Recovery time in target controlled infusion versus manual infusion of propofol in total intravenous anaesthesia for endoscopic retrograde cholangio-pancreatography procedure using laryngeal mask airway-gastro: A randomised comparative study.

Background and Aims: This study aimed to compare manual infusion versus target-controlled infusion (TCI) in total intravenous anaesthesia (TIVA) utilising laryngeal mask airway (LMA)-gastro during endoscopic retrograde cholangio-pancreatography (ERCP) procedures. Methods: This was a single-blind randomised trial. Patients were randomly allocated into two groups. TCI group included 27 patients, where TCI of propofol was implemented with the Schnider pharmacokinetic model driven by a computer-controlled syringe pump. The TIVA group included 27 patients with a loading dose of 2 mg/kg of propofol, followed by manual infusion of 15 mg/kg/h for the first 15 min, 13 mg/kg/h for the next 15 min, then 11 mg/kg/h for 30 min and 10 mg/kg/h for 60 min and finally maintained at 9 mg/kg/h. The primary objective was to compare recovery time following cessation of propofol infusion in both groups. The difference in the total dose of propofol, time to achieve anaesthesia induction, first attempt success rate, ease of LMA-gastro insertion, ease of insertion, success rate of endoscope device and post-anaesthesia care unit (PACU) discharge time were the secondary objectives. T-test and Chi-square test were used for statistical analysis. Results: The time required for the recovery was significantly less in the TCI group than in the TIVA group (mean ± standard deviation; 11.60 ± 2.27 versus 15.4 ± 3.25 minutes, P < 0.001). The duration of ERCP, ease of LMA and endoscope insertion were comparable between the groups. There was no post-operative recall of intra-operative events in the groups. Conclusion: TCI offers earlier recovery than TIVA in patients undergoing ERCP procedures using LMA-gastro.

Use of a human patient simulator for apnea studies: a preliminary in vitro trial.

BACKGROUND: Modern human patient simulators (HPSs) could be used for researching critical scenarios such as apnea oxygenation. We aimed to study the use of a high-fidelity HPS to assess prolonged apnea using various oxygenation strategies with a simple high-flow nasal cannula (15 L/min). METHODS: An experimental simulation study using an HPS (CAE Healthcare™) was conducted after obtaining approval from the Institutional Review Board. The HPS responded according to real-time physiologically modeled responses to external gases, such as oxygen (O2). Apnea experiments were performed with different physiological settings, such as shunt fraction (5%) and O2 consumption (250, 500, and 750 ml/min). The following four apnea experiments were conducted: no oxygenation (NO), apnea oxygenation alone (AO), preoxygenation alone (PO), and para-oxygenation (PAO). The time to 92%, 75%, and 50% saturation was recorded. Alveolar and arterial gas levels were recorded till 50% saturation. RESULTS: At 250 ml/min, PO (1121 s) and PAO (1274.5 s) had a significantly longer time to 50% saturation (400% increase) compared to NO (222.5 s) and AO (239 s). A similar trend was observed for the time to 92% and 75% saturation. At higher O2 consumption rates, a shorter time to desaturation was observed. CONCLUSIONS: Apnea trends in the HPS correlated with similar prior human experiments. AO without preoxygenation was found to provide no additional benefit. Preoxygenation with high-flow O2 via nasal cannula prolonged the time to desaturation in the PAO more than PO scenario. Therefore, HPSs can be used in future studies where patient safety is a concern.

Accuracy of non-invasive haemoglobin measurements in patients undergoing transurethral resection of prostate surgery.

BACKGROUND AND AIMS: The aim of this study was to evaluate the accuracy of non-invasive haemoglobin (SpHb) compared to laboratory venous haemoglobin (tHb) measurements among patients undergoing elective transurethral resection of prostate (TURP) surgery under spinal anaesthesia. METHODS: In a prospective, observational, outcome-assessor blinded, cohort trial, we enroled 50 American Society of Anesthesiologists physical status (ASA-PS) I-II patients with benign prostatic hyperplasia. The primary outcome included SpHb and tHb measurements performed at four perioperative time-points: just before initiating the fluid preload (T1), and at 30 min (T2), 1 h (T3), and 2 h (T4) after starting the prostate resection, respectively. Statistical tool included intra-class correlation (ICC), Bland-Altman plots, and linear regression analysis. RESULTS: We collected 200 SpHb/tHb data sets from 50 patients. The SpHb had a non-significant negative bias of -0.83 g/dL, -0.43 g/dL, -0.81 g/dL, and -0.46 g/dL, with limits of agreement of 2.6 g/dL to -4.2 g/dL, 2.4 g/dL to -3.3 g/dL, 1.3 g/dL to -2.8 g/dL, and 1.4 g/dL to -2.3 g/dL, for T1 to T4, respectively. The SpHb/tHb pairs correlated significantly (time-dependent increase in ICC from T1 to T4). The SpHb-tHb difference correlated significantly with corresponding serum sodium (T1 to T3), but not with perfusion index. No correlation existed between % change in SpHb-tHb difference (T1 to T4), and intraoperative blood loss or perioperative weight gain. CONCLUSION: The SpHb exhibited a clinically acceptable negative bias compared to tHb during TURP surgery. Although a wide limit of agreement between the SpHb/tHb pairs is a limitation, the real-time SpHb trends can still serve in clinical judgement.

Comparison of landmark versus pre-procedural ultrasonography-assisted midline approach for identification of subarachnoid space in elective caesarean section: A randomised controlled trial.

BACKGROUND AND AIMS: Identification of subarachnoid space in pregnant patients can pose a great challenge to anaesthesiologists. This study was designed to compare conventional landmark technique with pre-procedural ultrasonography-assisted midline approach for identification of the subarachnoid space in elective caesarean section. METHODS: After institute ethics committee approval and written informed consent, 100 parturients scheduled for elective caesarean section under spinal anaesthesia were included in this prospective randomised control trial and divided into Group L (n = 50) (landmark technique) and Group U (n = 50) (ultrasound-guided technique). Parameters such as time taken for the identification of the interspace, distance between skin and dura mater, number of insertion attempts (the primary outcome), number of passes and time taken were recorded in both the groups. Statistical analysis was done using SPSS software 16. RESULTS: Demographic profiles of both groups were comparable. The number of attempts for needle insertion (1.04 ± 0.19 vs. 1.97 ± 0.77), number of passes in the same interspinous space (1.26 ± 0.44 vs. 1.90 ± 0.51) and the total time for successful lumbar puncture (31.90 ± 6.30 vs. 51.80 ± 12.28 s) were significantly less in Group U as compared to Group L, but the time of identification of interspinous space was significantly more in Group U (56.70 ± 13.08 s) as compared to Group L (47.10 ± 10.45 s). CONCLUSION: Pre-procedural ultrasound is a useful tool for successful lumbar puncture in parturients as it reduces the number of attempts with fewer side effects as compared to conventional landmark technique.

A comparative study of nerve stimulator versus ultrasound-guided supraclavicular brachial plexus block.

INTRODUCTION: With the advent of ultrasound (US) guidance, this technique saw resurgence in the late 1990s. As US guidance provides real-time view of the block needle, the brachial plexus, and its spatial relationship to the surrounding vital structures; it not only increased the success rates, but also brought down the complication rates. Most of the studies show use of US guidance for performing brachial plexus block, results in near 100% success with or without complications. This study has been designed to examine the technique and usefulness of state-of-the-art US technology-guided supraclavicular brachial plexus block and compare it with routine nerve stimulator (NS)-guided technique. AIM: To note block execution time, time of onset of sensory and motor block, quality of block and success rates. SETTINGS AND DESIGN: Randomized controlled trial. MATERIALS AND METHODS: A total of 60 patients were enrolled in this prospective randomized study and were randomly divided into two groups: US (Group US) and NS (Group NS). Both groups received 1:1 mixture of 0.5% bupivacaine and 2% lignocaine with 1:200000 adrenaline. The amount of local anaesthetic injected calculated according to the body weight and not crossing the toxic dosage (Inj. bupivacaine 2 mg/kg, Inj. lignocaine with adrenaline 7 mg/kg). The parameters compared between the two groups are block execution time, time of onset of sensory and motor block, quality of sensory and motor block, success rates are noted. The failed blocks are supplemented with general anesthesia. STATISTICAL ANALYSIS: The data were analyzed using the SPSS (version 19) software. The parametric data were analyzed with student "t" test and the nonparametric data were analyzed with Chi-square test A P < 0.05 was considered significant. RESULTS: There was no significant difference between patient groups with regard to demographic data, the time of onset of sensory and motor block. Comparing the two groups, we found that the difference in the block execution time and success rates is not statistically significant. A failure rate of 10% in US and 20% in NS group observed and is statistically insignificant (P = 0.278). No complication observed in either group. CONCLUSIONS: US and NS group guidance for performing supraclavicular brachial plexus blocks ensures a high success rate and a decreased incidence of complications that are associated with the blind technique. However, our study did not prove the superiority of one technique over the other. The US-guided technique seemed to have an edge over the NS-guided technique. A larger study may be required to analyze the advantages of using US in performing supraclavicular brachial plexus blocks, which could help justify the cost of purchase of the US machine.

Intubating condition, hemodynamic parameters and upper airway morbidity: A comparison of intubating laryngeal mask airway with standard direct laryngoscopy.

BACKGROUND: Intubating Laryngeal Mask Airway (ILMA) is a relatively new device designed to have better intubating characteristics than the standard Laryngeal Mask Airway. This study was designed to compare Intubating Laryngeal Mask with standard Direct Laryngoscopy (DLS), taking into account ease of intubation, time taken for intubation, success rate of intubation, hemodynamic responses and upper airway morbidity. MATERIALS AND METHODS: Sixty patients, ASA I or II, of age between 20 and 60 years, were enrolled in this prospective and randomized study. They were randomly allocated to one of the two groups: group ILMA, Intubating Laryngeal Mask Airway; group DLS, Direct Laryngoscopy. The patients were intubated orally using either equipment after induction of general anesthesia. RESULTS AND CONCLUSIONS: DLS is comparatively a faster method to secure tracheal intubation than Intubating Laryngeal Mask. ILMA offers no advantage in attenuating the hemodynamic responses compared to direct laryngoscope. The success rate of intubation through Intubating Laryngeal Mask is comparable with that of DLS. The upper airway morbidity and mean oxygen saturation are comparable in both the groups.