Daryl Jones

Extracorporeal Membrane Oxygenation for 2009 Influenza A(H1N1) Acute Respiratory Distress Syndrome.

CONTEXT The novel influenza A(H1N1) pandemic affected Australia and New Zealand during the 2009 southern hemisphere winter. It caused an epidemic of critical illness and some patients developed severe acute respiratory distress syndrome (ARDS) and were treated with extracorporeal membrane oxygenation (ECMO). OBJECTIVES To describe the characteristics of all patients with 2009 influenza A(H1N1)-associated ARDS treated with ECMO and to report incidence, resource utilization, and patient outcomes. DESIGN, SETTING, AND PATIENTS An observational study of all patients (n = 68) with 2009 influenza A(H1N1)-associated ARDS treated with ECMO in 15 intensive care units (ICUs) in Australia and New Zealand between June 1 and August 31, 2009. MAIN OUTCOME MEASURES Incidence, clinical features, degree of pulmonary dysfunction, technical characteristics, duration of ECMO, complications, and survival. RESULTS Sixty-eight patients with severe influenza-associated ARDS were treated with ECMO, of whom 61 had either confirmed 2009 influenza A(H1N1) (n = 53) or influenza A not subtyped (n = 8), representing an incidence rate of 2.6 ECMO cases per million population. An additional 133 patients with influenza A received mechanical ventilation but no ECMO in the same ICUs. The 68 patients who received ECMO had a median (interquartile range [IQR]) age of 34.4 (26.6-43.1) years and 34 patients (50%) were men. Before ECMO, patients had severe respiratory failure despite advanced mechanical ventilatory support with a median (IQR) Pao(2)/fraction of inspired oxygen (Fio(2)) ratio of 56 (48-63), positive end-expiratory pressure of 18 (15-20) cm H(2)O, and an acute lung injury score of 3.8 (3.5-4.0). The median (IQR) duration of ECMO support was 10 (7-15) days. At the time of reporting, 48 of the 68 patients (71%; 95% confidence interval [CI], 60%-82%) had survived to ICU discharge, of whom 32 had survived to hospital discharge and 16 remained as hospital inpatients. Fourteen patients (21%; 95% CI, 11%-30%) had died and 6 remained in the ICU, 2 of whom were still receiving ECMO. CONCLUSIONS During June to August 2009 in Australia and New Zealand, the ICUs at regional referral centers provided mechanical ventilation for many patients with 2009 influenza A(H1N1)-associated respiratory failure, one-third of whom received ECMO. These ECMO-treated patients were often young adults with severe hypoxemia and had a 21% mortality rate at the end of the study period.

Rapid-Response Teams

Rapid-response teams aim to care for inpatients in whom acute respiratory, neurologic, or cardiac insufficiency is developing. This review describes the prevalence and consequences of sudden critical illness outside the ICU and discusses the rationale for rapid-response systems.

Epidemiology and 12-month outcomes from traumatic brain injury in Australia and New Zealand

BACKGROUND An epidemiologic profile of traumatic brain injury (TBI) in Australia and New Zealand was obtained following the publication of international evidence-based guidelines. METHODS Adult patients with TBI admitted to the intensive care units (ICU) of major trauma centers were studied in a 6-month prospective inception cohort study. Data including mechanisms of injury, prehospital interventions, secondary insults, operative and intensive care management, and outcome assessments 12-months postinjury were collected. RESULTS There were 635 patients recruited from 16 centers. The mean (+/-SD) age was 41.6 years +/- 19.6 years; 74.2% were men; 61.4% were due to vehicular trauma, 24.9% were falls in elderly patients, and 57.2% had severe TBI (Glasgow Coma Scale score </=8). Secondary brain insults were recorded in 28.5% and 34.8% underwent neurosurgical procedures before ICU admission. There was concordance with TBI and ICU practice guidelines, although intracranial pressure monitoring was used in 44.5% patients with severe TBI. Twelve-month mortality was 26.9% in all patients and 35.1% in patients with severe TBI. Favorable outcomes at 12 months were recorded in 58.8% of all patients and in 48.5% of patients with severe TBI. CONCLUSIONS In Australia and New Zealand, mortality and favorable neurologic outcomes after TBI were similar to published data before the advent of evidence-based guidelines. A high incidence of prehospital secondary brain insults and an ageing population may have contributed to these outcomes. Strategies to improve outcomes from TBI should be directed at preventive public health strategies and interventions to minimize secondary brain injuries in the prehospital period.

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.

Nurses’ attitudes to a medical emergency team service in a teaching hospital

Background: Cultural barriers including allegiance to traditional models of ward care and fear of criticism may restrict use of a medical emergency team (MET) service, particularly by nursing staff. A 1-year preparation and education programme was undertaken before implementing the MET at the Austin Hospital, Melbourne, Australia. During the 4 years after introduction of the MET, the programme has continued to inform staff of the benefits of the MET and to overcome barriers restricting its use. Objective: To assess whether nurses value the MET service and to determine whether barriers to calling the MET exist in a 400-bed teaching hospital. Methods: Immediately before hand-over of ward nursing, we conducted a modified personal interview, using a 17-item Likert agreement scale questionnaire. Results: We created a sample of 351 ward nurses and obtained a 100% response rate. This represents 50.9% of the 689 ward nurses employed at the hospital. Most nurses felt that the MET prevented cardiac arrests (91%) and helped manage unwell patients (97%). Few nurses suggested that they restricted MET calls because they feared criticism of their patient care (2%) or criticism that the patient was not sufficiently unwell to need a MET call (10%). 19% of the respondents indicated that MET calls are required because medical management by the doctors has been inadequate; many ascribed this to junior doctors and a lack of knowledge and experience. Despite hospital MET protocol, 72% of nurses suggested that they would call the covering doctor before the MET for a sick ward patient. However, 81% indicated that they would activate the MET if they were unable to contact the covering doctor. In line with hospital MET protocol, 56% suggested that they would make a MET call for a patient they were worried about even if the patient’s vital signs were normal. Further, 62% indicated that they would call the MET for a patient who fulfilled MET physiological criteria but did not look unwell. Conclusions: Nurses in the Austin Hospital value the MET service and appreciate its potential benefits. The major barrier to calling the MET appears to be allegiance to the traditional approach of initially calling parent medical unit doctors, rather than fear of criticism for calling the MET service. A further barrier seems to be underestimation of the clinical significance of the physiological perturbations associated with the presence of MET call criteria.

Effectiveness of the Medical Emergency Team: the importance of dose.

Up to 17% of hospital admissions are complicated by serious adverse events unrelated to the patients presenting medical condition. Rapid Response Teams (RRTs) review patients during early phase of deterioration to reduce patient morbidity and mortality. However, reports of the efficacy of these teams are varied. The aims of this article were to explore the concept of RRT dose, to assess whether RRT dose improves patient outcomes, and to assess whether there is evidence that inclusion of a physician in the team impacts on the effectiveness of the team. A review of available literature suggested that the method of reporting RRT utilization rate, (RRT dose) is calls per 1,000 admissions. Hospitals with mature RRTs that report improved patient outcome following RRT introduction have a RRT dose between 25.8 and 56.4 calls per 1,000 admissions. Four studies report an association between increasing RRT dose and reduced in-hospital cardiac arrest rates. Another reported that increasing RRT dose reduced in-hospital mortality for surgical but not medical patients. The MERIT study investigators reported a negative relationship between MET-like activity and the incidence of serious adverse events. Fourteen studies reported improved patient outcome in association with the introduction of a RRT, and 13/14 involved a Physician-led MET. These findings suggest that if the RRT is the major method for reviewing serious adverse events, the dose of RRT activation must be sufficient for the frequency and severity of the problem it is intended to treat. If the RRT dose is too low then it is unlikely to improve patient outcomes. Increasing RRT dose appears to be associated with reduction in cardiac arrests. The majority of studies reporting improved patient outcome in association with the introduction of an RRT involve a MET, suggesting that inclusion of a physician in the team is an important determinant of its effectiveness.

Characteristics and outcomes of patients receiving a medical emergency team review for acute change in conscious state or arrhythmias.

Objective: To describe the characteristics and outcomes of patients receiving a medical emergency team (MET) review for the MET syndromes of acute change in conscious state or arrhythmia and to assess the effect of delayed MET activation on their outcomes. Design: Retrospective analysis of medical records. Setting: University teaching hospital. Patients: Two cohorts of 100 patients for each of the MET syndromes of acute change in conscious state or arrhythmia. Interventions: None. Measurements and Main Results: We collected information on patient demographics, comorbidities, and presence of sepsis, hypovolemia, cardiogenic shock, and patient outcome. We also documented the presence and duration of delayed MET activation. The median age for both syndromes was >70 yrs, and major comorbidities were present in >10% of patients. A history of ischemic heart disease (p < .001) and congestive cardiac failure (p = .007) was more common in patients with arrhythmias. Cardiogenic shock and sepsis were common underlying causes of the MET calls for the two groups. However, cardiogenic shock was more common in patients with arrhythmias (p < .001). Hospital mortality was 35% for patients with an acute change in conscious state, compared with 18% for patients with arrhythmias (p = .01). Delayed MET activation occurred in 35% of acute change in conscious state patients and in 24% of arrhythmia patients (p = .09) with a median duration of delay of 16 and 13 hrs, respectively. Delayed MET activation was associated with increased mortality (odds ratio 3.1, 95% confidence interval 1.4–6.6, p = .005). Conclusions: An acute change in conscious state leading to a MET call carried a greater risk of death than activation due to arrhythmias. Delayed activation was common for both syndromes and was independently associated with an increased risk of death.

The role of the medical emergency team in end-of-life care : a multicenter, prospective, observational study

Objective:To investigate the role of medical emergency teams in end-of-life care planning. Design:One month prospective audit of medical emergency team calls. Setting:Seven university-affiliated hospitals in Australia, Canada, and Sweden. Patients:Five hundred eighteen patients who received a medical emergency team call over 1 month. Interventions:None. Measurements and Main Results:There were 652 medical emergency team calls in 518 patients, with multiple calls in 99 (19.1%) patients. There were 161 (31.1%) patients with limitations of medical therapy during the study period. The limitation of medical therapy was instituted in 105 (20.3%) and 56 (10.8%) patients before and after the medical emergency team call, respectively. In 78 patients who died with a limitation of medical therapy in place, the last medical emergency team review was on the day of death in 29.5% of patients, and within 2 days in another 28.2%.Compared with patients who did not have a limitation of medical therapy, those with a limitation of medical therapy were older (80 vs. 66 yrs; p < .001), less likely to be male (44.1% vs. 55.7%; p = .014), more likely to be medical admissions (70.8% vs. 51.3%; p < .001), and less likely to be admitted from home (74.5% vs. 92.2%, p < .001). In addition, those with a limitation of medical therapy were less likely to be discharged home (22.4% vs. 63.6%; p < .001) and more likely to die in hospital (48.4% vs. 12.3%; p < .001). There was a trend for increased likelihood of calls associated with limitations of medical therapy to occur out of hours (51.0% vs. 43.8%, p = .089). Conclusions:Issues around end-of-life care and limitations of medical therapy arose in approximately one-third of calls, suggesting a mismatch between patient needs for end-of-life care and resources at participating hospitals. These calls frequently occur in elderly medical patients and out of hours. Many such patients do not return home, and half die in hospital. There is a need for improved advanced care planning in our hospitals, and to confirm our findings in other organizations.

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.

Australasian resuscitation of sepsis evaluation(ARISE): A multi-centre, prospective, inception cohort study

AIM Determine current resuscitation practices and outcomes in patients presenting to the emergency department (ED) with sepsis and hypoperfusion or septic shock in Australia and New Zealand (ANZ). METHODS Three-month prospective, multi-centre, observational study of all adult patients with sepsis and hypoperfusion or septic shock in the ED of 32 ANZ tertiary-referral, metropolitan and rural hospitals. RESULTS 324 patients were enrolled (mean [SD] age 63.4 [19.2] years, APACHE II score 19.0 [8.2], 52.5% male). Pneumonia (n=138/324, 42.6%) and urinary tract infection (n=98/324, 30.2%) were the commonest sources of sepsis. Between ED presentation and 6hours post-enrolment (T6hrs), 44.4% (n=144/324) of patients received an intra-arterial catheter, 37% (n=120/324) a central venous catheter and 0% (n=0/324) a continuous central venous oxygen saturation (ScvO(2)) catheter. Between enrolment and T6hrs, 32.1% (n=104/324) received a vasopressor infusion, 7.4% (n=24/324) a red blood cell transfusion, 2.5% (n=8/324) a dobutamine infusion and 18.5% (n=60/324) invasive mechanical ventilation. Twenty patients (6.2%) were transferred from ED directly to the operating theatre, 36.4% (n=118/324) were admitted directly to ICU, 1.2% (n=4/324) died in the ED and 56.2% (n=182/324) were transferred to the hospital floor. Overall ICU admission rate was 52.4% (n=170/324). ICU and overall in-hospital mortality were 18.8% (n=32/170) and 23.1% (n=75/324) respectively. In-hospital mortality was not different between patients admitted to ICU (24.7%, n=42/170) and the hospital floor (21.4%, n=33/154). CONCLUSIONS Management of ANZ patients presenting to ED with sepsis does not routinely include protocolised, ScvO(2)-directed resuscitation. In-hospital mortality compares favourably with reported mortality in international sepsis trials and nationwide surveys of resuscitation practices.