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K D Wrenn

Publications and source records attributed to K D Wrenn.

At least 19 recordsLinked to original sources

A method for developing and maintaining a powerful but inexpensive computer data base of clinical information about emergency department patients.

We describe a method of creating and maintaining a computer data base containing demographic, diagnostic, procedural, and laboratory data on all emergency department patients. The data base is inexpensive because it avoids redundant data entry; instead, it relies on data already entered into the hospital computers. It is unobtrusive because the ED providers do not have to complete any extra paperwork; data captured on other hospital computers are transferred to the ED data base, making the ED computer a data "parasite." It is powerful because data can be extracted in arbitrarily complex ways using common relational data base software. The data base facilitates administrative, quality improvement, and research tasks for ED managers and researchers. By using standard diagnostic and procedural coding schemes, comparison of patient populations from different EDs can be accomplished. The technologic and financial requirements of this type of data base are within the reach of most EDs.

Computer Communication Networks

Multicenter study of a portable, hand-size, colorimetric end-tidal carbon dioxide detection device.

STUDY OBJECTIVES: To evaluate continuous, semiquantitative end-tidal carbon dioxide (ETCO2) monitoring in the prehospital and emergency department setting for confirming proper endotracheal tube placement and assessing prognosis and blood flow during CPR. TYPE OF PARTICIPANTS: Adult patients were included if an endotracheal tube was inserted by prehospital care providers or emergency physicians for cardiac arrest, respiratory arrest, respiratory insufficiency, or airway protection. DESIGN AND INTERVENTIONS: A small, portable, colorimetric ETCO2 detector was attached to the endotracheal tube immediately after each attempted endotracheal tube insertion. The color of the detector membrane was noted at the seventh breath following intubation. The color also was noted and recorded if there was return of spontaneous circulation (defined as a palpable pulse) immediately prior to and following conversion from manual to mechanical CPR. Survival to hospital admission was used as an end point to assess the prognostic value of the initial ETCO2 reading. MAIN RESULTS: A total of 227 patients (144 with cardiopulmonary arrest) were studied. In the 83 patients intubated but not in cardiopulmonary arrest, a reading on the ETCO2 detector signifying more than 0.5% ETCO2 was 100% sensitive and 93% specific in detecting proper endotracheal tube placement (100% specific with the endotracheal tube cuff inflated). In cardiac arrest patients, a longer period of estimated arrest appeared to be associated with a lower ETCO2 detector reading. A reading signifying more than 0.5% ETCO2 was 69% sensitive and 100% specific in detecting proper endotracheal tube placement. After proper endotracheal tube placement, all cardiac arrest patients who survived to hospital admission had an initial ETCO2 measurement signifying more than 0.5% ETCO2. Return of spontaneous circulation was usually accompanied by an improved ETCO2 value. Mechanical CPR always produced an ETCO2 value that was as high or higher than that produced by manual CPR. CONCLUSION: The colorimetric ETCO2 device is highly accurate for confirming endotracheal tube position in nonarrest patients. CONCLUSION: The colorimetric ETCO2 device is highly accurate for confirming endotracheal tube position in nonarrest patients. In cardiac arrest patients, a reading signifying more than 0.5% ETCO2 confirms correct endotracheal tube placement, while a value signifying less than 0.5% ETCO2 during resuscitation suggests that something is wrong (eg. esophageal intubation, inadequate circulatory flow, prolonged down-time interval, hypothermia, or significant ventilation/perfusion mismatch).

Adult

Osmolality.

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Acidosis, Lactic

The syndrome of alcoholic ketoacidosis.

PURPOSE: To further elucidate the clinical spectrum of alcoholic ketoacidosis (AKA). PATIENTS AND METHODS: A case series of 74 patients with AKA defined as a wide anion gap metabolic acidosis unexplained by any other disorder or toxin, including any patient with a history of chronic alcohol abuse. The setting was the Medical Emergency Department at Grady Memorial Hospital in Atlanta, Georgia, a university-affiliated inner-city hospital. RESULTS: AKA is a common disorder in the emergency department, more common than previously thought. The acid-base abnormalities are more diverse than just a wide-gap metabolic acidosis and often include a concomitant metabolic alkalosis, hyperchloremic acidosis, or respiratory alkalosis. Lactic acidosis is also common. Semiquantitative serum acetoacetate levels were positive in 96% of patients. Elevated blood alcohol levels were present in two thirds of patients in whom alcohol levels were determined, and levels consistent with intoxication were seen in 40% of these patients. Electrolyte disorders including hyponatremia, hypokalemia, hypophosphatemia, hyperglycemia, hypocalcemia, and hypomagnesemia were common on presentation. The most common symptoms were nausea, vomiting, and abdominal pain. The most common physical findings were tachycardia, tachypnea, and abdominal tenderness. Altered mental status, fever, hypothermia, or other abnormal findings were uncommon and reflected other underlying processes. CONCLUSIONS: AKA is a common disorder in chronic malnourished alcoholic persons. The acid-base abnormalities reflect not only the ketoacidosis, but also associated extracellular fluid volume depletion, alcohol withdrawal, pain, sepsis, or severe liver disease. Although the pathophysiology is complex, the syndrome is rapidly reversible and has a low mortality.

Acid-Base Imbalance

The febrile alcoholic in the emergency department.

The authors retrospectively reviewed the charts of 31 alcoholic patients admitted with fever without a defined source. In our population 58% of patients were subsequently found to have an infectious cause for their fever. Pneumonia was the most common infection, but occult urinary tract infections were seen surprisingly often. Noninfectious but serious disorders, such as delirium tremens, prolonged postictal state, and subarachnoid hemorrhage, were also common. Infectious and noninfectious causes commonly coexisted. The most common noninfectious cause was alcohol withdrawal, with or without seizures. The authors believe that indigent, malnourished, chronic alcoholics with fever for which a source cannot be readily identified, should usually be admitted to the hospital for observation and to await culture results.

Adult

Hemodynamically stable upper gastrointestinal bleeding.

This article is a prospective evaluation of 38 patients presenting to an emergency department (ED) with hematemesis but who were otherwise hemodynamically stable. Four patients were admitted, only one because of the development of hemodynamic instability. Thirty-three patients were discharged; on follow-up there was no evidence of major morbidity or mortality. Two patients were lost to follow-up, one who left against medical advice and one who lived in a county outside the service area of our hospital. Patients with hematemesis can be safely discharged from the ED after observation for 6 hours if they: (1) lack orthostatic vital sign changes; (2) lack associated significant underlying disease; (3) have a hemoglobin concentration greater than 10 gm/dL; (4) are less than 60 years of age; and (5) are thought to be reliable and compliant.

Adult

Experience with esmolol for the treatment of cocaine-associated cardiovascular complications.

The authors report their experience using esmolol, an ultra-short acting beta-adrenergic antagonist, for the treatment of seven patients with cocaine-associated cardiovascular complications. No consistent hemodynamic benefit was found with the use of this drug. Although there was a decline in mean heart rate of 23% (range 0% to 35%), they were unable to show a consistent antihypertensive response. Adverse effects occurred in three patients. This included one patient with a marked exacerbation of hypertension and one who became hypotensive. Another patient developed emesis and lethargy during esmolol therapy and required endotracheal intubation. They do not recommend the routine use of esmolol for cocaine cardiotoxicity.

Adrenergic beta-Antagonists

Monitoring EMS protocol deviations: a useful quality assurance tool.

STUDY OBJECTIVE: To determine the incidence, type, and outcome of protocol deviations in an emergency medical services (EMS) system. DESIGN: Retrospective consecutive case series. SETTING: Seven advanced life support ambulance services servicing five area hospital emergency departments. PATIENTS: 1,246 patients requiring advanced life support care. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Advanced life support ambulance runs during a two-month period were examined for protocol deviations. Of 1,246 runs examined, 16% had deviations. Approximately 55% of these deviations were minor, 38% were serious, and 7% were very serious in nature. The effects of the errors were evaluated using hospital records. Results showed that 89.5% of patients were unaffected, 5.0% improved, and 5.5% suffered complications from deviations. Emergency medical technicians committed 69% of the deviations without the consent of medical control, medical control committed an additional 18%, and both were responsible in 13% of cases. Incomplete histories were found in 8% of cases. CONCLUSION: Protocol deviations committed in prehospital care do not usually cause direct harm to patients. On review of these deviations, however, several disturbing trends were uncovered, including misconceptions in the use of IV therapy, a number of serious deviations in advanced cardiac life support protocols, and lack of communication with medical control. This type of quality assurance study has the ability to identify areas of strength and weakness in an EMS system, allowing planning of ongoing educational efforts in the system.

Clinical Protocols

The ability of physicians to predict hyperkalemia from the ECG.

STUDY OBJECTIVE: To determine whether physicians blinded to the serum potassium level can predict hyperkalemia (potassium concentration of more than 5.0 mmol/L) from the ECG. DESIGN: ECGs of patients at high risk for hyperkalemia were interpreted retrospectively by two physicians blinded not only to the specific clinical diagnosis of the patient and to their serum potassium measurement but also to each other's interpretation. The physicians predicted the presence or absence of hyperkalemia as well as the severity of hyperkalemia on a nominal scale (mild, moderate, or severe). SETTING: The emergency department of a university-affiliated urban county hospital. PATIENTS: Two hundred twenty consecutive patients admitted to the hospital from the ED with a diagnosis of renal failure or hyperkalemia. Eighty-seven patients had hyperkalemia, and 133 did not. RESULTS: The sensitivities of the readers for predicting hyperkalemia were .43 and .34, respectively (best positive predictive value, .65). The respective specificities for detecting hyperkalemia were .85 and .86 (best negative predictive value, .69). When only patients with moderate-to-severe hyperkalemia (potassium of more than 6.5 mmol/L) were analyzed, sensitivities were .62 and .55. The readers' ability to predict the severity of hyperkalemia was equally poor. CONCLUSION: The ECG is not a sensitive method of detecting hyperkalemia, even in high-risk patients. The specificity of the ECG is better for hyperkalemia, but empiric treatment of hyperkalemia based on the ECG alone will lead to mistreatment of at least 15% of patients.

Adult

Two methods for developing and maintaining a database of clinical information on outpatient encounters: a comparison of process, costs, and benefits.

We describe and compare two relational databases that capture and store clinical information about ambulatory patients. One system is based on an encounter form; the other is a "parasite" that passively collects data from other hospital computers. We compare the system development processes, costs, and benefits of these two computerization strategies.

Ambulatory Care Information Systems

Cocaine-related medical problems: consecutive series of 233 patients.

PURPOSE: Little information describing common cocaine-related medical problems is available. This study examined the nature, frequency, treatment, incidence of complications, and emergency department deaths of patients seeking medical care for acute and chronic cocaine-associated medical problems. PATIENTS AND METHODS: A consecutive series of 233 hospital visits by 216 cocaine-using patients over a 6-month period during 1986 and 1987 was studied. Medical records were retrospectively reviewed to determine patient characteristics, nature of complications, treatment, and outcome. RESULTS: Patients most commonly used cocaine intravenously (49%), but freebase or crack use was also common (23.3%). Concomitant abuse of other intoxicants, especially alcohol, was frequently seen (48.5%). The vast majority of complaints were cardiopulmonary (56.2%), neurologic (39.1%), and psychiatric (35.8%); multiple symptoms were often present (57.5%). The most common complaint was chest pain though rarely was it believed to represent ischemia. Altered mental status was common (27.4%) and ranged from psychosis to coma. Short-term pharmacologic intervention was necessary in only 24% of patients, and only 9.9% of patients were admitted. Acute mortality was less than 1%. CONCLUSION: Most medical complications of cocaine are short-lived and appear to be related to cocaine's hyperadrenergic effects. Patients usually do not require short-term therapy or hospital admission. Acute morbidity and mortality rates from cocaine use in patients presenting to the hospital are very low, suggesting that a major focus in the treatment of cocaine-related emergencies should be referral for drug abuse detoxification and treatment.

Adolescent

Predicting the severity of cocaine-associated rhabdomyolysis.

STUDY OBJECTIVES: The syndrome of rhabdomyolysis associated with cocaine use has been recently described, but the incidence, severity, risk factors, and complications are unknown. This study sought to describe the spectrum of the syndrome and identify clinical features of patients at risk. DESIGN: Retrospective case series with analysis of common clinical features. SETTING: Medical emergency department of an urban teaching hospital serving an indigent population. TYPES OF PARTICIPANTS: ED patients with acute cocaine intoxication and a serum creatine kinase (all MM) of more than 500 U/L (8.3 ukat/L) who were admitted for in-hospital management. MEASUREMENTS AND MAIN RESULTS: Twenty-nine patients, representing 5% of cocaine-related patient visits, were identified over 20 months. Patients were divided into three groups: mild, characterized by anxiety, tachycardia, diaphoresis, dyspnea, or chest pain; moderate, characterized by delirium, agitation, fever, leukocytosis, or an elevated serum creatinine; and severe, characterized by seizure, coma, hypotension, arrhythmia, or cardiac arrest. There was a significant association between the rating system for level of intoxication and the severity of rhabdomyolysis and its complications (P less than .01). Patients at highest risk for complications of rhabdomyolysis were those in the moderate or severe groups. CONCLUSION: This classification system may be useful for the management of patients with acute cocaine intoxication, predicting those patients in whom aggressive therapy should be initiated in the ED to minimize the complications of rhabdomyolysis.

Adult

The ability of physicians to predict electrolyte deficiency from the ECG.

The ECG is considered to be a fairly accurate reflection of a patient's electrolyte status. Two full-time academic emergency physicians, each board certified in two specialties, interpreted the ECGs of 97 consecutive alcoholic patients presenting to the emergency department. Serum potassium, calcium, and magnesium values were obtained on all patients within one hour of ECG performance. The physicians attempted to predict abnormalities of serum electrolytes from the ECG tracing alone when blinded to all laboratory values, the clinical situation, and each other's readings. The combined results of both readers yielded a sensitivity of .74 and a specificity of only .29. The positive predictive value of the ECG in predicting electrolyte deficiency was .41 and the negative predictive value was .63. Electrolyte disturbances cannot be accurately predicted from an ECG even in high-risk patients. Serum electrolyte determinations remain the most effective method of screening for these deficiencies.

Adolescent

Neurologic complications of alcoholism.

Neurologic and myopathic complications of alcoholism are multiple and diverse, affecting both the central and peripheral nervous systems. In the ED, initial concern is for diagnosing readily reversible causes and ruling out possible life- or limb-threatening etiologies. A rapid assessment of the ABCs, a fingerstick blood glucose determination, and, in cases of AMS, the administration of intravenous naloxone is indicated. In almost every instance of a potential neurologic complication, intravenous thiamine replacement is indicated initially, along with the parenteral administration of folic acid and the other B vitamins, including nicotinic acid and pyridoxine. Metabolic screening with electrolytes, glucose, blood urea nitrogen, creatinine, calcium, magnesium, liver enzymes (AST, alkaline phosphatase), bilirubin, arterial blood gases with carboxyhemoglobin determination, and a complete blood count are often warranted. Special tests such as CT scan, CK, ammonia, or toxicologic screens are indicated in specific instances. In terms of physical examination, attention to the presence of focal neurologic findings is paramount because of the possibility of a subdural or epidural hematoma. It is important not to miss meningitis and a low threshold for treatment or lumbar puncture should be maintained. Specialized consultation and referral are needed only after stabilization and appropriate tests are performed. If an organized approach to the evaluation of an alcoholic with neurologic symptoms is undertaken, occult disease will not be missed and outcomes will be improved.

Alcoholism

A toxicity study of parenteral thiamine hydrochloride.

Thiamine deficiency is not uncommon in certain populations and clinical disease states such as Wernicke's encephalopathy or beriberi. Rapid parenteral repletion may be required, yet questions about the safety of IV thiamine have been raised because of reports of anaphylaxis. Our study was a prospective evaluation of the safety of thiamine hydrochloride given as a 100-mg IV bolus in 989 consecutive patients (1,070 doses). A total of 12 adverse reactions (1.1%) were reported. Minor reactions consisting of transient local irritation were seen in 11 patients (1.02%), and there was only one major reaction (0.093%) consisting of generalized pruritus. Thiamine hydrochloride may be administered intravenously without undue concern. Intradermal test doses before administration are not warranted unless patients have had previous allergic reactions.

Adolescent