Raymond E. Jackson

Cardiac arrest in private locations: different strategies are needed to improve outcome☆

BACKGROUND A tremendous amount of public resources are focused on improving cardiac arrest (OHCA) survival in public places, yet most OHCAs occur in private residences. METHODS AND RESULTS A prospective, observational study of patients transported to seven urban and suburban hospitals and the individuals who called 911 at the time of a cardiac arrest (bystander) was performed. Bystanders (N=543) were interviewed via telephone beginning 2 weeks after the incident to obtain data regarding patient and bystander demographics, including cardiopulmonary resuscitation (CPR) training. Of all arrests 80.2% were in homes. Patients who arrested in public places were significantly younger (63.2 vs. 67.2, P<0.02), more often had an initial rhythm of VF (63.0 vs. 37.7%, P<0.001), were seen or heard to have collapsed by a bystander (74.8 vs. 48.1%, P<0.001), received bystander CPR (60.2 vs. 28.6%, P<0.001), and survived to DC (17.5 vs. 5.5%, P<0.001). Patients who arrested at home were older and had an older bystander (55.4 vs. 41.3, P<0.001). The bystander was less likely to be CPR trained (65.0 vs. 47.4%, P<0.001), less likely to be trained within the last 5 years (49.2 vs. 17.9, P<0.001), and less likely to perform CPR if trained (64.2 vs. 30.0%, P<0.001). Collapse to shock intervals for public versus home VF patients were not different. CONCLUSIONS Many important characteristics of cardiac arrest patients and the bystander differ in public versus private locations. Fundamentally different strategies are needed to improve survival from these events.

Early amelioration of neurologic deficit by lidoflazine after fifteen minutes of cardiopulmonary arrest in dogs

A prospective, controlled, blind study was done to test the effect of a calcium entry blocker on the neurologic integrity of dogs after cardiopulmonary arrest. Ten male mongrel dogs were anesthetized, prepared with sterile technique, and instrumented for pulmonary arterial (PA) and systematic arterial pressure monitoring. A left thoracotomy and pericardotomy were performed. Cardiac arrest was produced by injecting KCl (1 mEq/kg) through the PA line, and the respirator was stopped. Full arrest was maintained for 15 minutes. Thereafter, the dogs were resuscitated with ventilation, internal massage, fluids, bicarbonate, epinephrine, and internal defibrillation. All dogs were resuscitated within 6 to 10 minutes. Five control dogs received saline placebo, and five dogs were treated with lidoflazine (1 mg/kg) IV drip immediately post resuscitation. All dogs were scored neurologically every two hours by a deficit grading scale. All treated dogs had spontaneous ventilation, reactive pupils and corneals, voluntary movements, and responses to tactile stimulation at 12 hours post resuscitation. Four of five control dogs had maximum deficit scores without improvement. The difference in neurologic scores between the treated and control groups became increasingly divergent with time, and was statistically significant (P less than .05) by four hours post resuscitation. Thus the calcium antagonist lidoflazine produces improvement in neurologic recovery in the first 12 hours after cardiopulmonary arrest in dogs.

A Multicenter Randomized Controlled Trial Comparing Central Laboratory and Point-of-Care Cardiac Marker Testing Strategies: The Disposition Impacted by Serial Point of Care Markers in Acute Coronary Syndromes (DISPO-ACS) Trial

STUDY OBJECTIVE Point-of-care testing reduces time to cardiac marker results in patients evaluated for acute coronary syndromes, yet evidence this translates to a decreased length of stay is lacking. We hypothesized that point-of-care testing decreases length of stay in patients being evaluated for acute coronary syndromes in the emergency department (ED). METHODS Patients being evaluated for possible acute coronary syndromes at 4 EDs in the United States were randomized to having point-of-care markers as well as central laboratory markers, or central laboratory markers only (laboratory arm). Point-of-care markers were obtained using early serial testing at presentation and at 90, 180, and 360 minutes as required by the treating physician. Evaluation, treatment, and disposition decisions were at the treating physicians discretion. Length of stay was from presentation to the time of departure from the ED, either to an inpatient setting or to home. RESULTS There were 1,000 patients in each study arm. There were 520 patients discharged home from the ED. Median (interquartile range) time to discharge home was 4.6 hours (3.5 to 6.1 hours) in laboratory patients and 4.5 hours (3.5 to 6.1 hours) in point-of-care patients. Median (interquartile range) time to transfer to an inpatient setting for admitted patients was 5.5 hours (4.2 to 7.5 hours) in laboratory patients, and 5.4 hours (4.1 to 7.3 hours) in point-of-care patients. At one site, time to transfer to the floor was reduced in the point-of-care arm compared with the laboratory arm (difference in medians 0.45 hours; 95% confidence interval [CI] -0.14 to 1.04 hours). At one site, time to ED departure for discharged patients was higher in the point-of-care arm than the laboratory arm (difference in medians 1.25 hours; 95% CI 0.13 to 2.36 hours). CONCLUSION The effect of point-of-care testing on length of stay in the ED varies between settings. At one site, point-of-care testing decreased time to admission, whereas at another, point-of-care testing increased time to discharge. Potential effects of point-of-care testing on patient throughput should be considered in the full context of ED operations.

Dose-related response of centrally administered epinephrine on the change in aortic diastolic pressure during closed-chest massage in dogs

The current recommendation of the American Heart Association is to give 0.5 to 1.0 mg (7.5 to 15 micrograms/kg in a 70-kg man) of epinephrine intravenously every five minutes during cardiac arrest. The optimal dose of epinephrine to augment the aortic diastolic pressure (ADP) is not known. The effect of various doses of central bolus epinephrine on the ADP during closed-chest massage was studied. A group of 25 large dogs was divided equally into five groups: control and 15, 45, 75, and 150 micrograms/kg. After three minutes of cardiac arrest, closed-chest massage was initiated, and the study drug was given two minutes later. The ADP and right atrial pressures were monitored for 15 minutes. Changes in ADP peaked at two minutes after injection in all groups receiving epinephrine, and the drop in ADP over time noted in the control group was prevented by increasing doses of epinephrine. Among the groups receiving epinephrine, however, there was no difference in the absolute ADP and diastolic coronary perfusion pressure.

Sensitivity of the Ottawa Rules

STUDY OBJECTIVE To validate criteria predicting ankle and mid-foot fractures with 100% sensitivity. DESIGN Prospective validation study SETTING A 929-bed community teaching hospital with an annual census of 76,488 ED visits. PARTICIPANTS Convenience sample of patients older than 18 years with acute ankle or midfoot injury. INTERVENTIONS Radiography was performed in each patient received after pertinent history and physical examination findings were recorded. RESULTS Five hundred seventy radiographs were obtained in 484 patients. Four hundred twenty-one were of the ankle, and 149 were of the foot. There were 93 ankle fractures and 29 midfoot fractures, giving a fracture yield of 22.1% for ankle films and 19.5% for foot films. Decision rules had sensitivity of 94.6% and specificity of 15.5% for ankle fractures and sensitivity of 93.1% and specificity of 11.5% for midfoot fractures. Prospective criteria failed to predict fracture in five of the ankle group and two of the midfoot group. Physicians predicting fracture solely on the basis of clinical suspicion had a sensitivity of 69% in ankle injuries and 76% in midfoot injuries. CONCLUSION We were unable to validate with 100% sensitivity the Ottawa rules predicting ankle and midfoot fractures. However, the Ottawa rules were more sensitive than clinical suspicion alone.

Blood flow in the cerebral cortex during cardiac resuscitation in dogs

Regional cerebral cortical blood flow (rCCBF) in 15 large dogs was determined using the double thermistor dilution method during standard closed-chest massage (CCM), CCM with an epinephrine infusion at 30 micrograms/kg/min (CCM + Epi), and open-chest cardiac massage (OCCM). As a percentage of prearrest flow values, the rCCBF was 9.8% with CCM, 35% with CCM + Epi, and 156% with OCCM. The rCCBF was reduced significantly with CCM (P less than .005) and CCM + Epi (P less than .01). OCCM generated flows indistinguishable from prearrest values. The use of high-dose epinephrine significantly increased the rCCBF during CCM. The implications for intact neurologic resuscitation of these reductions in rCCBF with CCM are important.

Race and Survival After Out-of-Hospital Cardiac Arrest in a Suburban Community ☆ ☆☆ ★ ★★

STUDY OBJECTIVE To determine whether race, when controlled for income, is an independent predictor of survival to hospital discharge after out-of-hospital cardiac arrest (OHCA). METHODS Prospective OHCA data were collected over 4 years (1991-1994) from a convenience sample of OHCA patients transported to nine hospitals in three suburban counties. Race was determined from hospital and vital statistics records. The average household income was identified from ZIP codes and used as a marker of socioeconomic status. Demographic data and known predictors of survival were compared between blacks and whites. A logistic regression analysis was used to assess the association between race, income, and survival. RESULTS Of the 1,690 patients, 223 (13%) were blacks and 1,467 (87%) were whites. Average household income was less for blacks than for whites (

Use of pulse oximetry to predict in-hospital complications in normotensive patients with pulmonary embolism

40,225 versus

Estimated cost effectiveness of a police automated external defibrillator program in a suburban community: ☆ ☆☆: 7 years experience

46,193; P < .001), but both populations were affluent by national standards (national percentile ranks were 73% and 88%, respectively). The populations were no different in percentage of witnessed arrests (57% versus 61%; P = .465). Blacks were younger (mean +/- SD, 62 +/- 16 versus 68 +/- 15 years; P < .001); less frequently received bystander CPR (11% versus 20%; P = .002); less often had ventricular tachycardia or ventricular fibrillation (37% versus 50%; P < .001); and had a shorter advanced life support call-response interval (median, 4 versus 6 minutes; P < .001). The odds ratio for survival (white/black) was .931 (95% confidence interval, .446 to 1.945). CONCLUSION Race was not found to predict adverse OHCA outcomes in this affluent population.

Use of Two-Dimensional Echocardiography for the Diagnosis of Pulmonary Embolus

PURPOSE A simple method is needed to risk stratify normotensive patients with pulmonary embolism. We studied whether bedside clinical data can predict in-hospital complications from pulmonary embolism. METHODS We performed a multicenter derivation phase, followed by validation in a single center. All patients were normotensive; the diagnosis of pulmonary embolism was established by objective imaging. Classification and regression analysis was performed to derive a decision tree from 27 parameters recorded from 207 patients. The validation study was conducted on a separate group of 96 patients to determine the derived criterions diagnostic accuracy for in-hospital complications (cardiogenic shock, respiratory failure, or death). RESULTS Mortality in the derivation phase was 4% (n = 8) at 24 hours and 10% (n = 21) at 30 days. A room-air pulse oximetry reading <95% was the most important predictor of death; mortality was 2% (95% confidence interval [CI]: 0% to 6%) in patients with pulse oximetry >or=95% versus 20% (95% CI: 12% to 29%) with pulse oximetry <95%. In the validation phase, the room-air pulse oximetry was <95% at the time of diagnosis in 9 of 10 patients who developed an in-hospital complication (sensitivity, 90%) and >or=95% in 55 of 86 patients without complications (specificity, 64%). CONCLUSION Mortality from pulmonary embolism in normotensive patients is high. A room-air pulse oximetry reading >or=95% at diagnosis is associated with a significantly lower probability of in-hospital complications from pulmonary embolism.