A randomised double blinded study of Dexmedetomidine, clonidine,pethidine for control of post spinal shivering in patients undergoing elective surgeries

Shivering is a common complication of spinal anesthesia in 70 percent of patients undergoing surgery under spinal anesthesia .Shivering causes certain physiologic complications which includes increase in oxygen consumption, hypercarbia, increase in minute ventilation .It induces arterial hypoxemia , lactic acidosis, increased intraocular pressure,ICT,damage to dental prosthesis thereby interfering with patient monitoring.Various pharmacological and non pharmacological methods are control of shivering during spinal anesthesia . Pharmacological methods using various drugs include tramadol, clonidine , Dexmedetomidine,doxapram, pethidine, nefopam, neostigmine,magnesium sulphate, ketamine have been tried.Dexmedetomidine and clonidine is a selective alpha 2 adrenergic receptor agonist ,Dexmedetomidine is highly selective alpha 2 agonist with antihypertensive, sedative, analgesic properties along with antishivering properties

Pethidine is a mu opioid receptor agonist ,it has analgesic  and anti shivering properties.In this study we compare the efficacy of Dexmedetomidine, pethidine , clonidine  with respect to study time from drug administration to control of shivering,recurrence time .

AIM:

The aim of the study is to compare the control of post spinal shivering using Dexmedetomidine, clonidine , pethidine in patients undergoing elective surgeries

PRIMARY OBJECTIVE:

To compare the time taken to control shivering between Dexmedetomidine, clonidine using pethidine as control group

SECONDARY OBJECTIVE:

To assess sedation using Filos sedation scale

To assess other hemodynamic changes , adverse effects of these drugs over 120 mins

Study design: Prospective ,randomised, double blinded case study

Sample size

Cochran formula is

n=Z(square)pq/e(square)

Where:

Z is in general 1.96 at level of significance being 0.05

e is the desired level of precision (i.e. the margin of error),

p is the (estimated) proportion of the population which has the attribute in question,

q is 1 – p.

In the given proposal,

Z = 1.96

p = 0.22 (assumption based on the practical experience Ref : Halvadia et al 2020))

q = 0.78

e = 0.15 (assumption)

The sample size works out to 29.2986 which is approximately 30.

Hence the sample size suggested for the present study is 30 in each group.

Groups:

Group D - Dexmedetomidine group receiving single intravenous bolus dose of 0.5 mcg/ kg in 100 ml NS over 10 mins

Group P- Pethidine group patients receiving 0.5 mg/ kg Pethidine IV over 10 mins

Group C- clonidine group patients receiving 1 mcg/ kg clonidine IV  in 100 ml NS over 10 mins

Inclusion criteria:

Patients aged 20-60 years

ASA -1,2

Shivering grade 2-3 ( Crossley and Mahajan scale)

Elective surgeries

Exclusion criteria:

Age <20 and > 60

Fever, drug allergic reactions ,thyroid illness, neuromuscular diseases

Patients with cardiac disease( heart blocks,LVF) ,psychiatry illness

Patient who develop shivering even before giving spinal Anesthesia

ASA -3,4

All patients were instructed to fast  for 8 hrs for solid diet prior to surgery.All patients were pre medicated with Tablet ALPRAZOLAM 0.5 mg and Tablet PANTOPRAZOLE 40 mg orally on the night before surgery and morning of surgery. Informed and written consent will be obtained pre operatively.Patients baseline pre operative vitals will be recorded ( HR, BP, MAP, SPO2).The patient will be transferred to operating room.After entering OT room an intravenous (IV) line will be established with an 18 G IV catheter in the dorsum of hand or wrist vein.Standard monitoring with electrocardiography, non invasive blood pressure, pulse oximetry will be performed as per ASA guidelines.BP,HR, SPO2, Temperature will be measured at appropriate levels.Operation theatre temperature will be kept at 22-25 degree Celsius .Warmer, warming blankets, warm fluids will be kept.Under sterile aseptic precautions all patients will receive sub arachanoid block at L3-L4 or L4-L5, level with patients in sitting or lateral position using 25 or 26 G Quincke needle.After cerebrospinal fluid is detected Inj 0.5 Bupivacaine H will be injected along with Inj Buprenorphine  counting on the need for surgery as per Anesthesiologist decision .Shivering of grade 2 and grade 3 as proposed by Crossley and Mahajan scale of shivering will be considered to need of treatment

When patient developed shivering they were  allocated to 3 groups as computer generated random numbers as group D, C,P and the study drug was then administered intravenously as per assigned group .The time from drug administration until the disappearance of shivering will be noted accurately in second.Patients will be monitored at intervals of 1 min, 3 min, 5min, 10 mins, 20 mins, 30 mins until the  End of surger. Crossley and Mahajan scale of shivering ( grade0 - no shivering, grade 1- mild fasciculation of face or neck,grade2- visible tremor involving more than one muscle group, grade-3 gross muscular activity involving the entire body).Patients will be monitored  for drug failure, recurrence of shivering,side effects like Vomiting , hypotension.

Sedation score was evaluated with a four point scale as per filos I

References

Venkatraman R, Karthik K, Pushparani A, Mahalakshmi A. A prospective, randomized, double-blinded control study on comparison of tramadol, clonidine and dexmedetomidine for post spinal anesthesia shivering. Rev Bras Anestesiol. 2018;68:42–8. [PMCID: PMC9391672] [PubMed: 28546012]

Bajwa SJ, Gupta S, Kaur J, Singh A, Parmar S. Reduction in the incidence of shivering with perioperative dexmedetomidine: A randomized prospective study. J Anaesthesiol Clin Pharmacol. 2012;28:86–91. [PMCID: PMC3275980] [PubMed: 22345953]

Shukla U, Malhotra K, Prabhakar T. A comparative study of the effect of clonidine and tramadol on post-spinal anaesthesia shivering. Indian J Anaesth. 2011;55:242–6. [ PMCID: PMC3141147] [PubMed: 21808395]