 0.05). Compared to both esmolol groups, the placebo group had a substantially larger number of patients (eight out of fifteen) with a maximal heart rate above ninety beats per minute (p < 0.05). Systolic blood pressure values after tracheal intubation did not differ among groups except for those receiving the combinations of lidocaine and esmolol, and they had significantly lower blood pressure (BP) values compared with placebo (p < 0.05). They concluded that Esmolol 1 to 2 mg/kg is reliably effective in attenuating HR response to tracheal intubation. Neither of the two doses of esmolol tested nor that of lidocaine affected the BP response. Only the combination of lidocaine and esmolol attenuated both HR and BP responses to tracheal intubation.

Based on the current study's observations and analysis, it can be concluded that, when compared to lignocaine (1.5 mg/kg body weight) intravenous bolus given over 1 minute, 10 minutes prior to induction, magnesium sulphate (30 mg/kg body weight diluted to 20 ml) intravenous bolus administered over 3 minutes, 10 minutes prior to induction more effectively attenuates the hemodynamic response by limiting the extent of rises in heart rate and blood pressure.This study confirmed both study medications to be safe and free of any significant side effects.

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