Sachin Madhukar Kumbhar^*, V V Kulkarni, Shrikrishn Kamat

Department of Anaesthesiology, Dr V M Government Medical College, Solapur, Maharashtra, INDIA.

Email: skumbhar36@gmail.com

Table 1: General Characteristics

Mean pulse rates in both groups at baseline before test dose, after 3 min test dose, after induction, during intubation, after intubation 1min,3min,5min,10min wear recorded. In group Dexmedetomidine significant reduction in pulse rate compare to Clonidine group. Also pulse rate compared to base line is significantly reduced in dexmedetomidine group.

Table 2: comparison of Changes in PR at Various Term Periods

In group Dexmedetomidine significant reduction in systolic blood pressure compare to Clonidine group. Also changes in systolic blood pressure compared to base line was significantly reduced in dexmedetomidine group.

Table 3: Comparison of changes in systolic blood pressure (SBP)

In group Dexmedetomidine significant reduction in diastolic blood pressure compare to Clonidine group. Diastolic blood pressure compared to base line was significantly reduced in dexmedetomidine group.

Table 4: Comparison of changes in mean diastolic blood pressure (DBP)

In group Dexmedetomidine group significant reduction in mean arterial pressure compare to Clonidine group. Also percent changes in mean arterial pressure compared to base line was significantly reduced in dexmedetomidine group.

Table 5: Changes in MAP at Various Term Periods

Ramsey sedation score after 3 min end of test dose was statistically significant in Dexmedetomidine group as compared to clonidine group. The mean dose of thiopentone sodium (mg) required for loss of eye lash reflex in group I and Group II were 302.5±56.22 and 355.8±82.96 respectively and it was statistically highly significant decrease in dose of thiopentone sodium required for induction in dexmedetomidine group. Intraoperative (bradycardia) and post-operative complication (Post op nausea and vomiting and dryness of mouth) were observed in both groups, which was statistically not significant.

Table 5: other characteristics

DISCUSSION

Two predictors of perioperative cardiac morbidity are increase in heart rate and blood pressure. Increase in heart rate and acute hypertension deleteriously affect myocardial oxygen supply and demand. Different techniques are being tried to prevent or attenuate the hemodynamic effects following laryngoscopy and tracheal intubation, like deepening of anaesthesia, avoiding anticholinergic drugs prior to surgery, pre-treatment with lignocaine, vasodilators like nitroglycerin, beta blockers, calcium channel blockers and opioids. Baseline pulse rate in both groups were comparable and there was no statistically difference. Baseline pulse rate as group I and group II were 79.93+8.09 and 81.85+9.91 respectively. Similar to our study Bijoy Kumar et al.,⁴ and Shirsendu et al.,⁸ who have done comparison of clonidine and Dexmedetomidine and have also found fall in HR after its infusion. Scheinin et al.,⁹ reported that use of α2 agonist leads to bradycardia, not significant with present study. During intubation there was rise in pulse rate in both the groups which was more in Group II compare to Group I and this rise in PR in group II was statistically significant Similar to our result Shrisendu et al.,⁸ has also found statistically significant rise in PR during intubation in clonidine group compare to dexmedetomidine. In his study this statistically significant higher PR in clonidine group last upto 3 min after intubation.

In our study, after intubation there was statistically significant difference in PR between two groups. Bijoy Kumar et al.,⁴ in his study found rise in PR after intubation with only clonidine but not with Dexmedetomidine. A biphasic cardiovascular response has been described after the administration of Dexmedetomidine.¹⁰ A bolus of 1μg/kg results in a transient increase in arterial blood pressure and reflex increase in heart rate is due to α2 receptor stimulation of vascular smooth muscle. This can be markedly decreased by slow infusion over 10 min. In our study this effect was not noticed due to the slow infusion of the drug over 10 min.¹¹ Similarly to our study Nermin et al.,¹² found fall in BP after infusion of Dexmedetomidine and Gupta et al.,⁷ found fall in BP with Clonidine Shirsendu et al.,⁸ has also noticed significant rise in SBP in clonidine group almost 14.67% than in Dexmedetomidine where rise in SBP was only 7%. Bijoy Kumar et al.,⁴ has found comparatively more increase in SBP with Clonidine than Dexmedetomidine. Similar findings were noted in present study. Similar to SBP, DBP had significant rise in Group II in response to intubation compare to Group I. During laryngoscopy and intubation and immediately after it, rise in the HR and Blood pressure was maximum, these findings are in agreement with the studies done by Derbyshire et al.,¹² and Shribman et al.,¹ who concluded that the plasma catecholamine concentration increased to the maximum within 1 min after intubation. In both groups SBP and DBP started falling immediately after intubation but rate of fall in BP was more gradual in Group II, so Dexmedetomidine was more efficient in the attenuation of rise in MAP compared to Clonidine in response to intubation. Similarly, Scheininet al. et al.,⁹ has proved that Dexmedetomidine attenuate the cardiovascular response to laryngoscopy and intubation by measuring catecholamine concentration and found that the concentration of noradrenaline in mixed venous plasma was smaller in the Dexmedetomidine group during all phases of induction. In the study done by Bajwa S et al.,¹⁴ studied the attenuation of pressor response and dose sparing of opioid and anaesthetic requirement with preoperative administration of dexmedetomidine 1μcg/kg compared with fentanyl 2μcg/kg. They found that mean MAP was significantly lower in group D, 20 minutes after infusion of study drug compared with similar parameter in group F. Ramsay sedation score in Group I was higher than Group II. Shirsendu et al.,⁸ has also showed statistically higher Ramsay sedation score with Dexmedetomidine than with Clonidine. The major sedative and antinociceptive effects of Dexmedetomidine are attributable to its stimulation of α2 A subtype located in locus ceruleus. It is the 8 times more specificity of Dexmedetomidine for α2 receptor that makes it a more effective sedative and analgesic agent than Clonidine. Even though higher sedation score seen with Dexmedetomidine was not associated with fall in SpO2. Similarly Shirsendu et al.,⁸ also found no respiratory depression or decrease in SpO2 with similar doses of Dexmedetomidine, so we can conclude that Dexmedetomidine doesn’t cause significant respiratory depression. In clonidine group, no side effects were observed. One patient in group Dexmeditomine had developed bradycardia at 3rd minute after intubation; which was managed by inj. Atropine 0.6 mg. Bajwa S et al.,¹⁴ suggested that cardiac side effects of Dexmedetomidine like bradycardia and sinus pause could have warranted the use of atropine. Bijoy Kumar et al.,⁴ cleared that clonidine and dexmedetomidine does not cause any serious side effect. Use of intraoperative Bi -spectral Index monitoring might have been more precise for the depth of anaesthesia and anaesthetic dose requirement and this might be limitation of our present study.

CONCLUSION

Dexmedetomidine is better in position when compared to clonidine for attenuation of pressor response to laryngoscopy and endotracheal intubation and also decreases requirement of thiopentone sodium for induction of general anaesthesia. There were no any significant adverse effects found with intravenous Dexmedetomidine. This technique will definitely add to the safety of anaesthetic management of patients who are at increased risk of harmful effects of stress response during intubation.

REFERENCES

• Shribman AJ, Smith G, Achola J. Cardiovascular and catecholamine responses to laryngoscopy with or without tracheal intubation.Br J Anaesth 1987; 59:295-9.
• Saif GM, Singh V, Kumar A, Wahal R, Bhatia VK. A study of cardiovascular response during laryngoscopy and intubation and their attenuation by ultra-short acting beta-blocker esmolol.Ind J Anaesth 2002; 46:104-6.
• Joris JL, Chiche JD, Canivet JL, Jacquet NJ, Legros JJ, Lamy ML. Hemodynamic changes induced by laparoscopy and their endocrine correlates: Effects of clonidine. J Am CollCardiol 1998; 32:1389-96.
• GerlachAT, Dasta JF. Dexmedetomidine: An updated review. Ann Pharmacother 2007; 41:245-52.
• Bijoy Kumar Panda, Priyanka Singh, Sourabh Marne, AtmaramPawar, VarshaliKeniya, SushmaLadi, Sarita Swami. A Comparison study of Dexmedetomidine vsClonidine for sympathoadrenal response, perioperative drug requirements and cost analysis. Asian Pacific Journal of Tropical Disease (2012); 1-6.
• A Sagiroglu, M Celik, Z Orhon, S Yüzer, B Sen. Dıfferent Doses of Dexmedetomidine on Controllıng Haemodynamıc Responses to Tracheal Intubatıon. The Internet Journal of Anesthesiology.2009;27:2.
• Gupta Kumkum, Lakhanpal Mahima, GuptaPrashant, Krishan Atul, RastogiBhawna, TiwariVaibhav.Premedication with clonidine versus fentanyl for intraoperative hemodynamic stability and recovery outcome during laparoscopic cholecystectomy under general anesthesia. Anesthesia: Essays and Researches2013; 7 (1): 29-33
• Shirsendu Mondal, Hindol Mondal, Ritaban Sarkar, Musfikur Rahaman. Comparison of dexmedetomidine and clonidine for attenuation of sympathoadrenal responses and anesthetic requirements to laryngoscopy and endotracheal intubation. Int J Basic ClinPharmacol. 2014; 3(3): 501-506
• Scheinin B, Lindgren L, Randell T, et al.: Dexmedetomidine attenuates sympathoadrenal responses to tracheal intubation and reduces the need for thiopentone and perioperative fentanyl. Br J Anaesth 1992; 68:126-131.
• Hulya Basar, Serpil Akpinar; The effects of preanaesthetic, singledose dexmedetomidine on induction, hemodynamic and cardiovascular parameters. Journal of Clinical Anaesthesia 2008; 20:431-436.
• Sulaiman S, Karthikeyan RB, Vakamudi M, Sundar AS, Ravullapalli H, Gandham R. the effects of Dexmedetomidine on attenuation of stress response to endotracheal intubation in patients undergoing elective off-pump coronary artery bypass grafting. Ann Card Anaesth2012;15:39-43.
• Nermin Gogus, Belgin Akan, NurtenSerger, Mustafa Baydaret al. The comparison of the effects of dexmedetomidine, fentanyl and esmolol on prevention of hemodynamic response to intubation. Braz J Anesthesiol. 2014 Sep-Oct; 64(5):314-9.
• Debryshire DR, Fell D, Vaters M. Plasma catecholamineresponse to tracheal intubation. British Journal of Anaesthesia. 1983; 55: 855-9.
• Bajwa SS, Kaur J, Singh G, Kulshrestha A, et al. Attenuation of pressor response and dose sparing of opioids and anaesthetics with pre-operative dexmedetomidine. Indian J Anaesth 2012; 56:123-8.