ST segment elevation and the prediction of hospital life-threatening complications: the role of right ventricular and posterior leads.

UNLABELLED: Accurate prognosis in suspected acute myocardial infarction (AMI) is essential for appropriate use of thrombolytic therapy and primary angioplasty. However, previous models may be limited because the 12-lead electrocardiogram (ECG) does not examine the right ventricular (RV) and posterior myocardium. We evaluated ST segment elevation (STSE) in posterior (V7-V9) and RV (V4R-V6R) leads to determine their predictive value for hospital life-threatening complications (HLTCs). METHOD AND RESULTS: This prospective trial of seven Midwestern hospital emergency departments (EDs) had inclusion criteria of age 35 years, chest pain suggestive of ischemia, and coronary care unit (CCU) admission. ECG leads were test positive if STSE was > 0.1 mV. Patients were positive for HLTCs if ED or inpatient hospital course included: ventricular fibrillation or tachycardia, second- or third-degree block, shock, arrest, or death. Univariate and multivariate analyses were performed to test each lead's association with HLTCs. Of 533 patients, 64.7% (345/533) had AMI and 15.8% (85/533) had HLTCs. The sensitivity of 18 leads for HLTCS was increased by 5.8%, but specificity decreased by 8.2%. ECG subgroups by STSE were associated with the following HLTC rates: inferior/+RV (32.4%); anterior (29.5%), lateral (23.1%), inferior RV (17.9%), and posterior (16.2%). V1 (odds = 3.2) and V6R (odds = 3.1) were statistically significant independent predictors. CONCLUSION: Posterior and RV leads did not increase the ECG's overall prognostic value, but in the presence of inferior STSE, were associated with low and high complication rates, respectively. Right and left precordial leads were the best predictors of HTLCs.

Value of posterior and right ventricular leads in comparison to the standard 12-lead electrocardiogram in evaluation of ST-segment elevation in suspected acute myocardial infarction.

In this multicenter prospective trial, we studied posterior (V7 to V9) and right ventricular (V4R to V6R) leads to assess their accuracy compared with standard 12-lead electrocardiograms (ECGs) for the diagnosis of acute myocardial infarction (AMI). Patients aged >34 years with suspected AMI received posterior and right ventricular leads immediately after the initial 12-lead ECG. ST elevation of 0.1 mV in 2 leads was blindly determined and inter-rater reliability estimated. AMI was diagnosed by World Health Organization criteria. The diagnostic value of nonstandard leads was determined when 12-lead ST elevation was absent and present and multivariate stepwise regression analysis was also performed. Of 533 study patients, 64.7% (345 of 533) had AMI and 24.8% received thrombolytic therapy. Posterior and right ventricular leads increased sensitivity for AMI by 8.4% (p = 0.03) but decreased specificity by 7.0% (p = 0.06). The likelihood ratios of a positive test for 12, 12 + posterior, and 12 + right ventricular ECGs were 6.4, 5.6, and 4.5, respectively. Increased AMI rates (positive predictive values) were found when ST elevation was present on 6 nonstandard leads (69.1%), on 12 leads only (88.4%), and on both 6 and 12 leads (96.8%; p <0.001). Treatment rates with thrombolytic therapy increased in parallel with this electrocardiographic gradient. Logistic regression analysis showed that 4 leads were independently predictive of AMI (p <0.001): leads I, II, V3, V5R; V9 approached statistical significance (p = 0.055). The standard ECG is not optimal for detecting ST-segment elevation in AMI, but its accuracy is only modestly improved by the addition of posterior and right ventricular leads.

Skin and mucous membrane contacts with blood during surgical procedures: risk and prevention.

OBJECTIVE: To study the epidemiology and preventability of blood contact with skin and mucous membranes during surgical procedures. DESIGN: Observers present at 1,382 surgical procedures recorded information about the procedure, the personnel present, and the contacts that occurred. SETTING: Four US teaching hospitals during 1990. PARTICIPANTS: Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES: Numbers and circumstances of contact between the patient's blood (or other infective fluids) and surgical personnel's mucous membranes (mucous membrane contacts) or skin (skin contacts, excluding percutaneous injuries). RESULTS: A total of 1,069 skin (including 620 hand, 258 body, and 172 face) and 32 mucous membrane (all affecting eyes) contacts were observed. Surgeons sustained most contacts (19% had > or = 1 skin contact and 0.5% had > or = 1 mucous membrane-eye contact). Hand contacts were 72% lower among surgeons who double gloved, and face contacts were prevented reliably by face shields. Mucous membrane-eye contacts were significantly less frequent in surgeons wearing eyeglasses and were absent in surgeons wearing goggles or face shields. Among surgeons, risk factors for skin contact depended on the area of contact: hand contacts were associated most closely with procedure duration (adjusted odds ratio [OR], 9.4; > or = 4 versus < 1 hour); body contacts (arms, legs, and torso) with estimated blood losses (adjusted OR, 8.4; > or = 1,000 versus < 100 mL); and face contacts, with orthopedic service (adjusted OR, 7.5 compared with general surgery). CONCLUSION: Skin and mucous membrane contacts are preventable by appropriate barrier precautions, yet occur commonly during surgery. Surgeons who perform procedures similar to those included in this study should strongly consider double gloving, changing gloves routinely during surgery, or both.

Avulsion of the iliac crest apophysis: a rare fracture in adolescent athletes.

We report a case of an iliac apophyseal fracture in a 15-year-old boy, sustained while swinging a baseball bat. He presented with right hip pain one hour after the injury occurred. Diagnosis was made on the basis of radiographs of the pelvis. Pelvic avulsion fractures are uncommon injuries, seen almost exclusively in adolescent athletes. The iliac crest is an unusual site of injury for this avulsion fracture. Only one other well-described case of an acute, noncontact fracture of the iliac apophysis with a similar mechanism of injury has been reported.

Risk of human immunodeficiency virus infection among emergency department workers.

PURPOSE: To estimate (1) the prevalence of human immunodeficiency virus (HIV) infection in emergency department (ED) patients, (2) the frequency of blood contact (BC) in ED workers (EDWs), (3) the efficacy of gloves in preventing BC, and (4) the risk of HIV infection in EDWs due to BC. PATIENTS AND METHODS: We conducted an 8-month study in three pairs of inner-city and suburban hospital EDs in high AIDS incidence areas in the United States. At each hospital, blood specimens from approximately 3,400 ED patients were tested for HIV antibody. Observers monitored BC and glove use by EDWs. RESULTS: HIV seroprevalence was 4.1 to 8.9 per 100 patient visits in the 3 inner-city EDs, 6.1 in 1 suburban ED, and 0.2 and 0.7 in the other 2 suburban EDs. The HIV infection status of 69% of the infected patients was unknown to ED staff. Seroprevalence rates were highest among patients aged 15 to 44 years, males, blacks and Hispanics, and patients with pneumonia. BC was observed in 379 (3.9%) of 9,793 procedures; 362 (95%) of the BCs were on skin, 11 (3%) were on mucous membranes, and 6 (2%) were percutaneous. Overall procedure-adjusted skin BC rates were 11.2 BCs per 100 procedures for ungloved workers and 1.3 for gloved EDWs (relative risk = 8.8; 95% confidence interval = 7.3 to 10.3). In the high HIV seroprevalence EDs studied, 1 in every 40 full-time ED physicians or nurses can expect an HIV-positive percutaneous BC annually; in the low HIV seroprevalence EDs studied, 1 in every 575. The annual occupational risk of HIV infection for an individual ED physician or nurse from performing procedures observed in this study is estimated as 0.008% to 0.026% (1 in 13,100 to 1 in 3,800) in a high HIV seroprevalence area and 0.0005% to 0.002% (1 in 187,000 to 1 in 55,000) in a low HIV seroprevalence area. CONCLUSIONS: In both inner-city and suburban EDs, patient HIV seroprevalence varies with patient demographics and clinical presentation; the infection status of most HIV-positive patients is unknown to ED staff. The risk to an EDW of occupationally acquiring HIV infection varies by ED location and the nature and frequency of BC; this risk can be reduced by adherence to universal precautions.

Percutaneous injuries during surgical procedures.

OBJECTIVE: To study the numbers and circumstances of percutaneous injuries (eg, needle sticks, cuts) that occur during surgical procedures. Surgical personnel risk infection with blood-borne pathogens from percutaneous injuries; some injuries might also place patients at risk by exposing them to a health care worker's blood. DESIGN: Observers present at 1382 surgical procedures recorded information about the procedure, the personnel present, and percutaneous injuries that occurred. SETTING: Four US teaching hospitals during 1990. PARTICIPANTS: Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES: Numbers and circumstances of percutaneous injuries among surgical personnel and instances in which surgical instruments that had injured a worker recontacted the patient's surgical wound. RESULTS: Ninety-nine injuries occurred during 95 (6.9%) of the 1382 procedures. Seventy-six injuries (77%) were caused by suture needles and affected the nondominant hand (62 injuries [63%]), especially the distal forefinger. The risk of injury adjusted for confounding variables by logistic regression was higher during vaginal hysterectomy (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.6 to 7.5) and lower during certain orthopedic procedures (OR, 0.2; CI, 0.1 to 0.7) than during 11 other types of procedures (reference group; OR, 1.0). Use of fingers rather than an instrument to hold the tissue being sutured was associated with 35 injuries (35%). Eighty-eight injuries (89%) were sustained by resident or attending surgeons; in 28 (32%) of the 88 injuries in surgeons, the sharp object that caused the injury recontacted the patient. CONCLUSION: Percutaneous injuries occur regularly during surgery, placing surgical personnel and, to a lesser extent, patients at risk for infection with blood-borne pathogens. Many such injuries may be preventable with changes in devices, techniques, or protective equipment; all such measures require careful evaluation to determine their efficacy in reducing injury and their effect on patient care.

Delayed traumatic intrapericardial diaphragmatic hernia associated with cardiac tamponade.

We describe a case of delayed presentation of traumatic intrapericardial diaphragmatic hernia associated with cardiac tamponade. A 71-year-old woman presented to our emergency department complaining of epigastric and midabdominal pain one month after hospitalization for multiple injuries suffered in an automobile accident. Chest radiograph showed a diaphragmatic hernia. In the ED, the patient became hypotensive and tachycardic with elevated central venous pressure. At surgery, she was found to have omentum and transverse colon herniated into the pericardial sac causing cardiac tamponade. The defect was repaired, and her postoperative course was uncomplicated. Cardiac tamponade should be included in the differential diagnosis of hypotension in patients with radiographic evidence of diaphragmatic hernia.

Treatment of caffeine toxicity with esmolol.

We present the case of a 58-year-old woman who ingested more than 35 g of caffeine in a suicide attempt. She manifested all the clinical symptoms and signs of caffeine toxicity. Esmolol, an ultrashort-acting beta 1-selective antagonist, controlled her multiple dysrhythmias and symptoms of sympathetic nervous system hyperstimulation. We suggest the use of esmolol for treatment of dysrhythmias secondary to caffeine toxicity; to the best of our knowledge, the use of esmolol has not been reported for this purpose.

Microcomputer-assisted transmission of disaster data by cellular telephone.

Voice communication of information during disasters is often inadequate. In particular, simultaneous transmission by multiple callers on the same frequency can result in blocked transmissions and miscommunications. In contrast, nonvoice transmission of data requires less time than does voice communication of the same data, and may be more accurate. We conducted a pilot study to test the feasibility of a microcomputer assisted communication (MAC) network linking the disaster scene and the command hospital. The radio chosen to transmit data from the field disaster site to the command hospital was a cellular telephone connected to the microcomputer by modem. Typed communications between the microcomputer operators enabled dialogue between the disaster site and the hospitals. A computer program using commercially available software (Symphony by Lotus, Inc.) was written to allow for data entry, data transmission, and reports. Patient data, including age, sex, severity of injury, identification number, major injuries, and hospital destination were successfully transmitted from the disaster site command post to the command hospital. This pilot test demonstrated the potential applicability of MAC for facilitating transmission of patient data during a disaster.

The prevalence of hepatitis B serologic markers in suburban paramedics.

Urban emergency medical services personnel have documented hepatitis B virus (HBV) seropositivity rates ranging from 0.6% to 25%. We studied 85 suburban paramedics for Hepatitis B serologic markers. All paramedics answered a questionnaire describing age, race, duration of employment, known hepatitis exposure, blood transfusions, gamma globulin injections, and Hepatitis B vaccination. HBV surface antibodies (Anti-HBs) were present in 6/85 (7.1%) paramedics of whom one (1.2%) had reactive HBV core antibodies (Anti-HBc). No paramedic had HBV surface antigen (HBsAg). Seropositivity was not associated with duration of employment, or exposure to a patient with either jaundice (28.2%) or confirmed hepatitis B (20.0%) within the six months prior to testing. The 7.1% prevalence of HBV markers found in this group of suburban paramedics is intermediate between previously reported rates for urban paramedics. We conclude that prehospital personnel do not constitute a homogenous occupational category at risk for hepatitis B infection.

Relationship of bacteremia to antipyretic therapy in febrile children.

We undertook a prospective study of children from three to 24 months of age with rectal temperatures of greater than or equal to 40.0 degrees C (104.0 degrees F) to determine if children whose fevers fail to respond to antipyretic therapy are more likely to be bacteremic than children whose fevers are lowered by antipyretic measures. Children from two clinical settings were studied: primarily black lower-class children at an inner-city hospital (n = 188) and primarily white middle-class children at a suburban hospital (n = 45). We found an overall prevalence of bacteremia of 7.3%, which was not statistically different between two hospitals. A response to antipyretic therapy, defined as a decrease in temperature of at least 1 degrees C, was seen in 83.7% of children. Children who did not respond to antipyretics had no more increased prevalence of bacteremia than did responders. We conclude that lack of fever response to antipyretics is not a clinical marker for bacteremia in children.