Analgesic effect provided by femoral nerve block versus intravenous fentanyl prior to positioning for sub arachnoid block in patients with fracture femur- An open label, prospective, clinical study

Pain during positioning in patients with fracture femurresults in improper position and makes subarachnoid block difficult. The aim of our study was to evaluate femoral nerve block and intravenous fentanyl for positioning the patient for subarachnoid block. This open labelled prospective, clinical study was carried out in 60 patients aged 18-70 years of either sex, of ASAPS/ EASAPS – I, II and III, posted for fracture femur surgery under subarachnoid block and likely to have pain while positioning and who understand VAS score. Patients with contraindications to subarachnoid block, allergy to study drugs, history of drug or alcohol abuse, patient with multiple fractures and unable to understand VAS score were excluded from the study. Patients were assigned into two groups alternately in Group FNB(femoral nerve block was given) and Group FENT (intravenous Fentanyl 1µg/kg was given) for positioning before subarachnoid block. Assessment of pain was done using VAS score before and after positioning, time taken to achieve position, quality of position, patient acceptance and additional doses of fentanyl requirement during positioning. Patients were also observed for sedation score, pulse rate, NIBP and oxygen saturation. VAS score 10 minutes after giving analgesia and during positioning was less in group FNB (1.97±0.56) as compared to group FENT (2.87±0.35), which was statistically very highly significant (P < 0.0001). None of the patient required additional dose in either group. FNB provides adequate analgesia, hence satisfactory positioning for sub arachnoid block with stable hemodynamics as compared to intravenous fentanyl.