QTc-interval abnormalities and psychotropic drug therapy in psychiatric patients

BACKGROUND

Sudden unexplained death in psychiatric patients may be due to drug-induced arrhythmia, of which lengthening of the rate-corrected QT interval (QTc) on the electrocardiogram is a predictive marker. We estimated the point prevalence of QTc lengthening in psychiatric patients and the effects of various psychotropic drugs.

METHODS

Electrocardiograms were obtained from 101 healthy reference individuals and 495 psychiatric patients in various inpatient and community settings and were analysed with a previously validated digitiser technique. Patients with and without QTc lengthening, QTc dispersion, and T-wave abnormality were compared by logistic regression to calculate odds ratios for predictive variables.

FINDINGS

Abnormal QTc was defined from the healthy reference group as more than 456 ms and was present in 8% (40 of 495) of patients. Age over 65 years (odds ratio 3.0 [95% CI 1.1-8.3]), use of tricyclic antidepressants (4.4 [1.6-12.1]), thioridazine (5.4 [2.0-13.7]), and droperidol (6.7 [1.8-24.8]) were robust predictors of QTc lengthening, as was antipsychotic dose (high dose 5.3 [1.2-24.4]; very high dose 8.2 [1.5-43.6]). Abnormal QT dispersion or T-wave abnormalities were not significantly associated with antipsychotic treatment, but were associated with lithium therapy.

INTERPRETATION

Antipsychotic drugs cause QTc lengthening in a dose-related manner. Risks are substantially higher for thioridazine and droperidol. These drugs may therefore confer an increased risk of drug-induced arrhythmia.

Decay in quality of closed-chest compressions over time

STUDY OBJECTIVE

To characterize fatigue-induced deterioration in the adequacy of closed-chest compressions performed over a period of 5 minutes and to determine whether CPR providers can recognize the effects of fatigue on compression adequacy.

DESIGN

Prospective evaluation of study subjects performing closed-chest compressions on an electronic mannequin that assesses compression placement and depth.

SETTING

Major resuscitation room in rural university hospital emergency department.

PARTICIPANTS

Eleven experienced nursing assistants who regularly provide CPR in the ED.

RESULTS

Each study participant performed 5 minutes of closed-chest compressions. Compression adequacy (for placement and depth) was assessed with the mannequin and reported on an attached monitor out of view of the study subjects. Subjects were asked to verbally indicate the point during their 5-minute compression period at which they felt too fatigued to provide effective compressions (arbitrarily defined as a minimum of 90% of all compressions being judged correct by the mannequin). We used one-way repeated-measures ANOVA and regression analysis to determine whether compression adequacy diminished over time. ANOVA was also used to determine whether the total compressions performed per minute diminished over time. The percentage of correct chest compressions decreased significantly after 1 minute of compressions (P = .0001). We found 92.9% of compressions performed during minute 1 to be correct. The percentages for minutes 2 through 5 were as follows: 67.1%, 39.2%, 31.2%, and 18.0%. Regression analysis revealed a decrement in compression adequacy of 18.6% per minute after the first minute of compressions. The number of total compressions attempted per minute did not decrease (P = .98). Study subjects did not accurately identify the point during their 5-minute sessions at which their fatigue caused compressions to become impaired. Whereas mean compression adequacy declined below 90% after only 1 minute, the time of indicated fatigue was 253 +/- 40 seconds (mean +/- SD).

CONCLUSION

Although compression rate was maintained over time, chest compression quality declined significantly over the study period. Because CPR providers could not recognize their inability to provide proper compressions, cardiac arrest team leaders should carefully monitor compression adequacy during CPR to assure maximally effective care for patients receiving CPR.

Timing of Fresh Frozen Plasma Administration and Rapid Correction of Coagulopathy in Warfarin-Related Intracerebral Hemorrhage

Background and Purpose— Anticoagulation-related intracerebral hemorrhage (ICH) is often fatal, and rapid reversal of anticoagulation is the most appealing strategy currently available for treatment. We sought to determine whether particular emergency department (ED) interventions are effective in reversing coagulopathy and improving outcome.

Methods— Consecutive patients with warfarin-related ICH presenting to an urban tertiary care hospital from 1998 to 2004 were prospectively captured in a database. ED records were retrospectively reviewed for dose and timing of fresh-frozen plasma (FFP) and vitamin K, as well as serial coagulation measures. After excluding patients with incomplete ED records, do-not-resuscitate orders established in the ED, initial international normalized ratio (INR) ≤1.4, and for whom no repeat INR was performed, 69 patients were available for analysis. The primary outcome was a documented INR ≤1.4 within 24 hours of ED presentation.

Results— Patients whose INR was successfully reversed within 24 hours had a shorter median time from diagnosis to first dose of FFP (90 minutes versus 210 minutes; P =0.02). In multivariable analysis, shorter time to vitamin K, as well as FFP, predicted INR correction. Every 30 minutes of delay in the first dose of FFP was associated with a 20% decreased odds of INR reversal within 24 hours (odds ratio, 0.8; 95% CI, 0.63 to 0.99). Dosing of FFP and vitamin K had no effect. No ED intervention was associated with improved clinical outcome.

Conclusions— Time to treatment is the most important determinant of 24-hour anticoagulation reversal. Although additional study is required to determine the clinical benefit of rapid reversal of anticoagulation, minimizing delays in FFP administration is a prudent first step in emergency management of warfarin-related ICH.

Paracetamol (acetaminophen) poisoning

Paracetamol poisoning caused by intentional overdose remains a common cause of morbidity. In this article the mechanism of toxicity and the clinical effects and treatment of poisoning, including specific antidotal therapy, are reviewed. Areas for further research directed at reducing morbidity and mortality from paracetamol poisoning are considered.

Chest Ultrasonography for the Diagnosis and Monitoring of High-Altitude Pulmonary Edema

BACKGROUND

The comet-tail technique of chest ultrasonography has been described for the diagnosis of cardiogenic pulmonary edema. This is the first report describing its use for the diagnosis and monitoring of high-altitude pulmonary edema (HAPE), the leading cause of death from altitude illness.

METHODS

Eleven consecutive patients presenting to the Himalayan Rescue Association clinic in Pheriche, Nepal (4,240 m) with a clinical diagnosis of HAPE underwent one to three chest ultrasound examinations using the comet-tail technique to determine the presence of extravascular lung water (EVLW). Seven patients with no evidence of HAPE or other altitude illness served as control subjects. All examinations were read by a blinded observer.

RESULTS

HAPE patients had higher comet-tail score (CTS) [mean +/- SD, 31 +/- 11 vs 0.86 +/- 0.83] and lower oxygen saturation (O(2)Sat) [61 +/- 9.2% vs 87 +/- 2.8%] than control subjects (p < 0.001 for both). Mean CTS was higher (35 +/- 11 vs 12 +/- 6.8, p < 0.001) and O(2)Sat was lower (60 +/- 11% vs 84 +/- 1.6%, p = 0.002) at hospital admission than at discharge for the HAPE patients with follow-up ultrasound examinations. Regression analysis showed CTS was predictive of O(2)Sat (p < 0.001), and for every 1-point increase in CTS O(2)Sat fell by 0.67% (95% confidence interval, 0.41 to 0.93%, p < 0.001).

CONCLUSIONS

The comet-tail technique effectively recognizes and monitors the degree of pulmonary edema in HAPE. Reduction in CTS parallels improved oxygenation and clinical status in HAPE. The feasibility of this technique in remote locations and rapid correlation with changes in EVLW make it a valuable research tool.

Effects of morphine analgesia on diagnostic accuracy in Emergency Department patients with abdominal pain: a prospective, randomized trial

BACKGROUND

Because of concerns about masking important physical findings, there is controversy surrounding whether it is safe to provide analgesia to patients with undifferentiated abdominal pain. The purpose of this study was to address the effects of analgesia on the physical examination and diagnostic accuracy for patients with abdominal pain.

STUDY DESIGN

The study was a prospective, double-blind clinical trial in which adult Emergency Department (ED) patients with undifferentiated abdominal pain were randomized to receive placebo (control group, n = 36) or morphine sulphate (MS group, n = 38). Diagnostic and physical examination assessments were recorded before and after a 60-minute period during which study medication was titrated. Diagnostic accuracy and physical examination changes were compared between groups using univariate statistical analyses.

RESULTS

There were no differences between control and MS groups with respect to changes in physical or diagnostic accuracy. The overall likelihood of change in severity of tenderness was similar in MS (37.7%) as compared with control (35.3%) patients (risk ratio [RR] 1.07, 95% confidence interval [CI] 0.64-1.78). MS patients were no more likely than controls to have a change in pain location (34.0% versus 41.2%, RR 0.82, 95% CI 0.50-1.36). Diagnostic accuracy did not differ between MS and control groups (64.2% versus 66.7%, RR 0.96, 95% CI 0.73-1.27). There were no differences between groups with respect to likelihood of any change occurring in the diagnostic list (37.7% versus 31.4%, RR 1.20, 95% CI 0.71-2.05). Correlation with clinical course and final diagnosis revealed no instance of masking of physical examination findings.

CONCLUSIONS

Results of this study support a practice of early provision of analgesia to patients with undifferentiated abdominal pain.

Delivery of a nebulized aerosol to a lung model during mechanical ventilation. Effect of ventilator settings and nebulizer type, position, and volume of fill

Several factors may affect the delivery of a nebulized aerosol to the lung through an endotracheal tube during mechanical ventilation. To study these factors in vitro, a model representing ventilation of an adult patient was constructed by linking a Servo 900C ventilator to a standard humidified circuit and an endotracheal (ET) tube positioned within a pipe representing the trachea. This was connected via a filter to a lung simulator. Nebulizers filled with 99mTc human serum albumin were positioned in the circuit, and the delivery of nebulized aerosol through the ET tube into the filter was measured using a gamma camera. With the use of an inspiratory phase-activated System 22 Acorn jet nebulizer, typical adult ventilator settings, and a 3-ml nebulizer solution volume, 5.4% of the nebulizer dose reached beyond the end of the ET tube. This was increased by increasing the inspiratory time, reducing the respiratory rate or respiratory minute volume, and by repositioning the nebulizer on the inspiratory limb of the Y-piece and was reduced by slowing the driving gas flow to the nebulizer. Under the same conditions, delivery was 3.1 and 4.4% using the Samsonic and Fisoneb ultrasonic nebulizers, respectively. Increasing the fill volume and the addition of an aerosol storage chamber increased delivery with all three nebulizers. These experiments suggest some simple ways of improving aerosol delivery during mechanical ventilation, including increasing the volume of nebulizer fill, repositioning the nebulizer in the ventilator circuit, adding an aerosol storage chamber, and adjusting ventilator settings to maximize delivery.

Anti-TNF agents for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease with a prevalence of approximately 1% and an annual incidence of 0.04%. Up to 50% of patients with RA are unable to work 10 years after diagnosis. The disease is associated with significant morbidity and mortality with associated medical costs to the UK of between £240 m and £600 m per year.

Non steroidal anti-inflammatory drugs (NSAIDs) have little effect on the underlying course of RA, but they have some anti-inflammatory and analgesic properties. Disease modifying antirheumatic drugs (DMARDs) have been shown to slow progression of RA and are currently recommended early in the course of treatment of RA which is when disease progression is most rapid.

Etanercept and infliximab belong to a new group of parentally administered antitumour necrosis factor (TNF) drugs.

Etanercept is licensed in the UK for the treatment of active rheumatoid arthritis in patients who have not responded to other DMARDs and in children with polyarticular-course juvenile arthritis who have not responded to or are intolerant of methotrexate. In adults it produces significant improvements in all measures of rheumatic disease activity compared to placebo. In patients whose disease remains active despite methotrexate treatment, further improvement in control is obtained with the addition of etanercept without an increase in toxicity. In one small trial, etanercept was found to be more effective than placebo in a selected group of children.

Infliximab is a monoclonal antibody which is currently licensed in the UK for Crohn's disease and, in combination with methotrexate for the treatment of rheumatoid arthritis in patients with active disease when the response to disease-modifying drugs, including methotrexate, has been inadequate. In clinical trials infliximab produced significant improvements in all measures of rheumatic disease activity compared with placebo. Infliximab in combination with methotrexate was shown to be superior to methotrexate or infliximab alone.

There are currently no predictors of a good response to anti-TNF drugs and a percentage of patients fail to respond to treatment (25% to 38% of etanercept patients; 21% to 42% of infliximab patients). Infliximab monotherapy induces the production of anti-infliximab antibodies, which may reduce its effectiveness. Adding methotrexate to infliximab therapy may prevent this response.

Anti-TNF drugs may affect host defences against infection and malignancy; whether these agents affect the development and course of malignancies and chronic infections is unknown and safety and efficacy in patients with immunosuppression or chronic infections has not been investigated. With infliximab, upper respiratory tract infections, general infections and those requiring antimicrobial treatment were more common in patients than placebo. Likewise, upper respiratory tract infections were more common in patients treated with etanercept than with placebo. Injection site reactions occur with both infliximab (16%–20%) and etanercept (37%).

There are approximately 600 000 patients with RA in the UK, and of these between 2% and 3.5% may have severe disease which has failed to respond to conventional treatment and who might be eligible for anti-TNF therapy. If between 50% and 70% of patients treated with anti-TNF drugs respond and continue on long-term treatment then the recurrent annual cost to the NHS could be between £48 m and £129 m .

Congenital anomalies after prenatal ecstasy exposure

Prospective follow-up of 136 babies exposed to ecstasy in utero indicated that the drug may be associated with a significantly increased risk of congenital defects (15.4% [95% CI 8.2-25.4]). Cardiovascular anomalies (26 per 1000 livebirths [3.0-90.0]) and musculoskeletal anomalies (38 per 1000 [8.0-109.0]) were predominant.

Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multigroup, randomised controlled trial

BACKGROUND

The excruciating pain of patients with renal colic on presentation to the emergency department requires effective analgesia to be administered in the shortest possible time. Trials comparing intramuscular non-steroidal anti-inflammatory drugs with intravenous opioids or paracetamol have been inconclusive because of the challenges associated with concealment of randomisation, small sample size, differences in outcome measures, and inadequate masking of participants and assessors. We did this trial to develop definitive evidence regarding the choice of initial analgesia and route of administration in participants presenting with renal colic to the emergency department.

METHODS

In this three-treatment group, double-blind, randomised controlled trial, adult participants (aged 18-65 years) presenting to the emergency department of an academic, tertiary care hospital in Qatar, with moderate to severe renal colic (Numerical pain Rating Scale ≥ 4) were recruited. With the use of computer-generated block randomisation (block sizes of six and nine), participants were assigned (1:1:1) to receive diclofenac (75 mg/3 mL intramuscular), morphine (0.1 mg/kg intravenous), or paracetamol (1 g/100 mL intravenous). Participants, clinicians, and trial personnel were masked to treatment assignment. The primary outcome was the proportion of participants achieving at least a 50% reduction in initial pain score at 30 min after analgesia, assessed by intention-to-treat analysis and per-protocol analysis, which included patients where a calculus in the urinary tract was detected with imaging. This trial is registered with ClinicalTrials.gov, number NCT02187614.

FINDINGS

Between Aug 5, 2014, and March 15, 2015, we randomly assigned 1645 participants, of whom 1644 were included in the intention-to-treat analysis (547 in the diclofenac group, 548 in the paracetemol group, and 549 in the morphine group). Ureteric calculi were detected in 1316 patients, who were analysed as the per-protocol population (438 in the diclofenac group, 435 in the paracetemol group, and 443 in the morphine group). The primary outcome was achieved in 371 (68%) patients in the diclofenac group, 364 (66%) in the paracetamol group, and 335 (61%) in the morphine group in the intention-to-treat population. Compared to morphine, diclofenac was significantly more effective in achieving the primary outcome (odds ratio [OR] 1·35, 95% CI 1·05-1·73, p=0·0187), whereas no difference was detected in the effectiveness of morphine compared with intravenous paracetamol (1·26, 0·99-1·62, p=0·0629). In the per-protocol population, diclofenac (OR 1·49, 95% CI 1·13-1·97, p=0·0046) and paracetamol (1·40, 1·06-1·85, p=0·0166) were more effective than morphine in achieving the primary outcome. Acute adverse events in the morphine group occurred in 19 (3%) participants. Significantly lower numbers of adverse events were recorded in the diclofenac group (7 [1%] participants, OR 0·31, 95% CI 0·12-0·78, p=0·0088) and paracetamol group (7 [1%] participants, 0·36, 0·15-0·87, p=0·0175) than in the morphine group. During the 2 week follow-up, no additional adverse events were noted in any group.

INTERPRETATION

Intramuscular non-steroidal anti-inflammatory drugs offer the most effective sustained analgesia for renal colic in the emergency department and seem to have fewer side-effects.

FUNDING

Hamad Medical Corporation Medical Research Center, Doha, Qatar.

Concentration-related pharmacodynamic effects of thioridazine and its metabolites in humans

OBJECTIVE

To measure cardiac and other effects of thioridazine and relate these to the plasma concentration of the parent drug and its principal metabolites.

METHODS

A double-blind, randomized-order crossover study involving nine healthy male subjects compared the effects of single doses of thioridazine (10 mg and 50 mg) with placebo. Plasma concentrations of thioridazine and its ring sulfoxide, side-chain sulfoxide, and side-chain sulfone metabolites were measured, together with effects on the ECG, blood pressure, salivary flow, and a batch of psychomotor tests for 72 hours after administration.

RESULTS

Thioridazine, 50 mg, reduced standing systolic blood pressure (mean peak changes from baseline [95% CI] -32 mm Hg [-55, 10 mm Hg]; p < 0.01 versus placebo) and diastolic blood pressure (-14 mm Hg [-26, -2 mm Hg]; p < 0.05), increased standing heart rate (7 beats/min [-1, 16 beats/min]; p < 0.05), impaired psychomotor function, and prolonged the JT (20 ms1/2 [7, 34 ms1/2]; p < 0.05), QTa (22 ms1/2 [8, 36 ms1/2]; p < 0.05), and QTc (22 ms1/2 [11, 33 ms1/2]; p < 0.01) intervals, but had no effect on QT dispersion (-12 ms1/2 [-31, 6 ms1/2]). Thioridazine, 1.0 mg, also significantly increased QTc, but the effect was less marked (9 ms1/2 [-1, 19 ms1/2]; p < 0.05). Plasma thioridazine and metabolite concentrations did not correlate significantly with these effects. Maximum effects on QTc occurred after peak concentrations of thioridazine but before peak concentrations of the ring sulfoxide and side-chain sulfone metabolites.

CONCLUSIONS

These data suggest that thioridazine has dose-related effects on ventricular repolarization and that the parent drug causes an important proportion of these effects, although its metabolites may also contribute.

Helicopter transport and blunt trauma mortality: a multicenter trial

BACKGROUND

Despite many studies addressing potential impact of helicopter transport on trauma mortality, debate as to the efficacy of air transport continues.

METHODS

This retrospective study combined trauma registry data from five urban Level I adult and pediatric centers. Logistic regression assessed effect of helicopter transport on mortality while adjusting for age, sex, transport year, receiving hospital, prehospital level of care (Advanced Life Support vs. Basic Life Support), ISS, and mission type (scene vs. interfacility).

RESULTS

The study database comprised 16,699 patients. Crude mortality for Air (9.4%) was 3.4 times (95% CI, 2.9-4.0, p < 0.001) that of Ground (3.0%) patients. In adjusted analysis, helicopter transport was found to be associated with a significant mortality reduction (odds ratio, 0.76; 95% CI, 0.59-0.98; p = 0.031).

CONCLUSION

The results of this study are consistent with an association between helicopter transport mode and increased survival in blunt trauma patients.

Lack of effect of inhaled morphine on exercise-induced breathlessness in chronic obstructive pulmonary disease

BACKGROUND

Inhaled nebulised morphine may reduce breathlessness in patients with lung disease, although the results of controlled trials are conflicting. A direct action of morphine on the lung has been postulated. This study aimed to investigate whether nebulised morphine reduced exercise-induced breathlessness in patients with chronic obstructive pulmonary disease (COPD) and to determine if this was a local pulmonary effect or occurred after systemic morphine absorption.

METHODS

A double blind, randomised, crossover study was performed in 12 men with COPD to compare the effects of nebulised morphine (10 and 25 mg), equivalent intravenous doses (1 and 2.5 mg), and placebo. Breathlessness (visual analogue scale), ventilation, gas exchange, and exercise endurance were measured during graded bicycle exercise.

RESULTS

None of the treatments altered breathlessness, ventilation, or gas exchange at rest or at any time during exercise, and exercise endurance was unaffected. At peak exercise mean (95% CI) changes from placebo in ventilation were -0.8 (-0.57 to 1.1) l/min and -0.4 (-2.8 to 2.0) l/min for the highest intravenous and nebulised doses, respectively. For breathlessness equivalent values were +2 (-5 to 9) and +1 (-9 to 11) mm. The study was of sufficient power that it is unlikely that a clinically important effect was missed.

CONCLUSIONS

Nebulised morphine in these doses has no effect on exercise-induced breathlessness. These findings do not support the hypothesis that intrapulmonary opiates modulate the sensation of breathlessness in patients with COPD.

Ongoing visual analog score display improves Emergency Department pain care

The study purpose was to test two methods of pain assessment and display: ongoing (11 times over 2 h) visual analog scale (VAS) determination with data tabulation in the ED chart (Tabulation group), and similar VAS assessments with display of the information at the head of the ED bed (Graph group). A Control group had initial and 2-h VAS ascertainments charted (not graphed). Tertiary-care university-affiliated ED patients were randomized into the three groups and pain care outcomes assessed. Compared to Controls, those in the Graph group had the following findings (p < 0.05): 1) treating physicians more likely aware of initial and final VAS scores, 2) earlier analgesia, 3) likelier perception (by patients and physicians) that VAS was useful and likelier patient perception that pain care was adequate. Tabulation group results were intermediate to those of Control and Graph patients. The data support further investigation of VAS display as a means of improving ED pain assessment.

Assessment of hyperglycemia after calcium channel blocker overdoses involving diltiazem or verapamil

BACKGROUND

Overdoses of calcium channel blocker agents result in hyperglycemia, primarily due to the blockade of pancreatic L-type calcium channels and insulin resistance on the cellular level. The clinical significance of the hyperglycemia in this setting has not previously been described.

METHODS

This study is a retrospective review of all adult (age, >or=15 yrs) patients with a discharge diagnosis of acute verapamil or diltiazem overdose at five university-affiliated teaching hospitals. The severity of overdose was assessed by determining whether a patient met the composite end points of in-hospital mortality, the necessity for a temporary pacemaker, or the need for vasopressors. We compared the initial and peak serum glucose concentrations with hemodynamic variables between patients who did and did not meet the composite end points.

RESULTS

A total of 40 patients met inclusion criteria, with verapamil and diltiazem accounting for 27 of 40 (67.5%) and 13 of 40 (32.5%) of the ingestions, respectively. For those patients who did and did not meet the composite end points, the median initial serum glucose concentrations were 188 (interquartile range, 143.5-270.5) mg/dL and 129 (98.5-156.5) mg/dL, respectively (p = .0058). The median peak serum glucose concentrations for these two groups were 364 (267.5-408.5) mg/dL and 145 (107.5-160.5) mg/dL, respectively (p = .0001). The median increase in blood glucose was 71.2% for those who met composite end points vs. 0% for those who did not meet composite end points (p = .0067). Neither the change in the median heart rate nor the change in systolic blood pressure was significantly different in any group.

CONCLUSION

Serum glucose concentrations correlate directly with the severity of the calcium channel blocker intoxication. The percentage increase of the peak glucose concentration is a better predictor of severity of illness than hemodynamic derangements. If validated prospectively, serum glucose concentration alone might be an indicator to begin hyperinsulinemia-euglycemia therapy.

Presentation of poisoned patients to accident and emergency departments in the north of England

1. A 12 week prospective survey of all patients of any age with confirmed or suspected poisoning presenting to six accident and emergency departments in the North East of England was performed to establish the local incidence and patterns of presentation of poisoning. 2. 945 episodes of poisoning involving 852 patients were recorded representing approximately 1.2% of all A&E presentations and suggesting an annual attendance rate of 2.7 per 1000 persons per year. 3. Attendance rates varied threefold between hospitals and were similar in males and females overall; between the ages of five and 14 attendances were more common in females (1.9 vs 0.6/10(3)/y) while between 0 and 4 y (3.1 vs 2.4) and 25 and 34 y (3.9 vs 2.9/10(3)/y) they were more common in males. 4. The median interval between poisoning and presentation was 2 h (mean 4.1 h) and only 19% of cases presented within 1 h. Presentation was most common between Friday evening and Tuesday morning and in the late afternoon and evening. 5. 6% of the patients presented more than once with poisoning during the study period and 37% had a past history of deliberate self-harm. The most common poisons involved were paracetamol (43%), opioids (15%) and benzodiazepines (15%). 6. The study illustrates the frequency of presentations of poisoning to A&E departments. The high rate of poisoning in young men and the increasing use of paracetamol are particular causes for concern.

Pulmonary deposition of a nebulised aerosol during mechanical ventilation

BACKGROUND

There is increasing use of therapeutic aerosols in patients undergoing mechanical ventilation. Few studies have measured aerosol delivery to the lungs under these conditions with adequate experimental methods. Hence this study was performed to measure pulmonary aerosol deposition and to determine the reproducibility of the method of measurement during mechanical ventilation.

METHODS

Nine male patients were studied during mechanical ventilation after open heart surgery and two experiments were performed in each to determine the reproducibility of the method. A solution of technetium-99m labelled human serum albumin (99mTc HSA (50 micrograms); activity in experiment 1, 74 MBq; in experiment 2, 185 MBq) in 3 ml saline was administered with a Siemens Servo 945 nebuliser system (high setting) and a System 22 Acorn nebuliser unit. Pulmonary deposition was quantified by means of a gamma camera and corrections derived from lung phantom studies.

RESULTS

Pulmonary aerosol deposition was completed in 22 (SD 4) minutes. Total pulmonary deposition (% nebuliser dose (SD)) was 2.2 (0.8)% with 1.5% and 0.7% depositing in the right and left lungs respectively; 0.9% of the nebuliser activity was detected in the endotracheal tube or trachea and 51% was retained within the nebuliser unit. Considerable variability between subjects was found for total deposition (coefficient of variation (CV) 46%), but within subject reproducibility was good (CV 15%).

CONCLUSIONS

Administration of aerosol in this way is inefficient and further research is needed to find more effective alternatives in patients who require mechanical respiratory support. This method of measurement seems suitable for the assessment of new methods of aerosol delivery in these patients.

The use of atypical antipsychotics in the management of schizophrenia

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: an estimated quarter to one third of patients are treatment-resistant; conventional antipsychotics have only a modest impact upon negative symptoms (poverty of thought, social withdrawal and loss of affect); and adverse effects, particularly extrapyramidal symptoms (EPS). Newer, so-called atypical, antipsychotics such as olanzapine, risperidone, sertindole and clozapine (an old drug which was re-introduced in 1990) are claimed to address these limitations. Atypical agents are, at a minimum, at least as effective as conventional drugs such as haloperidol. They also cause substantially fewer extrapyramidal symptoms. However, some other adverse effects are more common than with conventional drugs. For example, clozapine carries a significant risk of serious blood disorders, for which special monitoring is mandatory; it also causes troublesome drowsiness and increased salivation more often than conventional agents. Some atypical agents cause more weight gain or QT prolongation than older agents. The choice of therapy is, therefore, not straightforward. At present, atypical agents represent an advance for patients with severe or intolerable EPS. Most published evidence exists to support the use of clozapine, which has also been shown to be effective in schizophrenia refractory to conventional agents. However, the need for compliance with blood count monitoring and its sedative properties make careful patient selection important. The extent of any additional direct benefit offered by atypical agents on negative symptoms is not yet clear. The lack of a depot formulation for atypical drugs may pose a significant practical problem. To date, only two double-blind studies in which atypical agents were compared directly have been published. Neither provides compelling evidence for the choice of one agent over another. Atypical agents are many times more expensive than conventional drugs. Although drug treatment constitutes only a small proportion of the costs of managing schizophrenia, the additional annual cost of the use of atypical agents in, say, a quarter of the likely U.K. schizophrenic population would be about 56 M pound sterling. There is only limited evidence of cost-effectiveness. Atypical antipsychotics are not currently licensed for other conditions where conventional antipsychotics are commonly used, such as behaviour disturbance or dementia in the elderly. Their dose, and place in treatment in such cases have yet to be determined.

Can correct closed-chest compressions be performed during prehospital transport?

INTRODUCTION

The resuscitation rate from out-of-hospital cardiac arrest is low. There are many factors to be considered as contributing to this phenomenon. One factor not previously considered is the impact of a moving ambulance environment on the ability to perform closed-chest compressions.

HYPOTHESIS

Proper closed-chest compressions can be performed in a moving ambulance.

METHODS

A cardiopulmonary resuscitation (CPR) training mannequin with an attached skill meter (Skillmeter ResusciAnnie, Laerdal, Armonk, N.Y., USA) that measures each chest compression for proper depth and hand placement was used. Ten emergency medical technician-basic (EMT-B) certified prehospital providers were assigned into one of five teams. Each team performed a total of four sessions of five minutes of continuous closed-chest compressions on the mannequin. Two sessions were done by each team: one in the control environment with the mannequin placed on the floor, and the other in the experimental environment with the mannequin placed in the back of a moving ambulance. The ambulance was operated without warning lights and siren, and all traffic rules were obeyed. The percentage of correct closed-chest compressions was recorded for each session, and the mean values were compared using Student's t-test with alpha set at 0.01 for statistical significance.

RESULTS

Ten sessions of compressions were done in both environments. The mean percentage of correct compressions was 77.6 +/- 15.6 for the control group and 45.6 +/- 18.3 for the ambulance group (p = 0.0005).

CONCLUSION

A moving ambulance environment appears to impair the ability to perform closed-chest compressions.

Lives saved by helicopter emergency medical services: an overview of literature

INTRODUCTION

The objective of this review is to give an overview of literature on the survival benefits of Helicopter Emergency Medical Services (HEMS). The included studies were assessed by study design and statistical methodology.

METHODS

A literature search was performed in the National Library of Medicine's Medline database, extending from 1985 until April 2007. Manuscripts had to be written in English and describe effects of HEMS on survival expressed in number of lives saved. Moreover, analysis had to be performed using adequate adjustment for differences in case-mix.

RESULTS

Sixteen publications met the inclusion criteria. All indicated that HEMS assistance contributed to increased survival: Between 1.1 and 12.1 additional survivors were recorded for every 100 HEMS uses. A combination of four reliable studies shows overall mortality reduction of 2.7 additional lives saved per 100 HEMS deployments.

CONCLUSION

Literature shows a clear positive effect on survival associated with HEMS assistance. Efforts should be made to promote consistent methodology, including uniform outcome parameters, in order to provide sufficient scientific evidence to conclude the ongoing debate about the beneficial effects of HEMS.

High altitude headache: efficacy of acetaminophen vs. ibuprofen in a randomized, controlled trial

Ibuprofen has been shown to be more effective than placebo in the treatment of high altitude headache (HAH), but nonsteroidal anti-inflammatory agents have been linked to increased incidence of gastrointestinal (GI) side effects and high-altitude pulmonary edema (HAPE). We postulated that acetaminophen, which does not share ibuprofen's theorized causal link to GI side effects or HAPE, could provide effective HAH therapy. We conducted a prospective, randomized, double-blind, clinical trial of ibuprofen vs. acetaminophen in the Solu Khumbu, Nepal: Mt. Everest Base Camp, Pheriche, Dingboche (4240 m to 5315 m). Seventy-four consecutive patients (ages 13 to 61 years) were randomized, were assessed with the Lake Louise Acute Mountain Sickness (AMS) criteria, and received a physical examination (which included vital signs, oxygen saturation as measured by pulse oximetry (SpO(2)), and assessment of clinical Lake Louise AMS criteria). Patients then received either 400 mg of ibuprofen (IBU) or 1000 mg of acetaminophen (ACET), and were asked to rate their cephalgia using a 10-cm visual analog scale (VAS). Thirty-nine patients received IBU, and 35 received ACET. Baseline Lake Louise AMS scores were identical in the two groups (mean = 5.9). No differences in mean VAS scores between IBU and ACET groups were noted at time 0 (presentation), 30, 60, or 120 min. No cases of HAPE or high altitude cerebral edema were noted during the study period. In this study population, acetaminophen was as effective as ibuprofen in relieving the pain of HAH.

Report of the Task Force on National Fourth Year Medical Student Emergency Medicine Curriculum Guide

This manuscript reports recommendations of the National Fourth Year Medical Student Emergency Medicine Curriculum Guide Task Force. This task force was convened by 6 major emergency medicine organizations to develop a standardized curriculum for fourth year medical students. The structure of the curriculum is based on clerkship curricula from other specialties such as internal medicine and pediatrics. The report contains a historical context, global and targeted needs assessment, goals and objectives, recommended educational strategies, implementation guidelines, and suggestions on feedback and evaluation.