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Postoperative systemic inflammation after major abdominal surgery: patient-centred outcomes. Anaesthesia 2023; 78:1365-1375. [PMID: 37531295 PMCID: PMC10952313 DOI: 10.1111/anae.16104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2023] [Indexed: 08/04/2023]
Abstract
Postoperative systemic inflammation is strongly associated with surgical outcomes, but its relationship with patient-centred outcomes is largely unknown. Detection of excessive inflammation and patient and surgical factors associated with adverse patient-centred outcomes should inform preventative treatment options to be evaluated in clinical trials and current clinical care. This retrospective cohort study analysed prospectively collected data from 3000 high-risk, elective, major abdominal surgery patients in the restrictive vs. liberal fluid therapy for major abdominal surgery (RELIEF) trial from 47 centres in seven countries from May 2013 to September 2016. The co-primary endpoints were persistent disability or death up to 90 days after surgery, and quality of recovery using a 15-item quality of recovery score at days 3 and 30. Secondary endpoints included: 90-day and 1-year all-cause mortality; septic complications; acute kidney injury; unplanned admission to intensive care/high dependency unit; and total intensive care unit and hospital stays. Patients were assigned into quartiles of maximum postoperative C-reactive protein concentration up to day 3, after multiple imputations of missing values. The lowest (reference) group, quartile 1, C-reactive protein ≤ 85 mg.l-1 , was compared with three inflammation groups: quartile 2 > 85 mg.l-1 to 140 mg.l-1 ; quartile 3 > 140 mg.l-1 to 200 mg.l-1 ; and quartile 4 > 200 mg.l-1 to 587 mg.l-1 . Greater postoperative systemic inflammation had a higher adjusted risk ratio (95%CI) of persistent disability or death up to 90 days after surgery, quartile 4 vs. quartile 1 being 1.76 (1.31-2.36), p < 0.001. Increased inflammation was associated with increasing decline in risk-adjusted estimated medians (95%CI) for quality of recovery, the quartile 4 to quartile 1 difference being -14.4 (-17.38 to -10.71), p < 0.001 on day 3, and -5.94 (-8.92 to -2.95), p < 0.001 on day 30. Marked postoperative systemic inflammation was associated with increased risk of complications, poor quality of recovery and persistent disability or death up to 90 days after surgery.
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The epidemiology of Medical Emergency Team calls for orthopedic patients in a teaching hospital: A retrospective cohort study. Resuscitation 2020; 159:1-6. [PMID: 33347940 DOI: 10.1016/j.resuscitation.2020.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/31/2020] [Accepted: 12/04/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND Patients undergoing orthopedic surgery are at risk of post-operative complications and needing Medical Emergency Team (MET) review. We assessed the frequency of, and associations with MET calls in orthopedic patients, and whether this was associated with increased in-hospital morbidity and mortality. METHODS Retrospective cohort study of patients admitted over four years to a University teaching hospital using hospital administrative and MET call databases. RESULTS Amongst 6344 orthopedic patients, 55.8% were female, the median (IQR) age and Charlson comorbidity index were 66 years (47-79) and 3 (1-5), respectively. Overall, 54.5% of admissions were emergency admissions, 1130 (17.8%) were non-operative, and 605 (9.5%) patients received a MET call. The strongest independent associations with receiving a MET call was the operative procedure, especially hip and knee arthroplasty. Common MET triggers were hypotension (37.5%), tachycardia (25.0%) and tachypnoea (9.1%). Patients receiving a MET call were at increased risk of anemia, delirium, pressure injury, renal failure and wound infection. The mortality of patients who received a MET call was 9.8% compared with 0.8% for those who did not. After adjusting for pre-defined co-variates, requirement for a MET call was associated with an adjusted odd-ratio of 9.57 (95%CI 3.1-29.7) for risk of in-hospital death. CONCLUSIONS Approximately 10% of orthopedic patients received a MET call, which was most strongly associated with major hip and knee arthroplasty. Such patients are at increased risk of morbidity and in-hospital mortality. Further strategies are needed to more pro-actively manage at-risk orthopedic patients.
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The design and manufacture of 3D-printed adjuncts for powered air-purifying respirators. Anaesth Rep 2020; 8:e12055. [PMID: 32705085 PMCID: PMC7369400 DOI: 10.1002/anr3.12055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2020] [Indexed: 11/21/2022] Open
Abstract
Spurred in part by literature published in the immediate aftermath of the severe acute respiratory syndrome epidemic in 2003, powered air‐purifying respirators have seen increased use worldwide during the COVID‐19 pandemic. Whereas these devices provide excellent protection of the user, there is an added element of risk during doffing and cleaning of the device. An additional layer of barrier protection, in the form of a polypropylene gown, to be worn over the hood and motor belt, can be used to minimise this risk. However, the device entrains air perpendicular to the lie of the gown, resulting in the impermeable material being sucked into the air intake, and partial occlusion of flow. In this report, we describe a clinical‐academic partnership whereby a bespoke filter guard was designed to disrupt airflow and prevent gown entrainment, thereby enabling full barrier protection of both the device and user. This intervention was simple, cheap, scalable and able to be mass produced.
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Tranexamic acid in coronary artery surgery: One-year results of the Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) trial. J Thorac Cardiovasc Surg 2019; 157:644-652.e9. [DOI: 10.1016/j.jtcvs.2018.09.113] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 09/13/2018] [Accepted: 09/27/2018] [Indexed: 11/30/2022]
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Abstract
A practical method of breath-by-breath monitoring of metabolic gas exchange has been developed by GE Healthcare/Datex Ohmeda and incorporated into existing anaesthetic and critical care monitoring systems (M-COVX®). This device relates flow measurements made at the mouth by pneumotachograph to measurements of inspired and expired gas composition by matching the two waveforms thereby allowing continuous, breath-by-breath monitoring of an intubated patient's oxygen uptake and carbon dioxide production. Given that there is a paucity of data comparing this new device against methods more widely used clinically, we tested the device on 11 patients undergoing cardiopulmonary bypass surgery. Using a standard anaesthetic machine (Datex Ohmeda Excel 210 SE) with a semi-closed circle absorber system, oxygen uptake was measured at the mouth continuously throughout the operation at approximately six-second intervals. The data were compared against the reverse Fick method and against standard indirect calorimetry using the Haldane transformation. When compared to the calculated reverse Fick oxygen uptake, a mean difference of +16.5% was found pre-bypass and +9.9% post-bypass, consistent with uptake of oxygen by lung tissue, which is not taken into account by the reverse Fick method. Measurements made comparing the M-COVX metabolic monitor against standard Haldane showed a mean difference of +5.1% pre-bypass and –2.1% post-bypass. Given the ease with which this device can be incorporated into existing anaesthetic monitoring systems and its accuracy in measuring oxygen uptake, the M-COVX module is an attractive addition to existing perioperative monitoring.
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Abstract
Surveys allow convenient and inexpensive research. Surveys include mail-out questionnaires, email questionnaires, telephone interviews, and personal interviews. Despite a widespread perception that surveys are easy to conduct, good surveys need rigorous design, implementation and analysis. This requires substantial planning, time and effort. The most important step in designing a survey is to clearly define the question (s) the survey aims to answer. The target population, measured variables and types of associations being investigated should be specific and unambiguous. Investigators should concentrate on what they ‘need to know’ rather than what would be ‘nice to know’. During development surveys should be piloted to identify problems. The main goal when implementing a survey is to maximize the response rate to avoid misleading results. Evidence-based strategies, including brief personalized surveys with stamped return envelopes, can be used to maximize the response rate. A poorly conducted survey can lead to misleading or invalid conclusions and may undermine participation in subsequent surveys by the target population.
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A Review of the Risks and Benefits of Nitrous Oxide in Current Anaesthetic Practice. Anaesth Intensive Care 2019; 32:165-72. [PMID: 15957712 DOI: 10.1177/0310057x0403200202] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Perioperative Pulse Contour Cardiac Output Analysis in a Patient with Severe Cardiac Dysfunction. Anaesth Intensive Care 2019; 34:97-101. [PMID: 16494159 DOI: 10.1177/0310057x0603400118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe a patient with severe left ventricular dysfunction simultaneously monitored with pulse contour cardiac output (PiCCO) analysis, a continuous cardiac output pulmonary artery catheter (continuous COPAC) and intraoperative transoesophageal echocardiography (TOE). There was good agreement between cardiac output (CO) measurements obtained by the three techniques prior to cardiopulmonary bypass (CPB). Agreement of CO measurements following CPB was initially poor, but improved following recalibration of PiCCO. PiCCO-derived global end-diastolic volume index (GEDVI) and cardiac function index (CFI), were assessed as markers of left ventricular preload and myocardial contractility, respectively. GEDVI correlated well with CO in the postoperative period. CFI increased more than two -fold following coronary revascularization and milrinone administration, and there was also a temporal relationship between the CFI and the dose of milrinone in the first 24 hours of treatment. Global end-diastolic volume and cardiac function index may be useful additional measures of left ventricular preload and myocardial contractility in patients with severe left ventricular dysfunction.
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Book Review: Ethics and Law for the Health Professions, 4th edition. Anaesth Intensive Care 2019. [DOI: 10.1177/0310057x1404200419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Financial and Environmental Costs of Manual versus Automated Control of End-Tidal Gas Concentrations. Anaesth Intensive Care 2019; 41:95-101. [DOI: 10.1177/0310057x1304100116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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A systematic review and consensus definitions for standardised end-points in perioperative medicine: pulmonary complications. Br J Anaesth 2018; 120:1066-1079. [DOI: 10.1016/j.bja.2018.02.007] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/01/2018] [Accepted: 02/12/2018] [Indexed: 02/02/2023] Open
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Changing patterns in volatile anaesthetic agent consumption over seven years in Victorian public hospitals. Anaesth Intensive Care 2014; 42:579-83. [PMID: 25233170 DOI: 10.1177/0310057x1404200506] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Evidence-based choices of volatile agents can increase health cost efficiencies. In this pharmaco-economic study, we evaluated the trends and costs of volatile agent use in Australian public hospitals. The total number of volatile agent (isoflurane, sevoflurane and desflurane) bottles ordered and inflation-adjusted costs were collected from 65 Victorian public hospitals from 2005 to 2011. Environmental costs were measured through the 100-year global warming potential index as carbon dioxide equivalents. During this time period, the aggregate inflation-adjusted expenditure was $39,209,878. Time series analysis showed that bottles of isoflurane ordered decreased by 419/year (99% confidence interval (CI): -603 to -235); costs decreased by $56,017/year (99% CI: -$93,243 to -$18,791). Bottles of sevoflurane increased by 1,330/year (99% CI: 1141 to 1,519); costs decreased by $423,3573/year (99% CI: -$720,030 to -112,783). Bottles of desflurane increased by 726/year (99% CI: 288 to 1,164); costs increased by $171,578/year (99% CI: $136,951 to $206,205). The amount of calculated greenhouse gas emissions released into the atmosphere over this period was 37,000 tonnes of carbon dioxide equivalents, with isoflurane contributing 6%, sevoflurane 17%, and desflurane 77% of this total. In conclusion, isoflurane is no longer being used in the majority of Victorian public hospitals, with sevoflurane and desflurane remaining as the primary volatile agents, utilised respectively at a ratio of 2.2 to 1, and costs at 0.8 to 1.
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Hybrid measurement to achieve satisfactory precision in perioperative cardiac output monitoring. Anaesth Intensive Care 2014; 42:340-9. [PMID: 24794474 DOI: 10.1177/0310057x1404200311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Advanced haemodynamic monitoring employing minimally invasive cardiac output measurement may lead to significant improvements in patient outcomes in major surgery. However, the precision (scatter) of measurement of available generic technologies has been shown to be unsatisfactory with percentage error of agreement with bolus thermodilution (% error) of 40% to 50%. Simultaneous measurement and averaging by two or more technologies may reduce random measurement scatter and improve precision. This concept, called the hybrid method, was tested by comparing accuracy and precision of measurement relative to bolus thermodilution using combinations of three component methods. Thirty patients scheduled for either elective cardiac surgery or liver transplantation were studied. Agreement with simultaneous bolus thermodilution of hybrid combinations of continuous thermodilution (QtCCO) or Vigeleo™/FloTrac™ pulse contour measurement (QtFT) with pulmonary Capnotracking (QtCO2) was assessed pre- and post-cardiopulmonary bypass or pre- and post-reperfusion of the donor liver and compared with that of the component methods alone. Hybridisation of QtCO2 (% error 42.2) and QtCCO (% error 51.3) achieved significantly better precision (% error 31.3) than the component methods (P=0.0004) and (P=0.0195). Due to poor inherent precision of QtFT (% error 82.8), hybrid combination of QtFT with QtCO2 did not result in better precision than QtCO2 alone. Hybrid measurement can approach a 30% error, which is recommended as the upper limit for acceptability. This is a practical option where at least one component method, such as Capnotracking, is automated and does not increase the cost or complexity of the measurement process.
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Reply from the authors. Br J Anaesth 2014. [DOI: 10.1093/bja/aet576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Reply from the authors. Br J Anaesth 2014; 112:393-394. [PMID: 24571040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
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Monitoring anaesthetic gas concentrations in the exhaust of the cardiopulmonary bypass oxygenator. Br J Anaesth 2014; 112:173. [DOI: 10.1093/bja/aet461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
BACKGROUND This post hoc analysis aimed to determine whether neuraxial block was associated with a composite of cardiovascular death, non-fatal myocardial infarction (MI) and non-fatal cardiac arrest within 30 days of randomization in POISE trial patients. METHODS A total of 8351 non-cardiac surgical patients at high risk of cardiovascular complications were randomized to β-blocker or placebo. Neuraxial block was defined as spinal, lumbar or thoracic epidural anaesthesia. Logistic regression, with weighting using estimated propensity scores, was used to determine the association between neuraxial block and primary and secondary outcomes. RESULTS Neuraxial block was associated with an increased risk of the primary outcome [287 (7.3%) vs 229 (5.7%); odds ratio (OR), 1.24; 95% confidence interval (CI), 1.02-1.49; P=0.03] and MI [230 (5.9%) vs 177 (4.4%); OR, 1.32; 95% CI, 1.07-1.64; P=0.009] but not stroke [23 (0.6%) vs 32 (0.8%); OR, 0.76; 95% CI, 0.44-1.33; P=0.34], death [96 (2.5%) vs 111 (2.8%); OR, 0.87; 95% CI, 0.65-1.17; P=0.37] or clinically significant hypotension [522 (13.4%) vs 484 (12.1%); OR, 1.13; 95% CI, 0.99-1.30; P=0.08]. Thoracic epidural with general anaesthesia was associated with a worse primary outcome than general anaesthesia alone [86 (12.1%) vs 119 (5.4%); OR, 2.95; 95% CI, 2.00-4.35; P<0.001]. CONCLUSIONS In patients at high risk of cardiovascular morbidity, neuraxial block was associated with an increased risk of adverse cardiovascular outcomes, which could be causal or because of residual confounding.
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Book Review: Monitoring in Anesthesia and Perioperative Care. Anaesth Intensive Care 2012. [DOI: 10.1177/0310057x1204000330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Laboratory validation of the M-COVX metabolic module in measurement of oxygen uptake. Anaesth Intensive Care 2009; 37:399-406. [PMID: 19499859 DOI: 10.1177/0310057x0903700312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A practical method of breath-by-breath monitoring of metabolic gas exchange has previously been developed by GE Healthcare and can now be easily incorporated into existing anaesthetic and critical care monitoring (M-COVX). Previous research using this device has shown good accuracy and precision between the M-COVX measurements and a traditional measurement of gas uptake at the mouth and also against the reverse Fick method during cardiac surgery and critical care, but its accuracy in the paediatric situation and across a range of ventilatory settings awaits validation. We tested the M-COVX metabolic monitor in the laboratory comparing its measurement to a traditional Haldane transformation across a wide range of oxygen consumption values, from 50 ml/minute to just under 300 ml/minute, typical of those expected in anaesthetised adults and children. The M-COVX device showed acceptable accuracy with an overall mean bias of -3.3% (range -15.1 to +4.2%, P = 0.21). Excellent linearity was found, by y = 0.96x + 0.5 ml/minute, r = 0.99. The device showed acceptable robustness to ventilatory changes examined, including changes in respiratory rate, I:E ratio, FiO2 up to 75% and simulated spontaneous breathing. However any induced leak from around the simulated endotracheal tube caused a significant error in paediatric scenarios.
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Risk factors for severe postoperative nausea and vomiting in a randomized trial of nitrous oxide-based vs nitrous oxide-free anaesthesia. Br J Anaesth 2008; 101:498-505. [DOI: 10.1093/bja/aen230] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Effect of nitrous oxide on plasma homocysteine and folate in patients undergoing major surgery. Br J Anaesth 2008; 100:780-6. [DOI: 10.1093/bja/aen085] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Non-invasive metabolic monitoring of patients under anaesthesia by continuous indirect calorimetry—an in vivo trial of a new method. Br J Anaesth 2007; 98:45-52. [PMID: 17124187 DOI: 10.1093/bja/ael310] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Oxygen uptake is an important form of metabolic monitoring for patients under anaesthesia. In critically ill patients oxygen uptake has been shown to provide valuable clinical information in directed therapy and acts as a useful monitor of cardiovascular dysfunction. A new method of continuous real time monitoring of metabolic gas exchange was tested in patients during anaesthesia. METHODS Using a standard anaesthetic machine with attached semi-closed circle absorber system, oxygen uptake was measured continuously throughout surgery in 30 patients undergoing cardiopulmonary bypass surgery and compared with paired measurements made with the reverse Fick method. The method is an indirect calorimetry technique which uses fresh gas rotameters for control, regulation and measurement of the gas flows into the system, with continuous sampling of mixed exhaust gas. RESULTS When compared with the reverse Fick method the oxygen uptake showed a mean difference (and sd) of 20.7 ml min(-1) or 12.1% (25.3 ml min(-1)) pre-bypass and 13.9 ml min(-1) or 8.1% (27.0 ml min(-1)) post-bypass. This bias is consistent with previous studies comparing oxygen uptake measured at the mouth against oxygen uptake by reverse Fick, which have shown a difference of approximately 10-15% accounted for by the consumption of oxygen by lung tissue. CONCLUSIONS As the method allows continuous measurement of gas exchange and can be adapted to a modern anaesthetic workstation it is an attractive method for use in clinical setting.
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Contamination of anaesthetic gases with nitric oxide and its influence on oxygenation. Br J Anaesth 2005; 94:687; author reply 687-8. [PMID: 15814805 DOI: 10.1093/bja/aei543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Accuracy of the Foldes-Biro equation for measurement of oxygen uptake during anaesthesia: a laboratory simulation. Anaesthesia 2004; 59:541-4. [PMID: 15144292 DOI: 10.1111/j.1365-2044.2004.03737.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Laboratory benchtop testing was conducted of the Biro method for measurement of oxygen uptake from an anaesthetic breathing system by patients during low flow anaesthesia. A high precision flow and gas concentration measurement system was employed in conjunction with a physical gas exchange simulation model to test the theoretical basis of the method under controlled conditions. Simulated oxygen uptake values between 200 and 350 ml x min(-1) were modelled. The Biro-derived measurement of simulated O(2) uptake significantly underestimated the target value (mean difference -88.5 ml x min(-1), or -31.7%). The bias was directly proportional to the simulated O(2) uptake. The Biro method has a systematic bias that cannot be explained by random measurement imprecision.
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Abstract
The provision of supplementary oxygen via the laryngeal mask airway used in the recovery room is important for patient safety. Several devices have been described for this purpose, but these studies have not included an accurate measurement of the most clinically important variable, the end-tidal oxygen concentration. We constructed an artificial model of spontaneous ventilation to compare the efficacy and safety of four devices; a circuit filter, a Hudson mask, the 'T-bag' device and a T-piece. We combined the use of oximetry with a pneumotachograph to provide a continuous picture of the oxygen delivery characteristics of the devices at flow rates of 2, 4 and 8 l.min-1. The performances of the T-bag and the T-piece were superior to those of the filter and Hudson mask, with end-tidal oxygen concentrations of 46.1%, 45.8% and 35.4%, 34.8%, respectively, at 8 l.min-1. Single point assessments of oxygen delivery, such as peak inspired oxygen concentration, may overestimate the efficacy of test devices.
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Design of the multicenter Australian study of epidural anesthesia and analgesia in major surgery: the MASTER trial. CONTROLLED CLINICAL TRIALS 2000; 21:244-56. [PMID: 10822122 DOI: 10.1016/s0197-2456(00)00045-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The Multicenter Australian Study of Epidural Anesthesia and Analgesia in Major Surgery (The MASTER Trial) was designed to evaluate the possible benefit of epidural block in improving outcome in high-risk patients. The trial began in 1995 and is scheduled to reach the planned sample size of 900 during 2001. This paper describes the trial design and presents data comparing 455 patients randomized in 21 institutions in Australia, Hong Kong, and Malaysia, with 237 patients from the same hospitals who were eligible but not randomized. Nine categories of high-risk patients were defined as entry criteria for the trial. Protocols for ethical review, informed consent, randomization, clinical anesthesia and analgesia, and perioperative management were determined following extensive consultation with anesthesiologists throughout Australia. Clinical and research information was collected in participating hospitals by research staff who may not have been blind to allocation. Decisions about the presence or absence of endpoints were made primarily by a computer algorithm, supplemented by blinded clinical experts. Without unblinding the trial, comparison of eligibility criteria and incidence of endpoints between randomized and nonrandomized patients showed only small differences. We conclude that there is no strong evidence of important demographic or clinical differences between randomized and nonrandomized patients eligible for the MASTER Trial. Thus, the trial results are likely to be broadly generalizable.
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Abstract
This paper is a brief report of the symposium, "Improving the Evidence Base for Anaesthesia and Intensive Care", organized by the MASTER Anaesthesia Trial Study Group at the Annual Scientific Meeting of the Australian and New Zealand College of Anaesthetists, Newcastle, N.S.W., on Tuesday, May 5, 1998.
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An unusual and lethal tracheal foreign body. Anaesth Intensive Care 1993; 21:248-9. [PMID: 8517524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Continuous spinal anaesthesia. Anaesth Intensive Care 1992; 20:398-9. [PMID: 1524203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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