Kyung Chul Cha

Compression of the Left Ventricular Outflow Tract During Cardiopulmonary Resuscitation

OBJECTIVES This prospective observational study was performed to investigate if the hand position used for external chest compressions is in an optimal position for compressing the ventricles during standard cardiopulmonary resuscitation (CPR). METHODS Transesophageal echocardiography (TEE) was performed during standard CPR in 34 patients with nontraumatic cardiac arrest (24 males, mean +/- standard deviation [SD] age = 56 +/- 12 years). On the recorded image of TEE, an area of maximal compression (AMC) was identified, and the degree of compression at the AMC and the left ventricular stroke volume was calculated. RESULTS A significant narrowing of the left ventricular outflow tract (LVOT) or the aorta was noted in all patients, with the degree of compression at the AMC ranging from 19% to 83% (mean +/- SD = 49 +/- 19%). The AMC was found at the aorta in 20 patients (59%) and at the LVOT in 14 patients (41%). A significant narrowing of more than 50% of the diameter at the end of the relaxation phase occurred in 15 patients (44%). On linear regression, the left ventricular stroke volume was correlated with the location of the AMC (R(2) = 0.165, p = 0.017). CONCLUSIONS The outflow of the left ventricle is affected during standard CPR, resulting in varying degrees of narrowing in the LVOT and/or the aortic root.

Dapsone intoxication: clinical course and characteristics

Background and objectives. Dapsone is used as an antibiotic for leprosy and for dermatological disorders and may cause methemoglobinemia. The aims of this study are to analyze the clinical characteristics of patients presenting to the emergency department (ED) with dapsone ingestion to identify risk factors associated with mortality. Methods. We conducted a retrospective observational study of adult ED patients with methemoglobinemia because of dapsone intoxication admitted to a tertiary care hospital from September 2003 to December 2008. Data collected included demographic, clinical, and laboratory characteristics, as well as survival to discharge. Characteristics of young (less than or equal to 55 years) and older (greater than age 55) patients were compared. The main outcome was in-hospital mortality. Results. There were 46 patients included in the study. The minimum intoxication dose was two 100 mg tablets and the maximum was 100 tablets. Changes in mental status were more common in the older patients. Methemoglobin levels were slightly higher in the younger patients, but both groups were treated with similar doses of methylene blue. Shock and death were more common in the older patients. Conclusions. Late presentation to medical care and an altered mental status at the time of presentation were predictive of death after dapsone intoxication. Methemoglobin levels tended to be higher in those who died.

Features of myocardial injury in severe organophosphate poisoning

Abstract Background. In organophosphate (OP) poisoning cardiac complications may occur. However, the current body of knowledge largely consists of limited studies, and case reports are mainly on electrocardiogram (ECG) abnormalities. As definite myocardial injury is difficult to assess through ECG, we investigated the prevalence of myocardial injury through cardiac biochemical markers such as troponin I (TnI) in severe OP poisoning. Methods. We conducted a retrospective review of 99 consecutive OP insecticide poisoning cases that were diagnosed and treated at the emergency department of the Wonju Severance Christian Hospital between March 2008 and December 2013. Results. Based on Namba classification for OP poisoning, there were no patients with mild toxicity, 9 patients (9.1%) with moderate toxicity and 90 patients (90.9%) with severe toxicity. On ECG, normal sinus rhythm was most common, and ST depression and elevation were seen in 11 patients (11.1%). Elevation of TnI within 48 h was seen in 34 patients (34.3%). The median peak level and peak time of TnI were 0.305 (IQR, 0.078–2.335) ng/mL and 15 (IQR 6.9–34.4) hours, respectively. There were differences between patients with normal TnI and elevated TnI in terms of age (yrs), number of patients who were exposed to OP via the oral route, and initial Glasgow Coma Scale (GCS; 58 ± 17 vs. 66 ± 16, p = 0.015, 56 [87.5%] vs. 33 [97.1%], p = 0.048 and 12.0 [IQR, 8.0–15.0] vs. 9.0 [IQR, 5.8–12.0], p = 0.019). Conclusions. OP can cause direct myocardial injury during the acute early phase in severe OP poisoning. Monitoring of TnI may be needed in severe OP poisoning.

A Simple Audio-visual Prompt Device Can Improve CPR Performance

BACKGROUND An adjunct to assist cardiopulmonary resuscitation (CPR) might improve the quality of CPR performance. STUDY OBJECTIVES This study was conducted to evaluate whether a simple audio-visual prompt device improves CPR performance by emergency medical technicians (EMTs). METHODS From June 2008 to October 2008, 55 EMTs (39 men, mean age 34.9±4.8 years) participated in this study. A simple audio-visual prompt device was developed. The device generates continuous metronomic sounds for chest compression at a rate of 100 beats/min with a distinct 30(th) sound followed by two respiration sounds, each for 1 second. All EMTs were asked to perform a 2-min CPR series on a manikin without the device, and one 2-min CPR series with the device. RESULTS The average rate of chest compressions was more accurate when the device was used than when the device was not used (101.4±12.7 vs. 109.0±17.4/min, respectively, p=0.012; 95% confidence interval [CI] 97.2-103.8 vs. 104.5-113.5/min, respectively), and hands-off time during CPR was shorter when the device was used than when the device was not used (5.4±0.9 vs. 9.2±3.9 s, respectively, p<0.001; 95% CI 5.2-5.7 vs. 8.3-10.3 s, respectively). The mean tidal volume during CPR with the device was lower than without the device, resulting in the prevention of hyperventilation (477.6±60.0 vs. 636.6±153.4 mL, respectively, p<0.001; 95% CI 463.5-496.2 vs. 607.3-688.9 mL, respectively). CONCLUSION A simple audio-visual prompt device can improve CPR performance by emergency medical technicians.

Bilateral intracerebral hemorrhage following CPR

Intracranial hemorrhage is an extremely rare complication following cardiopulmonary resuscitation (CPR). Only a few cases of subarachnoid hemorrhage during the post-resuscitation period have been reported in the literature. A 55 year-old man, who was resuscitated following a cardiac arrest, sustained an intracranial hemorrhage during the post cardiac arrest period. His brain computerized tomography (CT), performed 4 hours after return of spontaneous circulation, showed no signs of intracranial hemorrhage. However, a brain CT performed 7 days after cardiac arrest revealed a massive intracerebral hemorrhage in both basal ganglia and thalami with an associated subarachnoid hemorrhage. This paper reports the first case of intracerebral hemorrhages in bilateral basal ganglia and thalami that developed following cardiac arrest and resuscitation.