The association between a quantitative computed tomography (CT) measurement of cerebral edema and outcomes in post-cardiac arrest—A validation study

Aim

Previous studies have examined the association between quantitative head computed tomography (CT) measures of cerebral edema and patient outcomes reporting that a calculated gray matter to white matter attenuation ratio (GWR) of <1.2 indicates a near 100% non-survivable injury post-cardiac arrest. The objective of the current study was to validate whether a GWR <1.2 reliably indicates poor survival post-cardiac arrest. We also sought to determine the inter-rater variability among reviewers, and examine the utility of a novel GWR measurement to facilitate easier practical use.

Methods

We performed a retrospective analysis of post-cardiac arrest patients admitted to a single center from 2008 to 2012. Inclusion criteria were age ≥18 years, non-traumatic arrest, and available CT imaging within 24 h after ROSC. Three independent physician reviewers from different specialties measured CT attenuation of pre-specified gray and white matter areas for GWR calculations.

Results

Out of 171 consecutive patients, 90 met the study inclusion criteria. Thirteen patients were excluded for technical reasons and/or significant additional pathology, leaving 77 head CT scans for evaluation. Median age was 66 years and 64% were male. In-hospital mortality was 65% and 70% of patients received therapeutic hypothermia. For the validation measurement, the intra-class correlation coefficient was 0.70. In our dataset, a GWR below 1.2 did not accurately predict mortality or poor neurological outcome (sensitivity 0.56–0.62 and specificity 0.63–0.81). A score below 1.1 predicted a near 100% mortality but was not a sensitive metric (sensitivity 0.14–0.20 and specificity 0.96–1.00). Similar results were found for the exploratory model.

Conclusion

A GWR <1.2 on CT imaging within 24 h after cardiac arrest was moderately specific for poor neurologic outcome and mortality. Based on our data, a threshold GWR <1.1 may be a safer cut-off to identify patients with low chance of survival and good neurological outcome. Intra-class correlation among reviewers was moderately good.     

Distribution of potassium levels on admission for CPR--severe hypokalaemia with dysmorphophobic eating disorders

Aim

To evaluate the prevalence and cause of severe hypokalaemia in patients administered for cardiopulmonary resuscitation (CPR) for non-traumatic cardiac arrest.

Methods

We conducted a retrospective database review in the setting of a University hospital on 281 consecutive adult patients admitted to emergency admission, cardiac catheterization laboratory or intensive care units for resuscitation from non-traumatic cardiac arrest. The first available potassium value was evaluated.

Results

The mean potassium level was 3.9 ± 0.9 mmol/l and thus within the reference range of 3.5-5.0 mmol/l, but the overall prevalence of hypokalaemia was high (31.0%). Moderate rather than severe hypokalaemia was typically observed, with 95% of patients exhibiting potassium levels above 2.7 mmol/l. Among those six patients with extreme hypokalaemia defined as a potassium levels below the 2.5 percentile, two adult females were identified to suffer from previously untreated body scheme disorder with furosemide abuse (potassium 1.1 and 1.4 mmol/l). Another patient (potassium 2.1 mmol/l) suffered from poorly controlled bulimia nervosa and acute diarrhoea due to GI infection and one (potassium 2.4 mmol/l) from untreated bulimic anorexia.

Conclusions

In contrast to moderately reduced potassium which is a frequent finding in adult patients at the time of admission for non-traumatic cardiac arrest, severe hypokalaemia is uncommon. The high prevalence of patients with body dysmorphophobic eating disorders in this group underscores accidental self-induced hypokalaemia may evolve as an important differential diagnosis in cardiac arrest in young female patients.     

S-100B is superior to NSE, BDNF and GFAP in predicting outcome of resuscitation from cardiac arrest with hypothermia treatment

Objective

To conduct a pilot study to evaluate the blood levels of brain derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE) and S-100B as prognostic markers for neurological outcome 6 months after hypothermia treatment following resuscitation from cardiac arrest.

Design

Prospective observational study.

Setting

One intensive care unit at Uppsala University Hospital.

Patients

Thirty-one unconscious patients resuscitated after cardiac arrest.

Interventions

None.

Measurements and main results

Unconscious patients after cardiac arrest with restoration of spontaneous circulation (ROSC) were treated with mild hypothermia to 32-34 °C for 26 h. Time from cardiac arrest to target temperature was measured. Blood samples were collected at intervals of 1-108 h after ROSC. Neurological outcome was assessed with Glasgow-Pittsburgh cerebral performance category (CPC) scale at discharge from intensive care and again 6 months later, when 15/31 patients were alive, of whom 14 had a good outcome (CPC 1-2). Among the predictive biomarkers, S-100B at 24 h after ROSC was the best, predicting poor outcome (CPC 3-5) with a sensitivity of 87% and a specificity of 100%. NSE at 96 h after ROSC predicted poor outcome, with sensitivity of 57% and specificity of 93%. BDNF and GFAP levels did not predict outcome. The time from cardiac arrest to target temperature was shorter for those with poor outcome.

Conclusions

The blood concentration of S-100B at 24 h after ROSC is highly predictive of outcome in patients treated with mild hypothermia after cardiac arrest.     

Quality of closed chest compression on a manikin in ambulance vehicles and flying helicopters with a real time automated feedback

Context

Automated verbal and visual feedback improves quality of resuscitation in out-of-hospital cardiac arrest and was proven to increase short-term survival. Quality of resuscitation may be hampered in more difficult situations like emergency transportation. Currently there is no evidence if feedback devices can improve resuscitation quality during different modes of transportation.

Objective

To assess the effect of real time automated feedback on the quality of resuscitation in an emergency transportation setting.

Design

Randomised cross-over trial.

Setting

Medical University of Vienna, Vienna Municipal Ambulance Service and Helicopter Emergency Medical Service Unit (Christophorus Flugrettungsverein) in September 2007.

Participants

European Resuscitation Council (ERC) certified health care professionals performing CPR in a flying helicopter and in a moving ambulance vehicle on a manikin with human-like chest properties.

Interventions

CPR sessions, with real time automated feedback as the intervention and standard CPR without feedback as control.

Main outcome measures

Quality of chest compression during resuscitation.

Results

Feedback resulted in less deviation from ideal compression rate 100 min⁻¹ (9 ± 9 min⁻¹, p < 0.0001) with this effect becoming steadily larger over time. Applied work was less in the feedback group compared to controls (373 ± 448 cm × compression; p < 0.001). Feedback did not influence ideal compression depth significantly. There was some indication of a learning effect of the feedback device.

Conclusions

Real time automated feedback improves certain aspects of CPR quality in flying helicopters and moving ambulance vehicles. The effect of feedback guidance was most pronounced for chest compression rate.     

A rodent model of emergency cardiopulmonary bypass resuscitation with different temperatures after asphyxial cardiac arrest

Background

The use of emergency cardiopulmonary bypass (ECPB) resuscitation after cardiac arrest may offer hope for survival when standard ACLS therapies fail. However, whether cooling adds benefit to ECPB is unknown and we lack an ECPB rodent model for experimental studies. We sought to (a) develop a 72 h survival rodent model using ECPB to treat asphyxial cardiac arrest and (b) use this new model to evaluate early mild and moderate hypothermia versus normothermia during ECPB resuscitation.

Methods

After 8 min of normothermic asphyxia, three groups of rats were resuscitated with ECPB at 37 °C (NORM), 34 °C (MILD) and 30 °C (MOD) for 1 h (n = 10 each). During the second resuscitation hour, ECPB was discontinued, ventilatory support was provided and body temperatures were maintained at 37 °C for NORM, 34 °C for MILD, and from 30 °C gradually up to 34 °C in 1 h for MOD animals. From hours 3 to 8, body temperature was maintained at 37 °C for NORM and 34 °C for MILD and MOD animals.

Results

All rats were initially resuscitated by ECPB. After 72 h, neurological outcome and survival in the MILD (60% survival) and MOD (80%) groups were significantly better than in the NORM (0%) group (p < 0.05). Overall performance recovery in the MOD group was best (vs. the NORM group), while the MILD group had an intermediate outcome.

Conclusions

A rodent model of ECPB is feasible and useful for resuscitation studies. The addition of early mild and moderate hypothermia to ECPB resuscitation significantly improves survival compared with normothermic ECPB in rats.     

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A review of the Japanese literature

Aim

Although favourable outcomes in patients receiving extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest have been frequently reported in Japanese journals since the late 1980s, there has been no meta-analysis of ECPR in Japan. This study reviewed and analysed all previous studies in Japan to clarify the survival rate of patients receiving ECPR.

Material and methods

Case reports, case series and abstracts of scientific meetings of ECPR for out-of-hospital cardiac arrest written in Japanese between 1983 and 2008 were collected. The characteristics and outcomes of patients were investigated, and the influence of publication bias of the case-series studies was examined by the funnel-plot method.

Results

There were 1282 out-of-hospital cardiac arrest patients, who received ECPR in 105 reports during the period. The survival rate at discharge given for 516 cases was 26.7 ± 1.4%. The funnel plot presented the relationship between the number of cases of each report and the survival rate at discharge as the reverse-funnel type that centred on the average survival rate. In-depth review of 139 cases found that the rates of good recovery, mild disability, severe disability, vegetative state, death at hospital discharge and non-recorded in all cases were 48.2%, 2.9%, 2.2%, 2.9%, 37.4% and 6.4%, respectively.

Conclusions

Based on the results of previous reports with low publication bias in Japan, ECPR appears to provide a higher survival rate with excellent neurological outcome in patients with out-of-hospital cardiac arrest.     

Transpulmonary cardiac output measurement in a rat model of cardiac arrest and CPR: Impact of vascular access

Objective

The present study investigated the impact of the vascular access site for cardiac output (CO) measurement by thermodilution on survival and neurohistopathological injury in a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Secondary the influence of the vascular access site on cardiac output measurements was examined.

Methods

Rats underwent asphyxial CA and CPR. Thermocouple probes were either placed via the femoral artery into the bifurcation of abdominal aorta/iliac artery (Femoral) or via the carotid artery into the aortic arch (Carotid). CPR was initiated after 9 min CA. Local cerebral blood flow (lCBF) and CO were assessed for 120 min after restoration of spontaneous circulation. Neurohistopathological injury was determined using Fluoro-Jade B staining.

Results

Survival was reduced in the Carotid group compared to the Femoral group (p < 0.01). Fluoro-Jade B staining in the hippocampus showed no difference between CA groups. CO measurements were comparable between femoral and carotid artery access sites. lCBF revealed a delayed hyperperfusion in the Carotid group only.

Conclusions

The present study demonstrates the influence of the vascular access site for placing thermocouple probes for CO measurement on animal survival after CA/CPR. CO did not differ between the two access sites with consequential different detection sites. Use of the femoral access for CO measurement is recommended for long-term survival after CA/CPR.     

A pilot study of mechanical chest compressions with the LUCAS™ device in cardiopulmonary resuscitation

Aim

The LUCAS™ device has been shown to improve organ perfusion during cardiac arrest in experimental studies. In this pilot study the aim was to compare short-term survival between cardiopulmonary resuscitation (CPR) performed with mechanical chest compressions using the LUCAS™ device and CPR performed with manual chest compressions. The intention was to use the results for power calculation in a larger randomised multicentre trial.

Methods

In a prospective pilot study, from February 1, 2005, to April 1, 2007, 149 patients with out-of hospital cardiac arrest in two Swedish cities were randomised to mechanical chest compressions or standard CPR with manual chest compressions.

Results

After exclusion, the LUCAS and the manual groups contained 75 and 73 patients, respectively. In the LUCAS and manual groups, spontaneous circulation with a palpable pulse returned in 30 and 23 patients (p = 0.30), spontaneous circulation with blood pressure above 80/50 mmHg remained for at least 5 min in 23 and 19 patients (p = 0.59), the number of patients hospitalised alive >4 h were 18 and 15 (p = 0.69), and the number discharged, alive 6 and 7 (p = 0.78), respectively.

Conclusions

In this pilot study of out-of-hospital cardiac arrest patients we found no difference in early survival between CPR performed with mechanical chest compression with the LUCAS™ device and CPR with manual chest compressions. Data have been used for power calculation in a forthcoming multicentre trial.     

Clinical predictors of survival in patients treated with therapeutic hypothermia following cardiac arrest

Introduction

Therapeutic hypothermia has been shown to provide neuroprotection and improved survival in patients suffering a cardiac arrest. We report outcomes of consecutive patients receiving therapeutic hypothermia for cardiac arrest and describe predictors of short and long-term survival.

Methods

Eighty patients receiving therapeutic hypothermia between January 2005 and December 2008 were identified and categorized as those who survived and died. Outcomes and predictors of survival were determined.

Results

Forty-five patients (56%) survived to hospital discharge and were alive at 30 days and among survivors 41 (91%) were alive 1 year after discharge. Survivors were younger, were more likely to present with VF, required less epinephrine during resuscitation, were more likely to have preserved renal function, and were less likely to be taking beta-blockers and ACE inhibitors. Predictors of survival included VF on presentation (OR 14.9, CI 2.7-83.2, p = 0.002), pre-cardiac arrest aspirin use (OR 9.7, CI 1.6-61.1, p = 0.02), return of spontaneous circulation <20 min (OR 9.4, CI 2.2-41.1, p = 0.003), absence of coronary artery disease (OR 5.3, CI 1.1-24.7, p = 0.002) and preserved renal function.

Conclusion

Therapeutic hypothermia is useful in the treatment of patients suffering a cardiac arrest. Several clinical factors may aid in predicting patients who are likely to survive after a cardiac arrest.     

Mild therapeutic hypothermia is associated with favourable outcome in patients after cardiac arrest with non-shockable rhythms

Aim

Mild therapeutic hypothermia (32-34 °C) improves neurological recovery and reduces the risk of death in comatose survivors of cardiac arrest when the initial rhythm is ventricular fibrillation or pulseless ventricular tachycardia. The aim of the presented study was to investigate the effect of mild therapeutic hypothermia (32-34 °C for 24 h) on neurological outcome and mortality in patients who had been successfully resuscitated from non-ventricular fibrillation cardiac arrest.

Methods

In this retrospective cohort study we included cardiac arrest survivors of 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest with asystole or pulseless electric activity as the first documented rhythm. Data were collected from 1992 to 2009. Main outcome measures were neurological outcome within six month and mortality after six months.

Results

Three hundred and seventy-four patients were analysed. Hypothermia was induced in 135 patients. Patients who were treated with mild therapeutic hypothermia were more likely to have good neurological outcomes in comparison to patients who were not treated with hypothermia with an odds ratio of 1.84 (95% confidence interval: 1.08-3.13). In addition, the rate of mortality was significantly lower in the hypothermia group (odds ratio: 0.56; 95% confidence interval: 0.34-0.93).

Conclusion

Treatment with mild therapeutic hypothermia at a temperature of 32-34 °C for 24 h is associated with improved neurological outcome and a reduced risk of death following out-of-hospital cardiac arrest with non-shockable rhythms.     

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms

Background

Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms.

Methods

Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital.

Results

Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P = 0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P = 0.04) and 5.65 (CI 1.66-19.23, P = 0.006) respectively.

Conclusion

Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.     

New conventional long-term survival normovolemic cardiac arrest pig model

Aim of the study

A reproducible long-term intensive care and outcome cardiac arrest model for exploring new cerebral preservation strategies is needed. We tried to determine effects and limitations of current therapies after different ‘no-flow’ times.

Methods

Thirty-five female Large White Breed pigs (26-37 kg) were included in the study. Three pigs served as sham animals without cardiac arrest (CA). Ventricular fibrillation (VF) CA was induced in 32 animals for 0, 7, 10 and 13 min (each group consisting of 8 animals), followed by 8 min of chest compressions, mechanical ventilation and vasopressors. Thereafter, up to 3 defibrillations were delivered. After restoration of spontaneous circulation (ROSC), the animals underwent intensive care for 20 h. Neurologic examination was performed at designated time points using a neurologic deficit (ND) and an overall performance category (OPC) score.

Results

Restoration of spontaneous circulation was achieved in 8 of 8 animals in the 0 min-group, 6 of 8 in the 7 min-group, 7 of 8 in the 10 min-group and 0 of 8 in the 13 min-group. All animals of the sham-group and 0 min-group were neurologically intact survivors; the 7 and 10 min-groups showed a median ND of 55%(26;94) and 73%(58;78), respectively. There were no significant differences between the 7 and 10 min-groups regarding OPC and NDS. Coronary perfusion pressure during CPR decreased concordantly with ‘no-flow’ times with a tendency towards significance.

Conclusion

This study established a reproducible cardiac arrest and resuscitation model in pigs which will be used to test novel resuscitation strategies to improve neurologic outcome after cardiac arrest.     

The Relationship of Transversus Abdominis and Lumbar Multifidus Activation and Prognostic Factors for Clinical Success With a Stabilization Exercise Program: A Cross-Sectional Study

Hebert JJ, Koppenhaver SL, Magel JS, Fritz JM. The relationship of transversus abdominis and lumbar multifidus activation and prognostic factors for clinical success with a stabilization exercise program: a cross-sectional study.

Objective

To examine the relationship between prognostic factors for clinical success with a stabilization exercise program and lumbar multifidus (LM) and transversus abdominis (TrA) muscle activation assessed using rehabilitative ultrasound imaging (RUSI).

Design

Cross-sectional study.

Setting

Outpatient physical therapy clinic.

Participants

Volunteers with current low back pain (N=40).

Intervention

Not applicable.

Main Outcome Measures

We examined the relationship between prognostic factors associated with clinical success with a stabilization exercise program (positive prone instability test, age <40y, aberrant movements, straight leg raise >91°, presence of lumbar hypermobility) and degree of TrA and LM muscle activation assessed by RUSI.

Results

Significant univariate relationships were identified between LM muscle activation and the number of prognostic factors present (Pearson correlation coefficient [r] =−.558, P=.001), as well as the individual factors of a positive prone instability test (point biserial correlation coefficient [r_pbis]=.376, P=.018) and segmental hypermobility (r_pbis=.358, P=.025). The multivariate analyses indicated that after controlling for other variables, the addition of the variable “number of prognostic factors present” resulted in a significant increase in R² (P=.006). No significant univariate or multivariate relationships were observed between the prognostic factors and TrA muscle activation.

Conclusions

Decreased LM muscle activation, but not TrA muscle activation, is associated with the presence of factors predictive of clinical success with a stabilization exercise program. Our findings provide researchers and clinicians with evidence regarding the construct validity of the prognostic factors examined in this study, as well as the potential clinical importance of the LM muscle as a target for stabilization exercises.     

Association between clinical examination and outcome after cardiac arrest

Background

Neurologic prognostication after cardiac arrest relies on clinical examination findings derived before the advent of therapeutic hypothermia (TH). We measured the association between clinical examination findings at hospital arrival, 24, and 72 h after cardiac arrest in a modern intensive care unit setting.

Methods

Between 1/1/2005 and 3/31/2009, hospital charts were reviewed in 272 subjects for neurologic examination findings (Glasgow Coma Score - motor examination, pupil response, corneal response) at hospital arrival, 24, and 72 h following cardiac arrest. Primary outcome was survival to hospital discharge. Secondary outcome was “good outcome,” defined as discharge to home or acute rehabilitation facility.

Results

Mean age was 61 years; 155 (57%) were male. Most were treated with TH (N = 161; 59%) and 100 subjects (37%) were in ventricular fibrillation/ventricular tachycardia. Out-of-hospital cardiac arrest was common (N = 169; 62%). Ninety-one (33%) survived, with 54 (20%) experiencing a good outcome.In subjects with a GCS Motor score ≤3 at 24 and 72 h survival was 17% (13/76; 95% CI 7.9-26.2%) and 20% (6/27; 95% CI 6.3-33.6%), respectively. Subjects with a GCS Motor score ≤2 at 24 and 72 h survived in 14% (9/66; 95% CI 4.6-22.6%) and 18% (6/33; 95% CI 3.5-32.8%), respectively. Absent pupil reactivity on arrival did not exclude survival (7/65; 11%; 95% CI 2.4-19%). A lack of pupil reactivity or corneal response at 72 h was associated with death (pupil: 0/17; 95% CI 0, 2.9%; corneal: 0/21; 95% CI 0, 2.4%).

Conclusions

GCS Motor score ≤3 or ≤2 at 24 or 72 h following cardiac arrest does not exclude survival or good outcome. However, absent pupil or corneal response at 72 h appears to exclude survival and good outcome.     

Receiving hospital characteristics associated with survival after out-of-hospital cardiac arrest

Aim

Survival after out-of-hospital cardiac arrest (OOHCA) varies between regions, but the contribution of different factors to this variability is unknown. This study examined whether survival to hospital discharge was related to receiving hospital characteristics, including bed number, capability of performing cardiac catheterization and hospital volume of OOHCA cases.

Material and methods

Prospective observational database of non-traumatic OOHCA assessed by emergency medical services was created in 8 US and 2 Canadian sites from December 1, 2005 to July 1, 2007. Subjects received hospital care after OOHCA, defined as either (1) arriving at hospital with pulses, or (2) arriving at hospital without pulses, but discharged or died ≥1 day later.

Results

A total of 4087 OOHCA subjects were treated at 254 hospitals, and 32% survived to hospital discharge. A majority of subjects (68%) were treated at 116 (46%) hospitals capable of cardiac catheterization. Unadjusted survival to discharge was greater in hospitals performing cardiac catheterization (34% vs. 27%, p = 0.001), and in hospitals that received ≥40 patients/year compared to those that received <40 (37% vs. 30%, p = 0.01). Survival was not associated with hospital bed number, teaching status or trauma center designation. Length of stay (LOS) for surviving subjects was shorter at hospitals performing cardiac catheterization (p < 0.01). After adjusting for all variables, there were no independent associations between survival or LOS and hospital characteristics.

Conclusions

Some subsets of hospitals displayed higher survival and shorter LOS for OOHCA subjects but there was no independent association between hospital characteristics and outcome.     

Effect of time and day of admission on 1-month survival and neurologically favourable 1-month survival in out-of-hospital cardiopulmonary arrest patients

Aim

We sought to examine whether the outcomes of out-of-hospital cardiopulmonary arrest (OHCA) patients differed between weekday and weekend/holiday admissions, or between daytime and nighttime admissions.

Methods

From a national registry of OHCA events in Japan between 2005 and 2008, 173,137 cases where the call-to-hospital admission interval was shorter than 120 min and collapse was witnessed by a bystander were included in this study. One-month survival rate and neurologically favourable 1-month survival rate were used as outcome measures. Logistic regression was used to adjust for potential confounding factors.

Results

No significant differences in outcome were found between weekday and holiday/weekend admissions in rates of 1-month survival or neurologically favourable 1-month survival (p = 0.78 and p = 0.80, respectively). In contrast, patients admitted in the daytime exhibited significantly better outcomes than those admitted at night, on both outcome measures (p < 0.001 and p < 0.001). After adjusting for possible confounding factors, outcomes were significantly better for daytime admissions, with odds ratios of 1.26 (95% confidence interval (CI) 1.22-1.31; p < 0.001) for 1-month survival, and 1.26 (95% CI 1.20-1.32; p < 0.001) for neurologically favourable 1-month survival. In contrast, no significant differences on either outcome measure were found between weekday and weekend/holiday cases, with odds ratios of 1.00 (95% CI 0.96-1.04; p = 0.96) for 1-month survival and 0.99 (95% CI 0.94-1.04; p = 0.78) for neurologically favourable 1-month survival.

Conclusions

Even after adjusting for confounding factors, admission day (weekday vs. weekend/holiday) had no effect on 1-month survival or neurologically favourable 1-month survival. In contrast, daytime admission was associated with significantly better outcomes than nighttime admissions.     

Randomised comparison of percutaneous left ventricular assist device with open-chest cardiac massage and with surgical assist device during ischaemic cardiac arrest

Aims

A percutaneous left ventricular assist device can maintain blood flow to vital organs during ventricular fibrillation and may improve outcomes in ischaemic cardiac arrest. We compared haemodynamic and clinical effects of a percutaneous left ventricular assist device with a larger device deployed via endovascular prosthesis and with open-chest cardiac massage during ischaemic cardiac arrest.

Methods

Eighteen swine were randomised into three groups. After thoracotomy, coronary ischaemia and ventricular fibrillation was induced. Cardiac output was measured with transit-time flowmetry. Tissue perfusion was measured with microspheres. Defibrillation was performed after 20 min.

Results

Cardiac output with cardiac massage was 1129 mL min⁻¹ vs. 1169 mL min⁻¹ with the percutaneous- and 570 mL min⁻¹ with the surgical device (P < 0.05 surgical vs. others). End-tidal CO₂ was 3.3 kPa with cardiac massage vs. 3.2 kPa with the percutaneous- and 2.3 kPa with the surgical device (P < 0.05 surgical vs. others). Subepicardial perfusion was 0.33 mL min⁻¹ g⁻¹ with cardiac massage vs. 0.62 mL min⁻¹ g⁻¹ with both devices (P < 0.05 devices vs. massage), cerebral perfusion was comparable between groups (all reported values after 3 min cardiac arrest, all P < 0.05 vs. baseline, all P = NS for 3 min vs. 15 min). Return of spontaneous circulation was achieved in 5/6 subjects with cardiac massage vs. 6/6 with the percutaneous- and 4/6 with the surgical device (P = NS).

Conclusion

The percutaneous device improved myocardial perfusion, maintained cerebral perfusion and systemic circulation with similar rates of successful defibrillation vs. cardiac massage. Increased delivery was not obtained with the surgical device during cardiac arrest.     

Testing the validity of the ATLS classification of hypovolaemic shock

Aim

The Advanced Trauma Life Support system classifies the severity of shock. The aim of this study is to test the validity of this classification.

Methods

Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. Patients were divided into groups representing the four ATLS classes of shock, based on heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS). The relationships between variables were examined by classifying the cohort by each recorded variable in turn and deriving the median and interquartile range (IQR) of the remaining three variables. Patients with penetrating trauma and major injuries were examined in sub-group analyses.

Results

In blunt trauma patients grouped by HR, the median SBP decreased from 128 mm Hg in patients with HR < 100 BPM to 114 mm Hg in those with HR > 140 BPM. The median RR increased from 18 to 22 bpm and the GCS reduced from 15 to 14. The median HR in hypotensive patients was 88 BPM compared to 83 BPM in normotensive patients and the RR was the same. When grouped by RR, the HR increased with increasing RR but there were no changes in SBP.

Conclusion

In trauma patients there is an inter-relationship between derangements of HR, SBP, RR and GCS but not to the same degree as that suggested by the ATLS classification of shock.     

Early CT signs in out-of-hospital cardiac arrest survivors: Temporal profile and prognostic significance

Aim

Although computed tomography (CT) signs of ischaemia, including loss of boundary (LOB) between grey matter and white matter and cortical sulcal effacement, in cardiac arrest (CA) survivors are known, their temporal profile and prognostic significance remains unclear; their clarification is necessary.

Methods

Brain CT scans were obtained immediately after resuscitation in 75 non-traumatic CA survivors in a prospective fashion. They were divided into two groups according to the CA-return of spontaneous circulation (ROSC) interval: ≤20 min vs. >20 min. The incidence of the CT signs and predictability of these signs for outcome, assessed 6 months after CA, was evaluated and compared.

Results

The incidence of the positive LOB sign was 24% in the ≤20-min group and 83% in the >20-min group, and the difference was statistically significant (p < 0.001). The interval of 20 min seemed to be the time window for the LOB development. The incidence of the positive sulcal effacement sign was 0% in the ≤20 min group and 34% in the >20-min group, and the difference was statistically significant (p = 0.004). A positive LOB sign was predictive of unfavourable outcome with an 81% sensitivity and 92% specificity. A positive sulcal effacement sign was predictive of unfavourable outcome with a 32% sensitivity and 100% specificity.

Conclusion

A time window may exist for ischaemic CT signs in CA survivors. The LOB sign may develop when the CA-ROSC interval exceeds 20 min, whereas the sulcal effacement sign may develop later. However, their temporal profile and outcome predictability should be verified by multicentre studies.     

An evaluation of automated methods for measurement of serum 25-hydroxyvitamin D

Objectives

To compare two new automated assays with the well-established reference method, DiaSorin radioimmunoassay (RIA), for quantitation of serum total 25-hydroxyvitamin D [25(OH)D].

Methods

25(OH)D from human sera (n = 158) was measured using DiaSorin RIA and two automated platforms, DiaSorin “LIAISON 25 OH Vitamin D TOTAL”, and Roche Modular “Vitamin D3 (25-OH)”. Methods were compared by regression and Bland-Altman analyses.

Results

DiaSorin LIAISON demonstrated a stronger correlation (r = 0.918) and better agreement (bias = − 0.88 nmol/L) with DiaSorin RIA than the Roche Modular assay (r = 0.871, bias = − 2.55 nmol/L). Precision ranges (CV%) for the RIA, LIAISON, and Roche Modular assays, respectively, were: within run (6.8-12.9%, 2.8-8.1%, and 1.9-5.5%), and total precision (7.4-14.5%, 7.3-17.5%, and 7.6-14.5%).

Conclusion

DiaSorin LIAISON displayed the best correlation and agreement with DiaSorin RIA. The DiaSorin LIAISON 25 OH Vitamin D TOTAL assay is an accurate and precise automated tool for serum total 25(OH)D determination.