Airway management using LMA-evaluation of three insertional techniques-a prospective randomised study.

BACKGROUND AND AIMS: Laryngeal Mask Airway [LMA] insertion has become as a basic procedural skill needed for all health care providers. Search for the most successful insertion technique continues. We evaluated the success rate of the three LMA insertion techniques- standard, 90 degree rotational and 180 degree rotational technique. MATERIAL AND METHODS: A total of 180 patients of ASA I-II aged 18-65 years undergoing open superficial surgical procedures with (LMA® Unique™ Airway, Teleflex®, Teleflex Medical Europe Ltd, Ireland) as an airway management device and with neuromuscular blocking agents, were randomly allocated to three groups, in this prospective randomized study. In the standard technique group (n = 60), the LMA was inserted by standard digital intraoral method. In the 90 degree rotational technique group (n = 60), the LMA was rotated counter-clockwise through 90 degree in the mouth and advanced until the resistance of the hypopharynx was felt, and then straightened out in the hypopharynx. In 180 degree rotational technique, LMA was inserted back-to-front, like a Guedel airway. The parameters studied were: the LMA placement success at first attempt, insertion time, need for more than one attempt at insertion, need for external airway manipulations, postoperative sore throat, blood staining and other post-operative (airway related) complications. RESULTS: The first attempt success rate in the standard technique was 83.9%, in 90 degree rotational technique was 75% and 180 degree rotational was 93.5%. The first attempt success rate was higher in 180 degree rotational group compared to 90 degree rotational group (P < 0.05), but there was no statistically significant difference (P > 0.05) between 90 degree rotational group and the standard technique group. There was no statistically significant difference among the two groups in terms of the secondary outcomes. CONCLUSION: We conclude that 180 degree rotational technique of LMA insertion is more successful than 90 degree rotational technique in adult patients under general anaesthesia.

Ultrasound assessment of subglottic region for estimation of appropriate endotracheal tube size in pediatric anesthesia.

BACKGROUND AND AIMS: Endotracheal tube (ETT) selection in pediatric patients is mainly done with the age, height, or weight-based formula. We compared ultrasound assessment of the subglottic area to predict the outer diameter of the ETT, with that of modified Cole's formula. The aim of the study is to compare the appropriateness of uncuffed ETT selection based on modified Cole's formula with that of ultrasound assessment method of subglottic diameter in children undergoing surgical procedures under general anesthesia. MATERIAL AND METHODS: This is a prospective, randomized, parallel group study. One hundred and fifty American Society of Anesthesiologists I and II patients of age 2-6 years were randomly allotted into two groups: Group A - ETT selection based on ultrasound assessment of subglottic diameter. Group B - ETT selection based on modified Cole's formula. The study parameters are the internal diameter and external diameter (OD) of the predicted ETT by the two methods and that of the appropriate size ETT used. RESULTS: The incidence of appropriate tube selection was 74.7% in the ultrasound based group while it was 45.3% in the modified Cole's formula group. There was a strong correlation between OD of the optimal ETT used and the ultrasound assessed subglottic diameter. Bland-Altman analysis of OD of appropriately sized ETT and subglottic diameter by ultrasound assessment has a bias of 0.02 mm with limits of agreement of +1.78 to -1.74. CONCLUSION: Ultrasonographic assessment of the subglottic diameter at the cricoid region is a better tool in predicting the appropriate size uncuffed ETT than modified Cole's formula.

Randomized controlled study comparing the hemodynamic response to laryngoscopy and endotracheal intubation with McCoy, Macintosh, and C-MAC laryngoscopes in adult patients.

BACKGROUND AND AIMS: Earlier studies have shown that the type of laryngoscope blade influences the degree of hemodynamic response to endotracheal intubation. The aim of the study was to evaluate the hemodynamic response to oral endotracheal intubation with C-MAC laryngoscopy and McCoy laryngoscopy compared to that of Macintosh laryngoscopy in adult patients under general anesthesia. MATERIAL AND METHODS: This is a prospective randomized parallel group study. Ninety American Society of Anesthesiologists I patients were randomly allotted into three groups. Group A - Macintosh laryngoscopy (control group). Group B - laryngoscopy with McCoy laryngoscope. Group C - laryngoscopy with C-MAC video laryngoscope. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were monitored at baseline (just before induction), just before intubation (T0), 1 min (T1), 3 min (T3), 5 min (T5), and 10 min (T10) after intubation. Intergroup comparison of study parameters was done by unpaired sample t-test for normal data and Mann-Whitney U-test for skewed data. For within-group comparison, the repeated measures of ANOVA for normal data and Friedman followed by Wilcoxon signed rank test for skewed data were performed. RESULTS: In C-MAC group, the HR was significantly higher than the Macintosh group at 3 min after intubation, whereas SBP, DBP, and MAP were significantly higher at 1 min. McCoy group showed a similar response compared to Macintosh group at all time intervals. CONCLUSION: C-MAC video laryngoscope has a comparatively greater hemodynamic response than Macintosh laryngoscope.

Additive effects of mitochondrion-targeted cytochrome CYP2E1 and alcohol toxicity on cytochrome c oxidase function and stability of respirosome complexes.

Alcohol treatment induces oxidative stress by a combination of increased production of partially reduced oxygen species and decreased cellular antioxidant pool, including GSH. Recently, we showed that mitochondrion-targeted CYP2E1 augments alcohol-mediated toxicity, causing an increase in reactive oxygen species production and oxidative stress. Here, we show that cytochrome c oxidase (CcO), the terminal oxidase of the mitochondrial respiratory chain, is a critical target of CYP2E1-mediated alcohol toxicity. COS-7 and Hep G2 cell lines expressing predominantly mitochondrion-targeted (Mt(++)) CYP2E1 and livers from alcohol-treated rats showed loss of CcO activity and increased protein carbonylation, which was accompanied by a decline in the steady state levels of subunits I, IVI1, and Vb of the CcO complex. This was also accompanied by reduced mitochondrial DNA content and reduced mitochondrial mRNA. These changes were more prominent in Mt(++) cells in comparison with wild type (WT) CYP2E1-expressing or ER(+) (mostly microsome-targeted) cells. In addition, mitochondrion-specific antioxidants, ubiquinol conjugated to triphenyl phosphonium, triphenylphosphonium conjugated carboxyl proxyl, and the CYP2E1 inhibitor diallyl sulfide prevented the loss of CcO activity and the CcO subunits, most likely through reduced oxidative damage to the enzyme complex. Our results suggest that damage to CcO and dissociation of respirosome complexes are critical factors in alcohol-induced toxicity, which is augmented by mitochondrion-targeted CYP2E1. We propose that CcO is one of the direct and immediate targets of alcohol-induced toxicity causing respiratory dysfunction.

Comparison of Success Rates of Different Methods of Ultrasound-Guided Radial Artery Cannulation (Short-Axis and Long-Axis Methods) Against the Traditional Palpatory Method: A Prospective Randomized Study.

OBJECTIVE: Recent meta-analysis comparing the success rates of various methods of arterial cannulation in adult patients found heterogeneity in the available data. Hence, we did this study to evaluate and compare the success rate of palpatory method with that of ultrasound guided methods of radial artery cannulation. The aim is to compare the first-attempt success rate of the palpatory method with that of ultrasound-guided radial artery cannulation techniques, namely, the short-axis out-of-plane and the long-axis in-plane methods. METHODS: This is a prospective, randomized, parallel-arm study. Ninety patients aged from 18 to 50 years (presenting for various surgeries requiring radial artery cannulation for invasive blood pressure monitoring or frequent arterial blood gas analysis) were divided into 3 groups. Each group had one of the 3 techniques of radial arterial cannulation, namely palpatory, short-axis ultrasound method, and long-axis ultrasound method. The parameters analyzed were first-attempt success rate, number of attempts needed, cannulation time, need for crossover of technique, and incidence of complications. Multivariate analysis was done with one-way ANOVA, with Tukey's post hoc test. For categorical data, the chi-square test was used. The probability value of .05 was considered as a significant level. RESULTS: The first-attempt success rate was 76.7% in the long-axis method, 86.7% in the short-axis method, and 56.7% in the palpatory method. The short-axis method has been shown to have a shorter cannulation time, fewer attempts needed for successful cannulation, and lower need for crossover of techniques when the first 2 attempts fail. CONCLUSIONS: We conclude that the ultrasound-guided short-axis method of radial artery cannulation is associated with higher first-attempt success rate compared to the traditional palpatory method.

Perception of Learning Environment Among Anaesthesiology Residents During the Pandemic in a Tertiary Hospital in India: Comparative Cross-Sectional Study.

OBJECTIVE: The coronavirus disease pandemic has affected the postgraduate educational system infusing online teaching resulting in a blended teaching-learning experience especially in the field of anaesthesiology. Hence, we conducted this study to evaluate the effect of the introduc- tion of blended learning methods on students' perception of the learning environment among different years of anaesthesia residency training. METHODS: We invited 44 residents belonging to 3 years (Y1, Y2, and Y3) of anaesthesia residency to complete the Dundee Ready Education Environment Measure questionnaire. This study was done during the coronavirus disease pandemic after 6 months of incorporation of blended learning methods into the teaching program. The first-year cohort was not exposed to traditional anaesthesia teaching. The student's perception of learning was assessed after 6 months of change in the teaching method. The total Dundee Ready Education Environment Measure scores and the individual domains were compared among the 3 years. RESULTS: There was a significant difference in the corrected Dundee Ready Education Environment Measure score between Y1 (154.2 ± 20.73 [145.11-163.29]) and Y2 (138.27 ± 22.12 [125.2-151.34]) with P = .027. There was no significant difference in the individual domains. CONCLUSION: Higher score in the first-year residents suggests that it is appropriate to introduce blended learning from the beginning of the course rather than slowly merging with the existing traditional face-to-face teaching-learning methods.

Mitochondria-targeted cytochrome P450 2E1 induces oxidative damage and augments alcohol-mediated oxidative stress.

The ethanol-inducible cytochrome P450 2E1 (CYP2E1) is also induced under different pathological and physiological conditions. Studies including ours have shown that CYP2E1 is bimodally targeted to both the endoplasmic reticulum (microsomes) (mc CYP2E1) and mitochondria (mt CYP2E1). In this study we investigated the role of mtCYP2E1 in ethanol-mediated oxidative stress in stable cell lines expressing predominantly mt CYP2E1 or mc CYP2E1. The ER+ mutation (A2L, A9L), which increases the affinity of the nascent protein for binding to the signal recognition particle, preferentially targets CYP2E1 to the endoplasmic reticulum. The Mt+ (L17G) and Mt++ (I8R, L11R, L17R) mutant proteins, showing progressively lower affinity for signal recognition particle binding, were targeted to mitochondria at correspondingly higher levels. The rate of GSH depletion, used as a measure of oxidative stress, was higher in cells expressing Mt++ and Mt+ proteins as compared with cells expressing ER+ protein. In addition, the cellular level of F(2)-isoprostanes, a direct indicator of oxidative stress, was increased markedly in Mt++ cells after ethanol treatment. Notably, expression of Mt++ CYP2E1 protein in yeast cells caused more severe mitochondrial DNA damage and respiratory deficiency than the wild type or ER+ proteins as tested by the inability of cells to grow on glycerol or ethanol. Additionally, liver mitochondria from ethanol-fed rats containing high mt CYP2E1 showed higher levels of F(2)-isoprostane production. These results strongly suggest that mt CYP2E1 induces oxidative stress and augments alcohol-mediated cell/tissue injury.

ß-Naphthoflavone-Induced Mitochondrial Respiratory Damage in Cyp1 Knockout Mouse and in Cell Culture Systems: Attenuation by Resveratrol Treatment.

A number of xenobiotic-inducible cytochrome P450s (CYPs) are now known to be localized in the mitochondrial compartment, though their pharmacological or toxicological roles remain unclear. Here, we show that BNF treatment markedly inhibits liver mitochondrial O2 consumption rate (OCR), ADP-dependent OCR, and also reserve OCR, in wild-type mice but not in Cyp1a1/1a2(-/-) double knockout mice. BNF treatment markedly affected mitochondrial complex I and complex IV activities and also attenuated mitochondrial gene expression. Furthermore, under in vitro conditions, BNF treatment induced cellular ROS production, which was inhibited by mitochondria-targeted antioxidant Mito-CP and CYP inhibitor proadefin, suggesting that most of the ROS production was intramitochondrial and probably involved the catalytic activity of mitochondrial CYP1 enzymes. Interestingly, our results also show that the AHR antagonist resveratrol, markedly attenuated BNF-induced liver mitochondrial defects in wild-type mice, confirming the role of AHR and AHR-regulated CYP1 genes in eliciting mitochondrial dysfunction. These results are consistent with reduced BNF-induced mitochondrial toxicity in Cyp1a1/1a2(-/-) mice and elevated ROS production in COS cells stably expressing CYP1A1. We propose that increased mitochondrial ROS production and respiratory dysfunction are part of xenobiotic toxicity. Resveratrol, a chemopreventive agent, renders protection against BNF-induced toxicity.

Evaluation of clonidine as an adjuvant to bupivacaine in wound infiltration for providing postoperative analgesia after abdominal hysterectomy.

BACKGROUND: Clonidine is an effective adjuvant to local anesthetics in peripheral nerve blocks. We studied the effect of clonidine as an adjuvant in wound infiltration for postoperative analgesia. AIM: To evaluate the role of clonidine as an adjuvant to bupivacaine in wound infiltration in terms of quality and duration of postoperative analgesia in patients undergoing total abdominal hysterectomy. SETTINGS AND STUDY DESIGN: Prospective, randomized, double-blinded study. MATERIALS AND METHODS: One hundred patients of American Society of Anesthesiologists I-II posted for abdominal hysterectomy were randomly allotted to two groups. Group A received wound infiltration with 45 ml of 0.25% bupivacaine with 3 µg/kg clonidine while Group B received wound infiltration with 45 ml of 0.25% bupivacaine. A standard general anesthesia technique was used in all the patients. Postoperative analgesia was provided with injection ketorolac 0.5 mg/kg intravenous infusion and tramadol being the rescue analgesic. Postoperative pain score, duration of effective analgesia before the first rescue analgesic, percentage of patients requiring rescue analgesic at different time intervals, and total number of rescue analgesic doses in 24 h were compared between the groups. STATISTICAL ANALYSIS: Difference between the bivariate samples in independent groups with Mann-Whitney U-test. For categorical data, Chi-square test was used. RESULTS: Clonidine group has better pain score, longer duration of effective analgesia, lower percentage of patients requiring rescue analgesic, and less number of doses of rescue analgesia in the first 24 h. CONCLUSION: We conclude that Clonidine 3 µg/kg is an effective adjuvant to bupivacaine for wound infiltration in terms of quality and duration of postoperative analgesia following total abdominal hysterectomy.

Evaluation of skin temperature over carotid artery for temperature monitoring in comparison to nasopharyngeal temperature in adults under general anesthesia.

BACKGROUND: Thermoregulation is markedly affected in patients undergoing surgical procedures under anesthesia. Monitoring of temperature is very important during such conditions. Skin temperature is one of the easy and noninvasive ways of temperature monitoring. Common skin temperature monitoring sites are unreliable and did not correlate to the core temperature measurement. AIM: To compare and study the correlation of skin temperature over carotid artery in the neck to that of simultaneously measured nasopharyngeal temperature in adult patients undergoing surgical procedures under general anesthesia. SETTINGS AND DESIGN: Prospective double-blinded study in a Tertiary Care Center. MATERIALS AND METHODS: Ninety-seven consecutive American Society of Anesthesiologists I-II patients of age 18-40 years posted for elective surgical procedures under general anesthesia were included. Two temperature sites are monitored: The skin temperature over the carotid artery in the neck with a skin temperature probe T (skin-carotid) and the nasopharyngeal temperature T (naso) with another nasopharyngeal probe. The temperature readings are taken at 0, 15, 30, 45, and 60 min after induction of general anesthesia. STATISTICAL ANALYSIS: Paired t-test, Pearson correlation and Bland-Altman analysis for the rate of agreement. RESULTS: The skin over the carotid artery in the neck showed statistically significant lower values than simultaneously measured nasopharyngeal temperature. This comparison is done with paired t-test at P< 0.05 significance. Bland-Altman plots showed good agreement between the two sites of temperature measurement. CONCLUSION: This study has shown that the skin temperature over the carotid artery in the neck was strongly correlated to the nasopharyngeal temperature in adult patients undergoing surgical procedures under general anesthesia.

Prospective randomized study to compare between intravenous dexmedetomidine and esmolol for attenuation of hemodynamic response to endotracheal intubation.

BACKGROUND: Esmolol has an established role in attenuation of hemodynamic response to laryngoscopy and endotracheal intubation. We studied the effect of dexmedetomidine compared to that of esmolol in this study. AIM: To study the role of dexmedetomidine in attenuation of hemodynamic response to laryngoscopy and oral endotracheal intubation compared to that of esmolol hydrochloride in patients posted for elective surgery under general anesthesia. STUDY DESIGN: Prospective randomized study double-dummy blinding method. MATERIALS AND METHODS: A total of 60 American Society of Anesthesiologists I patients, aged 18-60 years randomly divided into two groups; Group A patients received dexmedetomidine 1 mcg/kg diluted in 50 ml with normal saline and infused over 10 min before induction and also 20 ml of normal saline intravenous (IV) 2 min before endotracheal intubation. Group B patients received 50 ml IV infusion of normal saline over 10 min before induction and IV bolus of esmolol 0.5 mg/kg diluted in 20 ml with normal saline given 2 min before intubation. Standard induction technique followed. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded just before induction and after intubation at 1 min, 3 min, and 5 min after intubation. STATISTICAL ANALYSIS: Independent samples t-test and repeated measures of analysis of variance. RESULTS: Dexmedetomidine group showed statistically significant reduction in all the study parameters at all study time intervals following intubation. While esmolol group showed significant attenuation of HR, SBP, and MAP following intubation but failed to produce significant reduction in DBP. CONCLUSION: Dexmedetomidine is more effective in attenuating the hemodynamic response to oral endotracheal intubation compared to that of esmolol hydrochloride.

Ultrasound evaluation of effect of different degree of wrist extension on radial artery dimension at the wrist joint.

CONTEXT: Successful arterial cannulation requires wide and patent arterial lumen. A recent study has shown that success rate of radial arterial cannulation at first attempt is more at 45° angle of wrist extension in both young and elderly patients. No study has reasoned whether these high success rates at 45° is because of less compression of the radial artery at this particular angle of wrist extension. Hence, we attempted to study whether the radial artery dimensions changes with increasing angles of wrist extension in young, healthy female volunteers using ultrasound examination. AIM: To investigate the effect of increasing angle of wrist extension of 0, 15, 30, 45, 60, and 75° on radial artery dimensions at the level of the wrist joint using ultrasound examination. SETTINGS AND DESIGN: A prospective single blinded study in volunteers. SUBJECTS AND METHODS: Sonographic measurements of radial artery dimension at the wrist level were performed in 48 young, healthy female subjects. Height (anteroposterior in mm), width (mediolateral in mm) and depth (skin to artery) were measured at wrist extension of 0, 15, 30, 45, 60, and 75°. The dimensions at each angle are compared with 0° as the control and statistical analysis done. STATISTICAL ANALYSIS: One-way analysis of variance test. RESULTS: No statistically significant change in dimension of the radial artery is observed with increasing angle of wrist extension. CONCLUSION: Ultrasound evaluation showed that increasing angle of wrist extension does not significantly change the dimensions of radial artery at the wrist joint level in young healthy female volunteers.

Hypopituitarism: A rare sequel of cerebral malaria - Presenting as delayed awakening from general anesthesia.

We report a case of delayed emergence from anesthesia in a 37-year-old male who came for emergency laparoscopic appendicectomy. This patient is hailing from one of the endemic zones of Malaria, Orissa State in India. Two months ago he had cerebral malaria and was treated in our intensive care unit. After recovering from cerebral malaria, he presented to us for acute abdomen, and he was taken for emergency laparoscopic appendicectomy. He had delayed emergence of around 2 h to extubate from the time of completion of surgery in spite of termination of anesthetic agents. Further investigations showed to have decreased serum levels of thyroid hormones and cortisol levels in the postoperative period. The Physician promptly diagnosed the condition as hypopituitarism a known sequel of cerebral malaria. The secondary thyroid insufficiency contributing to the delayed emergence from anesthesia. We also review the pertinent literature related to this rare sequelae of cerebral malaria and its perioperative implication to the anesthesiologist.

Midazolam as an adjuvant to intrathecal lignocaine: A prospective randomized control study.

CONTEXT: Unfortunately in the past decade, phenomenon of transient neurologic symptoms (TNS) cast doubts on the use of lignocaine for spinal anesthesia. Intrathecal midazolam has been proved to have its role in relieving neuropathic pain. We attempted to study the role of midazolam as an adjuvant to intrathecal lignocaine. AIMS: The primary objective of the study was to evaluate the effect of intrathecal midazolam as an adjuvant to spinal lignocaine in terms of quality and duration of spinal sensory blockade. The secondary objectives are to study the effect on hemodynamics and the incidence of TNS. SETTINGS AND DESIGN: A prospective randomized control double-blinded study in American Society of Anesthesiology I and II surgical population. MATERIALS AND METHODS: Hundred healthy adult patients scheduled for elective infraumbilical surgery were randomly assigned to group A patients received spinal anesthesia with 1.5 ml of 5% lignocaine heavy with 0.4 ml of 0.9% saline and group B (control group) received spinal anesthesia with 1.5 ml of 5% heavy lignocaine with 0.4 ml of preservative-free 0.5% midazolam. STATISTICAL ANALYSIS USED: Z test for study parameters and analysis of variance was used for hemodynamic parameters in the same group. P < 0.05 was considered statistically significant. RESULTS: Midazolam resulted in improved quality of sensory blockade in terms of early onset, increased duration of effective analgesia, and delayed two segment regression time and also decreases the incidence of TNS with intrathecal lignocaine. CONCLUSIONS: Midazolam is an effective adjuvant to intrathecal lignocaine.