Tracheal cuff pressure monitoring in the ICU: a literature review and survey of current practice in Queensland.

The application of tracheal cuff pressure monitoring is likely to vary between institutions. The aim of this study was therefore to review current evidence concerning this intervention in the intensive care unit (ICU) and to appraise regional practice by performing a state-wide survey. Publications for review were identified through searches of PubMed, EMBASE and Cochrane (1977 to 2014). All studies in English relevant to critical care and with complete data were included. Survey questions were developed by small-group consensus. Public and private ICUs across Queensland were contacted, with responses obtained from a representative member of the medical or nursing staff. Existing literature suggests significant variability in tracheal cuff pressure monitoring in the ICU, particularly in the applied technique, frequency of assessment and optimal intra-cuff pressures. Twenty-nine respondents completed the survey, representing 80.5% (29/36) of ICUs in Queensland. Twenty-eight out of twenty-nine respondents reported routinely monitoring tracheal cuff function, primarily employing cuff pressure measurement (26/28). Target cuff pressures varied, with 3/26 respondents aiming for 10 to 20 cmH2O, 10/26 for 21 to 25 cmH2O, and 13/26 for 26 to 30 cmH2O. Fifteen out of twenty-nine reported they had no current guideline or protocol for tracheal cuff management and only 16/29 indicated there was a dedicated area in the clinical record for reporting cuff intervention. Our results indicate that many ICUs across Queensland routinely measure tracheal cuff function, with most utilising pressure monitoring devices. Consistent with existing literature, the optimum cuff pressure remains uncertain. Most, however, considered that this should be a routine part of ICU care.

Copper removal strategies for Wilson's disease crisis in the ICU.

Wilson's disease is a rare, inherited, autosomal recessive disorder of copper metabolism which leads to an accumulation of copper in body tissues. If a patient develops a Wilson's crisis, mortality can approach 100%. The treatment of such patients is mostly organ support but a possible treatment goal is to try to rapidly remove copper from their system. We performed a literature search on methods for de-coppering strategies for patients in intensive care with known Wilson's disease. We found 11 case reports where therapeutic plasma exchange was used and six case reports where various forms of albumin dialysis were used as techniques for rapidly reducing serum copper levels. To date, the case reports are encouraging that therapeutic plasma exchange and albumin dialysis can either delay or prevent the need for liver transplantation in patients with fulminant hepatic failure due to Wilson's disease. However, these case reports are mainly in the paediatric or young adult population, thus further studies in adults are warranted.

The tyranny of distance: telemedicine for the critically ill in rural Australia.

A case of severe sepsis with multi-organ failure needing complex support was deemed too ill for transfer to a major centre. Telemedicine allowed direct patient review, collaborative advice and collegial support with maintained healthcare standards while avoiding long distance transfer from his home and family.

Respiratory dysfunction in ventilated patients: can inspiratory muscle training help?

Respiratory muscle dysfunction is associated with prolonged and difficult weaning from mechanical ventilation. This dysfunction in ventilator-dependent patients is multifactorial: there is evidence that inspiratory muscle weakness is partially explained by disuse atrophy secondary to ventilation, and positive end-expiratory pressure can further reduce muscle strength by negatively shifting the length-tension curve of the diaphragm. Polyneuropathy is also likely to contribute to apparent muscle weakness in critically ill patients, and nutritional and pharmaceutical effects may further compound muscle weakness. Moreover, psychological influences, including anxiety, may contribute to difficulty in weaning. There is recent evidence that inspiratory muscle training is safe and feasible in selected ventilator-dependent patients, and that this training can reduce the weaning period and improve overall weaning success rates. Extrapolating from evidence in sports medicine, as well as the known effects of inspiratory muscle training in chronic lung disease, a theoretical model is proposed to describe how inspiratory muscle training enhances weaning and recovery from mechanical ventilation. Possible mechanisms include increased protein synthesis (both Type 1 and Type 2 muscle fibres), enhanced limb perfusion via dampening of a sympathetically-mediated metaboreflex, reduced lactate levels and modulation of the perception of exertion, resulting in less dyspnoea and enhanced exercise capacity.

Experience with high frequency oscillation ventilation during the 2009 H1N1 influenza pandemic in Australia and New Zealand.

During the 2009 H1N1 pandemic, large numbers of patients had severe respiratory failure. High frequency oscillation ventilation was used as a salvage technique for profound hypoxaemia. Our aim was to compare this experience with high frequency oscillation ventilation during the 2009 H1N1 pandemic with the same period in 2008 by performing a three-month period prevalence study in Australian and New Zealand intensive care units. The main study end-points were clinical demographics, care delivery and survival. Nine intensive care units contributed data. During 2009 there were 22 H1N1 patients (17 adults, five children) and 10 non-H1N1 patients (five adults, five children), while in 2008, 18 patients (two adults, 16 children) received high frequency oscillation ventilation. The principal non-H1N1 high frequency oscillation ventilation indication was bacterial or viral pneumonia (56%). For H1N1 patients, the median duration of high frequency oscillation ventilation was 3.7 days (interquartile range 1.8 to 5) with concomitant therapies including recruitment manoeuvres (22%), prone ventilation (41%), inhaled prostacyclins (18%) and inhaled nitric oxide (36%). Seven patients received extracorporeal membrane oxygenation, six having H1N1. Three patients had extracorporeal membrane oxygenation concurrently, two as salvage therapy following the commencement of high frequency oscillation ventilation. In 2008, no high frequency oscillation ventilation patient received extracorporeal membrane oxygenation. Overall hospital survival was 77% in H1N1 patients, while survival in patients having adjunctive extracorporeal membrane oxygenation was similar to those receiving high frequency oscillation ventilation alone (65% compared to 71%, P = 1.00). Survival rates were comparable to published extracorporeal membrane oxygenation outcomes. High frequency oscillation ventilation was used successfully as a rescue therapy for severe respiratory failure. High frequency oscillation ventilation was only available in a limited number of intensive care units during the H1N1 pandemic.

'Safe' methaemoglobin concentrations are a mortality risk factor in patients receiving inhaled nitric oxide.

Inhaled nitric oxide (iNO) can reduce pulmonary arterial hypertension and improve oxygenation in some patients with severe respiratory or heart failure. Despite this, iNO has not been found to improve survival. This study aimed to perform a local practice audit to assess the mortality predictors of critically ill patients who had received iNO as therapy for pulmonary hypertension and respiratory or heart failure. A retrospective audit in a single tertiary centre intensive care unit of patients receiving iNO was conducted between 2004 and 2009. The indications for iNO use, comorbidities, severity of illness, organ function, oxygenation, Sequential Organ Failure Assessment scores, patterns of iNO use, adverse events and outcomes were reviewed. In 215 patients receiving iNO, improvement in oxygenation after one hour from iNO commencement did not predict either intensive care unit (P = 0.36) or hospital (P = 0.72) mortality. The independent risk factors for intensive care unit mortality were worsening Sequential Organ Failure Assessment scores within 24 hours of commencing iNO (adjusted odds ratio 1.07, 95% confidence interval 1.05 to 1.18), the Charlson Comorbidity Score (adjusted odds ratio 1.49, 95% confidence interval 1.16 to 1.91) and the peak methaemoglobin concentration in arterial blood while receiving iNO (adjusted odds ratio 2.67, 95% confidence interval 1.42 to 4.96). Inhaled nitric oxide as salvage therapy for severe respiratory failure in critically ill patients is not routinely justified. Increased methaemoglobin concentration during iNO therapy, even when predominantly less than 3%, is associated with increased mortality.

Determining authorship in multicenter trials: a systematic review.

The practical and ethical issues in determining authorship in multicenter trials raise significant and unique challenges. This systematic review examines methods of assigning authorship in multicenter clinical trials. A literature search (October 2009) was conducted to identify articles with the terms 'authorship' and 'clinical trial,' 'multicenter' or 'multicentre.' Abstracts were reviewed for potential relevance and the complete manuscript was obtained where indicated. Additional articles were identified by a review of the reference list from sourced articles. Methods for determining authorship were reviewed in terms of practicality, fairness and the time course for decision-making. Eight methods for determining authorship were identified: four used a scoring system, two articles contained guidelines with reference to scoring systems and two articles outlined general guidelines. All methods attempted to provide a fair and practical approach and appeared to achieve this to varying degrees. No one method was applicable across all multicenter trials. The authors propose a guide for determining authorship based on the methods identified and the number of collaborators and anticipated publications. For smaller collaborative groups (e.g. <10 persons), byline inclusion of all authors based on relative contributions is recommended. For larger collaborations (e.g. ≥ 10 persons), authorship guidelines should be explicit from the outset of the trial with consideration of relevant scoring systems.

The role of surveillance cultures in the prediction of susceptibility patterns of Gram-negative bacilli in the intensive care unit.

Surveillance cultures may detect colonisation with drug-resistant Gram-negative bacteria and can be hypothesised to guide appropriate initial antibiotic treatment for intensive care unit (ICU) patients. We investigated the microbiological data of 228 episodes of nosocomial bloodstream infection (BSI) due to Gram-negative bacteria in an ICU in which piperacillin/tazobactam or meropenem was used empirically for serious infections, to evaluate the contribution of surveillance cultures to an appropriate choice of initial antibiotic therapy. Surveillance cultures were taken in advance of BSI in 218 (95.6%) of 228 episodes. Concordant organisms with identical identification and susceptibilities were found in prior surveillance cultures and subsequent blood cultures in 65 (29.8%) of 218 episodes. Surveillance cultures predicted resistance in 52.9% and 51.4% of BSIs caused by resistant pathogens to piperacillin/tazobactam and meropenem, respectively. The negative predictive value of surveillance cultures negative for a resistant organism also exceeded 90% for piperacillin/tazobactam and meropenem. Given that the overall resistant rates of BSI pathogens of our study were 11.3% to piperacillin/tazobactam and 16.4% to meropenem, surveillance cultures in our setting may provide important information on the probability of drug resistance of the causative pathogens and some utility in aiding empiric antibiotic therapy for ICU patients who subsequently develop BSI.

Can learning to sustain life be BASIC? Teaching for the initial management of the critically ill in Australia and New Zealand.

Commonly in Australia and New Zealand, initial intensive care support of critically ill patients is by non-intensive care trained medical and nursing staff Basic Assessment and Support in Intensive Care (BASIC) is an internationally run short course to assist practitioners to gain knowledge and skills to manage the early hours of critical illness. The aim of this study was to assess the performance and acceptance of the BASIC course as conducted in an Australian metropolitan teaching hospital and a major regional centre in New Zealand. Performance on pre- and post-course multiple choice examinations and the overall course assessment by all participants attending between 2005 and 2009 was analysed. Of 796 participants, 338 (42%) were in Australia and 458 (58%) in New Zealand. Compared to New Zealand, Australian non-intensive care consultants and junior medical staff attended more commonly at 9% vs 4% and 62% vs 42% respectively, while nurses more frequently attended in New Zealand (47% compared to 12%, P < 0.001). The pre-course open book examination result averaged 79% (95% confidence interval 78 to 80) and the post-course closed book examination was 64% (95% confidence interval 63 to 65). The post-course examination score was predicted by pre-course examination score (beta = 0.22, 95% confidence interval 0.17 to 0.27), nursing occupation, (beta = -3.96, 95% confidence interval -5.03 to -2.90) and the availability of a scenario-based simulation module (beta = 0.22, 95% confidence interval 0.17 to 0.27, R2 = 0.38, P < 0.001). Participants generally found they had learned a great deal from the program and that the course material was of an appropriate level. The BASIC course was found to be a positive learning experience for health care practitioners inexperienced in the management of the critically ill.

They just don't get enough! Variable intern experience in bedside procedural skills.

BACKGROUND: Medical school and resident training programmes offer different learning opportunities and outcomes. The aim of the study was to assess medical student and intern experience in common clinical procedures. METHODS: Interns employed in a metropolitan teaching hospital from 2000 to 2004 completed a survey of experience and confidence in clinical procedures at the beginning and end of their intern year. Attendance at and the contribution to procedural confidence of a voluntary procedural skill-training programme were examined. RESULTS: For the 314 interns, clinical experience before and during internship varied for each procedure and between year cohorts as did training programme attendance (44-84%). Student procedural confidence was predicted by pre-intern experience either on patients or by simulation (beta = 0.17, 95% confidence interval (CI) 0.02-0.21, P = 0.03) and age >30 years on commencing internship (beta = 8.44, 95%CI 3.03-14.06, P = 0.003. Adjusted R(2) = 0.08, P = 0.002). Intern procedural confidence by year's end was predicted by attendance at the training programme (beta = 0.48, 95%CI 0.34-0.62, P < 0.001), intern experience with patient procedures (beta = 0.34, 95%CI 0.21-0.47, P < 0.001) and a clear decision to enter a postgraduate training programme (beta = 0.13, 95%CI 0.04-0.22, P = 0.007, Adjusted R(2) = 0.50, P < 0.001). CONCLUSION: Interns and students receive variable experience to carry out procedural skills on patients. This makes designing training programmes difficult as training needs vary each year. Both mandatory supervision of key skills and opportunities to supplement limited experience are needed during the intern year to ensure a uniform experience.

Lessons learnt in the pharmacokinetic analysis of the effect of haemoperfusion for acute overdose with sustained-release diltiazem.

The effect of charcoal haemoperfusion on the pharmacokinetics of diltiazem is described in a patient with severe clinical toxicity following acute overdose. The patient presented within 3 h following acute ingestion of multiple medications including sustained-release diltiazem. Routine resuscitation and supportive care were administered, but hypotension did not resolve despite intravenous fluids and infusions of calcium, adrenaline, noradrenaline and vasopressin. Multiple-doses of activated charcoal, haemodialysis and charcoal haemoperfusion were prescribed to expedite the elimination of diltiazem. The maximum diltiazem concentration (577 microg.l(-1)) was recorded 7 h post ingestion which was followed by an erratic and prolonged elimination phase. The maximum clearance of diltiazem due to haemoperfusion was calculated to be 19.4 and 15.1 ml.min(-1) at different times, equating to removal of approximately 1.5 mg diltiazem during 4 h of haemoperfusion. Haemoperfusion did not appear to remove sufficient diltiazem to recommend its routine use in the treatment of patients with acute diltiazem overdose.

Fire-eater's lung.

Hydrocarbon aspiration from fire-eating can result in severe necrotising pneumonia with complex cyst formation and large pleural effusions. Despite this, there is usually minimal persistent lung injury. We report the progress of two clinical cases, one of whom is the first reported case of citronella oil aspiration.

An unusual case of intra-abdominal apoplexy.

Abdominal apoplexy is an uncommon disorder typically due to atheromatous vascular disease, inflammatory processes such as pancreatitis eroding into large blood vessels or vasculitis. We describe an unusual case due to unrecognised syphilis masquerading as pancreatitis.

Missed foreign body and nessitans empyema.

A recurrent empyema over a three-month period ultimately presented as an empyema necessitans (an empyema pointing through the skin) due to Fusobacterium varium. The recurrence of the empyema was due to an animal vertebra aspirated, during a bar-room altercation, into the right main bronchus, mimicking an endobronchial tumour.

Difficult decisions in the intensive care unit: an illustrative case.

Difficult clinical decision-making is a common experience in intensive care units. There is often considerable pressure on time and decisions may have to be made in a stressful environment. Patients in the intensive care unit not infrequently present with extreme or rare manifestations of a disease process. Clinical evidence to guide management of such patients may be incomplete, non-existent, or its relevance to the problem at hand may be questionable. In this context, formal decision-making analytical tools are often impractical. Unconscious cognitive biases have been shown to play an important role in medical decision-making, particularly in these settings. While mostly these contribute to doctors making appropriate and timely decisions, occasionally they lead to errors. Despite 30 years of research into models of clinical reasoning, most doctors are unaware of how biases affect their thinking and are unfamiliar with techniques of detecting and neutralising bias in clinical practice. We present the case of a patient with Wegener's granulomatosis, which highlights many of the difficulties outlined above. We review the clinical evidence for our decisions at each stage and explain the rationale for our choices, highlighting the many situations for which high quality evidence was lacking. Examples of cognitive bias are identified and techniques of metacognition (thinking about thinking) that can be useful in limiting the effects of bias on complex decision-making are reviewed. The intensivist's evaluation of management alternatives has an important role in steering medical management towards optimal patient outcomes.

Use of elastin fibres detected in non-directed low volume bronchial lavage in ventilated ICU patients.

Elastin fibres in sputum have been described as a more sensitive marker of pulmonary necrosis than plain chest X-rays. This study aimed to determine the prevalence of elastin fibres using non-directed non-protected mini-bronchoalveolar lavage (BM-BAL) in mechanically ventilated patients in the intensive care unit. Patients admitted to the general intensive care unit of a tertiary referral hospital requiring more than 48 hours of mechanical ventilation had surveillance BM-BAL performed on admission and were then examined weekly using potassium hydroxide wet preparations for the presence of elastin fibres. All positive and a random selection of 16 negative preparations from patients with acute respiratory distress syndrome or pneumonia were fixed and examined using Weigert's staining method for elastin. Of 412 patients enrolled, 130 (32%) had pneumonia on admission, 50 (12%) developed 58 episodes of ventilator-associated pneumonia and acute respiratory distress syndrome was diagnosed in 86 patients (21%). No chest X-ray showed cavitating infiltrates. Of 985 specimens examined, only seven had elastin fibres. Elastin fibres are uncommonly found using BM-BAL in general screening, acute respiratory distress syndrome or pneumonia in the intensive care unit, the incidence too low to be a useful indicator of pulmonary necrosis.

The entrapped central venous catheter.

The central venous catheter (CVC) is associated with numerous complications more so during the process of insertion. We report for the first time how an indwelling catheter was entrapped by a replacement catheter on the same side, after being speared by the introducer needle and guidewire. The diagnosis was made when there was difficulty in removing the old catheter. Subsequently, interventional radiology services were used to define the problem and help in removal of the entrapped catheter. The mechanism of entrapment and the actual procedure used for removal of the catheter is described. The dangers of insertion of a CVC on the same side as a pre-existing one are highlighted.

Near-hanging as presenting to hospitals in Queensland: recommendations for practice.

Near-hanging is an increasing presentation to hospitals in Australasia. We reviewed the clinical management and outcome of these patients as they presented to public hospitals in Queensland. A retrospective clinical record audit was made at five public hospitals between 1991 and 2000. Of 161 patients enrolled, 82% were male, 8% were indigenous and 10% had made a previous hanging attempt. Chronic medical illnesses were documented in 11% and previous psychiatric disorders in 42%. Of the 38 patients with a Glasgow Coma Scale score (GCS) of 3 on arrival at hospital, 32% returned to independent living and 63% died. Fifty-two patients received CPR, of whom 46% had an independent functional outcome. Independent predictors of mortality were a GCS on hospital arrival of 3 (AOR 150, CI 95% 12.4-1818, P<0.001), taking plain X-rays of the cervical spine (AOR 0.06, CI 95% 0.004-0.97, P=0.047) and contact with the ground (AOR 0.03, CI 95% 0.002-0.62, P=0.02). Only 66% had imaging of the cervical spine performed with other imaging performed infrequently. There were three laryngeal, two hyoid bone and three cervical spine injuries and one carotid dissection. The number of cervical spine X-rays required to find a significant cervical spine fracture was 54. Near-hanging presenting to hospital with a poor conscious state or even cardiac arrest can have a favourable clinical outcome. Radiological investigations are infrequently performed despite a low GCS precluding early accurate assessment. Given the general favourable outcome, an aggressive approach to searching for correctable injuries is recommended.