Pulak Tosh

Effectiveness of transnasal humidified rapid-insufflation ventilatory exchange versus traditional preoxygenation followed by apnoeic oxygenation in delaying desaturation during apnoea: A preliminary study

Background and Aims: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) during apnoea has shown to delay desaturation. The primary objective was to compare time to desaturate to <90% during apnoea with THRIVE versus traditional preoxygenation followed by apnoeic oxygenation. Methods: This prospective, randomised, single-blinded study was conducted in 10 adult patients presenting for direct laryngoscopy under general anaesthesia without endotracheal intubation. Group P patients were preoxygenated with 100% oxygen, and in Group H, high-flow humidified oxygen was delivered using nasal cannula for 3 min. After induction and neuromuscular blockade, time to desaturate to 90%, while receiving apnoeic oxygenation, was noted. Chi-square test and Mann–Whitney tests were used. Results: Group H had a significantly longer apnoea time as compared to Group P (796.00 ± 43.36 vs. 444.00 ± 52.56 s). All patients in Group H continued to have nearly 100% saturation even at 12 min of apnoea. However, in Group P, 80% of patients desaturated to <90% after 6 min of apnoea. Baseline blood gases, that following preoxygenation and at 3 min of apnoea time were comparable in both groups. At 6 min, Group H had a significantly higher PaO2 (295.20 ± 122.26 vs. 135.00 ± 116.78) and PaCO2 (69.46 ± 7.15 vs. 59.00 ± 4.64). Group H continued to have a PaO2of >200 mmHg even at 12 min of apnoea with a significant rise in PaCO2along with fall in pH after 6 min. Conclusion: During apnoeic periods time to desaturate to <90% was significantly prolonged with use of THRIVE.

Effect of inhaled budesonide suspension, administered using a metered dose inhaler, on post-operative sore throat, hoarseness of voice and cough

Background and Aims: Post-operative sore throat (POST) is often considered an inevitable consequence of tracheal intubation. This study was performed to compare the effect of inhaled budesonide suspension, administered using a metered dose inhaler, on the incidence and severity of POST. Methods: In this prospective randomised study, 46 patients undergoing laparoscopic surgeries lasting <2 h were randomly allotted into two equal groups. Group A received 200 μg budesonide inhalation suspension, using a metered dose inhaler, 10 min before intubation, and repeated 6 h after extubation. No such intervention was performed in Group B. The primary outcome was the incidence and severity of POST. Secondary outocomes included the incidence of post-operative hoarseness and cough. Pearsons Chi-square test, Fishers exact test and Independent sample t-test were used as applicable. Results: Compared to Group B, significantly fewer patients had POST in Group A at 2, 6, 12 and 24 h (P < 0.001). Although more patients in Group B had post-operative hoarseness of voice and cough at all-time points, the difference was statistically significant only at 12 h and 24 h for post-operative hoarseness and at 2 h and 12 h for post-operative cough. Severity as well as the incidence of POST showed downward trends in both groups over time, and by 24 h no patient in Group A had sore throat. Conclusion: Inhaled budesonide suspension is effective in significantly reducing the incidence and severity of POST.

Comparison of efficacy and safety of transdermal buprenorphine patch applied 48 versus 72 hours preoperatively in providing adequate postoperative analgesia following major abdominal surgeries

Introduction: A transdermal drug delivery system provides steady and continuous drug delivery. As the onset of action is delayed, it has to be applied preoperatively to provide optimal postoperative analgesia. Aim: To compare the efficacy and safety of transdermal buprenorphine patches applied 48 and 72 h preoperatively in providing adequate postoperative analgesia following major abdominal surgeries and the incidence of side effects. Materials and Methods: This prospective randomized, double-blinded study was conducted in a tertiary care institution. Thirty patients undergoing laparotomy were recruited. Group A (n = 15) received a transdermal buprenorphine 10 mg patch with a delivery rate of 10 μg/h, which was applied approximately 48 h before surgery, whereas in group B (n = 15) buprenorphine 10 mg patch was applied 72 h preoperatively. All patients received general anesthesia following standardized protocol. Postoperative pain was assessed using numerical rating scale (NRS). The Mann–Whitney U test and independent t-test were used for statistical analysis. Results: NRS was significantly high in group A for up to 30 h postoperatively as compared to group B. From 36 to 48 h, it was comparable. The need for rescue analgesia was significantly high in group A as compared to group B. Significant number of patients in group B experienced nausea and vomiting (53.33% vs. 26.67%) and sedation (20% vs. 13.33%) in the preoperative period. Conclusion: Transdermal buprenorphine patch applied 72 h preoperatively provided better analgesia than the one applied 48 h before surgery. However, its preoperative use in patients without painful conditions predisposes them to develop side effects.

Effect of lactate versus acetate-based intravenous fluids on acid-base balance in patients undergoing free flap reconstructive surgeries

Background and Aims: Use of lactated intravenous fluids during long surgeries could cause lactate accumulation and lactic acidosis. Acetate-based solutions could be advantageous as they are devoid of lactate. The primary aim of the study was to assess the effect of use of an acetated solution or Ringers lactate (RL) as intraoperative fluid on lactate levels in patients without hepatic dysfunction undergoing prolonged surgeries. Material and Methods: This was a prospective, randomized, controlled trial involving sixty patients belonging to American Society of Anesthesiologists Physical Status I to II undergoing major head and neck surgeries with free flap reconstruction. Patients were randomly allocated into two equal groups, Group sterofundin (SF) and Group RL. Group SF was started on acetate-based crystalloid solution (sterofundin B Braun®) and Group RL received RL intravenously at the rate of 10 ml/kg/h to maintain systolic blood pressure above 90 mmHg. Blood loss >20% was replaced with packed cells. Arterial blood gas analysis was done 2nd hourly till 8 h. Chi-square test was used to compare categorical variables. Independent sample t-test was used to compare means. Results: Intraoperative lactate levels were significantly high in RL group at 2, 4, 6, and 8 h. The pH was comparable between groups except at 8 h where RL group had a significantly lower pH than SF group (7.42 ± 0.1 vs. 7.4 ± 0.1). Sodium, potassium, chloride, bicarbonate, and pCO2did not show any significant difference between the groups. Conclusion: Use of acetate-based intravenous solutions reduced levels of lactate in comparison with RL in patients undergoing free flap reconstructive surgeries.

Efficacy of oral tolvaptan versus 3% hypertonic saline for correction of hyponatraemia in post-operative patients

Background and Aims: Hyponatraemia is frequent in post-operative patients and may be corrected with hypertonic saline (HTS). Oral tolvaptan is used to treat hypervolaemic or euvolaemic hyponatraemia. This study was performed to assess the efficacy of oral tolvaptan in correcting postoperative hyponatraemia compared to HTS. Methods: This prospective, randomised study was conducted in 40 symptomatic patients with serum sodium level ≤130 mEq/L. In Group H (n = 20), 3% HTS was infused at 20–30 mL/h aiming for correction of 6 mEq/L/day. Group T received oral tolvaptan 15 mg on the 1st day. If daily correction was <4 mEq/L, the dose was increased by 15 mg/day to a maximum of 45 mg. The primary outcome was serum sodium concentration 48 hours after starting treatment. Paired t-test was used to compare changes in sodium levels. Results: Baseline sodium and values at 12, 24 and 48 h were comparable in both groups. At 72 h, Group T had significantly higher sodium levels as compared to Group H (133.4 ± 1.9 vs. 131.3 ± 2.4 mEq/L). Intragroup analysis had shown a significant increase in sodium levels from baseline values in both groups at 12, 24, 48 and 72 h. Group H had a significantly lower potassium level and lower negative fluid balance on day 3. Conclusion: Oral tolvaptan and 3% HTS were equally effective in correcting hyponatraemia at 48 hours, but serum sodium levels were higher at 72 hours after oral tolvaptan.

Oral clonidine premedication attenuates hemodynamic responses of ketamine during total intravenous anesthesia

Background: The most commonly used drug for total intravenous anesthesia (TIVA) is ketamine which results in cardiovascular stimulation. Aims: The primary aim of this study was to assess the effect of oral clonidine premedication on attenuating the hemodynamic responses following ketamine administration. Settings and Designs: This was a prospective, observational, comparative study conducted in a tertiary care institution. Subjects and Methods: A total of 40 female patients aged 18–55 years who were posted for elective short gynecological procedures under TIVA were recruited for this study. Group A patients were given oral clonidine 150 μg 60 min before proposed surgical procedure, whereas Group B patients received a placebo tablet. Before induction, all patients received glycopyrrolate 0.2 mg, midazolam 2 mg, and fentanyl 2 μg/kg intravenously. Anesthesia was induced with ketamine 1.5 mg/kg body weight intravenously over 2–3 min. The hemodynamics after premedication and induction were assessed. Statistical Analysis Used: To test the statistical significance or difference between the mean change from the basal value at various time points, students t-test was applied. Results: At 20, 30, 40, 50, and 60 min postpremedication and after induction at 1, 3, 5, 10, 15, 20, and 30 min, Group B showed significantly higher heart rate. Systolic and diastolic blood pressures showed a significant decrease in Group A after induction up to 30 min. Nearly 6.7% of the patients in Group B had emergence delirium with none in Group A, which was not statistically significant. Conclusion: Oral premedication with clonidine 150 μg, administered 60 min before the conduct of TIVA, attenuated hemodynamic responses of intravenous ketamine.

Does restrictive fluid strategy during robotic pelvic surgeries obtund intraoperative rise in intraocular pressure

Background: Robotic pelvic surgeries require steep Trendelenburg position which may result in rise in intraocular pressure (IOP). Aim: The aim of this study was to compare the changes that occur in IOP during robotic pelvic surgeries in steep Trendelenburg position with a restrictive intravenous fluid administration. Settings and Design: This prospective observational study was conducted in a tertiary care institution. Subjects and Methods: Twenty consenting patients scheduled for pelvic robotic gynecological surgeries were enrolled. All patients received general anesthesia following a standardized protocol. IOP was measured before induction of anesthesia, immediately after induction and intubation, at the end of surgery immediately after making the patient supine and immediately after extubation. Ringers lactate was administered intravenously at a rate of 4 mL/kg/h targeting a mean arterial pressure of >65 mmHg and urine output of >0.5 mL/kg/h. Statistical Analysis Used: Paired t-test was used in this study. Results: There was a fall in IOP soon after induction from baseline which was not significant. Immediately, following intubation, there was a significant rise in IOP. At the end of surgery, though IOP remained high, it was not statistically significant. However, following extubation, IOP rose further and the difference from the baseline became statistically significant. Although there was a moderate increase in peak airway pressure and highest EtCO2levels during Trendelenburg from baseline values, the differences were statistically insignificant. Conclusion: During robotic pelvic surgeries, adopting a restrictive intravenous fluid strategy with the maintenance of normal end-tidal carbon dioxide levels could abate effects of steep Trendelenburg position on IOP.