Effect of intrathecal Dexmedetomidine on incidence of postdural puncture headache (PDPH) in parturients undergoing elective LSCS:A randomized control double blind study.

•This prospective randomized control clinical trial will be conducted at Graphic Era institute of medical sciences, Dehradun, Uttarakhand after approval from institutional ethics committee and registering with Clinical Trial Registry of India (CTRI). A total of 130 parturients, ASA-II,20-40 years of age, posted for elective LSCS, weighing less than 80kgs will be enrolled in the study. Written informed consent will be taken from all the patients. Exclusion criteria will include those with recurrent headache (migraine), neurological dysfunction, hypertension, diabetes, thyroid disease, spinal deformity, refusal to participate and contraindications to SAB.All patients will undergo detailed preanaesthetic check. Eighteen-gauge cannula will be secured in nondominant hand preoperatively. Fasting duration will also be noted in all the parturients. During this time, Ringer lactate (RL) will be infused @ 4ml/kg/hr. In operation theatre, standard ASA monitors (noninvasive blood pressure, pulse oximeter and electrocardiogram) will be attached.

•Parturients will be divided into two groups randomly using a computer-generated random number list, with Group C (control) receiving 2.2 ml of 0.5% hyperbaric bupivacaine AND 0.2ml NS in SAB. Group D (dexmedetomidine)will receive 2.2 ml of 0.5% hyperbaric bupivacaine and preservative free dexmedetomidine 5ug in SAB.  SAB will be given in sitting position under all aseptic precautions with 26G quincke spinal needle, bevel oriented parallel to dural fibers, at L3-L4 or L2-L3 intervertebral space after locally anaesthetizing the field of needle insertion with 2ml of 2% lidocaine. Incision will be given once T6 sensory level is achieved.  All spinal blocks will be given in single prick. Those requiring multiple pricks will be excluded from the analysis. Parturients will be positioned 15 degree left lateral to avoid aortocaval compression. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR) and arterial oxygen saturation(SpO2) will be noted every 2mins till 10 mins and every 5min thereafter post spinal injection. Intraoperative hypotension will be labelled as SPB <100mmHg or MAP<60 mmHg and will be managed by boluses of IV ephedrine 5mg.Bradycardia will be considered at HR of <50bpm and treated with IV atropine 0.6mg stat. After delivery of baby, IV oxytocin 20U will be given as slow infusion for uterine contraction. Apgar score will be assessed by a pediatrician at 1 and 5 min of delivery of baby.

•Parturients will be divided into two groups randomly using a computer-generated random number list, with Group C (control) receiving 2.2 ml of 0.5% hyperbaric bupivacaine AND 0.2ml NS in SAB. Group D (dexmedetomidine)will receive 2.2 ml of 0.5% hyperbaric bupivacaine and preservative free dexmedetomidine 5ug in SAB.  SAB will be given in sitting position under all aseptic precautions with 26G quincke spinal needle, bevel oriented parallel to dural fibers, at L3-L4 or L2-L3 intervertebral space after locally anaesthetizing the field of needle insertion with 2ml of 2% lidocaine. Incision will be given once T6 sensory level is achieved.  All spinal blocks will be given in single prick. Those requiring multiple pricks will be excluded from the analysis. Parturients will be positioned 15 degree left lateral to avoid aortocaval compression. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR) and arterial oxygen saturation(SpO2) will be noted every 2mins till 10 mins and every 5min thereafter post spinal injection. Intraoperative hypotension will be labelled as SPB <100mmHg or MAP<60 mmHg and will be managed by boluses of IV ephedrine 5mg.Bradycardia will be considered at HR of <50bpm and treated with IV atropine 0.6mg stat. After delivery of baby, IV oxytocin 20U will be given as slow infusion for uterine contraction. Apgar score will be assessed by a pediatrician at 1 and 5 min of delivery of baby.