bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Retrospective Study to Determine Whether accessing Frequency Affects the Incidence of Microbial Colonisation in Peripheral Arterial Catheters
Authors: Koh D. B. C. , Robertson I. K. , Watts M. , Davies A. N. 
Published: January 2019

Peripheral arterial catheters are used for the continuous monitoring of blood pressure and repeated blood sampling in critically ill patients, but can be a source of catheter-related bloodstream infection. A common assumption is that the more frequently an arterial catheter is accessed, the greater the likelihood of contamination and colonisation to occur. We sought to determine whether the accessing frequency has an influence on the rate of colonisation in a peripheral arterial catheter. A retrospective, unmatched, nested case control study was conducted in our intensive care unit. The intensive care unit charts of 96 arterial catheters from 83 patients were examined to measure the number of times each respective arterial catheter was accessed. Multivariate Cox proportional hazards regression was used to compare the rate of accessing of arterial catheters and account for varying arterial catheter in situ duration. Arterial catheters which had a high access rate of 8.1 or more times/day (five colonised of 32 patients: hazards ratio 1.69, 95% confidence interval 0.52 to 5.49; P=0.77), or a medium access rate of 6.7 to 8.0 times/day (six colonised of 32 patients: hazards ratio, 1.35, 95% confidence interval, 0.37 to 4.92: P=0.65) were not significantly more colonised when compared to arterial catheters which had a low access rate of 0 to 6.6 times/day (six colonised of 32 patients), adjusted for arterial catheter insertion site and place in hospital where the arterial catheter insertion was performed. We were unable to demonstrate that the accessing frequency of an arterial catheter was a major predisposing factor for the likelihood of colonisation. Other mechanisms other than hub colonisation should be investigated further.
Perioperative Melatonin Use
Authors: Jarratt J. 
Published: January 2019

Melatonin is a substance chiefly produced by the pineal gland and has a key role in the sleep-wake cycle. It also has an important antioxidant role. Exogenous melatonin has a short half-life and is available in a range of preparations. Newer analogues targeted for the recently discovered melatonin MT1 and MT2 receptors have also been developed. Exogenous melatonin is used as a resynchronisation agent in jet lag and for other sleep disturbances. Perioperatively, melatonin has been used as a premedicant, sedative and analgesic. It decreases paediatric emergence delirium. The antioxidant properties of melatonin are being investigated for use in sepsis and reperfusion injuries. It would appear that patients on melatonin supplements should continue taking them perioperatively because there may be benefits. Melatonin and its analogues will be increasingly encountered in the perioperative setting.
The Development of a System to Guide Volatile Anaesthetic Administration
Authors: Kennedy R. R. , French R. A. 
Published: January 2019

We have developed and deployed within our operating rooms a system which provides real-time estimates of effect-site levels of inhalational anaesthetic agents along with forward predictions of end-tidal and effect-site concentrations. The initial aim of this project was to provide users of inhalational agents with tools similar to those available in target-controlled infusion systems. This paper describes the development and implementation of the system and outlines evaluation and uses of the system. The prototype was developed by combining a locally developed data logging and trend display system with a model of uptake developed as a teaching tool in 1982. This uptake model performs as well as contemporary models of propofol uptake and distribution. Following initial evaluation, the system has been deployed in over half our operating rooms and uses data gathered from the Datex/GE Anaesthesia Delivery Unit anaesthetic machines. We have conducted a number of studies of the system itself, explored aspects of the underlying models, and used the system to investigate effect-site guided anesthesia and as a tool for data collection in other studies. The system has been well accepted locally and has been shown to facilitate faster changes in inhalational levels. We have also seen a significant decrease in fresh gas flow rates over recent years and attribute this in part to the predictive system, which simplifies the task of determining the appropriate combination of gas flow and vapour dial setting. The system also provides a useful platform for a range of research projects.
Empirical Aspects of Linking Intensive Care Registry Data to Hospital Discharge Data without the use of Direct Patient Identifiers
Authors: Bohensky M. A. , Jolley D. , Sundararajan V. , Pilcher D. V. , Evans S. , Brand C. A. 
Published: January 2019

In the field of intensive care, clinical data registries are commonly used to support clinical audit and develop evidence-based practice. However, they are often restricted to the intensive care unit episode only, limiting their ability to follow long-term patient outcomes and identify patient readmissions. Data linkage can be used to supplement existing data, but a lack of unique patient identifiers may compromise the accuracy of the linkage process. The aim of this study was to assess the quality of linking the Australia/New Zealand critical care registry to a state financial claims database using a method without direct patient identifiers and to identify possible sources of bias from this method. We used a linkage method relying on indirect patient identifiers and compared the accuracy of this method to one that also included the patient medical record number and date of birth. The overall linkage rate using the method with indirect identifiers was 92.3% compared to 94.5% using the method with direct identifiers. Factors most strongly associated with not being a correct link in the first method included patients at one study hospital, admissions in 2002 and 2003 and having a hospital length of stay of 20 days or more. Linking the Australia/New Zealand critical care without direct patient identifiers is a valid linkage method that will enable the measurement of long-term patient survival and readmissions. While some sources of bias have been identified, this method provides sufficient quality linkage that will support broad analyses designed to signal future in-depth research.
Responses to Dural Puncture during Institution of Combined Spinal-Epidural Analgesia: A Comparison of 27 Gauge Pencil-Point and 27 Gauge Cutting-Edge Needles
Authors: van den Berg A. A. , Ghatge S. , Armendariz G. , Cornelius D. , Wang S. 
Published: January 2019

Pencil-point spinal needles are popular for combined spinal-epidural analgesia because they cause less dural puncture headache than cutting-edge spinal needles. However, many parturients move, grimace, vocalise or experience paraesthesia or dysaesthesia during dural puncture when performing ‘needle through needle’ combined spinal-epidural analgesia. We compared dural puncture responses induced by pencil-point and cutting-edge needles (both 27 gauge). With institutional approval, 115 parturients presenting for elective caesarean section or labour analgesia were audited. After lignocaine infiltration, a Tuohy-type needle was inserted to loss of resistance to saline at a mid-lumbar interspace, and either a 27 gauge cutting-edge or 27 gauge pencil-point needle was inserted ‘needle through needle’ through the dura. During dural penetration, the occurrence of patient movement, grimacing or vocalisation was noted by a blinded observer, as was the patient's response to the question “Did you feel that?” asked by the anaesthetist. The audit comprised two similar groups of patients (caesarean section, n=30; labour analgesia, n=85). In both groups, grimacing and movement during thecal penetration occurred more frequently with pencil-point needles (P <0.05 and P <0.025, respectively). Pooled data analysis revealed that pencil-point and cutting-edge needles induced grimacing and movement in 17 (22%) and 2 (5%), spontaneous vocalisation in 4 (5%) and 1 (3%) and was perceived by 13 (17%) and 3 (8%) parturients (P <0.025, P=NS, P=NS), respectively. Overall, 34 and 6 objective and subjective patient responses (P <0.005) occurred when inserting these needles, respectively. Dural puncture by a 27 gauge pencil-point needle inserted ‘needle through needle’ when instituting combined spinal-epidural analgesia induces more iatrogenic responses than a 27 gauge cutting-edge needle.
Effect of a Blood Conservation Device in Patients with Preserved Admission Haemoglobin in the Intensive Care Unit
Authors: Mukhopadhyay A. , See K. C. , Chan Y. H. , Yip H. S. , Phua J. 
Published: January 2019

An important iatrogenic cause of anaemia in the intensive care unit is loss of the discarded blood during phlebotomy via indwelling vascular catheters. A closed system blood conservation device has previously been shown to reduce the need for blood transfusion and to blunt the decrease of haemoglobin in intensive care unit patients. However, such a device may not benefit patients who are admitted with a relatively preserved haemoglobin. In this sub-group analysis of a before-and-after study, 128 patients had admission haemoglobin ≥115 g/l and did not receive any blood transfusions while in the intensive care unit. In the control group of 50 patients a blood conservation device was not used, while in the active group of 78 patients the device was used. Use of the blood conservation device did not affect the haemoglobin trends when both groups were compared using the general linear model. For patients with admission haemoglobin ≥115 g/l, use of a blood conservation device does not affect the subsequent rate of haemoglobin decline in the intensive care unit. These patients are unlikely to benefit from the use of such devices.
Intrabronchial Airway Pressures in Intubated Patients during Bronchoscopy under Volume Controlled and Pressure Controlled Ventilation
Authors: Nakstad E. R. , Opdahl H. , Skjønsberg O. H. , Borchsenius F. 
Published: January 2019

Bronchoscope insertion through an endotracheal tube increases airflow resistance. Constant tidal volume (TV) ventilation can be maintained by augmenting the inspiratory pressure, but increased outflow resistance cannot be compensated for. Air trapping distal to the tube may lead to higher airway pressures in volume controlled (VC) mode and reduced TV in pressure controlled (PC) mode. Increased end-expiratory airway pressures will not be detected by ventilator pressure sensors. In mechanically ventilated and sedated patients, the effects of bronchoscope insertion on intrabronchial pressures were recorded by a pressure transducer distal to the endoscope. In half of the patients, the ventilator was set in VC mode prior to bronchoscope insertion, keeping the previous TV constant. In the other half, the ventilator was set in PC mode, keeping previous peak inspiratory pressures constant. All patients underwent sequences of VC-PC-VC or PC-VC-PC ventilation with two-minute intervals between mode-changes. In VC mode, bronchoscope insertion increased peak airway pressure from 29 cmH2O (22 to 43) to 41 cmH2O (36 to 49) (P=0.012) and end-expiratory airway pressure from 11 cmH2O (6 to 18) to 22.5 cmH2O (15 to 30) (P=0.012). There were no significant changes in TV, PaCO2 or PaO2 after two minutes. In PC mode, peak airway pressure was unchanged and end-expiratory airway pressure increased from 9.5 cmH2O (7 to 10) to 10.5 cmH2O (9 to 18) (P=0.017). Median TV was reduced from 673 ml (585 to 800) to 450 ml (408 to 560) (P=0.012); median PaCO2 increased from 5.7 kPa to 6.5 kPa (P=0.012). Using distal measurement, positive end-expiratory airway pressure increased markedly in VC mode but only marginally in PC mode after bronchoscope insertion.
Observational Study of Admission and Triage Decisions for Patients Referred to a Regional Intensive Care Unit
Authors: Howe D. C. 
Published: January 2019

The objectives of this study were to identify factors associated with decisions concerning triage and admission to the intensive care unit and to describe the outcome of patients referred to intensive care unit for admission. The study was a single-centre, prospective, observational study. It was performed in the general intensive care unit of a tertiary regional hospital, over the period of February to June 2009. The patients were non-elective, acute medical in-patients. For 100 patients referred, only 36 were admitted to the intensive care unit. The remaining 64 were declined admission: nine were declined admission because they were assessed as too sick to benefit, 41 were declined admission because they were assessed as too well to benefit and 14 were deemed to potentially benefit from intensive care unit admission but were not admitted (‘triage’). Patients most likely to receive triage decisions were medical in-patients who had expressed wishes about end-of-life care, who were functionally limited with co-morbid conditions affecting their performance status. Patients referred by Resident Medical Officers were also more likely to receive a triage decision. Age, gender, Aboriginal and Torres Strait Islander status, diagnostic category and reason for referral did not impact on admission or triage decisions. Bed status in intensive care unit at the time of referral affected neither admission nor triage decisions. Hospital mortality in patients deemed too well to benefit from intensive care unit was 7.3%, suggesting that all patients referred for consideration of admission to intensive care unit should be classified as ‘high risk’.
Oesophageal Balloon Tracheoplasty in Early Tracheal Stenosis following Percutaneous Tracheostomy
Authors: Mahanta V. , Howson C. 
Published: January 2019

Percutaneous tracheostomy is an efficient technique used in intensive care units. Although a safe procedure, serious early and late complications can occur. A rare complication is suprastomal stenosis following inadvertent tracheal cartilage fracture resulting in stenosis. Management is complicated, often requiring specialised equipment. While surgical treatment techniques are evolving, none are universally applicable. We report a case of early tracheal stenosis following percutaneous tracheostomy, treated successfully using a novel technique of oesophageal balloon tracheoplasty. To our knowledge, this is the first reported case of immediate post percutaneous tracheostomy suprastomal stenosis treated with balloon tracheoplasty using an oesophageal balloon catheter which is readily available in most endoscopy units.
Automated external defibrillator use for in-hospital emergency management
Authors: Huschak G. , Dünnebier A. , Kaisers U. X. , Bercker S. 
Published: January 2019

Summary The in-hospital spread of automated external defibrillators (AEDs) is aimed to allow for a shock-delivery within three minutes. However, it has to be questioned if the implementation of AED alone really contributes to a ‘heart-safe hospital’. Methods Cohort study of 1008 in-hospital emergency calls in a university tertiary care hospital. Analysis of cardio-pulmonary resuscitation (CPR) cases with and without AED use. Results A number of 484 patients (48%) had cardiac arrest and received CPR. Response time of the emergency team was 4.3 ± 4.0 minutes. 8% percent of the CPR cases had a shockable rhythm. In only three cases of 43 placements a shock was delivered by the AED. There were no differences in survival between patients with CPR only and CPR with AED use. Conclusion Our data do not support the use of an AED for in-hospital CPR if a professional response team is rapidly available.
An Evaluation of a New Analyser for Inhaled Nitric Oxide Administration
Authors: Carter B. , Holt M. , Tibballs J. , Hochmann M. , Osborne A. 
Published: January 2019

We examined the ability of a new combined nitric oxide (NO)/nitrogen dioxide (NO2) electrochemical analyser (PrinterNOx, Micro Medical Limited, Chatham, Kent, England) to measure NO and NO2 concentrations. The PrinterNOx was compared to a chemiluminescence analyser (42H, Thermo Environmental Instruments Inc, Franklin MA, U.S.A.). NO and NO2 were generated in a standard ventilator circuit using a paediatric ventilator (900C, Siemens Elema, Sweden) connected to an artificial lung (260li, TTL Test Lung, Michigan Instruments, MI, U.S.A.). Forty-four paired NO measurements ranging from 2.56 ppm to 74.6 ppm and 50 paired NO2 measurements ranging from 0.0 ppm to 5.39 ppm were obtained. For the measurement of NO the PrinterNOx showed a tendency to overestimate the chemiluminescence analyser. Regression analysis showed a close relationship between the two analysers with r2=0.9981 and a regression equation of y=1.1658 x +0.0197. In the more clinically important range of 0-25 ppm, r2 increased to 0.9996 with a regression equation of y=1.1984 x -0.4657. Conversely the PrinterNOx underestimated the chemiluminescence analyser for the measurement of NO2. The regression equation describing this relationship was y=0.879 x -0.0447 (r2=0.9993). We conclude that the PrinterNOx is of sufficient accuracy to be of clinical use in the administration of NO.
Comfort and Safety in Eye Surgery under Local Anaesthesia
Authors: Bosman Y. K. , Krige S. J. , Edge K. R. , Newstead J. , Dutoit P. W. 
Published: January 2019

The study consisted of two parts: 1. The standard system in use at our hospital for gas delivery under the drapes during eye surgery under local anaesthesia was compared with one incorporating a venturi. 2. The oxygen concentration at the operation site was measured with three methods of draping using the two systems. Twenty-three patients and thirty-one volunteers from the operating room staff were subjected to operating conditions and gas concentrations and certain vital signs measured using both systems. The subjective response of the volunteers, none of whom had blocks or premedication, was noted. The burden of rebreathing seen with a significant proportion of cases using 6 l/min of fresh gas flow was not seen when the venturi system was used. The safety from fire hazard using 26% oxygen and diathermy was demonstrated with occlusive and free draping.
Anaesthesia Circuits, Humidity Output, and Mucociliary Structure and Function
Authors: Branson R. D. , Campbell R. S. , Davis K. , Porembka D. T. 
Published: January 2019

We compared the effects of humidity delivered by the circle system at low fresh gas flows (FGF) with a conventional two-limb and coaxial circuit on the structure and function of the tracheobronchial epithelium in dogs. Animals were anaesthetized and mechanically ventilated using an anaesthesia ventilator to maintain normocarbia. Group I (control) animals received a FGF equal to the required minute ventilation mimicking an open circuit technique. Group II and III animals had FGF set at 20% of the required minute ventilation. Group II used a two-limb circuit and Group III used a coaxial circuit. Relative humidity and temperature of inspired gases were measured at baseline and hourly afterwards. In the first experiment, biopsies of the tracheobronchial tree were obtained bronchoscopically at baseline and then hourly for six hours. Microscopic examination of these samples allowed calculation of mean ciliary length. In the second experiment, tracheal mucus flow velocity (TMFV) was measured at baseline and hourly afterward, using a cinebroncho-fibrescopic method. Delivered absolute humidity was greatest with low FGF and the coaxial circuit, followed by low FGF and a conventional circuit, and high FGF (15±1.4 vs 9±0.8 vs 5±0.4 mg H2O, P<0.01) after two hours. Mean cilia length (μ m) and TMFV (mm/min) fell during the first hour in all three groups. At hour two TMFV returned to baseline in Group III and was significantly greater than Groups I and II (0.8±0.4 vs 8.6±1.1 vs 15.4±2.1, P<0.001). Mean ciliary length demonstrated a similar pattern with reductions from baseline in all three groups for the first two hours. Groups II and III had an increase in cilia length beginning at hour three and were both significantly greater than Group I at hours 3 through 6 (1.3±0.5 vs 3.2±1.1 vs 4.2±0.8, P <0.001). Alterations in tracheobronchial structure and function result from exposure to dry gases and are amplified by the duration of exposure. Our findings suggest a minimum of 12 to 15 mg H2O/l is necessary to prevent these alterations. In this study, the combination of low FGF and a coaxial anaesthesia circuit reached this minimum threshold more quickly than a conventional two-limb circuit.
Undergraduate Education in Anaesthesia: The Influence of Role Models on Skills Learnt and Career Choice
Authors: Watts R. W. , Marley J. , Worley P. 
Published: January 2019

Undergraduate teaching of anaesthesia occurs in about two-thirds of Australian departments of anaesthesia: however, student contact hours are limited compared with those of other disciplines. Seventy-five directors of anaesthesia were surveyed by written questionnaire concerning the time devoted in their department to undergraduate study and teaching of practice/skills to undergraduate students (40 responded). One hundred and sixty final year students were surveyed regarding career choice, anaesthesia skills taught them and role models identified during their training (101 responded). Most final year students had been taught and had learnt the basic skills of life support such as bag and mask ventilation, cardiopulmonary resuscitation and intravenous cannulation. However, fewer were taught more specialized skills such as induction of anaesthesia and spinal anaesthesia. Positive role models in teaching anaesthetists were identified by 66% of students, more commonly if they were taught advanced skills, and were significantly associated with satisfaction with theoretical and practical training. For those students intending a career in anaesthesia (18%), 94% identified a positive role model compared to 65% who did not (P=0.03).
Patient Evaluation and Comparison of the Recovery Profile between Propofol and Thiopentone as Induction Agents in Day Surgery
Authors: Kern C. , Weber A. , Aurilio C. , Forster A. 
Published: January 2019

The patient's subjective perception of the quality of his/her recovery after day case anaesthesia with propofol or thiopentone as induction agents is still controversial. The authors investigated the perception and quality of awakening after anaesthesia during the recovery period and at 24 hours and 72 hours, in outpatients undergoing anaesthesia induced either with propofol or thiopentone and maintained with a volatile anaesthetic. In a double-blind study in adults undergoing knee arthroscopy in a day surgery unit, propofol and thiopentone were compared as induction agents in 60 randomized outpatients. A Critical Flicker Fusion Threshold test (CFFT), verbal test for anxiety, visual analog scale for anxiety and pain, and questionnaires were used to assess objectively and subjectively the quality of anaesthesia and awakening during the postoperative period. Demographic data and mean duration of anaesthesia were similar. In the propofol group, patients awoke more rapidly (9.2±5.8 vs 12.3±5.8 min) (P<0.05); however, the CFFT measurements did not show any significant difference between the groups, except at time=0 min, when 17 patients in the propofol group were able to perform the test versus only 10 patients in the thiopentone group (P<0.05). At 4, 24, and 72 hours postoperatively, the authors were unable to detect any difference between the two groups. Except for early recovery, there were no differences between the intermediate and late recovery profiles, when propofol or thiopentone was used as the anaesthetic induction agent in day surgery.