Impact of lay responder actions on out-of-hospital cardiac arrest outcome.

INTRODUCTION: Little peer-reviewed literature exists regarding the actions of the person who recognized and called 911 at the time of an out-of-hospital cardiac arrest (OHCA). OBJECTIVES: To describe the characteristics of persons who recognized OHCAs and to assess the impact of their actions on survival. METHODS: Subjects were a convenience sample of individuals who called 911 after a case of home OHCA in which the victim was transported to one of two suburban community teaching hospitals. A retrospective mail survey was conducted asking demographics, including age, race, educational level, prior first aid training, and actions upon recognition of OHCA, including phone calls made and caller estimate from collapse to 911 call. Callers whose initial action was calling 911 were compared with those who made other calls first. Outcomes (discharged alive, DC) were obtained from hospital records. Fisher's exact test and chi-square tests were used for analysis. RESULTS: Of 378 cases, 173 (45.8%) responded to the mail survey. The lay responders (LRs) who called 911 were younger than the victims (59.9 vs 68.0, p < 0.001) and were most commonly spouses (65.3%) or adult children (22.0%) of the patient. Most (84.7%) called 911 first at the time of recognition of arrest. A first call to 911 tended to predict DC (11.0% vs 0.0%, p = 0.13). When a phone call other than 911 was made first, there were no survivors (0/23). An estimated delay to 911 call of >4 minutes was not associated with an adverse outcome (10.5% vs 6.9%, p = 0.49). There was no difference in demographic variables between immediate and delayed 911 callers. CONCLUSION: Lay responder demographics are similar to those of patients. In this study, an LR call to 911 first appears to be associated with improved OHCA survival. The LR estimates of delay to 911 call were not associated with increased mortality. The authors identified no patient or witness characteristics that were associated with a delay to calling 911 first.

Medical therapy of acute myocardial infarction: Part I. Role of thrombolytic and antithrombotic therapy.

Thrombolytic therapy has been established as a safe and effective therapeutic strategy in acute myocardial infarction (MI). Its efficacy is improved with early administration, although modest benefits can be demonstrated for up to 12 hours. Tissue plasminogen activator (TPA) appears to offer benefits over streptokinase when administered to patients who present within 4 hours, those with an anterior MI, and who are less than 75 years old. Age alone is not a contraindication for thrombolysis because the risk of bleeding complications in the elderly is outweighed by a significant improvement in mortality. One of the major limitations of thrombolytic therapy in acute MI is reocclusion. Use of adjunctive antithrombotic therapy can reduce the rate of reocclusion following successful thrombolysis. The beneficial role of aspirin is well established. Use of intravenous heparin in conjunction with streptokinase offers no clinical benefit. The efficacy of heparin when administered with other thrombolytic agents remains to be established. These issues and the role of newer antiplatelet and antithrombin agents are being examined in ongoing clinical trials. The objective of this review is to provide the information needed for careful and appropriate judgment in the use of thrombolytic agents and antithrombotic therapy. General principles are emphasized, and specific recommendations are included as guidelines.

Nuclear scintigraphy in the evaluation of renal colic.

Forty patients with acute onset renal colic were studied using technetium-99m DTPA renal scintigraphy. Thirty-two were found to have varying degrees of obstruction. In the obstructed group the level was determined by the scan alone in 24 of 32 cases (75%). When the analysis included an abdominal radiograph, the level of obstruction was ascertained in 29 of 32 cases (91%). A delayed nephrogram, as evidenced by an "empty renal pelvis sign" at 5 minutes, was observed in all but one of the cases of obstruction (97%). Delayed clearance of activity from the pyelocalyceal system or ureter was also seen in 97%. In all cases of obstruction either one or both of these signs were observed. However, delayed clearance was found to be a nonspecific finding and was noted in 25% of nonobstructed cases. The finding of the "empty renal pelvis sign" at 5 minutes was found to be specific and was not seen in the nonobstructed group. The authors conclude that radionuclide renal scanning is an effective method for evaluating selected patients with suspected renal colic.

Commercial tanning facilities: a new source of eye injury.

A retrospective review of patients visits to two urban emergency departments was undertaken to ascertain the impact of commercial tanning facilities (CTFs) on the incidence of corneal burns. Ocular injury and/or infection represented 1.9% of the total patient census, with corneal burns being 7.6% of the eye pathology. Prior to the opening of a number of CTFs, corneal burns had three causes in the two emergency departments reported here: ultraviolet (UV) keratitis from electric arc welders, (32.5%) chemical or physical agents (28%), and UV keratitis from home sunlamps or reflected sunlight while sunbathing or boating (10.5%). Within a single year, UV keratitis from CTFs became the second most common source of corneal burns, injuring 29% of all patients. While most corneal burns resolved with symptomatic treatment, an additional two patients received retinal burns from the CTFs. Both patients were left with permanent visual deficits. Treatment and aspects of UV ocular injury are discussed.

Acute digitalis poisoning: the role of intravenous magnesium sulfate.

Acute digitalis poisoning is a complex emergency with a reported mortality rate of 3% to 25%. In severe overdose, the sodium, potassium-adenosine triphosphatase system is severely inhibited, leading to cardiac dysrhythmias and an elevation of the serum potassium. Magnesium, a cofactor regulating this ion transport system, can successfully treat acute digitalis-induced rhythm disturbances and restore the transmembrane potassium gradient. This paper discusses the cellular mechanism involved in digitalis toxicity and reviews the literature concerning the use of magnesium in acute cardiac glycoside poisoning.

Renal artery obstruction.

A 57-year-old woman with an extensive cardiac history presented complaining of left flank pain. An intravenous pyelogram performed for the presumptive diagnosis of renal calculus showed poor function of the left kidney. Angiography demonstrated a 95% obstructing embolus in the left renal artery, which was removed surgically. This case illustrates some of the pitfalls in the diagnosis of renal artery obstruction and the need for a high index of suspicion. The intrarenal infusion of thrombolytic agents such as streptokinase may become the treatment of choice despite the success of surgical embolectomy. The diagnosis, laboratory analysis, and treatment of renal artery obstruction is discussed.

Pancreatic injury associated with interposed abdominal compressions in pediatric cardiopulmonary resuscitation.

A case in which conventional CPR was augmented with interposed abdominal compressions on a child is reported. Animal studies and electrical models of this new form of CPR have demonstrated improved hemodynamics without instance of intra-abdominal injury. In this case, intraperitoneal visceral injury was noticed in the form of blood within the stomach and small intestine and parenchymal hemorrhage within the pancreas. Similar pancreatic injury has not been reported with conventional pediatric CPR, and caution may have to be exercised if this form of CPR with interposed abdominal compressions is to be used on children.