Comparison of the effects of dexmedetomidine and nitroglycerin on cerebral oxygen saturation using near-infrared spectroscopy in patients undergoing controlled hypotensive anaesthesia: A randomised controlled non-inferiority trial.

Background and Aims: There is limited literature wherein the hypotensive drugs have been compared to know the cerebral effects by monitoring regional cerebral oxygen saturation (rScO2). This study aimed to compare the effects of dexmedetomidine and nitroglycerin on rScO2 during controlled hypotensive anaesthesia using near-infrared spectroscopy (NIRS). The primary objective was to evaluate the non-inferiority of dexmedetomidine versus nitroglycerin in the occurrence of cerebral desaturation events (CDEs) during hypotensive anaesthesia. Methods: Adult patients scheduled to undergo head and neck surgery under general anaesthesia randomised to receive either dexmedetomidine or nitroglycerin infusion for controlled hypotensive anaesthesia. Cerebral oximetry was monitored with NIRS, and data regarding CDEs, bilateral rScO2, and peri-operative haemodynamics were collected. Continuous data were analysed using unpaired Student's t-tests except for intra-group analyses, which were analysed using paired t-tests. Categorical data were analysed using the Chi-square test. For comparison of time to CDEs, Kaplan-Meier survival analysis with log-rank test was performed. Results: Of the 82 patients in both groups, CDEs were observed in 15 patients each. A decrease from baseline by 20% was observed in three patients: one in Group N and two in Group D. Statistically, there was an equal risk of getting CDEs in the groups. The time to CDE was comparable (P > 0.05). The difference in heart rate was statistically significant (P < 0.001). Conclusion: Dexmedetomidine is non-inferior to nitroglycerin in terms of the occurrence of cerebral desaturation events when used for controlled hypotensive anaesthesia in head and neck surgeries.

Continuous erector spinae plane block for analgesia and better pulmonary functions in patients with multiple rib fractures: a prospective descriptive study

Abstract Background: The present study explored the role of continuous erector spinae plane (ESP) block for analgesia as well as its impact on pulmonary functions in patients with multiple rib fractures. Methods: Ten patients with multiple rib fractures were enrolled after getting informed and written consent. Ultrasound-guided ESP block was performed at the level midway between the fractured ribs followed by the insertion of the catheter. Pre- and post-block VAS score, hemodynamics, respiratory rate (RR), peripheral oxygen saturation (SpO2), inspiratory capacity (IC), blood gases (PaO2 and PCO2), and complications were compared. Results: Pain scores at rest as well as on movement showed a significant reduction from 5.9 and 7.5 pre block to 1.6 and 2.5 respectively at 96 hours (p < 0.0001). Similarly, RR, SpO2, IC, and PaO2 were significantly better after the block placement (p < 0.001). Conclusion: Continuous ESP block provide adequate analgesia with better respiratory functions in patients with multiple rib fractures.

Hydrogen Evolution Activity of Nitrogen-Rich g-C3-xN4+x Synthesized by Solid-Gas Interface Method.

Synthesis of a metal-free carbon nitride (g-C3N4) photocatalyst in the form of nitrogen-rich g-C3-xN4+x derivatives is desirable for efficient solar to hydrogen conversion and remains a challenging task to achieve. Herein we report the development of homogeneous sheets of nitrogen-rich graphitic carbon nitride samples from melamine by a solid-gas interface approach. Using this method, pure g-C3N4 (CN), g-C3-xN4+x under ammonia flow (CN-NH3) and g-C3-xN4+x under nitrogen flow (CN-N2) are prepared. The g-C3-xN4+x (CN-NH3) sample shows better surface conductivity, wide optical absorbance in the visible region, reduced recombination and high electron donor density, and higher performance toward photoelectrochemical hydrogen evolution (HER). The g-C3-xN4+x (CN-NH3) generates a photocurrent of 2.06 µA cm-2, which is 2.5 times higher than that of the pure g-C3N4 (CN) sample (0.85 µA cm-2). It also shows higher photocatalytic water splitting ability compared to the CN and CN-N2 samples, generating 634 µmol g-1 hydrogen without cocatalyst and 1163 µmol g-1 of hydrogen with Pt cocatalyst. Density functional calculations suggest that the progressive band gap reduction with the increase in the N-dopant percentage can be attributed to the gradual increase in the partial π-occupations, which can lead to a significant stabilization of the conduction band minima. The theoretical modeling, however, indicates a saturation in the band gap effect after 75% of N-dopant. The onset potential of g-C3-xN4+x for HER appears at η = 0.43 V in dark and η = 0.34 V vs Ag/AgCl under solar light illumination of 1 sun.

Comparison of continuous erector spinae plane block and thoracic paravertebral block for postoperative analgaesia in patients undergoing modified radical mastectomy: A randomised controlled non-inferiority trial.

Background and Aims: Modified radical mastectomy (MRM) is associated with significant postoperative pain for which many blocks including thoracic paravertebral (TPV) block are being used. Erector spinae plane (ESP) block is a recently described technique. We planned to compare the efficacy and safety of ultrasound-guided continuous ESP and TPV blocks for postoperative analgaesia following MRM. Methods: Sixty-six patients belonging to American Society of Anaesthesiologists physical status I and II, aged 25-85 years, undergoing MRM were enrolled and randomly allocated into two groups. Ipsilateral block was given preoperatively at T3 or T4 level with 20 ml of 0.5% ropivacaine and 50 µg fentanyl. Infusion of 0.5% and 0.2% ropivacaine with fentanyl 2 µg/ml at a rate of 5 ml/hr was continued during intraoperative and postoperative period, respectively. Pain was assessed using visual analogue scale (VAS) till 24 hours. Block performance time, time to first rescue analgaesia, total amount of rescue analgaesic consumed, the incidence of procedure-related and postoperative complications, failure rate and patient satisfaction score were also recorded. Data collected were analysed using the Chi-square test or Student's t-test with the help of SPSS 22.0. Results: Demographics, baseline vitals, VAS scores both at rest and on movement, block performance time, time to first rescue analgaesia, the total amount of rescue analgaesia and patient satisfaction score were comparable in both groups (P value > 0.05). No complications were observed in either group. Conclusion: In patients undergoing MRM, continuous catheter technique ESP block is as efficacious and safe as TPV block for providing prolonged postoperative analgaesia.

The midpoint transverse process to pleura (MTP) block for postoperative analgesia in patients undergoing modified radical mastectomy: A case series.

Among the various regional anesthesia techniques used for postoperative analgesia in the modified radical mastectomy (MRM), thoracic paravertebral block (TPVB) is presently considered the technique of choice. Nevertheless, TPVB may lead to complications like inadvertent vascular puncture, hypotension, epidural or intrathecal spread, pleural puncture, or pneumothorax. Recently, a newer technique "midpoint transverse process to pleura" (MTP) block has been described in which the tip of the needle is placed at the midpoint between the transverse process and pleura. In this case series, we included ten patients of American Society of Anesthesiologist status I/II scheduled for MRM. Ultrasound-guided MTP block was performed and the catheter was inserted on the side of the surgery at the level of T4 level. The block was successful in the all patients as their median visual analogue score at rest and movement was 2 and 3, respectively, in first 24 h postoperatively. Only three patients required rescue analgesia in the first 24 h. No procedural-related complications were noticed in any patient. We concluded that MTP block provided effective perioperative analgesia with minimal rescue analgesia requirement and satisfactory safety profile.

Comparison of intranasal and nebulized dexmedetomidine for premedication in pediatric patients: A non-inferiority randomized controlled trial.

Background and Aims: Dexmedetomidine is a highly selective α-2 adrenoreceptor agonist and has been found to be an effective premedication agent when administered via the intranasal route. We aimed to compare the efficacy of dexmedetomidine premedication administered via intranasal route and through nebulization in pediatric patients. Material and Methods: This non-inferiority randomized controlled trial was conducted after getting approval from institutes ethics committee and informed written parental consent. Sixty-four children aged 2-8 years scheduled for elective surgery under general anesthesia were enrolled and were divided into two groups. Group I (Intranasal, n = 33) received 2 mcg/kg dexmedetomidine via intranasal route and group N (Nebulized, n = 31) received 2 mcg/kg dexmedetomidine through nebulization. The primary outcome was number of patients with satisfactory sedation 30 minutes after premedication at separation from parent. The secondary outcome included ease of medication acceptance, anxiety at parental separation, acceptance of anesthesia mask, perioperative hemodynamics, emergence agitation during recovery and adverse effects. Data collected was analyzed using Chi-square test, Student "t" test and Mann-Whitney U test with the help of SPSS 22. A one tailed P value < 0.025 was considered significant. Results: Demographic profile was comparable between groups. On arrival in OR 27 (81.8%) patients in group I and 21 (67.7%) patients in group N had satisfactory sedation score (P = 0.19). The median (IQR) sedation score was comparable between group I and group N (P = 0.057). Patients in Group I showed significantly better medication and mask acceptance scores (P < 0.0001, P = 0.001 respectively), parental separation anxiety score (P < 0.0001) and emergence agitation score (P = 0.001). There were no significant differences in hemodynamic parameters and adverse effects between the groups. Conclusion: Although nebulized dexmedetomidine is non-inferior to intranasal dexmedetomidine in providing desired level of sedation but intranasal administration had better acceptance of medication and anesthesia mask with lesser anxiety at parental separation and postoperative emergence agitation.

Prediction of post-induction hypotension in young adults using ultrasound-derived inferior vena cava parameters: An observational study.

BACKGROUND AND AIMS: Inferior vena cava (IVC) diameter and its respiratory variability have been shown to predict post-induction hypotension with high specificity in a mixed population of patients. We assessed whether these parameters could be as reliable in healthy adult patients as in a mixed patient population. METHODS: In the present prospective observational study, 110 patients of either sex, aged between 18 and 50 years, belonging to American Society of Anesthesiologists class I and II, fasted as per the institutional protocol and scheduled for elective surgery under general anaesthesia were enroled. Prior to induction, ultrasound examination of IVC was done and variation in IVC diameter with respiration was assessed. Maximum and minimum IVC diameters [(dIVCmax) and (dIVCmin), respectively] over a single respiratory cycle were measured and collapsibility index (CI) was calculated. Vitals were recorded just before induction and at every minute after induction for 10 min. Episodes of hypotension (mean arterial pressure [MAP] <65 mmHg or fall in MAP >30% from baseline) during the observation period were recorded. The receiver operating characteristic (ROC) curve was constructed for determining optimum cut-off with sensitivity and specificity of IVC diameters and CI for development of hypotension. RESULTS: IVC was not visualised in 22 patients. Out of the remaining 88 patients, 17 (19.3%) patients developed hypotension after induction. The dIVCmax, dIVCmin and CI were comparable between patients who developed and who did not develop hypotension. The area under curve of ROC for CI, dIVCmax and dIVCmin was 0.51, 0.55 and 0.52, respectively, with optimum cut-off value of 0.46, 1.42 and 0.73, respectively. CONCLUSION: Ultrasound-derived IVC parameters demonstrate poor diagnostic accuracy for prediction of hypotension after induction in healthy adult patients.

Gastric emptying time of two different quantities of clear fluids in children: A double-blinded randomized controlled study.

BACKGROUND: Perioperative pulmonary aspiration risk increases with increased preoperative gastric volume; hence traditionally, healthy children are kept fasted overnight before surgery. Current guidelines recommend 2-h clear fluids fasting prior to anesthesia. However, emerging evidence favors allowing 3 ml/kg clear fluids up to 1-h before anesthesia. We compared the gastric volume and gastric emptying time after ingestion of 3 ml/kg and 5 ml/kg of clear fluids. METHODS: The present study enrolled 44 children, aged between 6 and 14 years. On the day of surgery, baseline gastric volume was estimated using ultrasound and patients were randomly allocated into two groups of equal number, that is, Group 3 and Group 5 (patients received 3 ml/kg and 5 ml/kg 5% Dextrose respectively). Repeated gastric ultrasound was performed at every 5 min until the gastric volume reached baseline levels. The primary objective of the study was to compare gastric emptying time. Secondary objectives included comparison of antral cross-sectional area and gastric volume. RESULTS: The demographic profile, preoperative fasting duration for clear fluids, and baseline gastric volume were comparable between groups. In both groups, compared to baseline the antral cross-sectional area and gastric volume increased significantly following fluid ingestion and then decreased exponentially to reach baseline within 1-h. The median (IQR) (range) gastric emptying time (minutes) [35.0 (28.8, 40.0) (20.0-45.0) in group 3 and 40.0 (28.8, 45.0) (20.0-50.0) in group 5] and emptying half-time (minutes) [17.0 (15.7, 21.5) (14.4-24.0) in group 3 and 18.6 (16.0, 22.0) (15.1-23.8) in group 5] were comparable [median difference -5 (95% CI -7.8 to 2.1) and -1.5 (95% CI -2.3 to 1.0), respectively] (p = .16 and p = .44, respectively). CONCLUSION: As the gastric volume returned to baseline within 1-h even after ingesting 5 ml/kg clear fluids, the preoperative fasting time can be reduced to 1-h and healthy children undergoing elective procedure can be safely allowed to drink up to 5 ml/kg clear fluids.

Effect of combined versus sequential injection of 2% lidocaine and 0.5% bupivacaine on the onset and duration of supraclavicular brachial plexus block: A double blinded randomised controlled trial.

OBJECTIVE: To assess whether sequential (one after the other with a delay of 120 s) or combined (freshly prepared mixture) administration of 2% lidocaine and 0.5% bupivacaine in supraclavicular brachial plexus block (SCBPB) provides faster onset and prolonged duration of block. DESIGN: Randomised controlled double blinded study. SETTING: Single centre study in an operating theatre of a tertiary care facility between November 2018 and May 2020. PATIENTS: Ninety-seven patients of either sex, aged between 18 and 65 years, belonging to ASA I to III and undergoing surgery suitable to be performed under SCBPB were enrolled. INTERVENTION: Ultrasound guided SCBPB was performed with 20 mL of freshly prepared mixture of 2% lidocaine and 0.5% bupivacaine (10 mL each) in group C (combined) and 10 mL 2% lidocaine followed 120 s later by 10 mL 0.5% bupivacaine in group S (sequential). MAIN OUTCOME MEASURES: Time to onset of complete sensory block was the primary outcome while time to onset of first sensory block and complete motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, rescue analgesic consumption, and pain scores at rest and with movement were secondary outcomes. MAIN RESULTS: There was no significant difference between group C and group S in time to onset of complete sensory block [median (IQR) 16 (11, 20.5) and 15.5 (13, 21.75) minutes respectively] (p-value 0.58). The time to onset of first sensory block and motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, postoperative pain scores and rescue analgesic requirement were also similar (p-value >0.05). CONCLUSION: There was no advantage of sequential administration of 2% lidocaine and 0.5% bupivacaine over the administration of combination of both LAs in terms of onset and duration of block.

Comparison of 0.5% Ropivacaine and 0.5% Levobupivacaine for Sciatic Nerve Block Using Labat Approach in Foot and Ankle Surgery.

OBJECTIVE: Compared to ropivacaine, levobupivacaine is more lipophilic and a more potent vasoconstrictor. The study was conducted to compare the effect of 0.5% ropivacaine and 0.5% levobupivacaine in sciatic nerve block using conventional Labat approach in foot and ankle surgery. METHODS: A prospective double-blind, randomised study was carried out in 100 patients of either sex, aged between 20 to 60 years, and American Society of Anesthesiologist (ASA) grades I and II. Patients were randomly allocated into groups R and L of 50 each with 0.5% ropivacaine and 0.5% levobupivacaine, respectively, for sciatic nerve block using the Labat approach. We assessed the onset and duration of sensory and motor block, duration of analgesia, consumption of analgesic, and any untoward effect over 24 hours. RESULTS: Both the groups were comparable with regard to demographic variables and onset of sensory and motor block (p>0.05). Group L compared to group R had significantly longer median (95% confidence interval) duration of sensory block (647.50 min [624.99-674.41] vs. 535 min [524.77-559.83], respectively; p<0.0001) as well as motor block (1065.0 min [1054.5-1068.90] and 945 min [947.13-1013.30], respectively; p<0.0001). Postoperative analgesia also lasted significantly longer in group L compared to group R (1320 min [1273.4-1321.8] vs. 840 min [759.23-812.77]; p<0.0001]). Patients in group L had significantly better visual analogue scale (VAS) score and lesser consumption of analgesics (p<0.0001). None of the groups developed any adverse effect over the observation period. CONCLUSION: Levobupivacaine provides prolonged postoperative analgesia in sciatic nerve block with reduction in postoperative analgesic consumption.

Efficacy of dexmedetomidine for prevention of emergence agitation in patients posted for nasal surgery under desflurane anaesthesia: A prospective double-blinded randomised controlled trial.

BACKGROUND AND AIMS: Nasal surgery under desflurane anaesthesia is more prone to develop emergence agitation (EA). The present study aimed to evaluate the efficacy of dexmedetomidine for prevention of EA. METHODS: A total of 72 patients were randomised to group C and group D. Group C patients received placebo while group D patients received dexmedetomidine 1.0 µg/kg bolus followed by 0.4 µg/kg/h after induction of anesthesia. End tidal desflurane was adjusted to keep the bispectral index (BIS) 45-55. Study drug was stopped at extubation. EA was evaluated from extubation till the patient was shifted to postanaesthesia care unit (PACU). Primary outcome was incidence of EA. Secondary outcome measures were requirement of desflurane, haemodynamic stability, and recovery after anaesthesia. The results were analyzed using SPSS version 21. RESULTS: Infusion of dexmedetomidine significantly reduced the incidence of EA (Group C 52.8%; Group D 5.6%) by 89.5% (P = 0.00001). The endtidal desflurane concentration was significantly lower and there was an average 28.87% reduction in requirement of desflurane in group D compared to group C (P < 0.001). The mean heart rate was significantly higher in Group C (P < 0.001). In group C time to extubation, time to achieve BIS 90 and time to response on verbal command was significantly lesser compared to group D (P < 0.0001). CONCLUSION: Dexmedetomidine significantly reduced the incidence of EA and requirement of desflurane in patients undergoing nasal surgery. However, it was associated with delayed extubation, residual sedation, and prolonged PACU stay.

Comparison of caudal and intravenous dexamethasone as adjuvants for caudal epidural block: A double blinded randomised controlled trial.

BACKGROUND AND AIMS: Dexamethasone has a powerful anti-inflammatory action with significant analgesic benefits. The aim of this study was to compare the efficacy of dexamethasone administered through intravenous (IV) and caudal route on post-operative analgesia in paediatric inguinal herniotomy patients. METHODS: One hundred and five paediatric patients undergoing inguinal herniotomy were included and divided into three groups. Each patient received a single caudal dose of ropivacaine 0.15%, 1.5 mL/kg combined with either corresponding volume of normal saline (Group 1) or caudal dexamethasone 0.1 mg/kg (Group 2) or IV dexamethasone 0.5 mg/kg (Group 3). Baseline, intra- and post-operative haemodynamic parameters, pain scores, time to rescue analgesia, total analgesic consumption and adverse effects were evaluated for 24 h after surgery. Unpaired Student's t-test and analysis of variance were applied for quantitative data and Chi-square test for qualitative data. Time to first analgesic administration was analysed by Kaplan-Meier survival analysis and log-rank test. RESULTS: Duration of analgesia was significantly longer (P < 0.001), and total consumption of analgesics was significantly lower (P < 0.001) in Group II and III compared to Group I. The incidence of nausea and vomiting was higher in Group I (31.4%) compared to Group II and III (8.6%). CONCLUSIONS: Addition of dexamethasone both caudally or intravenously as an adjuvant to caudal 0.15% ropivacaine significantly reduced the intensity of post-operative pain and prolonged the duration of post-operative analgesia with the significant advantage of caudal over IV route.