Effect of dexmedetomidine as an adjuvant to bupivacaine in femoral nerve block for perioperative analgesia in patients undergoing total knee replacement arthroplasty: A dose-response study.

CONTEXT: Dexmedetomidine is being increasingly used in nerve blocks. However, there are only a few dose determination studies. AIMS: To compare two doses of dexmedetomidine, in femoral nerve block, for postoperative analgesia after total knee arthroplasty (TKA). SETTINGS AND DESIGN: A prospective, randomized, controlled trial was conducted in the Department of Anesthesia at AIIMS, a Tertiary Care Hospital. MATERIALS AND METHODS: Sixty American Society of Anesthesiologists I-II patients undergoing TKA under subarachnoid block were randomized to three Groups A, B, and C. Control Group A received 20 ml (0.25%) of bupivacaine in femoral nerve block. Groups B and C received 1 and 2 µg/kg dexmedetomidine along with bupivacaine for the block, respectively. Outcomes measured were analgesic efficacy measured in terms of visual analog scale (VAS) score at rest and passive motion, duration of postoperative analgesia, and postoperative morphine consumption. Adverse effects of dexmedetomidine were also studied. STATISTICAL ANALYSIS USED: All qualitative data were analyzed using Chi-square test and VAS scores using Kruskal-Wallis test. Comparison of patient-controlled analgesia (PCA) morphine consumption and time to first use of PCA were done using ANOVA followed by Least Significant Difference test. A P < 0.05 was considered statistically significant. RESULTS: The VAS score at rest was significantly lower in Group C compared to Groups A and B (P < 0.05). There was no difference in VAS score at motion between Groups B and C. The mean duration of analgesia was significantly longer in Group C (6.66 h) compared to Groups A (4.55 h) and B (5.70 h). Postoperative mean morphine consumption was significantly lower in Group C (22.85 mg) compared to Group A (32.15 mg) but was comparable to Group B (27.05 mg). There was no significant difference in adverse effects between the groups. CONCLUSION: The use of dexmedetomidine at 2 µg/kg dose in femoral nerve block is superior to 1 µg/kg for providing analgesia after TKA, although its role in facilitating early ambulation needs further evaluation.

A case of single atrium and single ventricle physiology with bilateral cleft lip and palate for lip repair surgery.

Bilateral cleft lip and palate may occasionally be associated with complex congenital cyanotic heart disease. An infant with common atrium and single ventricle with infundibular pulmonary stenosis (Blalock-Taussig shunt done recently) presented for lip repair surgery. Balanced general anesthesia was administered using sevoflurane along with a regional nerve block to maintain optimal pulmonary and systemic vascular resistance.

Bispectral index correlates well with Richmond agitation sedation scale in mechanically ventilated critically ill patients.

PURPOSE: The clinical sedation scores available for assessing sedation in the intensive care unit (ICU) have drawbacks and limit their usefulness in paralyzed and deeply sedated patients. An objective tool, the bispectral index (BIS), could prove beneficial in such circumstances. We evaluated the ability of BIS to assess the level of sedation and its correlation with the Richmond agitation sedation scale (RASS) in ICU. METHODS: Twenty-four, mechanically ventilated, critically ill patients of either sex, 15-65 years of age, were studied over a period of 24 h. They received a standard sedation regimen consisting of a bolus dose of propofol 0.5 mg/kg and fentanyl 1 microg/kg followed by infusions of propofol and fentanyl ranging from 1.5 to 5 mg/kg/h and 0.5 to 2.0 microg/kg/h, respectively. Hemodynamic parameters, temperature, end-tidal carbon dioxide, BIS and RASS values were recorded. The correlation of BIS and RASS was expressed as Kendall correlation coefficients (tau). A p value of <0.05 was considered statistically significant. RESULTS: A total of 414 readings was obtained. On comparing BIS values for all patients with the corresponding RASS values, there was a statistically highly significant correlation between the two. (tau = 0.56, p < 0.0001). For adequate sedation as judged by a RASS value of 0 to -3, the median BIS value was found to be 56 (range 42-89). A BIS value of 70 had a high sensitivity (85%) and specificity (80%) to differentiate adequate from inadequate sedation. CONCLUSION: Our results illustrate that BIS correlates well with RASS when assessing the level of sedation in mechanically ventilated critically ill patients. BIS reliably differentiates inadequate from adequate sedation.

Unusual complication of internal jugular vein cannulation.

Internal jugular cannulation is a common procedure in the hospitals. We report a rare complication where the guide wire was pushed into the internal jugular vein without threading the catheter through. Complications due to central venous cannulation are also discussed.

Echocardiographic predictors of survival in patients undergoing radiofrequency ablation of postinfarct clinical ventricular tachycardia.

INTRODUCTION: The aim of this study was to determine the predictive value of echocardiographic parameters of systolic left ventricular (LV) dysfunction for survival in a group of patients with "mappable" ventricular tachycardia (VT) after myocardial infarction who underwent radiofrequency ablation (RFA) of their clinical VT(s). METHODS AND RESULTS: RFA of at least one inducible, "mappable," and clinical VT was attempted in 61 patients. In total, 63 (79%) of 80 target clinical VTs were ablated successfully, such that clinical VT(s) were noninducible in 49 (80%) of 61 patients. At the last recorded follow-up (range 2 to 98 months; mean 21 +/- 20), nonfatal VT recurrences were observed in 11 (22%) patients; 10 (16%) patients died. On univariate analysis, a higher LV end-diastolic volume (LVEDV; P = 0.008) and, by multivariate analysis, applying backward selection of variables, older age (P = 0.03) with a higher LVEDV (P = 0.003) predicted patients more likely to die. When age and LV ejection fraction (LVEF) were excluded, LV end-systolic diameter (LVESD; P = 0.007) was the most significant predictor of survival. CONCLUSION: In our patient population with postinfarct VT who underwent RFA of mappable clinical VT(s), LVEF did not predict survival. In this group of patients with overall low mean LVEF (<35%), older age together with higher LVEDV and LVESD predicted patients who were more prone to die. LV size rather than LVEF correlated with survival.