Comparison of effect of intranasal midazolam and dexmedetomidine as premedication on haemodynamic stability among paediatric patients

Shilpa S Naik^1*, Shobana Gupta²

Abstract               Background: Fear of unpleasant and painful procedures, separation from parents and an unwillingness to breathe through an anaesthesia face mask may produce stormy anaesthetic induction in unpremedicated patients. Because of this premedication should be an integral part of paediatric anaesthetic practice. Objective: To Compare the Effect of Intranasal administration of Midazolam and Dexmedetomidine as Premedication On Haemodynamic Stability Among Pediatric Patients. Methodology: A Prospective Comparative study was carried out at Department of Anaesthesiology at Shri M.P. Shah Medical College, Jamnagar, Gujarat from December 2011to May 2012. A total of 60 Pediatric Patients of of both sex age group between 1- 5 year from the routine surgical list of our Hospital were included in the study. The children were divided into groups i.e. 30 in each based on the premedication received and by random allotted numbers. Results: The two groups were comparable with regards to demographic data. There was no significant statistical difference in age,weight,sex, duration of surgery and type of surgery between the two groups. The Blood Pressure, Pulse and Respirator rate was found to differ between group after 30 min of drug administration. Spo2 was found to constant in both the groups. Conclusion: Intranasal dexmedetomidine causes some degree of cardiovascular depression in pediatric patients when administered by intranasal midazolam; however, they do impart cardiovascular stability to patients undergoing the stress of surgery.

Key Words: Pediatric, Intranasal, Hemodynamics,Midazolam, Premedication.

INTRODUCTION

The American editor Anaesthetist, Frank Hoffer McMechan in 1920 used the word “PREMEDICATION”.Sington¹ and Hewer² in their first edition of “Recent advances in anaesthesia” also used the word Premedication. The preanaesthetic medication forms an eternal part of any kind of anaesthetic management for all types of surgery. Few types of premedication are almost universally administered before induction of anaesthesia. In ancient days both wine and opium were given to lessen the fear of surgery. Anaesthetic management begins with the preoperative psychological preparation of the patient and administration of a drug or combination of selected drugs to produce specific pharmacological responses before to the induction of anaesthesia. Traditionally this initial psychological and pharmacological component of anaesthetic management is referred to as preoperative medication. The objectives of premedication are:^3,4

1. To lessen preoperative anxiety and fear.
2. To assist anaesthesia, enhance the quality of induction, maintenance and recovery from anaesthesia.
3. To prevent autonomic reflexes.
4. To prevent undesirable side effects.

Fear of unpleasant and painful procedures, separation from parents and an unwillingness to breathe through an anaesthesia face mask may produce stormy anaesthetic induction in unpremedicated patients.^3,4,5 Because of this premedication should be an integral part of paediatric anaesthetic practice. Preanaesthetic medication Plays a crucial role in the children who are given anaesthesia. Preparing a child for the elective surgery should be facilitated byvarious booklets with pictorial presentation slide show s or through few movie scenes and then by the reinforcement of the information by the anaesthesiologist. Among children there are few drugs which are used as preanasthetic medication. One such type of drugs is Diazepam which has a very good anxiolytic property with poor antiemetic effect but doesn’t have analgesic or antisialogogue effect. Similarly, trimeprazine also provide good sedation and had a mild antisialogogue effect but it is associated with more chances of postoperative restlessness. Use of intranasal midazolam spray as premedication has come into practice from early nineties.^6,7. Owing to high mucosal vascularity, intranasal route offers rapid and virtually complete absorption within one-two hours into systemic circulation. As midazolam has high hepatic clearance, avoidance of hepatic first pass metabolism offers greater systemic bioavailability^6,8. It has faster onset than oral or rectal route.⁹ New drugs such as the α_2- agonists have emerged as alternatives for premedication in pediatric anaesthesia. A highly selective α_{2 –}agonist Dexmedetomedine which has both sedative and analgesic properties and is devoid of respiratory depressant effect. These properties render it potentially useful for anaesthesia premedication.¹⁰ In our present study we used Midazolamintranasaland Dexmedetomidine Intranasal.

AIMS AND OBJECTIVE

To Compare the Effect of Intranasal Midazolam and Intranasal Dexmedetomidine as Premedication On Haemodynamic Stability Among Pediatric Patients.

MATERIALS AND METHODS

A Prospective Comparative study was carried out at Department of Anaesthesiology Shri M.P. Shah Medical College, Jamnagar, Gujarat December 2011 to May 2012 A total of 60 Pediatric Patients of of both sex age group between 1- 5 years. The selected children ASA physical status was from I and II who are posted for the routine surgical list of our Hospital were included in the study. All the patients who were selected for the purpose of the study were thoroughly examined and history of any past or present illness was taken and a detailed general as well as systemic examination was done. Out of the selected 60 subjects 30 were allotted into each group based on the random numbers which was generated by computer and respective premedication were given to the children. In the children belonging to GROUP-M Premedication was given in form of intranasal midazolam spray 0.5mg/kg body weight. In the GROUP-D Premedicationwasintranasal dexmedetomedine instillation 1mcg/kg body weight. In the preanaesthetic room, vital parameters, dosing time and acceptance of premedicant were noted.The Vital parameters like. pulse rate, respiratory rate, blood pressure, oxygen saturation (SpO2) was noted before the preanasthetic medication, 1 min, 5 min, 15 min, 30 min, 45 min after Premidication were noted.

RESULTS

The two groups were comparable with regards to demographic data. There was no significant statistical difference between the two groups with regards to distribution of sex, weight, age, type of surgery and duration of anaesthesia.

Table 1: Demographic Data of the study groups

In group M numbers of Male and Female patients were 26 and 4 respectively with a male: female ratio was 6.5:1. In group D numbers of Male and Female patients were 25 and 5 respectively with a male: female ratio was 5:1.

Table 2: Mean Blood Pressure changes in Both Groups

In the above table the Blood Pressure changes (Mean) in both the groups M and D was recorded before the administration of Premedication and after 1, 5,15,30 and 45 Minutes of Premedication. The Blood pressure between the groups was found to be statistically significant only at the 30 min and highly significant at 45 minutes after the administration of premedication. Blood Pressure Before and after the premedication at 1,5 and 15 minutes was not statistically significant.

Table 3: Mean Respiratory Rate changes in Both Groups

From the analysis of data, it is evident that the mean respiratory rate was comparable in both groups. Also the mean respiratory rate did not change significantly till 15 after premedication. But it is evident that there was change in respiratory rate at 15 min, 30 min and 45 min in group as compared to group and thus was statistically significant.

Table 4: Mean Pulse Rate changes in Both Groups

It is evident that mean pulse rate was comparable in both groups at it was found to statistically significant at 30 and 45 min after premedication’s only. Mean pulse rate did not change significantly up to 15 min after premedication. At 15min and 45min in both group M and group patients became calm and sedated. Pulse rate was better controlled in group D as compared to patients in group M, so significant difference was seen at 15 and 45min.

Table 5: Mean changes in oxygen saturation (%) by pulse oximeter (SpO2) in Both Groups

There was no drop in the oxygen saturation among the study subjects in both the groups. The association of oxygen saturation was found to be statistically not significant between the groups.

DISCUSSION

Premedication is necessary to make the patient calm and to lessen the anxiety related to surgery and anesthesia Anesthesiologistsresponsibility in premedicating a patient before induction of anaesthesia is of vital importance. There is universal agreement on the need for some premedication. It forms an integral part of anaesthetic management. Preanaesthetic medication may reduce the risks of adverse psychological^11,12 and physiological^13,14 sequel of induction of anaesthesia in a distressed child. Anaesthetic management begins with the preoperative preparation of the patient and administration of a drug or combination of drugs selected to produce specific pharmacological responses prior to induction of anaesthesia. Physiological and psychological makeup of a child differs from adults and this affects him as a subject for anaesthesia. He is much upset emotionally from being snatched away from his parents.^3,6 Physiologically child is unstable than adults; so there is marked fluctuation of pulse, blood pressure, respiration and secretion during anaesthesia, if dose is altered slightly¹¹. The mean pulse rate was comparable in two groups. As per the statistical analysis, it appears that dexmedetomedine group showed decrease in heart rate and mean arterial pressure with time when compared to group midazolam. But to rule out any cardiovascular depression that might not be evident from the monitoring of pulse rate only, we decided to measure the mean blood pressure. Hence measurement of blood pressure was recorded on the preoperative assessment and then only immediately after premedication and then at 5min15 min, 30 min and 45 min after premedication. There was significant decrease in heart rate and decrease in systolic blood pressure after 30 min in group D as compared to group M. The findings of our study was comparable and similar to the study findings of Vivian M et al¹⁵ who concluded that heart rate and systolic blood pressure significantly decreased with time in dexmedetomedine group than midazolam group. In another study done by Ghali AM et al¹⁶ concluded that Thus, dexmedetomedine causes cardiovascular depression in pediatric patients when administered by the intranasal route as compared to midazolam. The Respiratory Effects of the Premedication in our study was similar to the study findings of the Naqash et al^17, Lee-Kim, S.J., S. Fadavi, et al.¹⁸and Vivian M Yuen et al ¹⁵.All the mentioned studies concluded that there was Oxygen Saturation was maintained by both the groups throughout the operation time. The study findings of Malinovsky⁹was little contrast to our study findings where a case of respiratory depression was noted.

CONCLUSION

We concluded that intranasal dexmedetomidine 1 mcg/kg as instillation is an effective premedicant as compared to intranasal midazolam. in pediatric patients undergoing surgical procedure. Intranasal dexmedetomidine causes some degree of cardiovascular depression in pediatric patients when administered by intranasal midazolam; however, they do impart cardiovascular stability to patients undergoing the stress of surgery, by ameliorating the psychological and physiological aspect of anxiety. There is no significant respiratory depression and fall in arterial saturation seen in both groups. Intranasal dexmedetomidine provides better postoperative recovery than intranasal midazolam.           

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