Comparative study of heart rate responses to laryngoscopic endotracheal intubation and to endotracheal intubation using intubating laryngeal mask airway under general anaesthesia in patients with pure mitral stenosis for closed mitral commissurotomy.

The various drugs and methods studied in an attempt to curb the haemodynamic stress response associated with conventional laryngoscopic endotracheal intubation have not been found to be ompletely satisfactory. The rise in heart rate can be detrimental to patients with mitral stenosis. This study was aimed to compare the heart rate responses to endotracheal intubation using conventional laryngoscope and with the help of intubating laryngeal mask airway (ILMA) in patients with isolated mitral stenosis. Thirty-four adult patients of either sex, aged between 18 and 40 years with isolated mitral stenosis to undergo closed mitral commissurotomy were randomly allocated into two groups : Group A (n=17)- To be intubated using laryngoscopy. Group B (n=17)- To be intubated with the help of ILMA. The heart rate was recorded immediately preinduction, just prior to introducing the intubating device and postintubation every minute up to first 5 minutes. On applying statistical tests, it was found that the median heart rate values in group A at 2, 3, 4 and 5 minutes postintubation were significantly higher than in group B (p<0.05). Although use of both laryngosope and ILMA for endotracheal intubation was associated with rise in heart rate, the rise was less with ILMA compared to laryngoscope. Hence, it can be concluded that use of ILMA may be a preferable device for endotracheal intubation laryngoscopy in patients with isolated mitral stenosis.

A comparison between volume-controlled ventilation and pressure-controlled ventilation in providing better oxygenation in obese patients undergoing laparoscopic cholecystectomy.

BACKGROUND: The maintenance of oxygenation is a commonly encountered problem in obese patients undergoing laparoscopic cholecystectomy. There is no specific guideline on the ventilation modes for this group of patients. Although several studies have been performed to determine the optimal ventilatory settings in these patients, the answer is yet to be found. The aim of this study was to evaluate the efficacy of pressure-controlled ventilation (PCV) in comparison with volume-controlled ventilation (VCV) for maintaining oxygenation during laparoscopic cholecystectomy in obese patients. METHODS: One hundred and two adult patients of ASA physical status I and II, Body Mass Index of 30-40 kg/m(2), scheduled for laparoscopic cholecystectomy were included in this prospective randomized open-label parallel group study. To start with, all patients received VCV. Fifteen minutes after creation of pneumoperitoneum, they were randomized to receive either VCV (Group V) or PCV (Group P). The ventilatory parameters were adjusted accordingly to maintain the end-tidal CO(2) between 35 and 40 mmHg. Respiratory rate, tidal volume, minute ventilation and peak airway pressure were noted. Arterial blood gas analyses were done 15 min after creation of pneumoperitoneum and at 20-min intervals thereafter till the end of the surgery. All data were analysed statistically. RESULTS: Patients in Group P showed a statistically significant (P < 0.05) higher level of PaO(2) and lower value of PAO(2)-PaO(2) than those in Group V. CONCLUSION: PCV is a more effective mode of ventilation in comparison with VCV regarding oxygenation in obese patients undergoing laparoscopic cholecystectomy.

Impact of general versus epidural anesthesia on early post-operative cognitive dysfunction following hip and knee surgery.

BACKGROUND: Post-operative cognitive dysfunction is the subtle cerebral complication temporally seen following surgery. The aim of this study was to compare the influence of either general anesthesia (GA) or epidural anesthesia (EA) on the early post-operative neurocognitive outcome in elderly (>59 years) subjects undergoing hip and knee surgery. METHODS: A total of 60 patients were recruited in a prospective, randomized, parallel-group study, comparable by age and sex. They were enrolled and randomized to receive either EA (n = 30) or GA (n = 30). All of them were screened using the Mini Mental State Examination (MMSE), with components of the Kolkata Cognitive Screening Battery. The operated patients were re-evaluated 1 week after surgery using the same scale. The data collected were analyzed to assess statistical significance. RESULTS: We observed no statistical difference in cognitive behavior in either group pre-operatively, which were comparable with respect to age, sex and type of surgery. Grossly, a significant difference was seen between the two groups with respect to the perioperative changes in verbal fluency for categories and MMSE scores. However, these differences were not significant after the application of the Bonferroni correction for multiple analyses, except the significant differences observed only in the MMSE scores. CONCLUSIONS: We observed a difference in cognitive outcome with GA compared with EA. Certain aspects of the cognition were affected to a greater extent in this group of patients undergoing hip and knee surgery.

Effect of magnesium infusion on thoracic epidural analgesia.

INTRODUCTION: Patients of lung volume reduction surgery (LVRS) having an ASA status III or more are likely to be further downgraded by surgery to critical levels of pulmonary function. AIM: To compare the efficacy of thoracic epidural block with (0.125%) bupivacaine, fentanyl combination and (0.125%) bupivacaine, fentanyl combination with adjunctive intravenous magnesium infusion for the relief of postoperative pain in patients undergoing LVRS. METHODS: Patients were operated under general anesthesia. Thirty minutes before the anticipated completion of skin closure in both groups, (Group A and Group B) 7 ml of (0.125%) bupivacaine calculated as 1.5 ml/thoracic segment space for achieving analgesia in dermatomes of T4, T5, T6, T7, and T8 segments, along with fentanyl 50 µg (0.5 ml), was administered through the catheter, activating the epidural block, and the time was noted. Thereafter, in patients of Group A, magnesium sulfate injection 30 mg/kg i.v. bolus was followed by infusion of magnesium sulfate at 10 mg/kg/hr and continued up to 24 hours. Group B was treated as control. RESULTS AND ANALYSIS: A significant increase in the mean and maximum duration of analgesia in Group A in comparison with Group B (P<0.05) was observed. Total epidural dose of fentanyl and bupivacaine required in Group A was significantly lower in comparison with Group B in 24 hours. DISCUSSION: Requirement of total doses of local anesthetics along with opioids could be minimized by magnesium infusion; therefore, the further downgradation of patients of LVRS may be prevented. CONCLUSION: Intravenous magnesium can prolong opioid-induced analgesia while minimizing nausea, pruritus, and somnolence.

Evaluation of Ondansetron-induced QT interval prolongation in the prophylaxis of postoperative emesis.

BACKGROUND: To avert nausea and vomiting the 5-Hydroxytryptamine3 (5-HT3) antagonists have become the first line of treatment ifassociated with cardiovascular effects andappear to cause QT prolongation. OBJECTIVE: Evaluate the effect of 1 mg, 4 mg, and 8 mg bolus doses of intravenous Ondansetron, relative to placebo, in prevention of postoperative nausea and vomiting (PONV) and to find out the changes of QT interval corrected for heart rate (QTc). MATERIALS AND METHODS: This prospective randomized, placebo-controlled, double-blind study was carried out among 136 adult participants of both sexes in a tertiary care postgraduate teaching institute at Kolkata. mg, 4 mg or 8 mg inj. Ondansetron was diluted to 10 ml with normal saline, was infused 30 min before extubation in relation with a control group. Time to first rescue antiemetic medication and in QTc interval at different time intervals, in each group was noted in different in the various surgical operation theaters (OTs). RESULTS: Requirement of the first rescue antiemetic in the postoperative period between 60 to 120 min in the mg, 4 mg or 8 mg Ondansetron groups was in 28%, 24% and 7% participants respectively; between 120 to 240 min in 63%, 72% and 57% respectively; and within 360 min in 9%, 4% and 36% respectively. Significant and maximal QTc prolongation was observed in the participants with mg or 8 mg Ondansetron 3 and 5 min of drug administration. CONCLUSIONS: One mg Ondansetron in healthy adult participants can effectively prevent PONV causing no or insignificant prolongation of QTc interval.

Controlled transient respiratory arrest along with rapid right ventricular pacing for improving balloon stability during balloon valvuloplasty in pediatric patients with congenital aortic stenosis--a retrospective case series analysis.

Rapid right ventricular pacing is safe, effective, and established method to provide balloon stability during balloon aortic valvuloplasty (BAV). Controlled transient respiratory arrest at this point of time may further reduce left ventricular stroke volume, providing an additional benefit to maintain balloon stability. Two groups were studied. Among the 10 patients, five had rapid pacing alone (Group A), while the other five were provided with cessation of positive pressure breathing as well (Group B). The outcomes of BAV in the two groups of patients were studied. One patient in Group A had failed balloon dilatation even after the fourth attempt, while in Group B there were no failures. The peak systolic gradient reduction was higher in Group B (70.05% in comparison to 52.16% of group A). In Group A, five subjects developed aortic regurgitation (grade 2 in four and grade 3 in one, while no grade 3 aortic regurgitation developed in any patient in Group B). Controlled transient respiratory arrest along with rapid ventricular pacing may be effective in maintaining balloon stability and improve the outcome of BAV.

Analgesia in post-thoracotomy patients: Comparison between thoracic epidural and thoracic paravertebral blocks.

BACKGROUND: Acute postoperative pain can cause detrimental effects on multiple organ systems, leading to chronic pain syndromes. OBJECTIVE: To compare thoracic epidural block (TEB) and paravertebral block (PVB) for relief of postoperative pain in adult patients undergoing thoracotomy. MATERIALS AND METHODS: In this randomized, single-blinded, prospective study, 60 adult patients of both sexes, belonging to ASA physical status I and II, were scheduled for elective thoracotomy under general anesthesia. They were randomly divided into two groups, A and B of 30 each, who were comparable in terms of demographic parameters and body weight. Group A received TEB and Group B received PVB. All the patients underwent thoracotomy under general anesthesia using a uniform standard anesthetic technique. Thirty minutes before the anticipated end of skin suture, blocks were activated in both the groups with 7.5 ml for TEB and 15 ml for thoracic PVB of 0.25% bupivacaine, along with 1 ml of fentanyl for postoperative analgesia. RESULTS: Patients receiving PVB for postoperative analgesia experienced better analgesia than those receiving TEB from the immediate postoperative period that lasted longer. Intragroup comparison showed that in the cases receiving TEB, there was a significant statistical difference in preoperative and postoperative values with regard to the mean systolic blood pressure (SBP), mean arterial pressure and mean pulse rate. However, in patients receiving PVB, significant difference in preoperative and postoperative values was seen in mean SBP only. CONCLUSIONS: We observed longer duration of analgesia with PVB compared to TEB.

A Comparative Study to Determine the Effect of Intravenous Magnesium on Postoperative Bleeding after on Pump CABG in Patients Receiving Pre-Operative Aspirin.

SUMMARY: Hypomagnesaemia is a common complication after cardiopulmonary bypass (CPB) and predisposes to the development of cardiac arrhythmias. Previous studies showed that intravenous magnesium reduces the incidence of postoperative cardiac arrhythmias but it also inhibits platelet function. Our aim was to compare the postoperative blood loss in patients not receiving magnesium after CPB with the group who received magnesium and to compare the requirement of blood, fresh frozen plasma (FFP) and platelets within 24 hours after surgery. This prospective randomized controlled study was conducted in 80 adult patients on oral aspirin undergoing elective CABG requiring CPB. Group A patients had not received magnesium infusion after recovery from CPB. Group B patients received magnesium infusion after recovery from CPB. Postoperative bleeding was assessed in both the groups. All the data were statistically analyzed. There was a insignificant increase in 24 hours postoperative drainage in magnesium recipient group compared to control group (p>0.05). Requirements of blood and blood products to maintain haematocrit and coagulation profile revealed insignificant (p > 0.05). Increase in requirement of PRC, FFP and platelets in magnesium recipient patients than the control group. Incidence of atrial fibrillation (Gr A 2.5%, Gr B 2.5%) and atrial extrasystoles (Gr A 2.5%, Gr B 10%) revealed comparable (p > 0.05) between the groups, but incidence of ventricular arrhythmias were significantly (p<0.05) high in the patients of Gr A(17.5%) than Gr B(5%). To conclude, magnesium may be administered to patients who continue pre-operative aspirin to undergo on-pump CABG surgery.