Lakshmi Kumar

Outcomes associated with stroke volume variation versus central venous pressure guided fluid replacements during major abdominal surgery.

Background and Aims: There is limited data on the impact of perioperative fluid therapy guided by dynamic preload variables like stroke volume variation (SVV) on outcomes after abdominal surgery. We studied the effect of SVV guided versus central venous pressure (CVP) guided perioperative fluid administration on outcomes after major abdominal surgery. Material and Methods: Sixty patients undergoing major abdominal surgeries were randomized into two equal groups in this prospective single blind randomized study. In the standard care group, the CVP was maintained at 10-12 mmHg while in the intervention group a SVV of 10% was achieved by the administration of fluids. The primary end-points were the length of Intensive Care Unit (ICU) and hospital stay. The secondary end points were intraoperative lactate, intravenous fluid use, requirement for inotropes, postoperative ventilation and return of bowel function. Results: The ICU stay was significantly shorter in the intervention group as compared to the control group (2.9 ± 1.15 vs. 5.4 ± 2.71 days). The length of hospital stay was also shorter in the intervention group, (9.9 ± 2.68 vs. 11.96 ± 5.15 days) though not statistically significant. The use of intraoperative fluids was significantly lower in the intervention group than the control group (7721.5 ± 4138.9 vs. 9216.33 ± 2821.38 ml). Other secondary outcomes were comparable between the two groups. Conclusion: Implementation of fluid replacement guided by a dynamic preload variable (SVV) versus conventional static variables (CVP) is associated with lesser postoperative ICU stay and reduced fluid requirements in major abdominal surgery.

Outcomes of implementation of enhanced goal directed therapy in high-risk patients undergoing abdominal surgery

Background and Aims: Advanced monitoring targeting haemodynamic and oxygenation variables can improve outcomes of surgery in high-risk patients. We aimed to assess the impact of goal directed therapy (GDT) targeting cardiac index (CI) and oxygen extraction ratio (O 2 ER) on outcomes of high-risk patients undergoing abdominal surgery. Methods: In a prospective randomised trial, forty patients (American Society of Anaesthesiologists II and III) undergoing major abdominal surgeries were randomised into two groups. In-Group A mean arterial pressure ≥ 65 mmHg, central venous pressure ≥ 8-10 mmHg, urine output ≥ 0.5 mL/kg/h and central venous oxygen saturation ≥ 70% were targeted intra-operatively and 12 h postoperatively. In-Group-B (enhanced GDT), in addition to the monitoring in-Group-A, CI ≥ 2.5 L/min/m 2 and O 2 ER ≤ 27% were targeted. The end-points were lactate levels and base deficit during and after surgery. The secondary end points were length of Intensive Care Unit (ICU) and hospital stay and postoperative complications. Wilcoxon Mann Whitney and Chi-square tests were used for statistical assessment. Results: Lactate levels postoperatively at 4 and 8 h were lower in-Group-B (P < 0.05). The mean base deficit at 3, 4, 5 and 6 h intra-operatively and postoperatively after 4, 8 and 12 h were lower in-Group-B (P < 0.05). There were no significant differences in ICU stay (2.10 ± 1.52 vs. 2.90 ± 2.51 days) or hospital stay (10.85 + 4.39 vs. 13.35 + 6.77 days) between Group A and B. Conclusions: Implementation of enhanced GDT targeting CI and OER was associated with improved tissue oxygenation.

Effectiveness of single dose conivaptan for correction of hyponatraemia in post-operative patients following major head and neck surgeries

Background and Aims: Conivaptan, a vasopressin receptor antagonist, is commonly used for the treatment of euvolaemic, hypervolaemic hyponatraemia. Usually, an intravenous (IV) bolus followed by infusion is administered for many days. We decided to assess the effectiveness of single dose conivaptan for correction of hyponatraemia in post-operative patients. Methods: This was a prospective, randomised trial conducted in 40 symptomatic post-operative Intensive Care Unit (ICU) patients with a serum sodium level of ≤130 mEq/L. Group A patients received IV conivaptan 20 mg over 30 min, whereas in group B infusion of 3% hypertonic saline was started as an infusion at the rate of 20-30 ml/h. Serum sodium levels were measured at 12, 24, 48 and 72 h and the daily fluid balance was measured for 3 days. The Chi-square test, Wilcoxon signed rank test and Mann-Whitney tests were used as applicable. Results: The serum sodium levels before initiating treatment were comparable between groups. However, subsequent sodium levels at 12, 24 and 48 h showed significantly high values in group A. Though at 72 h the mean sodium value was high in group A, it was not statistically significant. Group A showed a significantly high fluid loss on day 1, 2 and 3. The mean volume of hypertonic saline required in group B showed a steady decline from day 1 to 3 and only 13 patients required hypertonic saline on the 3 rd day. Conclusion: Single dose conivaptan is effective in increasing serum sodium levels in post-operative ICU patients up to 72 h associated with a significant negative fluid balance.

A comparison of effects of oral premedication with clonidine and metoprolol on intraoperative hemodynamics and surgical conditions during functional endoscopic sinus surgery.

Context: Establishing a near perfect surgical field during functional endoscopic sinus surgery (FESS) is essential and even a minor bleeding can severely compromise an already restricted view. So, if controlled hypotension can be provided without compromising the safety of patient by a relatively effortless method, surgical field can be improved greatly. Aims: The aim of this study was to compare the hemodynamic changes and surgical conditions during FESS following oral premedication with clonidine and metoprolol. Settings and Design: A total of 40 patients undergoing FESS were included in this prospective, randomized controlled study. Subjects and Methods: Patients were divided into two equal groups. Group A patients were premedicated with oral clonidine 300 mcg and Group B with oral metoprolol 50 mg, 2 h before surgery. All patients received fentanyl 2 mcg/kg and induced with propofol 2 mg/kg. Intubation was done following vecuronium 1 mg/kg. Anesthesia was maintained with 66% N2O, 33% O2 and 1% isoflurane. The heart rate (HR) and blood pressure (BP) were measured before induction and thereafter every 15 min up to 2 h. The surgeons were asked to estimate the quality of the operative field using a pre-defined category scale with scores 1-5. Statistical Analysis: Difference within the groups was analyzed using analysis of variance and post-hoc test was used to test the difference between individual groups. Chi-square test was used to find out the association between categorical variables. Results: Comparison of category scale revealed a lower score in Group A up to 60 min. Group B patients showed a statistically lower HR from pre-induction up to 90 min while systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure did not show a significant difference. Conclusions: Oral premedication with 300 mcg of clonidine produced a better operative field than oral metoprolol 50 mg during FESS.

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.

Efficacy of intranasal dexmedetomidine versus oral midazolam for paediatric premedication

Background and Aims: Premedication is an integral component of paediatric anaesthesia which, when optimal, allows comfortable separation of the child from the parent for induction and conduct of anaesthesia. Midazolam has been accepted as a safe and effective oral premedicant. Dexmedetomidine is a selective alpha-2 agonist with sedative and analgesic effects, which is effective through the transmucosal route. We compared the efficacy and safety of standard premedication with oral midazolam versus intranasal dexmedetomidine as premedication in children undergoing elective lower abdominal surgery. Methods: This was a prospective randomised double-blinded trial comparing the effects of premedication with 0.5 mg/kg oral midazolam versus 1 μg/kg intranasal dexmedetomidine in children between 2 and 12 years undergoing abdominal surgery. Sedation scores at separation and induction were the primary outcome measures. Behaviour scores and haemodynamic changes were secondary outcomes. Students t-test and Chi-square were used for analysis of the variables. Results: Sedation scores were superior in Group B (dexmedetomidine) than Group A (midazolam) at separation and induction (P < 0.001).The behaviour scores at separation, induction and wake up scores at extubation were similar between the two groups. The heart rate and blood pressure showed significant differences at 15, 30 and 45 min in Group B but did not require pharmacological intervention for correction. Conclusion: Intranasal dexmedetomidine at a dose of 1 μg/kg produced superior sedation scores at separation and induction but normal behavioural scores in comparison to oral midazolam in paediatric patients.

Comparison of perioperative thoracic epidural fentanyl with bupivacaine and intravenous fentanyl for analgesia in patients undergoing coronary artery bypass grafting surgery

Context: Two-thirds of patients undergoing coronary artery bypass grafting (CABG) surgery report moderate to severe pain, particularly with ambulatory or respiratory effort. Aims: The aim of this study is to compare the analgesic effect of perioperative thoracic epidural fentanyl with bupivacaine and intravenous fentanyl in patients undergoing CABG surgery. Settings and Design: The study was a prospective, randomized, nonblinded comparative study. Materials and Methods: A total of 60 patients coming under the American Society of Anesthesiologists Class III who were posted for CABG surgery were recruited in this study. The patients were randomized into one of two groups, higher thoracic epidural analgesia (HTEA) group receiving general anesthesia with thoracic epidural analgesia (TEA) in the postoperative period, and intravenous fentanyl analgesia group receiving general anesthesia with fentanyl infusion in the postoperative period. The pain was assessed at 4 h after extubation when the patient was fully awake, then at 8, 12, 18, and 24 h. Both groups received intravenous tramadol 100 mg as rescue analgesia whenever visual analog scale score was 5 and above. Heart rate, mean arterial pressure (MAP), sedation scores, and physiotherapy cooperation were also assessed. Statistical Analysis Used: The numerical data were analyzed using an independent t-test, repeated-measures ANOVA, and Mann–Whitney U-test. Results: Pain at rest and on cough was significantly lower in HTEA patients as compared to control group. Patients HTEA group got less frequent rescue analgesia than the control group. Physiotherapy cooperation was significantly better in HTEA patients at 4, 12, and 24 h postextubation. They also had significantly lower heart rate, MAP, and sedation scores. Conclusion: Perioperative TEA using fentanyl with bupivacaine provided optimal postoperative analgesia at rest and during coughing in patients following CABG surgery as compared to postoperative analgesia with intravenous fentanyl. It also resulted in optimal postoperative hemodynamic status, good cooperation to chest physiotherapy with less sedation.

Carbon dioxide embolism during endoscopic thyroidectomy

Sir, A 48-year-old American Society of Anesthesiologists physical status I patient, weighing 68 kg with diagnosis of bilateral thyroid nodules (4 cm × 5 cm) and euthyroid, was posted for endoscopic total thyroidectomy. General anaesthesia was induced and maintained following a standardised protocol. Intra-operatively, heart rate (HR) ranged from 70 to 90/min, systolic blood pressure (BP) 110–130 mmHg, and oxygen saturation (SpO2) 99–100%. Electrocardiogram showed normal sinus rhythm. Respiratory rate and tidal volume were adjusted to maintain end tidal carbon dioxide (EtCO2) between 30 and 35 mmHg. By the end of 3 h, dissection of gland was complete with good haemostasis. Suddenly, EtCO2 dropped from 34 to 8 mmHg, SpO2 to 60%, with hypotension (BP-80/50 mmHg) and bradycardia (HR-42/min). There were no disconnections or leaks in the circuit. Auscultation was not possible as the surgical ports were placed at axilla and areola of nipple bilaterally, but chest showed adequate and equal expansion. With a presumptive diagnosis of pulmonary embolism, surgery was stopped and sample for an arterial blood gas (ABG) was sent. The patient position was changed from head up to head down, but we were not able to give left lateral position as laparoscopic ports were still in situ. The diagnosis of pulmonary embolism was presumed with ABG showing pH of 7.081, PaCO2 84.5 mmHg, PaO2 61.2 mmHg and bicarbonate 24.0 mmol/L corresponding to an EtCO2 of 8 mmHg. After administration of glycopyrrolate 0.2 mg, ephedrine 6 mg and 100% O2, in 5 min the HR was 84/min, BP 130/86 mmHg, SpO2 98% and EtCO2 34 mmHg. An arterial line was introduced and ABG taken at this point showed pH 7.38, pCO2 33.8 mmHg, pO2 165 mmHg, bicarbonate 19.7 mmol/L. A re-evaluation of the equipment and settings showed CO2 inflation pressure erroneously set at 20 mmHg. As the only remaining surgical procedure was external removal of the already dissected gland, endoscopy was allowed again. The inflation pressure was reduced to 14 mmHg, positive end-expiratory pressure (PEEP) of 6 cm H2O was added and an intravenous fluid bolus of about 500 ml was administered. Surgery lasted for 30 min longer and was uneventful with a normal EtCO2 (32–34 mmHg), vitals and ABG (pH 7.313, pCO2 41.2 mmHg, pO2 229 mmHg, bicarbonate 20.3 mmol/L). At the end of surgery, patient was reversed of neuromuscular blockade and trachea extubated. Clinically significant carbon dioxide embolism is a rare but potentially fatal complication and may result from direct intravascular insufflation of CO2 during surgery.[1] During neck surgeries, many vessels need to be dissected and it is possible to miss a tear in a small vein as it may remain collapsed due to compression by gas under pressure in the cavity created by the inflated gas. If the intra-cavitary pressure is high, gas can be forced into circulation through the opening causing pulmonary embolism. Gas embolism should be suspected if there is a sudden drop in EtCO2[2,3] and is suggestive with hypercarbia and hypoxia. This indicates a failure of gas exchange due to reduction in alveolar perfusion. The sudden recovery following discontinuation of CO2 in our case could be explained by the high solubility of CO2. The blood gases with normal bicarbonate at the point of occurrence of the embolus could be explained by the fact that renal compensation may not have occurred at the time of the event. Although a transthoracic or trans-oesophageal echo could have confirmed the diagnosis,[4] the rapidity of events did not allow us to get the monitors. Aggressive volume expansion and PEEP reduce gas embolism by increasing venous pressure.[5,6] This incident stresses the chance of carbon dioxide pulmonary embolus during endoscopic surgeries. Although definitive confirmatory tests may be unavailable at the time of manifestation, continuous EtCO2 monitoring and vigilance may help in an early detection. Timed appropriate treatment may help in the management of this potentially catastrophic situation. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Respiratory and hemodynamic outcomes following exchange extubation with laryngeal mask airway as compared to traditional awake extubation.

Background: Traditional awake extubation leads to respiratory complications and hemodynamic response which are detrimental in neurosurgery, ENT surgery and patients with comorbidities. Aims: The primary objective was to compare the respiratory complications and hemodynamic stress response between traditional awake extubation of a endotracheal tube (ETT) and that following exchange extubation of ETT by using a laryngeal mask airway (LMA). Settings and Design: This prospective randomized study was conducted in a Tertiary Care Centre in 60 American Society of Anesthesiologists I and II patients coming for general surgery. Materials and Methods: Patients were randomized by permuted blocks into traditional awake extubation group and exchange extubation group. At the end of surgery in traditional group, awake extubation of ETT was done. In exchange group, 0.3 mg/kg propofol was administered, and the ETT was exchanged for a LMA. Awake extubation of LMA was then performed. Respiratory complications such as bucking, coughing, desaturation and the need for airway maneuvers and hemodynamic response were noted in both groups. Analysis Tools: Chi-square test, independent sample t- and paired t-tests were used as applicable. Results: Incidence of respiratory complication was 93.3% in traditional extubation while it was only 36.7% in exchange extubation group (P < 0.001). Hemodynamic response measured immediately at extubation in terms of heart rate, systolic blood pressure (BP), diastolic BP, mean arterial pressure, and rate pressure product were all significantly lesser in exchange group when compared to traditional extubation. Conclusion: Exchange extubation with LMA decreases respiratory complications and hemodynamic stress response when compared to traditional awake extubation.