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Year : 2014  |  Volume : 5  |  Issue : 2  |  Page : 117-120

Effects of esmolol on hemodynamic responses to laryngoscopy and tracheal intubation in diabetic and non-diabetic patients

Department of Anaesthesiology, Kasturba Medical College, Mangalore, Manipal University, Manipal, Karnataka, India

Date of Web Publication1-Jul-2014

Correspondence Address:
Shaila S Kamath
Krithika, 5-7-710/2, Near Sathya Sai Nursing Home, Dongerkery, Mangalore - 575 003, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0975-9727.135738

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Background: The hemodynamic response to laryngoscopy and endotracheal intubation is of concern in diabetic patients. They usually have underlying coronary and cerebrovascular disease which may lead to catastrophes during anesthesia. Materials and Methods: Seventy controlled diabetic and 70 non-diabetic patients were allocated in to four groups. Esmolol 1 mg/kg to study groups and normal saline to control groups was infused slowly over 1 min. Later all patients induced with propofol 2 mg/kg and rocuronium 0.6 mg/kg. SBP, DBP, HR, and SpO 2 recorded every minute after intubation for 10 min. Results: In non-diabetic esmolol (NDE) and diabetic esmolol (DE) group we observed increase in heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), more in DE group compared to NDE group, but was non-significant (P > 0.05). In group non-diabetic control (NDC) and diabetic control (DC) there was significant increase (P = < 0.05) in HR, SBP, DBP for first 2 mins of intubation when compared with base line values. Rise is more marked in DC group than NDC group. Blood glucose measured after 10 mins of intubation shows no significant difference among both groups. Conclusion: Esmolol with low dose fentanyl is a near ideal drug for attenuating pressor response to laryngoscopy and intubation in controlled diabetics.

Keywords: Controlled diabetic, esmolol, fentanyl, pressor response

How to cite this article:
Osmani SG, Kamath SS. Effects of esmolol on hemodynamic responses to laryngoscopy and tracheal intubation in diabetic and non-diabetic patients. Muller J Med Sci Res 2014;5:117-20

How to cite this URL:
Osmani SG, Kamath SS. Effects of esmolol on hemodynamic responses to laryngoscopy and tracheal intubation in diabetic and non-diabetic patients. Muller J Med Sci Res [serial online] 2014 [cited 2023 Jan 30];5:117-20. Available from: https://www.mjmsr.net/text.asp?2014/5/2/117/135738

  Introduction Top

Laryngoscopy and tracheal intubation are associated with increase in blood pressure (BP) and heart rate (HR) that may be deleterious in patients with underlying cardiovascular and cerebrovascular disease. To inhibit this pressor response various methods have been tried including adrenergic blockers, vasodilators, calcium channel blockers, alpha-2 agonists, narcotics and inhalational anesthetics. [1],[2] Hemodynamic changes are generally temporary without any sequel. However, these changes can facilitate and accelerate the development of myocardial ischemia, arrhythmia, infarction, and cerebral hemorrhage in patients with coronary artery disease, hypertension or cerebrovascular disease. [3],[4],[5]

Availability of a β-blocking agent such as esmolol, where action is rapid in onset, can be titrated very rapidly terminated when required, would provide an important safety factor in these settings while testing and treating the acute problem.

Esmolol is an ultra-short acting, β1 cardio selective, β blocking agent with a short half-life (9 min). This agent has been used to reduce the increase in heart rate and blood pressure in response to tracheal intubation. [6],[7] It has variable effectiveness in the recommended doses (100-200 mg). [8],[9] A combination of fentanyl and esmolol might prove to be more efficacious than either agent alone. The purpose of this study is to show the effectiveness of esmolol, a short-acting β blocker agent, on blocking the hemodynamic response to laryngoscopy and tracheal intubation in non-diabetic and diabetic patients, as diabetic patients are at high risk for myocardial ischemia.

  Materials and Methods Top

After obtaining institutional ethics committee approval, patients were given information about the procedure and written informed consent was taken. Controlled diabetic (HbA1c ≤7.5 on insulin or oral hypoglycemic drugs) or non-diabetic patients who were scheduled to undergo elective operations under general endotracheal anesthesia selected. After complete pre-anesthetic evaluation with laboratory investigations and electrocardiogram, those with significant cardiopulmonary disease, blood pressure not between 100/50-150/100 mmHg, smoking history, expected difficult airway, prolonged intubation longer than 20 secs. Patients with signs of autonomic neuropathy, severe liver and renal insufficiency were excluded from study groups.

One hundred forty patients were randomly divided into four groups as non-diabetic control (NDC), non-diabetic esmolol (NDE), diabetic control (DC) and diabetic esmolol (DE), with each group having 35 patients as study sample. Study is prospective randomized, double-blind study conducted at Government Wenlock Hospital and KMC Hospitals, Mangalore, Over a duration of one and half year. Patient age, gender, height and weight were recorded. All patients were given 2 mg of Tab lorazepam previous night and 2 hrs before proposed surgery.

After arrival in operation theatre electrocardiogram, baseline systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), peripheral oxygen saturation (SpO 2 ), and preoperative blood sugar were recorded. Patients were preloaded with 10 mlkg-1 RL/NS I.V fluids, 100% oxygen given before induction of general anesthesia. Esmolol 1 mg/kg to Groups DE and NDE and normal saline solution to Groups DC and NDC was infused slowly over 1 min in a volume of 10 ml following premedication with fentanyl l.5 μg/kg, later all patients received propofol 2 mg/kg (or titrated doses) and Rocuronium 0.6 mg/kg for the induction of general anesthesia. Intubation was done by the anesthesiologist with minimum 2 years experience after 3 min of bag and mask ventilation using oxygen and 1% isoflurane. SBP, DBP, HR, and SpO 2 values were recorded every minute after intubation for 10 min. During this period, starting of surgery was not allowed. Blood glucose levels were measured at 10 th min after intubation.

After tracheal intubation, anesthesia was maintained with 60% nitrous oxide in oxygen and 1% isoflurane in order to provide a MAC of 1. Normothermia was maintained during the whole procedure. Hypotension and bradycardia is defined as SBP less than 90 mmHg and HR less than 45 beats/min, respectively. Those patients experiencing hypotension or bradycardia were treated with ephedrine 5 mg or atropine 0.5 mg, respectively.

The results thus achieved were compared using ANOVA, Bonferoni t test, and Students paired t test.

  Results Top

In this study comparison between the groups by ANOVA test shows highly significant difference among the age of the patients. It shows diabetic group patients being older than non-diabetic group [Table 1]. Comparison of sex incidence among total of 47.9% females and 52.1% males in the groups, non-significant p value showing sex is not an influencing factor among the four groups [Table 2].
Table 1: Age distribution

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Table 2: Gender distribution

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In both control groups there was significant rise in heart rate for up to 3 min. of intubation compared to preoperative values. Initial rise in heart rate seen in diabetic esmolol group for first 2 min of intubation, but this rise is insignificant compared to other groups. Increase in the heart rate settles below baseline values by the end of 10 min [Figure 1].
Figure 1: Change in heart rate

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SBP in Group NDE after intubation was significantly lower than SBP before infusion (P < 0.05). In the same group, SBP measurements at the first 3mins after intubation shows insignificant rise compared to baseline values (P > 0.05) and measurements at the subsequent minutes after intubation were significantly low (P < 0.05). In DC it shows, significant rise (P < 0.05) in SBP values for first 2 mins of intubation, which settles down early [Figure 2]. In DE Group rise in SBP was significant for first 2 mins of intubation but settles to normal range early. Rise in SBP was less compared to control groups.
Figure 2: Change in systolic blood pressure

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In Group NDE, DBP measurements after intubation were similar to DBP measurements before intubation (P < 0.05). In the same group, all DBP measurements at the 3rd and following minutes after intubation were low compared to baseline values [Figure 3]. In Group NDC, DBP measurements in the 1 st , 2 nd min after intubation were significantly higher (P < 0.05) than DBP measurements before intubation. However, all DBP measurements in the 3 rd and following minutes after intubation were significantly low (P < 0.05) In Group DC, DBP measurements at the 1 st -3 rd min after intubation were higher than DBP before intubation (P < 0.05), but all DBP measurements after the 3rd min were significantly low (P < 0.05). In Group DE, DBP measurements after intubation were higher than DBP measurements before intubation (P < 0.05), but all DBP measurements eventually comes down to preoperative level by 3 rd minute onwards.
Figure 3: Change in diastolic blood pressure

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There was no significance difference among preoperative GRBS values of each group and GRBS values at the end of 10 minutes of intubation. This shows esmolol has no significance effect on blood sugar [Figure 4].
Figure 4: Changes in blood sugar

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  Discussion Top

Strategies to circumvent pressor response have included minimizing the duration of laryngoscopy, IV narcotics, topical lidocaine, vasodilators, long acting beta blockers, inhaled anesthetics, and calcium channel blockers. [10],[11]

However, none of these techniques are fool proof and have not gained widespread acceptance as each techniques has disadvantages the most obvious being prevention outlast the stimulus. Esmolol with desirable properties of short duration of action, cardio-selective β-adrenergic blocker, and short duration of action has been used in our study along with low-dose fentanyl.

The optimal time of injection of fentanyl is 5 min before intubation, low-dose fentanyl 2 μg/kg given 5 min before intubation was found to be more effective in controlling both HR and BP. [12]

In a comparative, study the effectiveness of lignocaine, fentanyl and esmolol for attenuation of cardiovascular to laryngoscopy and intubation. Results showed that only esmolol could reliably offer protection against the increase in both heart rate, SBP, low-dose fentanyl 3 mcg/kg prevented hypertension but not tachycardia and lidocaine had no effect to blunt the hemodynamic response. [13]

A combination of low-dose fentanyl and esmolol was found to blunt the hemodynamic response to intubation more effectively than either drug alone. [14]

Tachycardia along with hypertension increases ischemia risk in patient with coronary artery disease more in diabetic patients. There is limited number of studies evaluating esmolol in patient with diabetes who have silent underlying coronary artery disease; there are studies to show usefulness of beta blocker in such patients. [10]

In above study the maximum cardiovascular response occurred 2 min after intubation. They also noted that the responses are proportional to the duration of laryngoscopy, response start showing at 15 sec and peak up at 45 sec., hence they recommend that the duration of laryngotracheal intubation should not exceed 30 sec. [10]

In our study, we employed only bolus dose of esmolol 1 mg/kg following premedication with fentanyl 1.5 μg/kg by virtue of simplicity, rapidity and convenience, this dose combination selected since survey of literature shows that esmolol alone at higher doses produce hypotension and bradycardia.

It is known that the effect on heart rate after esmolol bolus dose comes at 1 min, whereas the effect of BP comes after 2 min. [14] Similar to results in our study group NDE no significant rise in HR and SBP seen after intubation but in group DE effect is more pronounced on HR than BP. In other groups HR and SBP increased significantly, Rise in HR and SBP seen for first 2 minutes which comes down gradually after 2 mins. Blood sugar measured before induction and after 10 mins of intubation show no significant difference in all four groups.

Esmolol is known to cause dose-dependent bradycardia, hypotension, atrio-ventricular block and bronchospasm as adverse effect, but in our study hypotension seen only in few patients in NDE group no other adverse effect seen and no patient in study showed significant difference in saturation (SpO 2 ).

  Conclusions Top

Attenuating effect is more marked on heart rate than on blood pressure, No side effects occur in healthy subjects (ASA 1 and 2) with concomitant administration of opiates, sedatives and inhalational anesthetics. From this study we conclude that esmolol with low-dose fentanyl is a near ideal drug for attenuating pressor response to laryngoscopy and intubation in controlled diabetics.

  Acknowledgement Top

We would like to acknowledge the support and help of K.M.C. Mangalore and Manipal University in performing this study.

  References Top

1.Helfman SM, Gold MI, DeLisser EA, Herrington CA. Which drug prevents tachycardia and hypertension associated with tracheal intubation: Lidocaine, fentanyl or esmolol? Anesth Analg 1991;72:482-6.  Back to cited text no. 1
2.Mikawa K, Ikegaki J, Maekawa N, Goto R, Kaetsu H, Obara H. The effects of diltiazem on the cardiovascular response to tracheal intubation. Anaesthesia 1990;45:289-93.  Back to cited text no. 2
3.Kindler CH, Schumacher PG, Schneider MC, Urwyler A. Effects of intravenous lidocaine and or esmolol on haemodynamic responses to laryngoscopy and intubation: A double-blind, controlled clinical trial. J Clin Anesth 1996;8:491-6.  Back to cited text no. 3
4.Saitoh N, Mikawa K, Kitamura S, Maekawa N, Goto R, Yaku H, et al. Effects of trimetaphan on the cardiovascular response to tracheal intubation. Br J Anaesth 1991;66:340-4.  Back to cited text no. 4
5.Fox EJ, Sklar GS, Hill CH, Villanueva R, King BD. Complications related to the pressor response to endotracheal intubation. Anesthesiology 1977;47:524-5.  Back to cited text no. 5
6.Wolman RL, Fiedler MA. Esmolol and beta-adrenergic blockade. AANA J 1991;59:541-8.  Back to cited text no. 6
7.Barbier GH, Shettigar UR, Appunn DO. Clinical rationale for the use of an ultra-short acting beta-blocker: Esmolol. Int J Clin Pharmacol Ther 1995;33:212-8.  Back to cited text no. 7
8.Miller DR, Martineau RJ. Esmolol for control of haemodynamic responses during anaesthetic induction. Can J Anaesth 1989;36:S164-5.  Back to cited text no. 8
9.Cole CP. Bolus esmolol and the post intubation response in patients induced with fentanyl/thiopental. Anesth Analg 1990;70:S65.  Back to cited text no. 9
10.Ebert O, Pearson JO, Gelman B. Circulatory responses to laryngoscopy: The comparative effects of placebo, fentanyl and esmolol. Can J Anaesth 1989;36:301-6.  Back to cited text no. 10
11.Figueredo E, Garcia-Fuentes EM. Assessment of the efficacy of esmolol on the haemodynamic changes induced by laryngoscopy and tracheal intubation: A meta-analysis. Acta Anaesthesiol Scand 2001;45:1011-22.  Back to cited text no. 11
12.Ko SH, Kim DC, Han YJ, Song HS. Small-dose fentanyl: Optimal time of injection for blunting the circulatory responses to tracheal intubation. Anesth Analg 1998;86:658-61.  Back to cited text no. 12
13.Feng CK, Chan KH, Liu KN, Lee TY. A comparison of lidocaine, fentanyl and esmolol for attenuation of cardiovascular response to laryngoscopy and tracheal intubation. Acta Anaesthesiol Sin 1996;34:61-7.  Back to cited text no. 13
14.Chung KS, Sinatra RS, Halevy JD, Paige D, Silverman DG. A comparison of fentanyl, esmolol and their combination for blunting haemodynamic responses during rapid-sequence induction. Can J Anaesth 1992;39:774-9.  Back to cited text no. 14


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2]


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