European Journal of Molecular & Clinical Medicine

Background & Aim: Direct laryngoscopy & Endotracheal intubation causes sympathetic response which is deleterious to patient. Various drugs are used to attenuate this response for better hemodynamic control. In this study, we aim to compare the efficacy of esmolol to that of mgso4 for attenuation of this response. Methods: After obtaining approval from institution ethics committee and informed written consent from the patients, 60 patients coming for elective surgeries under general anesthesia were randomly allocated into 2 groups, Group E (Esmolol 1mg/kg) and Group M (Magnesium sulfate (MgSO4) 25mg /kg), with 30 patients in each group. Patients received drugs 5 min before intubation; HR, SBP, DBP and MAP were calculated at baseline, 0 min, 1 min, 3 min, 5 min and 10 min. Results: Baseline parameters were compared between 2 groups, which were statistically not significant. HR at 1 min (p=0.034) and 3 min (p=0.025) was statistically significant in favor of Group M. SBP, DBP and MAP were reduced better with Group E than Group M, but statistically not significant. Conclusion: MgSO4 reduces the sympathetic stimulation to laryngoscopy and intubation as effectively as Esmolol. MgSO4 also has the advantage of providing analgesia, reducing the dose of anesthetics, and provides better hemodynamic profile throughout intra-operative period.

Electrophysiological studies revealed that Esmolol causes an increase in sinus cycle length
and sinus node recovery time. Electrocardiographic parameters like 'PR' 'QRS' and 'QT'
intervals were not prolonged. In contrast to other beta blockers, electrophysiological values
return to baseline values within a period of 30 minutes after withdrawing the drug. When
infused at a dose of 200 micrograms/kg/minute, Esmolol can significantly reduce the namely,
resting heart rate, Systolic blood pressure, rate pressure product, cardiac index. Esmolol can
also attenuate isoprenaline induced tachycardia. After obtaining clearance from the
Institutional Ethical Committee and informed written consent, a prospective randomized
double-blinded study was conducted on sixty patients scheduled for various elective surgical
procedures belonging to patients physical status American Society of Anesthesiologists
(ASA) Classes I and II were included in the study. In esmolol group the basal heart rate was
97.8bpm. During reversal heart rate increased to 102.7bpm. During drug injection and
subsequently heart rate decreased as shown in table. At 15min post extubation heart rate was
84.6bpm which was less than basal.
In labetalol group the basal heart rate was 97.5bpm. During reversal heart rate increased to
103.1bpm. During drug injection and subsequently heart rate decreased as shown in table. At
15min post extubation heart rate was 69.9bpm which was much less than basal.

Complications after trachea extubation are three times more common than complications occurring
during tracheal intubation and induction of anaesthesia. Hypertension and tachycardia are well
documented events during extubation. These hemodynamic responses reflects sympatho-adrenal reflex
stimulation (epipharyngeal and laryngo pharyngeal stimulation) with concomitant increase in plasma
level of catecholamines and activation of alpha and beta adrenergic receptors. A routine preanesthetic
examination was conducted assessing the general condition of the patients on the evening before
surgery. From all patients, informed consent was obtained. All patients were kept nil per oral for 8 h.
On arrival in the operating room, i.v. line was established, and fluid dextrose with normal saline was
started. Patients were connected to multichannel monitor which records HR, noninvasive blood
pressure, end-tidal carbon dioxide, and oxygen saturation. Statistical evaluation between the group
showed there was no significance of SBP between the group at basal, extubation upto 1th minute post
extubation (p>0.05). At 2th min (p=0.034), 3rd min (p-0.023) and 15th min (p=0.024) post extubation
there was significance esmolol> labetalol at 2nd and 3rd, labetalol >esmolol at 15th min.

The advantages of controlled hypotension to the anaesthesiologists are reduced intraoperative bleeding and hence minimization of the need for blood transfusion and a reduced duration of anaesthesia. The surgeon enjoys a dry (bloodless) operative field with minimal use of diathermy and suturing and an overall reduction in the surgical duration. Patients with subnormal or abnormal laboratory or clinical findings were excluded from the study. All patients received Tab: Alprazolam 0.5mg and Tab: Ranitidine 150mg after the Night meal on the day prior to the surgery. All patients were starved for a minimum of 8 hours prior to induction of anesthesia. The fall in MAP from basal levels to the hypotensive period was much higher in the NTG group (24.28%) than that in the ESM group (6.80%). The intra-group difference was also statistically significant.