Helen Opdam

Prospective controlled trial of effect of medical emergency team on postoperative morbidity and mortality rates

ObjectiveTo determine whether the introduction of an intensive care unit-based medical emergency team, responding to hospital-wide preset criteria of physiologic instability, would decrease the rate of predefined adverse outcomes in patients having major surgery. DesignProspective, controlled before-and-after trial. SettingUniversity-affiliated hospital. PatientsConsecutive patients admitted to hospital for major surgery during a 4-month control phase and during a 4-month intervention phase. InterventionsIntroduction of a hospital-wide intensive care unit-based medical emergency team to evaluate and treat in-patients deemed at risk of developing an adverse outcome by nursing, paramedical, and/or medical staff. Measurements and Main ResultsWe measured incidence of serious adverse events, mortality after major surgery, and mean duration of hospital stay. There were 1,369 operations in 1,116 patients during the control period and 1,313 in 1,067 patients during the medical emergency team intervention period. In the control period, there were 336 adverse outcomes in 190 patients (301 outcomes/1,000 surgical admissions), which decreased to 136 in 105 patients (127 outcomes/1,000 surgical admissions) during the intervention period (relative risk reduction, 57.8%; p < .0001). These changes were due to significant decreases in the number of cases of respiratory failure (relative risk reduction, 79.1%; p < .0001), stroke (relative risk reduction, 78.2%; p = .0026), severe sepsis (relative risk reduction, 74.3%; p = .0044), and acute renal failure requiring renal replacement therapy (relative risk reduction, 88.5%; p < .0001). Emergency intensive care unit admissions were also reduced (relative risk reduction, 44.4%; p = .001). The introduction of the medical emergency team was also associated with a significant decrease in the number of postoperative deaths (relative risk reduction, 36.6%; p = .0178). Duration of hospital stay after major surgery decreased from a mean of 23.8 days to 19.8 days (p = .0092). ConclusionsThe introduction of an intensive care unit-based medical emergency team in a teaching hospital was associated with a reduced incidence of postoperative adverse outcomes, postoperative mortality rate, and mean duration of hospital stay.

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.

Percutaneous versus surgical tracheostomy: A randomized controlled study with long-term follow-up*

Objective:To compare the safety, availability, and long-term sequelae of percutaneous vs. surgical tracheostomy. Design:Prospective, randomized, controlled study. Setting:Combined medical/surgical intensive care unit in a tertiary referral hospital. Patients:Two hundred critically ill mechanically ventilated patients who required tracheostomy. Interventions:Tracheostomy by either percutaneous tracheostomy or surgical tracheostomy performed in the intensive care unit. Measurements and Main Results:The primary outcome measure was the aggregate incidence of predefined moderate or severe complications. The secondary outcome measures were the incidence of each of the components of the primary outcome. Long-term follow-up included clinical assessment, flow volume loops, and bronchoscopy. Both groups were well matched for age, gender, admission Acute Physiology and Chronic Health Evaluation II score, period of endotracheal intubation, reason for intubation, and admission diagnosis. There was no statistical difference between groups for the primary outcome. Bleeding requiring surgical intervention occurred in three percutaneous tracheostomy patients and in no surgical tracheostomy patient (p = .2). Postoperative infection (p = .044) and cosmetic sequelae (p = .08) were more common in surgical tracheostomy patients. There was a shorter delay from randomization to percutaneous tracheostomy vs. surgical tracheostomy (p = .006). Long-term follow-up revealed no complications in either group. Conclusions:Both percutaneous tracheostomies and surgical tracheostomies can be safely performed at the bedside by experienced, skilled practitioners.

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.

A Sheep Model for the Study of Focal Epilepsy with Concurrent Intracranial EEG and Functional MRI

Summary:  Purpose: We describe a sheep model of penicillin‐induced seizure activity using electroencephalography (EEG) and functional MRI (fMRI).

The acute respiratory management of cervical spinal cord injury in the first 6 weeks after injury: a systematic review.

Study design:Systematic review.Objectives:Identify, evaluate, and synthesize evidence regarding the effectiveness of various treatment strategies for the respiratory management of acute tetraplegia.Setting:Melbourne, Australia.Methods:A search of multiple electronic databases (Medline, Cinahl, EMBASE, Cochrane Library, Web of Science, http://www.guideline.gov and http://www.icord.org/scire) was undertaken accompanied by the reference lists of all relevant articles identified. Methodological quality was assessed using the Newcastle–Ottawa Scale and the PEDro Scale. Descriptive analysis was performed.Results:Twenty-one studies including 1263 patients were identified. The majority of the studies were case series (n=13). A variety of interventions were used for the management of respiratory complications. Mortality (ARR=0.4, 95% confidence interval (CI) 0.18, 0.61), the incidence of respiratory complications (ARR=0.36, 95% CI (0.08, 0.58)), and requirement for a tracheostomy (ARR=0.18, 95% CI (−0.05, 0.4)) were significantly reduced by using a respiratory protocol. A clinical pathway reduced duration of mechanical ventilation by 6 days 95% CI (−0.56, 12.56), intensive care unit length of stay by 6.8 days 95% CI (0.17–13.77) and costs. Intubation, mechanical ventilation, and tracheostomy are the mainstay of respiratory management for complete injuries above the level of C5.Conclusion:This review showed a clinical pathway with a structured respiratory protocol that includes a combination of treatment techniques provided regularly is effective in reducing respiratory complications and cost. The overall study quality was moderate and further studies using specific interventions that target respiratory complications are associated with specific regions of the cervical spine using more methodologically rigorous designs are required.

Brief breath holding may confound functional magnetic resonance imaging studies.

We demonstrate that breath holding of short durations may confound functional magnetic resonance imaging (fMRI) studies. Some subjects may hold their breath for a short time during task performance, especially if the task is challenging. Breath holding may therefore need to be considered specifically when interpreting fMRI experiments. We studied the temporal and spatial characteristics of cerebral T2*‐weighted signal during short periods of breath holding by seven individuals in a 3‐tesla MR scanner. We demonstrate that breath‐holds as short as 3 s can result in regions of significant cerebral activation. More interestingly, we show that focal activation remains present when the data is analysed in a number of different ways, including analyses that correct for motion and model the task epoch as if it were 10 times longer than the actual breath‐hold length. These findings have potential relevance for many researchers carrying out fMRI studies. Hum. Brain Mapping 24:284–290, 2005.

Identifying the potential organ donor: an audit of hospital deaths

ObjectiveTo quantify the potential for organ donation in Victoria and identify missed opportunities for organ donation.Design and settingProspective medical record audit of all deaths in 12 Victorian hospitals.MeasurementsData on deaths, total potential donors, organ donors and outcome of requests for organ donation were collected. Patients in whom brain death was confirmed or likely to occur and in whom organ donation was not requested (unrealised potential donors) were classified by an independent panel. Rates of organ donation and unrealised donors were determined as a proportion of total potential donors and hospital deaths and the maximal potential organ donor rate was estimated.ResultsOf 5551 deaths, there were 112 potential donors, with 66 requests for organ donation resulting in 39 consents (consent rate of 59%) and 37 organ donors (33% of total potential donors; 0.7% of hospital deaths). Two consented potential donors did not donate due to failed physiological support (5%). There were 46 medically suitable unrealised potential donors; 3 with confirmed brain death. Approximately half of these patients had treatment withdrawn in the intensive care unit and half in the Emergency Department. The estimated maximal potential donor rate was 30 per million population.ConclusionsThe potential for organ donation in Victoria is relatively low compared with previous estimates in Australia and overseas. An increase in the organ donation rate may be possible through increasing consent and the identification and support of potential donors. This would require substantial changes in clinical practice that have resource and ethical implications.

An assessment of early tracheostomy after anterior cervical stabilization in patients with acute cervical spine trauma.

BACKGROUND The optimal timing of tracheostomy after anterior cervical spine surgery remains controversial because of the potential for deep infection. The aims of this study were to compare the infection rates in patients requiring tracheostomy who underwent anterior versus posterior cervical spine surgery, and to report the timing of tracheostomy tube placement in such patients. METHOD All patients admitted to a referral Intensive Care Unit for spinal trauma from January 1998 until May 2005, who underwent surgical stabilization with instrumentation and also received a tracheostomy, were retrospectively evaluated for demographic data, severity of neurologic injury, and complications including infection to a surgical site and timing and type of tracheostomy procedure. RESULTS We identified 71 patients, all who had a diagnosis of acute cervical spine injury. Thirty-two (45%) underwent anterior stabilization, 15 (21%) had posterior stabilizations, and 24 (34%) required both anterior and posterior approaches. The mean time from stabilization to tracheostomy for an anterior approach was 3.8 +/- 2.6 days. There was no significant difference in the timing of tracheostomy for different surgical approaches. Seventeen patients (25%) had a positive culture of their cervical and or tracheostomy incision site. Only one patient, however, had infection with the same organism at both the tracheostomy site and the anterior stabilization site. Suspected infection was managed with antibiotics and no further surgical intervention was required. CONCLUSIONS Early tracheostomy after spinal stabilization is associated with a low risk of infection even after the anterior approach.

A classification and regression tree to assist clinical decision making in airway management for patients with cervical spinal cord injury

Study design:This was a prospective observational study.Objectives:To review airway management of patients with acute cervical spinal cord injury (CSCI) who are admitted to the intensive care unit (ICU) and to develop a classification and regression tree (CART) to direct clinical decision making in airway management.Setting:This study was carried out in Australia.Methods:All patients with CSCI who required intubation and mechanical ventilation and who were admitted to ICU in three tertiary hospitals in Melbourne between October 2004 and May 2009 and two other interstate hospitals between December 2004 and December 2005 were included. Airway management was recorded.Results:A total of 114 patients were included. Tracheostomy insertion occurred in 68 patients (59.7%). Using CART analysis, it was found that the variables forced vital capacity, the volume of pulmonary secretion and gas exchange were predictive of airway management on 82.3% occasions with an 8.7% extubation failure rate.Conclusion:A CART can be useful in clinical decision making regarding airway management in CSCI.