A prospective observational study of skin to subarachnoid space depth in the Indian population.

BACKGROUND AND AIMS: A pre-puncture estimate of skin to subarachnoid space depth (SSD) may guide spinal needle placement and reduce complications associated with lumbar puncture. Our aim was to determine (1) The SSD in Indian males, females, parturients and the overall population; (2) To derive formulae for predicting SSD and (3) To determine which previously suggested formula best suited our population. METHODS: In this prospective, observational study, 800 adult Indian patients undergoing surgery under spinal anaesthesia were divided into three groups: Males (Group M), females (Group F) and parturients (Group PF). SSD was measured after lumbar puncture. The relationship between SSD and patient characteristics was studied and statistical models were used to derive formula for predicting SSD. Statistical analysis included One-way ANOVA with post hoc analysis, forward stepwise multivariate regression analysis and paired t-tests. RESULTS: Mean SSD was 4.71 ± 0.70 cm in the overall population. SSD in adult males (4.81 ± 0.68 cm) was significantly longer than that observed in females (4.55 ± 0.66 cm) but was comparable with SSD in parturients (4.73 ± 0.73 cm). Formula for predicting SSD in the overall population was 2.71 + 0.09 × Body Mass Index (BMI). Stocker's formula when applied correlated best with the observed SSD. Formulae were derived for the three groups. CONCLUSIONS: We found gender-based differences in SSD, with SSD in males being significantly greater than that observed in the female population. SSD correlated with BMI in the parturient and the overall population. Amongst the previously proposed formulae, Stocker's formula was most accurate in predicting SSD in our population.

Granisetron versus ondansetron for post-operative nausea and vomiting prophylaxis in elective craniotomies for brain tumors: A randomized controlled double-blind study.

CONTEXT: Post-operative nausea and vomiting (PONV) pose unique challenges in neurosurgical patients that warrant its study separate from other surgical groups. SETTING AND DESIGN: This prospective, randomized, double-blind study was carried out to compare and to evaluate the efficacy and safety of three antiemetic combinations for PONV prophylaxis following craniotomy. MATERIALS AND METHODS: A total of 75 anesthesiologist status I/II patients undergoing elective craniotomy for brain tumors were randomized into three groups, G, O and D, to receive single doses of dexamethasone 8 mg at induction with either granisetron 1 mg, ondansetron 4 mg or normal saline 2 ml at the time of dural closure respectively. Episodes of nausea, retching, vomiting and number of rescue antiemetic (RAE) were noted for 48 h post-operatively. STATISTICAL ANALYSIS: Analysis of variance with post-hoc significance and Chi-square test with fisher exact correction were used for statistical analysis. P <0.05 was considered to be significant and P < 0.001 as highly significant. RESULTS: We found that the incidence and number of vomiting episodes and RAE required were significantly low in Group G and O compared with Group D; P < 0.05. However, incidence of nausea and retching were comparable among all groups. The anti-nausea and anti-retching efficacy of all the three groups was comparable. CONCLUSIONS: Single dose administration of granisetron 1 mg or ondansetron 4 mg at the time of dural closure with dexamethasone 8 mg provide an effective and superior prophylaxis against vomiting compared with dexamethasone alone without interfering with post-operative recovery and neurocognitive monitoring and hence important in post-operative neurosurgical care.

Randomized double-blind comparison of prophylactic ketamine, clonidine and tramadol for the control of shivering under neuraxial anaesthesia.

BACKGROUND: Shivering is a common problem during neuraxial anaesthesia. Neuraxial anaesthesia impairs thermoregulatory control and up to a 56.7% incidence of shivering has been reported. AIM: To evaluate the effectiveness of prophylactic use of intravenous ketamine, clonidine and tramadol in control of shivering and to note any side-effects of the drugs used. SETTING AND DESIGN: Randomised double-blind study. METHODS: This study was conducted in 200 ASA grade I and II patients. Neuraxial block was performed with 2.8 mL (14 mg) of 0.5% bupivacaine heavy in all patients. The patients were randomly allocated into four groups of 50 each to receive saline as placebo (group P), ketamine 0.5 mg/kg (group K), Clonidine 75 mcg (group C) and Tramadol 0.5 mg/kg (group T). Temperature and hemodynamic parameters were recorded at every 5-min interval. Shivering was graded from 0 to 4 grades and, if grade 3 shivering occurred, the study drug was considered as ineffective and intravenous pethidine 25 mg was given as rescue drug. STATISTICAL ANALYSIS: Data among groups was compared using one-way ANOVA. The incidence of shivering and side-effects were compared using the chi-square test. RESULTS: The incidence of grade 3 shivering showed a statistically significant difference (P=0.001) in group P (27/50) as compared with the other groups (group K=5/50, group C=2/50, group T=4/50). No drug showed any statistically significant advantage over the other. No major hemodynamic changes were seen with prophylactic use of test drugs; however, sedation score was significantly higher in group K (P<0.05) as compared with the other groups. CONCLUSION: The prophylactic use of ketamine, clonidine and tramadol were effective in preventing shivering during neuraxial anaesthesia without causing any major untoward side-effects.

Postoperative hypertension following radical neck dissection.

Baroreflex failure results in wide excursions of blood pressure and heart rate. We report two cases that developed severe postoperative hypertension after radical neck dissection. Carotid sinus denervation during neck dissection may be the cause of the reflex hypertension once general anesthesia-induced vasodilatation has ended.

Comparative evaluation of the sniffing position with simple head extension for laryngoscopic view and intubation difficulty in adults undergoing elective surgery.

The effect of patient position on mask ventilation, laryngoscopic view, intubation difficulty, and the stance adopted by the anesthesiologist during laryngoscopy and tracheal intubation was investigated in 546 anesthetized adults in this prospective, randomized study. Patients were randomly assigned to either the sniffing position group or the simple extension group. The distribution of Cormack grades was comparable between the two groups (P = 0.144). The IDS score [median (IQR)] was 0 (0-2) in the sniffing group and 1 (0-2) in the simple extension group; P = 0.002. There were significant differences between groups with regard to intensity of lifting force, external laryngeal manipulation, alternate techniques used, number of attempts, and the stance adopted by anesthesiologist. We conclude that the sniffing position is superior to simple head extension with regard to ease of intubation as assessed by IDS. An upright stance is adopted by more anesthesiologists performing intubation with patients in the sniffing position.

Anesthetic management of schwannoma of the base of the tongue.

Schwannoma arising from the base of the tongue are very rare and only a few cases have been reported so far. Definitive diagnosis is always made after a histological examination. Apart from an anticipated difficult airway with a risk of airway obstruction upon induction of general anesthesia, anesthetic concerns also include possibility of trauma to the growth and bleeding with attendant risks. We discuss the awake fiberoptic technique used for endotracheal intubation in such a case. This case report highlights the importance of detailed history taking and clinical examination, with emphasis on airway assessment and preoperative planning.

Analgesic efficacy of two doses of intrathecal midazolam with bupivacaine in patients undergoing cesarean delivery.

OBJECTIVES: In this prospective, randomized, double-blind, placebo-controlled study, we investigated the postoperative analgesic efficacy of 2 doses of intrathecal midazolam as an adjunct to bupivacaine for spinal anesthesia. METHODS: Sixty patients undergoing elective cesarean delivery under spinal anesthesia were allocated randomly to 3 groups: group B, 2 mL hyperbaric bupivicaine 0.5%; group BM1, 2 mL bupivacaine plus midazolam 1 mg (preservative free); and group BM2, 2 mL bupivicaine plus midazolam 2 mg. RESULTS: The mean duration of postoperative analgesia (determined by request for rescue medication) was 3.8 +/- 0.5 hours in group B compared with 4.3 +/- 0.7 hours in group BM1 (P = .18), and 6.1 +/- 1.0 hours in group BM2 (P = .001). Supplemental analgesic requirements with diclofenac were significantly less in group BM2 (93 +/- 29 mg) compared with group B (145 +/- 12 mg) and group BM1 (148 +/- 16 mg, P < .001). Time to block regression was longer in group B (182 +/- 30 minutes) compared with group BM1 (152 +/- 32 minutes) and group B (126 +/- 20 minutes) (both P < .001). Arterial pressure, heart rate, oxygen saturation, sedation score, and time to first void were comparable between groups. Group B had a significantly higher incidence of nausea and vomiting than groups BM1 and BM2 (P = .02). No neurologic deficits were observed. CONCLUSIONS: Intrathecal midazolam 2 mg provided a moderate prolongation of postoperative analgesia when used as an adjunct to bupivacaine in patients undergoing cesarean delivery. Intrathecal midazolam, 1 mg and 2 mg, decreased postoperative nausea and vomiting.