Effect of etomidate and propofol on airway mechanics during induction - A prospective randomized trial.

Background and Aims: Intravenous induction agents like propofol and etomidate change the airway mechanics and thus influence mask ventilation. These changes have an impact on the administration of muscle relaxant in a difficult mask ventilation scenario. The difference in dynamics of airway after administration of two different intravenous agents has been assessed in this study. Material and Methods: After formal registry in clinical trials, patients undergoing general anesthesia were recruited and randomized into group P and E. Patients were induced with either of the intravenous agents, and mask ventilation was performed with a ventilator. After 60 s, rocuronium was administered and ventilation continued. Measurements of tidal volume, peak airway pressure, and compliance were taken from the anesthesia ventilator at different time points - induction, relaxant, and intubation. Results: There was no statistically significant difference between the two groups with respect to demographics, airway parameters, and airway mechanics, as measured by tidal volume, peak airway pressure, and lung compliance. There was an improvement in the tidal volume and compliance following induction with propofol, with a P value of 0.007 and 0.032, respectively, obtained in within-group comparison. Conclusion: Propofol and etomidate were comparable in airway mechanics, but compliance and tidal volumes improved with propofol, which facilitated face mask ventilation.

Comparison of median and paramedian technique of thoracic epidural anaesthesia in patients undergoing laparotomy under combined general and epidural anaesthesia - A prospective observational study.

Background and Aims: Most studies have found that lumbar epidural catheterisation is technically easier with a paramedian than median approach. There is scant literature comparing the two approaches to the epidural space in the mid-thoracic spine. This study aims to compare the median versus paramedian approaches in the location of epidural space in the T7-9 region in patients undergoing laparotomy under combined general and epidural anaesthesia. Methods: A prospective observational study was conducted after ethical approval and written informed consent on 70 patients undergoing major abdominal surgery. The patients received epidural analgesia either through a median or paramedian approach (Group M, n = 35 and Group P, n = 35). The primary objective was the incidence of successful epidural catheter placement in the first attempt. The secondary objectives were the overall success rate, the requirement of change of intervertebral space, approach or operator and complications associated with the procedure. Results: Sixty-seven patients were analysed. Epidural catheter was placed successfully in the first attempt in 40% of patients in Group M and 78.1% in Group P (P = 0.003). The overall success rate was 74.3% in Group M and 87.5% in Group P (P = 0.223). The number of attempts in Group M was more (one attempt 14, two 6, three 5 and four 1) as compared to Group P (one 25, two 2, three 1 and four 0) (P = 0.014). The incidence of complications was comparable between the groups. Conclusion: Epidural catheter insertion was technically easier in paramedian as compared to the median approach in T7-9 thoracic region with no difference in complications.

Evaluation of respiratory exchange ratio (RER) for predicting postoperative outcomes in elderly patients undergoing oncological resection for gastrointestinal malignancies - A prospective cohort study.

Background and Aims: Predicting complications after major oncosurgery is particularly daunting in the elderly subcategory of patients owing to factors like preexisting age-related immune cellular senescence and a significant imbalance of oxygen delivery (DO2) and consumption (VO2) characteristic of major oncological surgeries. The respiratory exchange ratio (RER) indicates DO2-VO2 balance and onset of anaerobic metabolism. We evaluated the ability of RER in predicting the occurrence of postoperative complications following geriatric oncosurgery. Materials and Methods: In the study, we enrolled 96 patients aged 65 years and above undergoing definitive surgery for gastrointestinal malignancy. The RER was calculated at predefined time points by a non-volumetric method from the respiratory parameters as RER = (end-tidal fractional carbon dioxide [FetCO2] - fraction of inspired carbon dioxide [FiCO2]/fraction of inspired oxygen [FiO2] - end-tidal fractional oxygen [FetO2]). Other indices of tissue perfusion, like central venous oxygen saturation and lactate levels, were also recorded. The patients were followed up for postsurgical complications. The predictive value of RER and other perfusion parameters was assessed and compared by appropriate statistical methods. Results: The patients who sustained major complications had a higher RER than the patients who did not sustain complications (1.47 ± 0.99 vs. 0.90 ± 0.31, P = 0.001). An intraoperative cutoff value of RER ≥0.89 was found to best predict postoperative complications at a specificity and sensitivity rate of 81.2% and 76%, respectively. End-operative partial pressure of carbon dioxide (pCO2) gap of >5.2 mm and elevated arterial lactate could also predict postsurgical complications in this age group. Conclusion: The RER can serve as a noninvasive, real-time and sensitive indicator of tissue hypoperfusion and postoperative complications in geriatric gastrointestinal oncosurgery.

Effect of pregabalin on postoperative pain and instrumentation-induced dysuria in patients undergoing percutaneous nephrolithotomy: A prospective randomized, double-blinded placebo-controlled study.

Background and Aims: The manipulation of urinary tract, the mandatory requirement of ureteral stenting, and bladder catheterization in patients undergoing percutaneous nephrolithotomy (PCNL) produces significant pain and dysuria postoperatively. The present study compared the efficacy of pregabalin with placebo in attenuation of these symptoms in patients undergoing PCNL. Material and Methods: This randomized controlled study was conducted in 110 patients of either sex, aged 18-65 years undergoing elective PCNL requiring nephrostomy tube under general anesthesia. Group G (n: 53) received pregabalin 150 mg and Group P received placebo (n: 49) orally 1 h before the anesthetic induction. All the patients received standard anesthetic protocol. Pain at the site of nephrostomy, instrumentation-induced dysuria (IID), anxiety, and sedation scores were recorded at 0 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h postoperatively. Hemodynamics, total requirement of rescue analgesia, and incidence of any adverse effects were also noted. Results: Patients were demographically comparable between the two groups. There is no difference in nephrostomy site pain between the groups at different points of measurements. IID was less with pregabalin at 0 min, 15 min, 30 min, 1 h, and 2 h after extubation (P value < 0.05, 43% in Group G vs. 68% in group P). Severe urgency was seen in 4%, moderate in 31%, and mild in 33% of patients in placebo group. No patient in pregabalin had severe grade of instrumentation-induced dysuria score (P < 0.05). Patients in Group P required more rescue analgesic (P: 0.009). Anxiety scores, sedation scores, and hemodynamic parameters were comparable. Conclusion: A single dose of 150 mg pregabalin as oral premedication given 1 h before surgery reduced the incidence and intensity of IID compared to placebo in patients undergoing PCNL without significant adverse effects.

Administration of Intravenous Amino Acids Attenuates Postoperative Hypothermia in Patients Undergoing Percutaneous Nephrolithotomy.

OBJECTIVE: Amino acids attenuate hypothermia during the perioperative period by increasing thermogenesis and stimulating energy consumption. Percutaneous nephrolithotomy (PCNL) induces profound hypothermia owing to the use of large volumes of irrigating fluids. The role of amino acids in this group of surgeries for hypothermia and shivering prevention has been evaluated in this study because there is no available literature of concern. METHODS: This prospective randomised controlled trial was conducted in patients undergoing PCNL. Group A received amino acids at 60 mL h-1 an hour before surgery until the end of surgery. Group C received normal saline infusion. Perioperative nasopharyngeal temperature, haemodynamics, and postoperative shivering were recorded. RESULTS: Although there was no significant difference in temperature in the intraoperative period, postoperative decrease in the temperature was less in the amino acid group. In the postoperative period, 2 patients in the amino acid group and 11 patients in the control group experienced shivering. CONCLUSION: Intravenous administration of amino acids attenuated postoperative hypothermia and reduced shivering in patients undergoing PCNL without any adverse effects.

A negative preoperative 99mTechnetium tetrofosmin myocardial perfusion imaging scan with postoperative acute coronary syndrome - A case of balanced ischaemia.

Perioperative myocardial infarction (PMI) is an important indicator of outcome after noncardiac surgery. Identifying patients at risk of PMI helps in risk stratification and modification. Myocardial perfusion imaging (MPI) is an established diagnostic modality for detection and prognostication of coronary artery disease (CAD). We report a case wherein preoperative MPI was negative for CAD but patient presented with acute coronary event in the postoperative period. We identify and evaluate the reasons for the failure of MPI in detection of CAD in our patient.

Evaluation of the Effect of Regional Anaesthesia on Microvascular Free Flaps.

OBJECTIVE: Multiple factors influence the success of microvascular free flap surgeries. Anaesthesia is an important factor to maximise the success rate of microvascular free flaps both by controlling haemodynamics and improving the perfusion of free vascularised tissue. The debate on the usefulness of regional and general anaesthesia for free tissue transfer is ongoing. This retrospective study was conducted to evaluate the effects of regional anaesthesia and other perioperative factors on outcomes of microvascular free flaps. METHODS: This retrospective observational study was conducted on 165 patients undergoing microvascular free flap surgeries between January 2014 and December 2015 after obtaining approval from the Institutional Ethics Committee (Nizams Institute Ethics Committee, Nizams Institute of Medical Sciences, India). Perioperative variables analysed included the type of surgery, indication, ASA physical status, type of anaesthesia, perioperative haemodynamics, fluids used, duration of surgery, re-explorations, blood transfusion and duration of hospital stay. The primary outcome measure was to assess the effect of regional anaesthesia on the success of free flap. RESULTS: Multivariate analysis identified the type of anaesthesia and preoperative haemodynamics as independent risk factors for predicting the failure of flap with an odds ratio of 0.208 and 7.469, respectively. A subgroup analysis of 55 acute trauma patients revealed preoperative haemodynamic instability as an individual independent risk factor for graft failure with an odds ratio of 11.90. CONCLUSION: The results of this study emphasise the importance of the choice of anaesthesia and preoperative optimisation in improving the success of free flap surgeries.

Regional anesthesia is safe and effective for lower limb orthopedic surgery in patient with renal tubular acidosis and hypokalemia.

Renal tubular acidosis (RTA) with hypokalemia may precipitate acute respiratory failure and potentially fatal arrhythmias like ventricular fibrillation. Though there are random reports of respiratory failure needing mechanical ventilation and sudden death in patients with RTA and hypokalemia, the anesthetic management of these patients has not been clearly elucidated. Acidosis and hypokalemia have significant interactions with both general and local anesthetics and alter their effect substantially. Proper preoperative planning and optimization are required for the safe conduct of anesthesia in this subset of patients. We describe a case of distal RTA, hypokalemia, and metabolic bone disease in whom central neuraxial anesthesia was effectively used for lower limb orthopedic surgery with no complications.

The effect of different dose regimens of tranexamic acid in reducing blood loss during hip surgery.

BACKGROUND AND AIMS: Antifibrinolytics may help bleeding in orthopaedic surgeries. The present study was undertaken to compare two dose regimens of tranexamic acid (TA) on perioperative blood loss in patients undergoing hip surgeries. METHODS: In a prospective, randomised, controlled study, 59 patients scheduled for hip surgery were divided into Group C: receiving normal saline (n - 20), Group B: receiving single dose of TA (10 mg/kg) (n - 21), and Group I: receiving a bolus (10 mg/kg) plus infusion (1 mg/kg/h) of TA up to 4 h postoperatively (n - 18). Blood loss, haemoglobin and allogeneic blood transfusions were compared between the groups. For parametric data, P was calculated by ANOVA. Intergroup comparison was done by post hoc analysis with Bonferroni test. P < 0.05 was considered significant. RESULTS: The intra-operative blood loss was lower in the patients who received TA (525 ± 150, 456 ± 156 and 400 ± 133 ml in Group C, B and I respectively; P = 0.05). The 6th hourly drain collection in Group I was lower than Group B and C (41 ± 18, 46 ± 14 and 31 ± 14 ml in Group C, B, and I respectively; P = 0.018). The blood loss at 24 h was less in groups receiving TA (146 ± 32, 120 ± 76, 107 ± 37 ml for Group C, B and I, respectively; P = 0.02). The requirement of blood transfusions was lower in Group I. CONCLUSIONS: A bolus of tranexamic acid followed by infusion is more useful than a single dose in decreasing perioperative blood loss in patients undergoing hip surgeries. It reduces allogenic blood transfusion without increasing risk of thromboembolic events.

Difficult mask ventilation made easy: Three cases of Parry Romberg syndrome.

Parry Romberg syndrome presenting as hemifacial atrophy poses various perioperative problems due to multi-system involvement. These patients have several anaesthetic implications which are published as case reports. In spite of several case reports, airway issues associated with this disease is under-discussed. This report of three cases discusses airway difficulties and the multiple methods to tackle them in an easier way by focussing concentration on airway assessment and appropriate preoperative planning.

Comparison of hemodynamic response to adrenaline infiltration in children undergoing cleft palate repair during general anesthesia with sevoflurane and isoflurane.

BACKGROUND AND AIMS: Systemic absorption of adrenaline often used for infiltration during cleft palate surgery leads to adverse hemodynamic responses. These hemodynamic responses may be attenuated by the volatile anesthetics. This study aims to compare the hemodynamic responses to adrenaline infiltration during isoflurane (ISO) and sevoflurane (SEVO) anesthesia. MATERIAL AND METHODS: Sixty children aged between 9 months and 48 months, weighing between 8 kg and 20 kg, undergoing primary repair of cleft palate were randomly allocated into two groups: Group ISO - anesthesia maintained with ISO (2 minimum alveolar concentrations [MAC]) and nitrous oxide 50% and group SEVO - maintained on SEVO (2 MAC) and nitrous oxide 50%. Surgical site was infiltrated with 1 ml/kg of 1:200,000 solution of adrenaline with 0.5% lignocaine. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) were noted at the end of infiltration and every 1 min for 5 min following infiltration. The percentage change of hemodynamic responses from baseline, following infiltration were compared between the two groups. RESULTS: There was no significant change in HR from baseline, and the response was comparable between the agents at all times. The blood pressure (BP) increased from baseline in both the groups but the increase was greater in SEVO than ISO group at 2 and 3 min after infiltration. The maximum change in HR from baseline (group ISO median 10.9% [interquartile range (IQR) 4.5-23.0] vs. group SEVO 26.5% [11.9-44.6]) was comparable in both the groups (P = 0.169). The maximum change in SBP was significantly greater in group SEVO than group ISO (42.8% [IQR 20.0-60.9] vs. 26.0 [11.3-44.5], P = 0.04). The incidence of significant change (>20%) of SBP, DBP, and MAP from baseline was significantly greater in group SEVO after infiltration and 1 min and 2 min after infiltration. There were no arrhythmias in any of the groups. CONCLUSION: Isoflurane results in greater attenuation of rise in BP during adrenaline infiltration compared to SEVO at similar MAC.

Perioperative management of patient with intracoronary stent presenting for noncardiac surgery.

As the number of percutaneous coronary interventions increase annually, patients with intracoronary stents (ICS) who present for noncardiac surgery (NCS) are also on the rise. ICS is associated with stent thrombosis (STH) and requires mandatory antiplatelet therapy to prevent major adverse cardiac events. The risks of bleeding and ischemia remain significant and the management of these patients, especially in the initial year of ICS is challenging. The American College of Cardiologists guidelines on the management of patients with ICS recommend dual antiplatelet therapy (DAT) for minimal 14 days after balloon angioplasty, 30 days for bare metal stents, and 365 days for drug-eluting stents. Postponement of elective surgery is advocated during this period, but guidelines concerning emergency NCS are ambiguous. The risk of STH and surgical bleeding needs to be assessed carefully and many factors which are implicated in STH, apart from the type of stent and the duration of DAT, need to be considered when decision to discontinue DAT is made. DAT management should be a multidisciplinary exercise and bridging therapy with shorter acting intravenous antiplatelet drugs should be contemplated whenever possible. Well conducted clinical trials are needed to establish guidelines as regards to the appropriate tests for platelet function monitoring in patients undergoing NCS while on DAT.

Spinal and Epidural Anesthesia in Patients With Recent Stable Fractures of Vertebral Column.

BACKGROUND: The use of central neuraxial block (CNB) in patients with spinal injuries with or without spinal cord injury continues to be a contentious issue due to paucity of evidence supporting or refuting its use. There are only a few case reports reporting the use of the technique in these patients. We performed a retrospective record review of patients who underwent neuraxial blockade for lower limb orthopedic surgery in the presence of coexisting recent spine injury (defined as spine injury within 1 month) to assess the occurrence of postoperative deterioration of spinal cord function or occurrence of new spinal cord dysfunction. MATERIALS AND METHODS: The hospital records of patients with recent stable traumatic fractures of the vertebral column who underwent lower limb orthopedic surgery under CNB from January 2010 to December 2013 were reviewed. Data collected included age, sex, level of fracture, number of vertebrae injured, presence of neurological deficits, interval between injury and surgery, number of surgeries, level of CNB, number of vertebral segments between the site of injury and CNB, position of patient used for CNB and surgery, and perioperative adverse hemodynamic events. All patients underwent detailed postoperative neurological examination and any deterioration or occurrence of new spinal cord dysfunction was noted. RESULTS: Nineteen patients underwent 21 CNBs for lower limb orthopedic procedures. There were 12 men and 7 women. Thoracolumbar area (18/19) was the commonest site of fractures. Two patients had neurological deficits due to cervical spine trauma. More than 50% of the patients had multiple bone fractures and nearly 30% had associated nonorthopedic trauma. Six patients underwent surgery within the first week (4 to 7 d) after trauma. In 80% of the patients, there was a gap of atleast 2 vertebrae between the level of injury and CNB administration. There were no perioperative adverse hemodynamic events requiring prolonged inotropic support. None of the patients had neurological deterioration or new changes. CONCLUSIONS: Spinal and epidural anesthesia in patients with recent stable fractures of the spine was not associated with adverse neurological events. The findings of this study may be particularly relevant to patients with recent stable vertebral fractures who require surgery but present with conditions that place them at high risk for general anesthesia.

An observational study of the feasibility of Airtraq guided intubations with Ring Adair Elvin tubes in pediatric population with cleft lip and palate.

CONTEXT: The airway management requires refined skills and technical help when associated with cleft lip and palate. Airtraq has improved our airway management skills and has been successfully used for rescue intubation in difficult pediatric airways. AIMS: This study was to evaluate the efficacy of Airtraq as the primary intubation device in patients with cleft lip and palate. The study adheres to the STrengthening the Reporting of OBservational Studies Epidemiology Statement. SUBJECTS AND METHODS: A total of 85 children posted consecutively for lip and palate repair were enrolled. Children were intubated with Ring Adair Elvin (RAE) tube using size 1 and 2 of Airtraq device. The design of Airtraq has an anatomical limitation to hold RAE tubes. The preformed bend of the tube was straightened with a malleable stylet. The intubations were assessed for device manipulations and time taken for glottis visualization and intubation, airway complications such as bleeding, laryngospasm and failed intubations. STATISTICAL ANALYSIS USED: The outcome data were reported as numbers and percentages or range with identified median value, where applicable. RESULTS: The success rate of Airtraq guided intubations was 98.21%. The cumulative insertion times and intubation times were 31.50 ± 12.57 s and 48.04 ± 35.73 s respectively. Airtraq manipulations were applied in 25.45% subjects. CONCLUSIONS: The presence of cleft lip or palate did not hamper the insertion of Airtraq. The use of malleable stylet to facilitate the loading of the preformed tube into the guide channel is a simple and efficacious improvisation. Airtraq can be utilized as a primary intubation device in children with orofacial clefts.

Comparison of electroencephalogram entropy versus loss of verbal response to determine the requirement of propofol for induction of general anaesthesia.

BACKGROUND AND AIMS: Propofol causes dose-dependent reduction in blood pressure (BP). This study was done to evaluate the use of spectral entropy on the dose of propofol required and the haemodynamic stability during induction of general anaesthesia (GA). METHODS: In this randomised controlled study, 72 American Society of Anesthesiologists' physical status I and II patients undergoing general and orthopaedic surgeries were divided into Group S (n-36) and Group C (n-36). Patients in Group C were induced with propofol till loss of response to verbal commands and in Group S until the state entropy was <50 and state and response entropy difference was <10. The induction dose of propofol, haemodynamic parameters and the entropy values were recorded. Numerical data were expressed as a mean ± standard deviation and analysed using unpaired, two-tailed t-test. Categorical data were compared using Chi-square test. P < 0.05 value was considered significant. RESULTS: The dose of propofol per kg was significantly more in the entropy group (1.80 ± 0.23 mg/kg in the Group C and 1.98 ± 0.217 mg/kg in the Group S [P < 0.05]). After induction, at intubation and 1 min after intubation, entropy values were lower in Group S than Group C (P < 0.05). The BP decreased significantly after induction compared with the baseline (P < 0.05), but there was no difference between the groups. CONCLUSION: Propofol required for induction of GA when guided by electroencephalogram entropy was significantly higher than the induction dose based on loss of verbal response. Both conventional induction and induction with entropy as the endpoint resulted in similar haemodynamic profile.

Effect of perineural dexmedetomidine on the quality of supraclavicular brachial plexus block with 0.5% ropivacaine and its interaction with general anaesthesia.

BACKGROUND AND AIMS: The effect of perineural dexmedetomidine on the time to onset, quality and duration of motor block with ropivacaine has been equivocal and its interaction with general anaesthesia (GA) has not been reported. We assessed the influence of dexmedetomidine added to 0.5% ropivacaine on the characteristics of supraclavicular brachial plexus block and its interaction with GA. METHODS: In a randomised, double blind study, 36 patients scheduled for orthopaedic surgery on the upper limb under supraclavicular block and GA were divided into either R group (35 ml of 0.5% ropivacaine with 0.5 ml of normal saline [n - 18]) or RD group (35 mL of 0.5% ropivacaine with 50 µg dexmedetomidine [n - 18]). The onset time and duration of motor and sensory blockade were noted. The requirement of general anaesthetics was recorded. RESULTS: Both the groups were comparable in demographic characteristics. The time of onset of sensory block was not significantly different. The proportion of patients who achieved complete motor blockade was more in the RD group. The onset of motor block was earlier in group RD than group R (P < 0.05). The durations of analgesia, sensory and motor blockade were significantly prolonged in group RD (P < 0.00). The requirement of entropy guided anaesthetic agents was not different in both groups. CONCLUSIONS: The addition of dexmedetomidine to 0.5% ropivacaine improved the time of onset, quality and duration of supraclavicular brachial plexus block but did not decrease the requirement of anaesthetic agents during GA.

Evaluation of the Efficacy of Tranexamic Acid on the Surgical Field in Primary Cleft Palate Surgery on Children-A Prospective, Randomized Clinical Study.

OBJECTIVE: To assess the effect of tranexamic acid on the quality of the surgical field. DESIGN: Prospective, randomized, double-blind study. SETTING: Institutional, tertiary referral hospital. PARTICIPANTS: American Society of Anesthesiologists physical status class I patients, aged 8 to 60 months with Group II or III (Balakrishnan's classification) clefts scheduled for cleft palate repair. INTERVENTIONS: Children were randomized into two groups. The control group received saline, and the tranexamic acid group received tranexamic acid 10 mg/kg as a bolus, 15 minutes before incision. MAIN OUTCOME MEASURES: Grade of surgical field on a 10-point scale, surgeon satisfaction, and primary hemorrhage. RESULTS: Significant improvements were noted in surgeon satisfaction and median grade of assessment of the surgical field (4 [interquartile range, 4 to 6] in the control group vs. 3 [interquartile range, 2 to 4] in the test group; P = .003) in the tranexamic acid group compared to the control group. CONCLUSION: Preincision administration of 10 mg/kg of tranexamic acid significantly improved the surgical field during cleft palate repair.