Samantha Bates

An assessment of the RIFLE criteria for acute renal failure in hospitalized patients

Objective:The Acute Dialysis Quality Initiative (ADQI) Group published a consensus definition (the RIFLE criteria) for acute renal failure. We sought to assess the ability of the RIFLE criteria to predict mortality in hospital patients. Design:Retrospective single-center study. Setting:University-affiliated hospital. Patients:All patients admitted to the study hospital between January 2000 and December 2002. Patients were excluded if they were younger than 15 yrs old, were on chronic dialysis, or had kidney transplant or if their length of hospital stay was <24 hrs. Interventions:None. Measurements and Main Results:We included 20,126 patients. Mean age was 64 yrs, 14.7% of patients required intensive care unit admission, and hospital mortality was 8.0%. According to the RIFLE criteria, 9.1% of all patients were in the Risk category for acute renal failure, 5.2% were in the Injury category, and 3.7% were in the Failure category. There was an almost linear increase in hospital mortality from Normal to Failure (Normal, 4.4%; Risk, 15.1%; Injury, 29.2%; and Failure, 41.1%). Multivariate logistic regression analysis showed that all RIFLE criteria were significantly predictive factors for hospital mortality, with an almost linear increase in odds ratios from Risk to Failure (odds ratios, Risk 2.5, Injury 5.4, Failure 10.1). Conclusions:The RIFLE criteria for acute renal failure classified close to 20% of our study patients as having some degrees of acute impairment in renal function and were useful in predicting their hospital mortality.

Long term effect of a medical emergency team on cardiac arrests in a teaching hospital

IntroductionIt is unknown whether the reported short-term reduction in cardiac arrests associated with the introduction of the medical emergency team (MET) system can be sustained.MethodWe conducted a prospective, controlled before-and-after examination of the effect of a MET system on the long-term incidence of cardiac arrests. We included consecutive patients admitted during three study periods: before the introduction of the MET; during the education phase preceding the implementation of the MET; and a period of four years from the implementation of the MET system. Cardiac arrests were identified from a log book of cardiac arrest calls and cross-referenced with case report forms and the intensive care unit admissions database. We measured the number of hospital admissions and MET reviews during each period, performed multivariate logistic regression analysis to identify predictors of mortality following cardiac arrest and studied the correlation between the rate of MET calls with the rate of cardiac arrests.ResultsBefore the introduction of the MET system there were 66 cardiac arrests and 16,246 admissions (4.06 cardiac arrests per 1,000 admissions). During the education period, the incidence of cardiac arrests decreased to 2.45 per 1,000 admissions (odds ratio (OR) for cardiac arrest 0.60; 95% confidence interval (CI) 0.43–0.86; p = 0.004). After the implementation of the MET system, the incidence of cardiac arrests further decreased to 1.90 per 1,000 admissions (OR for cardiac arrest 0.47; 95% CI 0.35–0.62; p < 0.0001). There was an inverse correlation between the number of MET calls in each calendar year and the number of cardiac arrests for the same year (r2 = 0.84; p = 0.01), with 17 MET calls being associated with one less cardiac arrest. Male gender (OR 2.88; 95% CI 1.34–6.19) and an initial rhythm of either asystole (OR 7.58; 95% CI 3.15–18.25; p < 0.0001) or pulseless electrical activity (OR 4.09; 95% CI 1.59–10.51; p = 0.003) predicted an increased risk of death.ConclusionIntroduction of a MET system into a teaching hospital was associated with a sustained and progressive reduction in cardiac arrests over a four year period. Our findings show sustainability and suggest that, for every 17 MET calls, one cardiac arrest might be prevented.

Dexmedetomidine vs. haloperidol in delirious, agitated, intubated patients: a randomised open-label trial.

IntroductionAgitated delirium is common in patients undergoing mechanical ventilation, and is often treated with haloperidol despite concerns about safety and efficacy. Use of conventional sedatives to control agitation can preclude extubation. Dexmedetomidine, a novel sedative and anxiolytic agent, may have particular utility in these patients. We sought to compare the efficacy of haloperidol and dexmedetomidine in facilitating extubation.MethodsWe conducted a randomised, open-label, parallel-groups pilot trial in the medical and surgical intensive care unit of a university hospital. Twenty patients undergoing mechanical ventilation in whom extubation was not possible solely because of agitated delirium were randomised to receive an infusion of either haloperidol 0.5 to 2 mg/hour or dexmedetomidine 0.2 to 0.7 μg/kg/hr, with or without loading doses of 2.5 mg haloperidol or 1 μg/kg dexmedetomidine, according to clinician preference.ResultsDexmedetomidine significantly shortened median time to extubation from 42.5 (IQR 23.2 to 117.8) to 19.9 (IQR 7.3 to 24) hours (P = 0.016). Dexmedetomidine significantly decreased ICU length of stay, from 6.5 (IQR 4 to 9) to 1.5 (IQR 1 to 3) days (P = 0.004) after study drug commencement. Of patients who required ongoing propofol sedation, the proportion of time propofol was required was halved in those who received dexmedetomidine (79.5% (95% CI 61.8 to 97.2%) vs. 41.2% (95% CI 0 to 88.1%) of the time intubated; P = 0.05). No patients were reintubated; three receiving haloperidol could not be successfully extubated and underwent tracheostomy. One patient prematurely discontinued haloperidol due to QTc interval prolongation.ConclusionsIn this preliminary pilot study, we found dexmedetomidine a promising agent for the treatment of ICU-associated delirious agitation, and we suggest this warrants further testing in a definitive double-blind multi-centre trial.Trial registrationClinicaltrials.gov NCT00505804

Myoglobin clearance by super high-flux hemofiltration in a case of severe rhabdomyolysis: a case report

ObjectiveTo test the ability of a novel super high-flux (SHF) membrane with a larger pore size to clear myoglobin from serum.SettingThe intensive care unit of a university teaching hospital.SubjectA patient with serotonin syndrome complicated by severe rhabodomyolysis and oliguric acute renal failureMethodInitially continuous veno-venous hemofiltration was performed at 2 l/hour ultrafiltration (UF) with a standard polysulphone 1.4 m2 membrane (cutoff point, 20 kDa), followed by continuous veno-venous hemofiltration with a SHF membrane (cutoff point, 100 kDa) at 2 l/hour UF, then at 3 l/hour UF and then at 4 l/hour UF, in an attempt to clear myoglobin.ResultsThe myoglobin concentration in the ultrafiltrate at 2 l/hour exchange was at least five times greater with the SHF membrane than with the conventional membrane (>100,000 μg/l versus 23,003 μg/l). The sieving coefficients with the SHF membrane at 3 l/hour UF and 4 l/hour UF were 72.2% and 68.8%, respectively. The amount of myoglobin removed with the conventional membrane was 1.1 g/day compared with 4.4–5.1 g/day for the SHF membrane. The SHF membrane achieved a clearance of up to 56.4 l/day, and achieved a reduction in serum myoglobin concentration from >100,000 μg/l to 16,542 μg/l in 48 hours.ConclusionsSHF hemofiltration achieved a much greater clearance of myoglobin than conventional hemofiltration, and it may provide a potential modality for the treatment of myoglobinuric acute renal failure.

Circadian pattern of activation of the medical emergency team in a teaching hospital

IntroductionHospital medical emergency teams (METs) have been implemented to reduce cardiac arrests and hospital mortality. The timing and system factors associated with their activation are poorly understood. We sought to determine the circadian pattern of MET activation and to relate it to nursing and medical activities.MethodWe conducted a retrospective observational study of the time of activation for 2568 incidents of MET attendance. Each attendance was allocated to one of 48 half-hour intervals over the 24-hour daily cycle. Activation was related nursing and medical activities.ResultsDuring the study period there were 120,000 consecutive overnight medical and surgical admissions. The hourly rate of MET calls was greater during the day (47% of calls in the 10 hours between 08:00 and 18:00), but 53% of the 2568 calls occurred between 18:00 and 08:00 hours. MET calls increased in the half-hour after routine nursing observation, and in the half-hour before each nursing handover. MET service utilization was 1.25 (95% confidence interval [CI] = 1.11–1.52) times more likely in the three 1-hour periods spanning routine nursing handover (P = 0.001). The greatest level of half-hourly utilization was seen between 20:00 and 20:30 (odds ratio [OR] = 1.76, 95% CI = 1.25–2.48; P = 0.001), before the evening nursing handover. Additional peaks were seen following routine nursing observations between 14:00 and 14:30 (OR = 1.53, 95% CI = 1.07–2.17; P = 0.022) and after the commencement of the daily medical shift (09:00–09:30; OR = 1.43, 95% CI = 1.00–2.04; P = 0.049).ConclusionPeak levels of MET service activation occur around the time of routine observations and nursing handover. Our findings raise questions about the appropriate frequency and methods of observation in at-risk hospital patients, reinforce the need for adequately trained medical staff to be available 24 hours per day, and provide useful information for allocation of resources and personnel for a MET service.

Effect of an education programme on the utilization of a medical emergency team in a teaching hospital.

Background: Medical Emergency Teams (MET) have been developed to identify, review and manage acutely unwell ward patients. Previous studies have suggested that there may be obstacles to the utilization and activation of the MET.

Auditing Operating Room Recycling: A Management Case Report.

Much waste arises from operating rooms (ORs). We estimated the practical and financial feasibility of an OR recycling program, weighing all waste from 6 ORs in Melbourne, Australia. Over 1 week, 237 operations produced 1265 kg in total: general waste 570 kg (45%), infectious waste 410 kg (32%), and recyclables 285 kg (23%). The achieved recycling had no infectious contamination. The achieved recycling/potential recycling rate was 285 kg/517 kg (55%). The average waste disposal costs were similar for general waste and recycling. OR recycling rates of 20%-25% total waste were achievable without compromising infection control or financial constraints.