Neutrophil activation during acute human anaphylaxis: analysis of MPO and sCD62L.

BACKGROUND: The mechanisms involved in the amplification of the mast cell response during anaphylaxis are unclear. Mouse models of anaphylaxis demonstrate the critical involvement of neutrophils. These innate immune cells are highly abundant in peripheral blood and can be rapidly activated to trigger both local and systemic inflammation. OBJECTIVE: To investigate neutrophil activation in peripheral blood during acute human anaphylaxis. METHODS: Patients presenting to the emergency department with anaphylaxis underwent blood sampling upon enrolment and at up to three subsequent time-points. Traditional anaphylaxis biomarkers, histamine and mast cell tryptase, were measured by ELISA and ImmunoCAP, respectively. Plasma myeloperoxidase concentrations were measured by ELISA, serum soluble CD62L concentrations by cytometric bead array, and both compared to healthy controls. RESULTS: In 72 patients, 37 (51%) had severe anaphylaxis, 33 (60%) were histamine positive, and 47 (70%) were mast cell tryptase positive. At enrolment, myeloperoxidase concentrations were 2.9- (95% CI: 1.3, 6.5) and 5.0- (95% CI: 2.4, 10.5) fold higher in moderate and severe patients, respectively, compared with healthy controls, and remained stable over the first 5 h following symptom onset. At enrolment, soluble CD62L was 29% (95% CI: 19, 38) and 31% (95% CI: 22, 40) lower in moderate and severe patients, respectively, than healthy controls, and was stable over the first 5 h. There were no associations between myeloperoxidase or soluble CD62L concentrations and either histamine or mast cell tryptase concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: These results provide compelling evidence for the involvement of neutrophils during acute human anaphylaxis, suggesting they are activated early in the reaction, regardless of mast cell activation. This important finding increases our understanding of the basic mechanisms of anaphylaxis, a necessary precursor to improving treatment and prevention.

Is comorbid status the best predictor of one-year mortality in patients with severe sepsis and sepsis with shock?

Understanding longer term outcomes in critically ill patients will assist treatment decisions, allocation of scarce resources and clinical research in that population. The aim of this study was to compare a well-validated means of determining comorbidity, the Charlson Comorbidity Score, to other verified risk stratification models in predicting one-year mortality and other outcomes in emergency department patients with severe sepsis and sepsis with shock. We conducted a planned subgroup analysis of a prospective observational study, the Critical Illness and Shock Study, in adult patients with sepsis meeting study criteria for critical illness. From emergency department arrival, patients were prospectively enrolled with data collected for a minimum of one year post-enrolment. Scoring systems were derived from this data and compared using receiver-operating characteristic curves. One hundred and four patients were enrolled. The 28-day mortality was 18% and one-year mortality 40%. For predicting one-year mortality, the area under the receiver-operating characteristic curve for age-weighted Charlson Comorbidity Score (0.71, 95% confidence interval 0.61 to 0.81) was at least as good or superior to other scoring systems analysed. The intensive care unit admission rate was 45% and the median hospital length-of-stay was eight days. We conclude that in patients who present to the emergency department with severe sepsis or sepsis with shock, age-weighted Charlson Comorbidity Score is a predictor of one-year mortality that is simple to calculate and at least as accurate as other validated scoring systems.

Correlation of paired plasma and saliva paracetamol levels following deliberate self-poisoning with paracetamol (the Salivary Paracetamol In Toxicology [SPIT] study).

AIM: To determine the correlation between plasma and saliva paracetamol levels following paracetamol deliberate self-poisoning. METHODS: Paired plasma and saliva paracetamol levels were measured. Saliva analysis was performed contemporaneously using a colorimetric method. RESULTS: 21 patients (76% female) mean age 28.3 +/- 12.9 years (range 15-55) were enrolled. Mean reported paracetamol ingestion was 10.3 g (range 2-20 g). Specimens were collected at a mean of 6.2 +/- 3.1 hours post-ingestion (range 4-13 hours) and mean plasma and saliva paracetamol levels were 48 mg/L and 62 mg/L respectively (mean difference 14; 95% CI 5-22; p < 0.004); Pearson's correlation r = 0.95 (p < 0.0001). No patient needing treatment would have been missed using saliva levels only. CONCLUSION: There is concordance between the indications for treatment of paracetamol deliberate self-poisoning based on plasma and saliva paracetamol levels. Saliva paracetamol levels are typically higher than plasma levels. Further studies involving larger numbers of patients, comparing plasma and saliva paracetamol levels in patients with potentially toxic plasma paracetamol concentrations, would be useful in determining the potential clinical value of this method.

Biphasic cardioversion of acute atrial fibrillation in the emergency department.

INTRODUCTION: There is a trend towards accelerated management of acute atrial fibrillation (AF) in the emergency department (ED). We report our experience with biphasic cardioversion of acute AF. METHODS: This was a prospective, descriptive study at a tertiary hospital ED over a 6 month period. Acute AF was defined as symptoms that had been present for <48 hours. Patients who received biphasic cardioversion for acute AF in the ED were enrolled. Data collected included: patient demographics, past medical history, details of biphasic cardioversion, outcome, complications, disposition, and length of stay. RESULTS: There were 34 attempts at cardioversion in 33 patients. The mean (SD) age was 56 (16) years and 21 patients (64%) were men. Biphasic cardioversion was successful in 31 attempts (91%). In 24 attempts (71%), 100 J was selected as the initial energy level. This was successful in 21 attempts (88%). There were three minor complications related to sedation. The mean (SD) length of stay was 5.6 (2.8) hours in the ED and 15 (25) hours in the hospital. The three patients who failed to revert were older (mean age 64 years), had underlying cardiovascular disease, and spent longer in hospital (50 v 12 hours, p = 0.01). Telephone follow up was conducted with 32 patients (97%) at 3 months. Recurrence of AF occurred in 7 patients (22%). Most patients (31, 97%) were satisfied with the biphasic cardioversion. CONCLUSIONS: Biphasic cardioversion of acute AF is effective. The majority of patients can be managed as outpatients, and there is very high patient satisfaction with this approach. An initial shock energy level of 100 J is usually effective.

Access block causes emergency department overcrowding and ambulance diversion in Perth, Western Australia.

OBJECTIVE: Access block refers to the situation where patients in the emergency department (ED) requiring inpatient care are unable to gain access to appropriate hospital beds within a reasonable time frame. We systematically evaluated the relationship between access block, ED overcrowding, ambulance diversion, and ED activity. METHODS: This was a retrospective analysis of data from the Emergency Department Information System for the three major central metropolitan EDs in Perth, Western Australia, for the calendar years 2001-2. Bivariate analyses were performed in order to study the relationship between a range of emergency department workload variables, including access block (>8 hour total ED stay for admitted patients), ambulance diversion, ED overcrowding, and ED waiting times. RESULTS: We studied 259,580 ED attendances. Total diversion hours increased 74% from 3.39 hours/day in 2001 to 5.90 hours/day in 2002. ED overcrowding (r = 0.96; 95% confidence interval (CI) 0.91 to 0.98), ambulance diversion (r = 0.75; 95% CI 0.49 to 0.88), and ED waiting times for care (r = 0.83; 95% CI 0.65 to 0.93) were strongly correlated with high levels of ED occupancy by access blocked patients. Total attendances, admissions, discharges, and low acuity patient attendances were not associated with ambulance diversion. CONCLUSION: Reducing access block should be the highest priority in allocating resources to reduce ED overcrowding. This would result in reduced overcrowding, reduced ambulance diversion, and improved ED waiting times. Improving hospital inpatient flow, which would directly reduce access block, is most likely to achieve this.

Entry overload, emergency department overcrowding, and ambulance bypass.

OBJECTIVES: To describe an experience of emergency department (ED) overcrowding and ambulance bypass. METHODS: A prospective observational study at Royal Perth Hospital, a major teaching hospital. Episodes of ambulance bypass and their characteristics were recorded. RESULTS: From 1 July 1999 to 30 June 2001, there were 141 episodes of ambulance bypass (mean duration 187 min, range 35-995). Monday was the most common day with 39 (28%) episodes. Entry block alone was the most common reason bypass was activated (n=38, 30.4%). The mean number of patients in ED at these times was 40 (occupancy 174%), including nine in the corridor, seven awaiting admission, and 14 waiting to be seen. Episodes attributable to entry block were typically preceded by a presentation rate of >/=10 patients per hour for >/=2 hours (OR 6.2, 95% CI 4.3 to 8.5). Mid-afternoon to early evening was the most common time for activation. Ambulance bypass is increasing in frequency and duration. CONCLUSIONS: Entry overload resulting in entry block results from overwhelming numbers of patients presenting to the ED in a short space of time. Entry block impairs access to emergency care. Unless something is done in the near future, the general public may no longer be able to rely on EDs for quality and timely emergency care. A "whole of system" approach is necessary to tackle the problem.

NTS versus waiting time: an indicator without definition.

OBJECTIVE: The National Triage Scale versus waiting time is a key performance indicator for Australasian emergency departments. However, the point at which the clock starts to measure waiting time has not been defined. The aim of this study was to determine how this indicator is measured in Australia, as well as a number of other issues relating to the application of the National Triage Scale. METHODS: A postal survey was sent to the directors of emergency medicine at 147 emergency departments in Australia. RESULTS: There were 105 responses (71.4%). For measurement of the National Triage Scale versus waiting time indicator, 52 (49.5%) started the clock at the time of patient arrival, 33 (31.4%) at the start of triage, and 11 (10.5%) at the end of triage. Seventy-four emergency departments (70.5%) change the National Triage Scale (NTS) after it has been assigned, and approximately half use set codes for given presentations. Only 28 (26.7%) automatically upgrade children one NTS category. The age definition of a child ranged from 3 years to 18 years. CONCLUSIONS: The measurement of this key performance indicator is not consistent across Australia. Therefore, caution is advised when comparing such data between departments. The Australasian College for Emergency Medicine should produce operational definitions relating to the use of the National Triage Scale in order to provide meaningful comparative data.

A randomized controlled trial of buffered lidocaine for local anesthetic infiltration in children and adults with simple lacerations.

This study assessed the efficacy of buffered lidocaine in children and adults for the repair of simple lacerations. We compared plain lidocaine (PL) with buffered lidocaine (BL) in a prospective, randomized, double-blind, placebo controlled trial. Children had a 10-point pain score assessed by a nurse using predetermined behavior criteria, and a visual analog pain score (VAS) as perceived by the parent. Adult visual analog scores were self reported. In 135 adults, the median VAS was 2.1 for PL and 2.0 for BL. In 136 children, the median nurse-rated pain score was 4.5 for both PL and BL. The parent's median VAS was 4.5 for PL and 4.0 for BL. In contrast to previous studies, we conclude that buffered lidocaine does not reduce infiltration pain in children or adults.

Do children need to be monitored after electric shocks?

OBJECTIVE: To determine whether cardiac monitoring is required in children sustaining electric shock at Australian household voltage. METHODOLOGY: Records of patients admitted via the Emergency Department of Princess Margaret Hospital for Children, Perth, Australia, for the period 1968-96 were retrospectively reviewed. The initial ECG findings of patients with an electric shock were recorded, and the development of any arrhythmia. RESULTS: Forty-four patients were identified, 40 of whom had sustained a household electrical injury. One patient had an abnormal ECG on admission, none developed an arrhythmia and all survived. CONCLUSIONS: Routine cardiac monitoring is not required after exposure to Australian household electricity supply if the child is asymptomatic and has a normal ECG on presentation.

Emergency department telephone advice.

OBJECTIVE: To evaluate telephone advice given in an emergency department. DESIGN: Prospective, observational study. SETTING: A community-based emergency department in a semi-rural/outer metropolitan setting, between August and November 1995. PARTICIPANTS: All people telephoning the emergency department for medical advice. METHODS: Details of all calls, callers and patients were recorded. Within 72 hours, a follow-up call was initiated seeking replies to a series of standardised questions. MAIN OUTCOME MEASURES: Number, timing and duration of calls; appropriateness of the advice given; compliance with the advice; and callers' satisfaction with the service. RESULTS: Over the four-month period, 1682 calls were received, 58% between 4pm and midnight. There were 33 telephone calls per 100 emergency department attendances. The mean call duration was 3.9 minutes (range, 0.25-25 minutes); 49% of patients were less than 14 years old, and 72% of callers phoned because of spontaneous illness. The advice given was considered inappropriate in only 1.4% of calls. Follow-up calls were made to 1132 people (67%), revealing a non-compliance rate of only 6.9% and a high level of caller satisfaction, with 99% of callers affirming a need for such a service. CONCLUSIONS: The provision of telephone advice by emergency department staff is rated highly by the community and compliance with the advice is strong. Paediatric problems, arising as a result of spontaneous illness, predominate and there is a large bias towards after-hours use of the service. Experienced staff provide better advice.

The Medical Emergency Team (MET): a model for the district general hospital.

BACKGROUND: Most hospitals have a Cardiac Arrest Team, activated after cardiopulmonary arrest. The Medical Emergency Team (MET) is a newer concept, encompassing a proactive response to a wide range of emergencies with the aim of preventing irreversible organ failure and cardiopulmonary arrest. AIM: To describe the application of the MET model to the district general hospital, the spectrum of clinical conditions encountered, outcomes and administrative problems. METHOD: Data regarding each MET activation was collected prospectively. RESULTS: The MET responded to 68 calls to 63 patients in 12 months. The mean age was 60.4 years (range: neonatal to 94 years). The most common conditions leading to MET activation were chest pain (19.1%), cardiopulmonary arrest (14.7%), seizures (14.7%) and respiratory distress (13.2%). CONCLUSION: This paper demonstrates that the application of the MET model to the district general hospital improves the process of patient care. We are unable to conclude whether the MET alters morbidity or mortality for hospital inpatients.

Magnesium in cardiac arrest (the magic trial).

The prognosis of out of hospital cardiac arrest (OHCA) is dismal. Recent reports indicate that high dose magnesium may improve survival. A prospective randomized double blind placebo controlled trial was conducted at the emergency department (ED) of Royal Perth Hospital, a University teaching hospital. Patients with OHCA of cardiac origin received either 5 g MgSO4 or placebo as first line drug therapy. The remainder of their management was standard advanced cardiac life support (ACLS). Study endpoints were: (1) ECG rhythm 2 min after the trial drug; (2) return of spontaneous circulation; (3) survival to leave the ED; (4) survival to leave intensive care; and (5) survival to hospital discharge. Of 67 patients enrolled, 31 received magnesium and 36 placebo. There were no significant differences between groups for all criteria, except that there were significantly more arrests witnessed after arrival of EMS personnel in the magnesium group (11 or 35% vs 4 or 11%). Return of spontaneous circulation occurred in seven (23%) patients receiving magnesium and eight (22%) placebo. Four patients in each group survived to leave the ED and one from the magnesium group survived to hospital discharge. There were no survivors in the placebo group. In this study, the use of high dose magnesium as first line drug therapy for OHCA was not associated with a significantly improved survival. Early defibrillation remains the single most important treatment for ventricular fibrillation (VF). Further studies are required to evaluate the role of magnesium in cardiac and cerebral resuscitation.

The use of thrombolytic therapy in patients presenting to a peripheral metropolitan emergency department with acute myocardial infarction.

BACKGROUND: While use of thrombolytic therapy in the management of acute myocardial infarction has become accepted practice in major teaching hospitals, its use in peripheral metropolitan hospitals has not been well accepted. AIM: To evaluate the use of thrombolytic therapy in the management of acute myocardial infarction in the Emergency Department (ED) of a peripheral metropolitan hospital. METHODS: A mixed prospective and retrospective observational study of 69 patients with acute myocardial infarction, who received thrombolytic therapy during a three year period, was conducted in a community based ED. RESULTS: Demographic data, door to drug interval, complications occurring during administration of thrombolytics and subsequent interhospital transfer were recorded. The mean door to drug interval in 1992 was 79.7 minutes (95% CI: 50.7 to 109.1) and by 1994 this had fallen to 25.6 minutes (95% CI: 18.9 to 32.3). Hypertension (22%) was the most common complication of therapy observed and cardiac arrest occurred in two cases (3.2%). A single episode of hypotension and vomiting were the only complications that occurred during interhospital transfer. There were no deaths during therapy or transfer. CONCLUSION: Thrombolytic therapy can be undertaken in the EDs of peripheral metropolitan hospitals in a safe and timely manner. There is little justification for routine medical escorts in the clinically stable post thrombolysis patient.

A randomized, controlled trial of oral midazolam and buffered lidocaine for suturing lacerations in children (the SLIC Trial).

STUDY OBJECTIVE: To evaluate the efficacy of oral midazolam (0.3 mg/kg) and buffered lidocaine in reducing the anxiety associated with the repair of childhood lacerations. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial. SETTING: Community-based emergency department. PARTICIPANTS: Children younger than 10 years. INTERVENTIONS: Each subject was randomized into one of four treatment groups: A, midazolam and buffered lidocaine (n = 25); B, placebo and buffered lidocaine (n = 27); C, midazolam and plain lidocaine (n = 32); and D, placebo and plain lidocaine (n = 23). RESULTS: Anxiety level was scored on a scale of 1 to 4 on the basis of predetermined behavior criteria before and during repair. Parents independently rated the child's distress using a visual analog scale. Vital signs were measured on admission and at discharge. There were no significant differences among the treatment groups for age, location and length of laceration, or initial anxiety scores. Midazolam decreased the number of children with anxiety levels 3 and 4 by 24% (95% CI, 7.5% to 41.3%). There was a 33% reduction of the parents' distress rating with midazolam (P < .01). Buffered lidocaine had no effect on anxiety level. CONCLUSION: Oral midazolam (0.3 mg/kg) is a safe and effective treatment for reducing anxiety during the suturing of lacerations in children less than 10 years of age. In this study, buffered lidocaine had no effect on anxiety level.

Electric shock in pregnancy.

Emergency physicians need to be alert to the potential effects of electric shock in pregnancy. A review of all case reports in the English language literature of pregnant women exposed to electric shock was performed. Information on voltage, gestation, injury-to-delivery interval, and outcome was collected. There were 15 victims of electric shock in pregnancy. Fetal mortality (N = 11) was 73% and there was only one normal pregnancy following electric shock. The fetus is much less resistant to electric shock than the mother. Any woman who suffers from an electric shock in pregnancy, however minor, requires prompt fetal monitoring and careful obstetric supervision.

Electrocution in Western Australia, 1976-1990.

OBJECTIVE: To describe the epidemiology of electrical fatalities in Western Australia between 1976 and 1990. DATA SOURCES: Data for the study were gathered from hospital records, autopsy reports and findings from State Energy Commission and coronal investigations. DATA EXTRACTION: Information that was abstracted included age, sex, occupation, voltage, history of incident and autopsy findings. DATA SYNTHESIS: There were 104 victims. Death occurred most frequently in young men exposed to low voltage current during summer, and nearly half the fatalities occurred in the workplace. Water was present in up to 52% of fatalities. Without exception, all victims developed a lethal arrhythmia at the time of exposure to the electric shock, which usually resulted in death at the scene. CONCLUSION: When a victim is exposed to a fatal electric shock, the lethal arrhythmia occurs at the time of electrocution and is just as likely to occur at home as in the workplace. Electrical fatalities can be prevented largely by the use of residual current devices.