The association between peri-operative acute risk change (ARC) and long-term survival after cardiac surgery.

Acute risk change has been described as the difference in calculated mortality risk between the pre-operative and postoperative periods of cardiac surgery. We aimed to assess whether this was associated with long-term survival after cardiac surgery. We retrospectively analysed 22,570 cardiac surgical patients, with minimum and maximum follow-up of 1.0 and 6.7 years. Acute risk change was calculated as the arithmetic difference between pre- and postoperative mortality risk. 'Rising risk' represented an increase in risk from pre- to postoperative phase. The primary outcome was one-year mortality. Secondary outcomes included mortality at 3 and 5 years and time to death. Univariable and multivariable analyses were undertaken to examine the relationship between acute risk change and outcomes. Rising risk was associated with higher mortality (5.6% vs. 3.5%, p < 0.001). After adjusting for baseline risk, rising risk was independently associated with increased 1-year mortality (OR 2.6, 95%CI 2.2-3.0, p < 0.001). The association of rising risk with long-term survival was greatest in patients with highest baseline risk. Cox regression confirmed rising risk was associated with shorter time to death (HR 1.86, 1.68-2.05, p < 0.001). Acute risk change may represent peri-operative clinical events in combination with unmeasured patient risk and noise. Measuring risk change could potentially identify patterns of events that may be amenable to investigation and intervention. Further work with case review, and risk scoring with shared variables, may identify mechanisms, including the interaction between miscalibration of risk and true differences in peri-operative care.

Improved hospital mortality with a low MET dose: the importance of a modified early warning score and communication tool.

Rapid response systems have been mandated for the recognition and management of the deteriorating patient. Increasing medical emergency team (MET) dose may be associated with improved outcomes. Large numbers of MET calls may divert resources from the program providing the service unless additional personnel are provided. To describe the implementation and outcomes of a multifaceted rapid response system (RRS) in a teaching hospital, we conducted an observational study. The RRS consisted of the introduction of a MET together with 1) redesign of the ward observation chart with the vital sign variables colour-coded to identify variation from normal; 2) mandated minimum frequency of vital sign measurement; 3) three formal levels of escalation based on the degree of physiological instability as measured by a modified early warning score (MEWS); 4) COMPASS© education and e-learning package with a two-hour face-to-face small group tutorial; 5) practise in escalation and communication using the ISBAR (Identify, Situation, Background, Assessment, Response/Recommendation) communication tool. The primary outcome measures were all-cause hospital mortality rate and hospital standardised mortality ratio (HSMR) compared to peer hospitals calculated by the Health Round Table. There were 161,153 separations and 1,994 hospital deaths from July 2008 to December 2012. The MET call rate was 11.3 per 1000 separations in 2012. There was a decline in all-cause hospital mortality from 13.8 to 11 deaths/1000 separations. The HSMR decreased from 95.7 in 2008 to 66 in the second half of 2012 (below the three standard deviation control limit). A low MET dose may be associated with improved hospital mortality when combined with a MEWS and an intervention to improve communication.

Acute risk change (ARC) identifies outlier institutions in perioperative cardiac surgical care when the standardized mortality ratio cannot.

BACKGROUND: With improvements in short-term mortality after cardiac surgery, the sensitivity of the standardized mortality ratio (SMR) as a performance-monitoring tool has declined. We assessed acute risk change (ARC) as a new and potentially more sensitive metric to differentiate overall cardiac surgical unit performance. METHODS: Retrospective analysis of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons database and Australian and New Zealand Intensive Care Society Adult Patient Database was performed. The 16 656 patients who underwent coronary artery bypass grafting or cardiac valve procedures during a 4 yr period were included. The ARC was generated using the change between preoperative and postoperative probability of death. Outlier institutions were those with higher (outside 99.8% confidence intervals) ARC or SMR on annual and 4 yr funnel plots. Outliers were grouped and compared with non-outliers for baseline characteristics, intraoperative events, and postoperative morbidity. RESULTS: No outliers were identified using SMR. Two outliers were identified using ARC. Outliers had higher rates of new renal failure (5.7 vs 4.5%, P=0.017), stroke (1.6 vs 0.9%, P=0.001), reoperation (9 vs 6.0%, P<0.001), and prolonged ventilation (15.3 vs 9.5%, P<0.001). Outliers transfused more blood products (P<0.001) and had longer cardiopulmonary bypass times (P<0.001) and less senior surgeons operating (P<0.001). CONCLUSIONS: Acute risk change was able to discriminate between units where SMR could not. Outliers had more adverse events. Acute risk change can be calculated before mortality outcome and identifies outliers with lower patient numbers. This may allow early recognition and investigation of outlier units.

Increased sedation requirements in patients receiving extracorporeal membrane oxygenation for respiratory and cardiorespiratory failure.

Critically ill patients receiving extracorporeal membrane oxygenation (ECMO) are often noted to have increased sedation requirements. However, data related to sedation in this complex group of patients is limited. The aim of our study was to characterise the sedation requirements in adult patients receiving ECMO for cardiorespiratory failure. A retrospective chart review was performed to collect sedation data for 30 consecutive patients who received venovenous or venoarterial ECMO between April 2009 and March 2011. To test for a difference in doses over time we used a regression model. The dose of midazolam received on ECMO support increased by an average of 18 mg per day (95% confidence interval 8, 29 mg, P=0.001), while the dose of morphine increased by 29 mg per day (95% confidence interval 4, 53 mg, P=0.021) The venovenous group received a daily midazolam dose that was 157 mg higher than the venoarterial group (95% confidence interval 53, 261 mg, P=0.005). We did not observe any significant increase in fentanyl doses over time (95% confidence interval 1269, 4337 µg, P=0.94). There is a significant increase in dose requirement for morphine and midazolam during ECMO. Patients on venovenous ECMO received higher sedative doses as compared to patients on venoarterial ECMO. Future research should focus on mechanisms behind these changes and also identify drugs that are most suitable for sedation during ECMO.

Trends in intra-aortic balloon counterpulsation: comparison of a 669 record Australian dataset with the multinational Benchmark Counterpulsation Outcomes Registry.

The aim of this study was to review and describe indications for intraaortic balloon counterpulsation (IABP) use and identify the impact these have on outcomes at an Australian cardiothoracic tertiary referral hospital. A secondary aim was comparison of the Australian practice with a large multinational IABP data registry. Patient demographics, IABP indication, IABP complication rate and mortality in 662 patients treated with IABP at The Prince Charles Hospital (TPCH), Brisbane, between January 1994 and December 2004 inclusive were compared with The Benchmark Counterpulsation Outcomes Registry. Data were collected between 1994 and 2000 by retrospective patient record review and prospectively using the Benchmark database from 2001 to 2004. Statistical analysis was undertaken using SAS (v8.2) software. The mean age of patients managed with IABP at TPCH (71.6% male) was 63.4 years (SD 12.4). In-hospital mortality rate was 22% and the complication rate was 10.3%. TPCH indications for IABP were: weaning from cardiopulmonary bypass (34.2%); cardiogenic shock (24.4%); preoperative support (13%); catheter laboratory support (10.6%); refractory ventricular failure (7.3%); ischaemia related to intractable ventricular arrhythmias (4.5%); unstable refractory angina (4%); mechanical complications due to acute myocardial infarction (1.2%) and other (0.4%) (0.4% not reported). In comparison to Benchmark, IABP at TPCH demonstrated a prejudice toward intraoperative use (34.2% versus 16.6%; P < or = 0.0001) and an aversion to catheter laboratory support (10.6% versus 19%; P < or = 0.0001). TPCH and Benchmark IABP outcomes demonstrated comparable mortality (22% versus 20.8%; P = ns) but increased TPCH complications (10.3% vs. 6.2%; P < or = 0.0001) owing to a 2% difference in observed insertion site bleeding.

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.

Traumatic liver injury complicating cardio-pulmonary resuscitation. The value of a major intensive care facility: a report of two cases.

Complications associated with external cardiac compression include trauma to the heart, chest wall, lungs and gastrointestinal viscera, with gastrointestinal visceral injury including, ruptured stomach, liver, oesophagus, spleen and colon. However, the use of thrombolytics and anticoagulants in patients with an acute myocardial infarction increases the incidence of a visceral haemorrhage when these patients need cardiopulmonary resuscitation. We report two out-of-hospital cardiac arrest patients whose immediate post-resuscitation phase was complicated by hepatic injury and significant haemoperitoneum. Conservative management in a major intensive care unit of both the liver trauma and the induced coagulopathy was associated with a successful outcome in both cases.

Pharmacokinetics of ciprofloxacin in ICU patients on continuous veno-venous haemodiafiltration.

OBJECTIVES: To investigate the pharmacokinetics of intravenous ciprofloxacin 200 mg every 8 h in critically ill patients on continuous veno-venous haemodiafiltration (CVVHDF), one form of continuous renal replacement therapy (CRRT). DESIGN AND SETTING: Open, prospective clinical study in a multidisciplinary, intensive care unit in a university-affiliated tertiary referral hospital. PATIENTS: Six critically ill patients with acute renal failure on CVVHDF. INTERVENTIONS: Timed blood and ultrafiltrate samples were collected to allow pharmacokinetics and clearances to be calculated of initial and subsequent doses of 200 mg intravenous ciprofloxacin. CVVHD was performed with 1 l/h of dialysate and 2 l/h of predilution filtration solution, producing 3 l/h of dialysis effluent. The blood was pumped at 200 ml/min using a Gambro BMM-10 blood pump through a Hospal AN69HF haemofilter. MEASUREMENTS AND RESULTS: Ten pharmacokinetic profiles were measured. The CVVHDF displayed a urea clearance of 42 +/- 3 ml/min, and removed ciprofloxacin with a clearance of 37 +/- 7 ml/min. This rate was 2-2.5 greater than previously published for ciprofloxacin in other forms of CRRT. On average the CVVHDF was responsible for clearing a fifth of all ciprofloxacin eliminated (21 +/- 10%). The total body clearance of ciprofloxacin was 12.2 +/- 4.3 l/h. The trough concentration following the initial dose was 0.7 +/- 0.3 mg/l. The area under the plasma concentration time curves over a 24-h period ranged from 21 to 55 mg.h l-1. CONCLUSIONS: Intravenous ciprofloxacin 600 mg/day in critically ill patients using this form of CRRT produced adequate plasma levels for many resistant microbes found in intensive care units.