Machine learning prediction of refractory ventricular fibrillation in out-of-hospital cardiac arrest using features available to EMS.

Background: Shock-refractory ventricular fibrillation (VF) or ventricular tachycardia (VT) is a treatment challenge in out-of-hospital cardiac arrest (OHCA). This study aimed to develop and validate machine learning models that could be implemented by emergency medical services (EMS) to predict refractory VF/VT in OHCA patients. Methods: This was a retrospective study examining adult non-traumatic OHCA patients brought into the emergency department by Singapore EMS from the Pan-Asian Resuscitation Outcomes Study (PAROS) registry. Data from April 2010 to March 2020 were extracted for this study. Refractory VF/VT was defined as VF/VT persisting or recurring after at least one shock. Features were selected based on expert clinical opinion and availability to dispatch prior to arrival at scene. Multivariable logistic regression (MVR), LASSO and random forest (RF) models were investigated. Model performance was evaluated using receiver operator characteristic (ROC) area under curve (AUC) analysis and calibration plots. Results: 20,713 patients were included in this study, of which 860 (4.1%) fulfilled the criteria for refractory VF/VT. All models performed comparably and were moderately well-calibrated. ROC-AUC were 0.732 (95% CI, 0.695 - 0.769) for MVR, 0.738 (95% CI, 0.701 - 0.774) for LASSO, and 0.731 (95% CI, 0.690 - 0.773) for RF. The shared important predictors across all models included male gender and public location. Conclusion: The machine learning models developed have potential clinical utility to improve outcomes in cases of refractory VF/VT OHCA. Prediction of refractory VF/VT prior to arrival at patient's side may allow for increased options for intervention both by EMS and tertiary care centres.

Comparing outcomes of out-of-hospital cardiac arrest patients with initial shockable rhythm in Singapore and Osaka using population-based databases.

BACKGROUND: Previous research indicated outcomes among refractory out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythm were different in Singapore and Osaka, Japan, possibly due to the differences in access to extracorporeal cardiopulmonary resuscitation. However, this previous study had a risk of selection bias. To address this concern, this study aimed to evaluate the outcomes between Singapore and Osaka for OHCA patients with initial shockable rhythm using only population-based databases. METHODS: This was a secondary analysis of two OHCA population-based databases in Osaka and Singapore, including adult OHCA patients with initial shockable rhythm. A machine-learning-based prediction model was derived from the Osaka data (n = 3088) and applied to the PAROS-SG data (n = 2905). We calculated the observed-expected ratio (OE ratio) for good neurological outcomes observed in Singapore and the expected derived from the data in Osaka by dividing subgroups with or without prehospital ROSC. RESULTS: The one-month good neurological outcomes in Osaka and Singapore among patients with prehospital ROSC were 70% (791/1,125) and 57% (440/773), and among patients without prehospital ROSC were 10% (196/1963) and 2.8% (60/2,132). After adjusting patient characteristics, the outcome in Singapore was slightly better than expected from Osaka in patients with ROSC (OE ratio, 1.067 [95%CI 1.012 to 1.125]), conversely, it was worse than expected in patients without prehospital ROSC (OE ratio, 0.238 [95%CI 0.173 to 0.294]). CONCLUSION: This study showed the outcomes of OHCA patients without prehospital ROSC in Singapore were worse than expected derived from Osaka data even using population-based databases. (249/250 words).

Outcome assessment for out-of-hospital cardiac arrest patients in Singapore and Japan with initial shockable rhythm.

BACKGROUND: Singapore and Osaka in Japan have comparable population sizes and prehospital management; however, the frequency of ECPR differs greatly for out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythm. Given this disparity, we hypothesized that the outcomes among the OHCA patients with initial shockable rhythm in Singapore were different from those in Osaka. The aim of this study was to evaluate the outcomes of OHCA patients with initial shockable rhythm in Singapore compared to the expected outcomes derived from Osaka data using machine learning-based prediction models. METHODS: This was a secondary analysis of two OHCA databases: the Singapore PAROS database (SG-PAROS) and the Osaka-CRITICAL database from Osaka, Japan. This study included adult (18-74 years) OHCA patients with initial shockable rhythm. A machine learning-based prediction model was derived and validated using data from the Osaka-CRITICAL database (derivation data 2012-2017, validation data 2018-2019), and applied to the SG-PAROS database (2010-2016 data), to predict the risk-adjusted probability of favorable neurological outcomes. The observed and expected outcomes were compared using the observed-expected ratio (OE ratio) with 95% confidence intervals (CI). RESULTS: From the SG-PAROS database, 1,789 patients were included in the analysis. For OHCA patients who achieved return of spontaneous circulation (ROSC) on hospital arrival, the observed favorable neurological outcome was at the same level as expected (OE ratio: 0.905 [95%CI: 0.784-1.036]). On the other hand, for those who had continued cardiac arrest on hospital arrival, the outcomes were lower than expected (shockable rhythm on hospital arrival, OE ratio: 0.369 [95%CI: 0.258-0.499], and nonshockable rhythm, OE ratio: 0.137 [95%CI: 0.065-0.235]). CONCLUSION: This observational study found that the outcomes for patients with initial shockable rhythm but who did not obtain ROSC on hospital arrival in Singapore were lower than expected from Osaka. We hypothesize this is mainly due to differences in the use of ECPR.

Does witness type affect the chance of receiving bystander CPR in out-of-hospital cardiac arrest?

OBJECTIVES: The relationship between the bystander witness type and receipt of bystander CPR (BCPR) is not well understood. Herein we compared BCPR administration between family and non-family witnessed out-of-hospital cardiac arrest (OHCA). BACKGROUND: In many communities, interventions in the past decade have contributed to an increased receipt of BCPR, for example in Singapore from 15% to 60%. However, BCPR rates have plateaued despite sustained and ongoing community-based interventions, which may be related to gaps in education or training for various witness types. The purpose of this study was to investigate the association between witness type and BCPR administration. METHODS: Singapore data from 2010-2020 was extracted from the Pan-Asian Resuscitation Outcomes Study (PAROS) network registry (n = 25,024). All adult, layperson witnessed, non-traumatic OHCAs were included in this study. RESULTS: Of 10,016 eligible OHCA cases, 6,895 were family witnessed and 3,121 were non-family witnessed. After adjustment for potential confounders, BCPR administration was less likely for non-family witnessed OHCA (OR 0.83, 95% CI 0.75, 0.93). After location stratification, non-family witnessed OHCAs were less likely to receive BCPR in residential settings (OR 0.75, 95% CI 0.66, 0.85). In non-residential settings, there was no statistically significant association between witness type and BCPR administration (OR 1.11, 95% CI 0.88, 1.39). Details regarding witness type and bystander CPR were limited. CONCLUSION: This study found differences in BCPR administration between family and non-family witnessed OHCA cases. Elucidation of witness characteristics may be useful to determine populations that would benefit most from CPR education and training.

Evaluation of telephone-assisted cardiopulmonary resuscitation recommendations for out-of-hospital cardiac arrest.

AIM OF THE STUDY: While out-of-hospital cardiac arrest (OHCA) is associated with poor survival, early bystander CPR (B-CPR) and telephone CPR (T-CPR) improves survival from OHCA. American Heart Association (AHA) Scientific Statements outline recommendations for T-CPR. We assessed these recommendations and hypothesized that meeting performance standards is associated with increased likelihood of survival. Additional variables were analyzed to identify future performance measurements. METHODS: We conducted a retrospective cohort study of non-traumatic, adult, OHCA using the Singapore Pan-Asian Resuscitation Outcomes Study. The primary outcome was likelihood of survival; secondary outcomes were pre-hospital Return of Spontaneous Circulation (ROSC) and B-CPR. RESULTS: From 2012 to 2016, 2,574 arrests met inclusion criteria. Mean age was 68 ± 15; of 2,574, 1,125 (44%) received T-CPR with 5% (135/2574) survival. T-CPR cases that met the Lerner et al. performance metrics analyzed, demonstrated no statistically significant association with survival. Cases which met the Kurz et al. criteria, "Time for Dispatch to Recognize Need for CPR" and "Time to First Compression," had adjusted odds ratios of survival of 1.01 (95% CI:1.00, 1.02; p = <0.01) and 0.99 (95% CI:0.99, 0.99; p = <0.01), respectively. Identified barriers to CPR decreased the odds of T-CPR and B-CPR being performed. Patients with prehospital ROSC had higher odds of B-CPR being performed. EMS response time < 8 minutes was associated with increased survival among patients receiving T-CPR. CONCLUSION: AHA scientific statements on T-CPR programs serve as ideal starting points for increasing the quality of T-CPR systems and patient outcomes. More work is needed to identify other system performance measures.

Validation of the CaRdiac Arrest Survival Score (CRASS) for predicting good neurological outcome after out-of-hospital cardiac arrest in an Asian emergency medical service system.

BACKGROUND: Survival with favorable neurological outcomes is an important indicator of successful resuscitation in out-of-hospital cardiac arrest (OHCA). We sought to validate the CaRdiac Arrest Survival Score (CRASS), derived using data from the German Resuscitation Registry, in predicting the likelihood of good neurological outcomes after OHCA in Singapore. METHODS: We conducted a retrospective population-based validation study among EMS-attended OHCA patients (≥18 years) in Singapore, using data from the prospective Pan-Asian Resuscitation Outcomes Study registry. Good neurological outcome was defined as a cerebral performance category of 1 or 2. To evaluate the CRASS score in light of the difference in patient characteristics, we used the default constant coefficient (0.8) and the adjusted coefficient (0.2) to calculate the probability of good neurological outcomes. RESULTS: Out of 11,404 analyzed patients recruited between April 2010 and December 2018, 260 had good and 11,144 had poor neurological function. The CRASS score demonstrated good discrimination, with an area under the curve of 0.963 (95% confidence interval: 0.952-0.974). Using the default constant coefficient of 0.8, the CRASS score consistently overestimated the predicted probability of a good outcome. Following adjustment of the coefficient to 0.2, the CRASS score showed improved calibration. CONCLUSION: CRASS demonstrated good discrimination and moderate calibration in predicting favorable neurological outcomes in the validation Singapore cohort. Our study established a good foundation for future large-scale, cross-country validations of the CRASS score in diverse sociocultural, geographical, and clinical settings.

The association between mode of transport and out-of-hospital cardiac arrest outcomes in Singapore.

OBJECTIVE: We aimed to examine the survival outcomes of out-of-hospital cardiac arrest (OHCA) patients, stratified by the transportation modes to the Emergency Department (ED). METHODS: This was a retrospective analysis of Singapore's Pan-Asian Resuscitation Outcomes Study registry from Apr 2010-Dec 2017. The primary outcome was survival to discharge or 30 days post-arrest. Secondary outcomes were the return of spontaneous circulation (ROSC) rate and neurological outcomes. A subgroup analysis was performed for OHCA cases who collapsed enroute. RESULTS: A total of 15,376 cases were analysed. 15,129 (98.4%) were conveyed by Emergency Medical Services (EMS), 111 (0.72%) by private ambulance, 106 (0.69%) by own transport and 30 (0.2%) by public transport. 80% of patients brought by public transport arrested enroute, compared to 48.1% by own transport, 25.2% by private ambulance and 2.5% in the EMS group. 33/120 (27.5%) of paediatric OHCA cases were brought in by non-EMS transport to paediatric hospitals. The EMS group had the lowest survival rate at 4.5%, compared to 13.3% for public transport, 11.3% for own transport and 14.4% for private ambulance. ROSC rate was statistically significant but not for neurological outcomes. For the subgroup analysis, there was no statistical difference for primary and secondary outcomes across the groups. CONCLUSION: In Singapore, most OHCA patients are conveyed by EMS to the hospital, but some OHCA patients still arrive via alternative transport without prehospital interventions like bystander CPR. More can be done to educate the public to recognise an impending cardiac arrest and to activate EMS early for such cases.

Impact of dispatcher-assisted cardiopulmonary resuscitation on performance of termination of resuscitation criteria.

BACKGROUND: Current Advanced Life Support Termination of Resuscitation (TOR) guidelines suggest when to cease cardiopulmonary resuscitation (CPR). With the significant increase of Dispatch-Assisted CPR (DA-CPR) programs, the impact of DA-CPR on the TOR criteria performance is not clear. METHODS: We conducted a secondary analysis of a prospectively collected registry, the Pan-Asian Resuscitation Outcomes Study. We included patients >15 years old with out-of-hospital cardiac arrest between 2014 and 2017 (after implementation of Singapore's DA-CPR program). We excluded patients with non-cardiac etiology, known do-not-resuscitate status, and healthcare provider bystanders. All cases were collected in accordance to Utstein standards. We evaluated the addition of DA-CPR to the diagnostic performance of TOR criteria using logistic regression modeling. The primary outcome was performance for predicting non-survival at 30 days. Sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Of the 6009 cases, 319 (5.3%) were still alive at 30 days. Patients had a mean age of 67.9 (standard deviation 15.7) years and were mostly male and Chinese. Almost half of patients had no bystander CPR. The TOR criteria differentiating DA-CPR from unassisted bystander CPR has a specificity of 94% and predictive value of death of 99%, which was not significantly different from undifferentiated CPR criteria. There were differences in adjusted association with survival between unassisted and DA-CPR. CONCLUSION: Advanced life support TOR criteria retain high specificity and predictive value of death in the context of DA-CPR. Further research should explore the differences between unassisted CPR and DA-CPR to understand differential survival outcomes.

Early Coronary Angiography Is Associated with Improved 30-Day Outcomes among Patients with Out-of-Hospital Cardiac Arrest.

We evaluated the association between early coronary angiography (CAG) and outcomes in resuscitated out-of-hospital cardiac arrest (OHCA) patients, by linking data from the Singapore Pan-Asian Resuscitation Outcomes Study, with a national registry of cardiac procedures. The 30-day survival and neurological outcome were compared between patients undergoing early CAG (within 1-calender day), versus patients not undergoing early CAG. Inverse probability weighted estimates (IPWE) adjusted for non-randomized CAG. Of 976 resuscitated OHCA patients of cardiac etiology between 2011-2015 (mean(SD) age 64(13) years, 73.7% males), 337 (34.5%) underwent early CAG, of whom, 230 (68.2%) underwent PCI. Those who underwent early CAG were significantly younger (60(12) vs. 66(14) years old), healthier (42% vs. 59% with heart disease; 29% vs. 44% with diabetes), more likely males (86% vs. 67%), and presented with shockable rhythms (69% vs. 36%), compared with those who did not. Early CAG with PCI was associated with better survival and neurological outcome (adjusted odds ratio 1.91 and 1.82 respectively), findings robust to IPWE adjustment. The rates of bleeding and stroke were similar. CAG with PCI within 24 h was associated with improved clinical outcomes after OHCA, without increasing complications. Further studies are required to identify the characteristics of patients who would benefit most from this invasive strategy.

Effect of vertical location on survival outcomes for out-of-hospital cardiac arrest in Singapore.

BACKGROUND: A large proportion of out-of-hospital cardiac arrest (OHCA) cases occur in high-rise residential buildings. This study aims to investigate the effect of vertical location on survival outcomes and response times. METHODS: This is a retrospective study based on data obtained from the Singapore cohort of the Pan-Asian Resuscitation Outcomes Study (PAROS) from January 2011 to December 2014. Study subjects were OHCA cases, unwitnessed and transported by EMS personnel, with known vertical location (floor) data. Traumatic arrests with no resuscitation attempted and missing vertical locations were excluded. The primary outcome was survival to hospital discharge or 30 days post-cardiac arrest. RESULTS: A total of 5678 OHCA cases were included in the study. The effect of floors on survival was manifested as a U-shaped response. Survival rates of 4.5% for the 4 pooled basement floors and 6.2% for the ground floor (floor 1) were contrasted by a substantial drop to 2.7% at floor 2 and continuing decline to 0.7% at floor 6. In a multivariable model using stepwise logistic regression, both linear (p = 0.0285) and quadratic (p = 0.0018) floor effects remained significant after adjustment for other significant risk factors, age, bystander witnessed arrest, first arrest rhythm, ROSC on scene/enroute, and EMS response times. Harrell's C-statistic for a predictive model incorporating these variables was 0.933. CONCLUSIONS: Vertical location is associated with OHCA survival probability with a U-shaped response, and this significance remained after adjustment for other significant OHCA variables. This relationship is likely multifactorial and more research is needed to elucidate the various factors.

Improvement in Door-to-Needle Time in Patients with Acute Ischemic Stroke via a Simple Stroke Activation Protocol.

BACKGROUND: In acute ischemic stroke (AIS), treatment with intravenous tissue-type plasminogen activator (IV-tPA) is time-sensitive. All stroke centers make continual efforts to reduce door-to-needle time (DNT) with varying success. We present the impact of modifications to our stroke activation protocol on DNT. METHODS: We included 404 consecutive patients with AIS receiving IV-tPA between January 2014 and December 2016. First changes in stroke activation protocol were made in March 2015 in the form of prenotification by paramedics, direct transfer from ambulance to computed tomography (CT) scanner, and rapid en route neurological assessment by an emergency physician and neurologist. In March 2016, a second amendment was made where a stroke nurse accompanied the patient to expedite various steps in the treatment pathway, including endovascular treatment in eligible cases. RESULTS: Both protocol amendments resulted in improvement in DNT and door-to-CT time from 84 ± 47 minutes before intervention to 69 ± 33 minutes after protocol amendment 1 to 59 ± 37 minutes after protocol amendment 2. In particular, the second amendment (144 patients) showed significant shortening of DNT compared with the 137 patients before (59 ± 37 minutes versus 69 ± 33 minutes, P = .020), with a higher percentage achieving the target of 60 minutes (68.1% versus 48.2%, P < .001). This finding was attributed to a reduction in both door-to-CT time and CT-to-needle time. This improvement remained consistent over subsequent months. CONCLUSIONS: The application of a simple systems-based, multidisciplinary stroke activation protocol may help in significant reduction in DNT. Encouraging increased patient ownership by stroke nurses appeared to be a promising approach for timely administration of definitive acute therapies.

Nongated Cardiac Computed Tomographic Angiograms for Detection of Embolic Sources in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: We assessed the feasibility of obtaining diagnostic quality images of the heart and thoracic aorta by extending the z axis coverage of a non-ECG-gated computed tomographic angiogram performed in the primary evaluation of acute stroke without increasing the contrast dose. METHODS: Twenty consecutive patients with acute ischemic stroke within the 4.5 hours of symptom onset were prospectively recruited. We increased the longitudinal coverage to the domes of the diaphragm to include the heart. Contrast administration (Omnipaque 350) remained unchanged (injected at 3-4 mL/s; total 60-80 mL, triggered by bolus tracking). Images of the heart and aorta, reconstructed at 5 mm slice thickness in 3 orthogonal planes, were read by a radiologist and cardiologist, findings conveyed to the treating neurologist, and correlated with the transthoracic or transesophageal echocardiogram performed within the next 24 hours. RESULTS: Of 20 patients studied, 3 (15%) had abnormal findings: a left ventricular thrombus, a Stanford type A aortic dissection, and a thrombus of the left atrial appendage. Both thrombi were confirmed by transesophageal echocardiography, and anticoagulation was started urgently the following day. None of the patients developed contrast-induced nephropathy on follow-up. The radiation dose was slightly increased from a mean of 4.26 mSV (range, 3.88-4.70 mSV) to 5.17 (range, 3.95 to 6.25 mSV). CONCLUSIONS: Including the heart and ascending aorta in a routine non-ECG-gated computed tomographic angiogram enhances an existing imaging modality, with no increased incidence of contrast-induced nephropathy and minimal increase in radiation dose. This may help in the detection of high-risk cardiac and aortic sources of embolism in acute stroke patients.

Barriers to dispatcher-assisted cardiopulmonary resuscitation in Singapore.

BACKGROUND: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is effective in increasing bystander CPR in out-of-hospital cardiac arrests (OHCA). Singapore has recently implemented a DA-CPR program. We aimed to characterize barriers to commencement of chest compressions by callers in Singapore. METHODS: We analyzed dispatch recordings of OHCA cases received by the ambulance call center between July 2012 and March 2015. Audio recordings of poor quality were excluded. Trained reviewers noted the sequential stages of the dispatcher's recognition of CPR, delivering CPR instructions and caller performing CPR. Time taken to reach these milestones was noted. Barriers to chest compressions were identified. RESULTS: A total of 4897 OHCA occurred during the study period, overall bystander CPR rate was 45.7%. 1885 dispatch recordings were reviewed with 1157 cases qualified for dispatcher CPR. In 1128 (97.5%) cases, the dispatcher correctly recognized the need for CPR. CPR instructions were delivered in 1056 (91.3%) cases. Of these, 1007 (87.0%) callers performed CPR to instruction. One or more barriers to chest compressions were identified in 430 (37.2%) cases. The commonest barrier identified was "could not move patient" (27%). Cases where barriers were identified were less likely to have the need for CPR recognized by the dispatcher (94.9% vs. 99.0%, p<0.001), CPR instructions given (79.3% vs. 98.3%, p<0.001) and CPR started (67.9% vs. 98.3%, p<0.001), while the time taken to reach each of these stages were significantly longer (p<0.001). CONCLUSION: Barriers were present in 37% of cases. They were associated with lower proportion of CPR started and longer delay to CPR.

Emergency Department Management of Sepsis Patients: A Randomized, Goal-Oriented, Noninvasive Sepsis Trial.

STUDY OBJECTIVE: The noninvasive cardiac output monitor and passive leg-raising maneuver has been shown to be reasonably accurate in predicting fluid responsiveness in critically ill patients. We examine whether using a noninvasive protocol would result in more rapid lactate clearance after 3 hours in patients with severe sepsis and septic shock in the emergency department. METHODS: In this open-label randomized controlled trial, 122 adult patients with sepsis and serum lactate concentration of greater than or equal to 3.0 mmol/L were randomized to receive usual care or intravenous fluid bolus administration guided by measurements of change of stroke volume index, using the noninvasive cardiac output monitor after passive leg-raising maneuver. The primary outcome was lactate clearance of more than 20% at 3 hours. Secondary outcomes included mortality, length of hospital and ICU stay, and total hospital cost. Analysis was intention to treat. RESULTS: Similar proportions of patients in the randomized intervention group (70.5%; N=61) versus control group (73.8%; N=61) achieved the primary outcome, with a relative risk of 0.96 (95% confidence interval [CI] 0.77 to 1.19). Secondary outcomes were similar in both groups (P>.05 for all comparisons). Hospital mortality occurred in 6 patients (9.8%) each in the intervention and control groups on or before 28 days (relative risk=1.00; 95% CI 0.34 to 2.93). Among a subgroup of patients with underlying fluid overload states, those in the intervention group tended to receive clinically significantly more intravenous fluids at 3 hours (difference=975 mL; 95% CI -450 to 1,725 mL) and attained better lactate clearance (difference=19.7%; 95% CI -34.6% to 60.2%) compared with the control group, with shorter hospital lengths of stay (difference=-4.5 days; 95% CI -9.5 to 2.5 days). CONCLUSION: Protocol-based fluid resuscitation of patients with severe sepsis and septic shock with the noninvasive cardiac output monitor and passive leg-raising maneuver did not result in better outcomes compared with usual care. Future studies to demonstrate the use of the noninvasive protocol-based care in patients with preexisting fluid overload states may be warranted.

Observation of handover process in an intensive care unit (ICU): barriers and quality improvement strategy.

OBJECTIVE: To describe the characteristics and barriers in the handover process in a medical intensive care unit. DESIGN: A cross-sectional descriptive study using a checklist to observe nurses and doctors during handover of patients in and out of the intensive care unit. SETTING: The study was conducted at a 1000-bed tertiary hospital in Singapore. The unit admits all patients under university medicine clusters, except those needing cardiology services. PARTICIPANTS: Handover between 90 pairs (180 participants)-50 nurse-to-nurse (100 nurses) and 40 doctor-to-doctor (80 doctors)--were passively observed in real time during morning and evening shifts over weekdays. MAIN OUTCOME MEASURES: The number and types of distractions and their relationship to the time spent during handover, the information included during handover, and the number of working shifts. RESULTS: The results showed that there were 1.26 (± 1.75) distractions per handover. In 45 (50%) handovers, no distraction occurred. The human factor was the most common distracting factor during handovers, whereas short message service and monitor alarms were not identified as distracting factors. The information included least often was 'do not resuscitate' (DNR). Nurses spent significantly longer during handovers than doctors. CONCLUSION: The findings provide information for improving the handover process during the transfer of patients in and out of the intensive care unit. Distractions during handovers are common and are associated with longer durations. Nurses and doctors rarely address DNR status during handover of ICU patients in this study.

Differences in the handover process and perception between nurses and residents in a critical care setting.

AIMS AND OBJECTIVES: To identify the differences in practices and perceptions of handovers between nurses and residents in the critical care setting, so as to improve the quality of the process. BACKGROUND: Critically ill patients with complex problems are ideal for the study of handovers. However, few handover studies have been conducted in intensive care units. DESIGN: Descriptive study using questionnaires. METHODS: We interviewed all nurses and residents involved in handovers of patients admitted to and discharged from a medical intensive care unit over a period of one month. Interviews were guided by a questionnaire and conducted between 24-48 hours of handovers. RESULTS: Out of 672 eligible participants, 580 (290 nurses and 290 residents) agreed to participate in the study (86·3% response rate). Compared to residents, nurses received more training on handovers, covered issues specific to allied health specialties more frequently during handovers, and reviewed patients earlier after handovers. The perceived importance of the different components of handover varied significantly: donor residents, donor nurses, recipient residents and recipient nurses emphasised the overall management plan, case complexity, management plan over the next 48 hours and past medical history, including allergies, respectively. Satisfaction in the handover was related to pre-handover review of electronic medical records, handover training and clarity level in the management plan following the handover, with only the last factor remaining significant on multivariate analysis. CONCLUSIONS: More nurses than residents received prior training in handovers. Nursing handovers were more inclusive of allied health specialties. The perceived importance of the components of handover varied. Greater clarity in management plans was associated with better satisfaction. RELEVANCE TO CLINICAL PRACTICE: Deficiencies in the handover process (lack of prior training in handovers, not including allied health specialties and not reviewing electronic records before handover) were identified, thus providing opportunities for mutual learning between nurses and residents.

Recognition and treatment of out-of-hospital cardiac arrests by non-emergency ambulance services in Singapore.

INTRODUCTION: Prompt recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) and defibrillation is necessary for good outcomes from out-of-hospital cardiac arrest (OHCA). This study aims to describe the recognition and treatment of OHCA in patients conveyed by non-emergency ambulance services (EAS) in Singapore. MATERIALS AND METHODS: This is a multi-centre, retrospective chart review, of cases presenting to public emergency departments (EDs), conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. The study was from October 2002 to August 2009. The following variables were examined: ability to recognise cardiac arrest, whether CPR was carried out by the ambulance crew and whether an automated external defibrillator (AED) was applied. RESULTS: Eighty-six patients were conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. Mean age was 63 years (SD 21.8), 70.9% were males. A total of 53.5% of arrests occurred in the ambulance while 70.9% were found to be asystolic upon ED arrival. Seven patients had a known terminal illness. Survival to discharge was 3.5%. Cardiac arrest went unrecognised by the ambulance crew in 38 patients (44.2%). CPR was performed in 35 patients (40.7%) of the 86 patients and AED was applied in only 10 patients (11.6%). CONCLUSION: We found inadequate recognition and delayed initiation of treatment for OHCA. Possible reasons include a lack of training in patient monitoring and detection of cardiac arrest, lack of CPR training, lack of confidence in performing CPR, lack of AEDs on ambulances and lack of training in their use.

Local inflammation induces complement crosstalk which amplifies the antimicrobial response.

By eliciting inflammatory responses, the human immunosurveillance system notably combats invading pathogens, during which acute phase proteins (CRP and cytokines) are elevated markedly. However, the Pseudomonas aeruginosa is a persistent opportunistic pathogen prevalent at the site of local inflammation, and its acquisition of multiple antibiotic-resistance factors poses grave challenges to patient healthcare management. Using blood samples from infected patients, we demonstrate that P. aeruginosa is effectively killed in the plasma under defined local infection-inflammation condition, where slight acidosis and reduced calcium levels (pH 6.5, 2 mM calcium) typically prevail. We showed that this powerful antimicrobial activity is provoked by crosstalk between two plasma proteins; CRPratioL-ficolin interaction led to communication between the complement classical and lectin pathways from which two amplification events emerged. Assays for C4 deposition, phagocytosis, and protein competition consistently proved the functional significance of the amplification pathways in boosting complement-mediated antimicrobial activity. The infection-inflammation condition induced a 100-fold increase in CRPratioL-ficolin interaction in a pH- and calcium-sensitive manner. We conclude that the infection-induced local inflammatory conditions trigger a strong interaction between CRPratioL-ficolin, eliciting complement-amplification pathways which are autonomous and which co-exist with and reinforce the classical and lectin pathways. Our findings provide new insights into the host immune response to P. aeruginosa infection under pathological conditions and the potential development of new therapeutic strategies against bacterial infection.