Search PubMed⌕ Search

Biomedical subjects

H A Werman

Publications and source records attributed to H A Werman.

35 records · Page 2Linked to original sources
PubMed1987

The effect of epinephrine versus methoxamine on regional myocardial blood flow and defibrillation rates following a prolonged cardiorespiratory arrest in a swine model.

Recent studies in swine have shown that larger doses of epinephrine than those currently employed for cardiopulmonary resuscitation (CPR) significantly improve regional myocardial blood flow following prolonged cardiac arrest. The dose-response effect of a pure alpha-adrenergic agonist, methoxamine, on regional myocardial blood flow has not been investigated in this setting. This study compared the effect of high-dose epinephrine with graded doses of methoxamine on regional myocardial blood flow, oxygen delivery/utilization, and defibrillation rates during CPR. Twenty swine were instrumented for regional myocardial blood flow measurements using radiolabeled tracer microspheres. Measurements of regional myocardial blood flow, oxygen delivery, and oxygen consumption were made during normal sinus rhythm. Ventricular fibrillation was then induced. Following 10 minutes of ventricular fibrillation, CPR was initiated with a pneumatic compressor. Regional myocardial blood flow, oxygen delivery, and oxygen consumption were then measured during CPR. Following 3 minutes of CPR, the swine were allocated to one of four treatment groups (five per group): group I, epinephrine 0.2 mg/kg; group II, methoxamine 0.1 mg/kg; group III, methoxamine 1.0 mg/kg; and group IV, methoxamine 10.0 mg/kg. One minute after drug administration, regional myocardial blood flow, oxygen delivery, and oxygen consumption measurements again were made. Three and one half minutes after drug administration, defibrillation was attempted. Regional myocardial blood flow following drug administration was compared using an analysis of covariance. Epinephrine (0.2 mg/kg) significantly improved myocardial blood flow (P less than .002) for all tissues examined compared with all doses of methoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The beta error and sample size determination in clinical trials in emergency medicine.

In the analysis of a clinical trial an investigator may fail to discern a statistically significant difference in outcome between control and experimental groups, when in fact one exists. Failure to demonstrate such a difference when it actually exists is known as "type II" error, and its probability of occurring is termed "beta." The purpose of our study was to determine the distribution of beta errors in negative trials in the Journal of the American College of Emergency Physicians (JACEP) (1972-1979) and Annals of Emergency Medicine (1980-1984). All negative comparative clinical trials appearing in JACEP and Annals from volume 1 (1972) to volume 13 (1984) were surveyed and were eligible for inclusion in the study. A trial was defined as negative if the investigator specifically stated that there was no significant difference in outcome between the experimental and control groups. For each negative trial the following parameters were calculated: beta error, based on the sample size used and the difference determined to be important to detect clinically; sample size required to detect a clinically meaningful difference as determined by the authors of this study; and minimum true difference that had to be detected in the trial at a beta equal to 0.20, to discern a statistically significant result. For the 13 years surveyed, we found 21 endpoints in 14 negative trials that were analyzable. Only one of the trials (7.1%) addressed the issues of beta errors and sample size determination. In the remaining 13 negative trials, the calculated beta error ranged from .60 to .97. For the endpoints analyzed, a sample size of up to 450 times larger than that used would have been required to detect a clinically important difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Trials as Topic↗
PubMed1987

Basic trauma life support.

The impact of traumatic injuries on modern society in terms of morbidity, mortality, and economic cost is enormous. Studies have shown that both advanced life support skills and rapid stabilization and transport of the trauma victim have a beneficial effect on the patient's ultimate outcome. The Basic Trauma Life Support (BTLS) course was designed to provide pre-hospital care providers with the skills necessary to provide a thorough assessment, initial resuscitation, and rapid transportation of the trauma victim. Early studies suggest that the material is easily learned by prehospital care providers and that the on-scene time for trauma cases is reduced following training in BTLS. More widespread training in BTLS may have a significant effect on the mortality and morbidity associated with traumatic injuries.

Allied Health Personnel↗
PubMed1987

The effect of high-dose phenylephrine versus epinephrine on regional cerebral blood flow during CPR.

Prior studies have not found the alpha agonist phenylephrine, in a dose of 0.1 mg/kg, to be as effective as 0.20 mg/kg of epinephrine in improving regional cerebral blood flow (CBF) during CPR in swine. We undertook this study to assess whether higher doses of phenylephrine might improve regional CBF. Fifteen swine were allocated to receive either epinephrine 0.2 mg/kg, phenylephrine 1.0 mg/kg, or phenylephrine 10 mg/kg. Regional CBF measurements were made during normal sinus rhythm, during CPR, and during CPR following drug administration. Epinephrine 0.2 mg/kg was significantly better in improving regional CBF to the left and right cerebral cortices, cerebellum, midbrain, and cervical cord than was phenylephrine 1.0 mg/kg. There was no significant difference in regional CBF between the animals receiving epinephrine 0.2 mg/kg and phenylephrine 10 mg/kg. The study shows that large doses of epinephrine and phenylephrine may be required during CPR to improve regional cerebral blood flow following a prolonged arrest.

Animals↗
PubMed1987

Methoxamine versus epinephrine on regional cerebral blood flow during cardiopulmonary resuscitation.

The improvement in cerebral blood flow (CBF) during CPR after epinephrine administration has been attributed to epinephrine's alpha-adrenergic properties. Methoxamine, a pure alpha-1 agonist, has only been shown to be comparable to epinephrine in restoring circulation after cardiac arrest in a canine model. This study compares the effectiveness of equipotent doses of epinephrine and methoxamine in improving CBF during CPR after a prolonged cardiac arrest in a swine model. Twenty-five swine, weighing 15.9 to 28.2 kg, underwent instrumentation for regional CBF using tracer microspheres. CBF was determined during normal sinus rhythm. After 10 min of ventricular fibrillation, CPR was begun with a pneumatic compressor. CBF measurements were again made during CPR. After 3 min of CPR, the swine were randomized to receive 0.02 or 0.2 mg/kg epinephrine, 0.1, 1.0, or 10.0 mg/kg methoxamine. Five swine were allocated to each group. CBF measurements were determined after drug administration and compared using a Bonferroni multiple comparison procedure. A p-value less than .05 was considered statistically significant. This study demonstrated that, after a 10-min cardiac arrest, CBF was extremely low, averaging less than 7 ml/min X 100 g during external CPR. There were no clinically significant improvements in regional CBF after 0.02 mg/kg of epinephrine, or the two lowest doses of methoxamine. The addition of 10 mg/kg of methoxamine clinically improved blood flow only to the most caudal CNS structures, including the pons, medulla, and cervical spinal cord.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The effects of graded doses of epinephrine on regional myocardial blood flow during cardiopulmonary resuscitation in swine.

Although epinephrine has been shown to improve myocardial blood flow during cardiopulmonary resuscitation (CPR), the effects of standard as well as larger doses of epinephrine on regional myocardial blood flow have not been examined. In this study we compared the effects of various doses of epinephrine on regional myocardial blood flow after a 10 min arrest in a swine preparation. Fifteen swine weighing greater than 15 kg each were instrumented for regional myocardial blood flow measurements with tracer microspheres. Regional blood flow was measured during normal sinus rhythm. After 10 min of ventricular fibrillation, CPR was begun and regional myocardial blood flow was determined. Animals were then randomly assigned to receive 0.02, 0.2, or 2.0 mg/kg epinephrine by peripheral injection. One minute after drug administration, regional myocardial blood flow measurements were repeated. The adjusted regional myocardial blood flows (ml/min/100 g) for animals given 0.02, 0.2, and 2.0 mg/kg epinephrine, respectively, were as follows: left atrium, 0.9, 67.4, and 58.8; right atrium, 0.3, 46.2, and 38.5; right ventricle, 0.7, 82.3, and 66.9; right interventricular septum, 1.7, 125.5, and 99.1; left interventricular septum, 2.8, 182.8, 109.5; mesointerventricular septum, 16.8, 142.2, and 79.2; left ventricular epicardium, 19.2, 98.5 and 108.7; left ventricular mesocardium, 22.8, 135.0, and 115.8; and left ventricular endocardium, 2.5, 176.1, and 132.9). All comparisons between the groups receiving 0.02 and 0.2 mg/kg epinephrine were statistically significant (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Removal of foreign bodies of the nose.

Nasal foreign bodies are commonly encountered in the emergency department, particularly among children and mentally retarded patients. The diagnosis should be entertained in any patient who presents with a persistent unilateral nasal discharge. Nasal foreign bodies are either inanimate or, less commonly, animate objects. Successful diagnosis and treatment of nasal foreign bodies depends on a careful examination of the nasal cavity. Because of the difficulty in extracting nasal foreign bodies and the lack of cooperation among these patients, general anesthesia should be considered if there is any question concerning the adequacy of nasal examination.

Emergencies↗
PubMed1986

The comparative effects of epinephrine versus phenylephrine on regional cerebral blood flow during cardiopulmonary resuscitation.

Epinephrine in larger doses than currently recommended during cardiopulmonary resuscitation (CPR) has been shown to improve cerebral blood flow (CBF) following a 10-min arrest in a swine model. The purpose of this pilot study was to measure CBF during CPR, comparing high-dose epinephrine to a pure alpha-1 agonist, phenylephrine. Ten swine each weighing greater than 15 kg, were instrumented for regional CBF measurements using tracer microspheres. CBF was measured during normal sinus rhythm (NSR). Following 10 min of ventricular fibrillation, CPR was begun and regional CBF was again measured. Following 3 min of CPR, the swine were randomized to receive either epinephrine (0.2 mg/kg), or phenylephrine (0.1 mg/kg), through a peripheral intravenous line. Regional CBF was again measured 1 min after drug administration. Regional CBF following drug administration was compared using an analysis of covariance. Adjusted CBFs are expressed in ml/min per 100 g for epinephrine and phenylephrine, respectively: left cerebral cortex (12.5 vs. 2.3, P = 0.002); right cerebral cortex (13.0 vs. 2.8, P = 0.003); cerebellum (32.9 vs. 4.1, P = 0.004); midbrain (35.7 vs. 2.6, P = 0.0004), pons (30.3 vs. 2.9, P = O.006); medulla (49.5 vs. 13.6, P = 0.02) and cervical spinal cord (49.6 vs. 14.1, P = 0.003).

Animals↗
PubMed1986

Utility of urine cultures in the emergency department.

Urinary tract infection (UTI) is a common problem treated by emergency physicians. A midstream urine sample remains the most frequent method of culture collection. Although midstream urine culture growing more than 10(5) colony-forming units per milliliter (cfu/mL) has been considered diagnostic of UTI, high false-positive and false-negative rates as well as a lack of precision have been associated with this method of collection. Alternative methods of establishing the diagnosis of UTI have excellent sensitivity and may be utilized at the time of patient presentation. These include the detection of leukocyte esterase activity in urine and the presence of one or more bacteria on microscopic examination of an unspun urine sample. Women of child-bearing age represent the vast majority of patients seen with UTI. Uncomplicated infection of the urinary tract has a generally benign course in these patients, and is rarely associated with long-term complications. In addition, these patients are infected with a predictable spectrum of uropathogens that respond to the commonly used antibiotics. It appears that urine cultures provide little additional information in this patient population. Urine cultures should be obtained in patients at high risk for pyelonephritis or bacteremia/urosepsis, as well as in those expected to have uncommon or resistant organisms.

Adolescent↗
PubMed1986

Comparative effect of graded doses of epinephrine on regional brain blood flow during CPR in a swine model.

Cerebral blood flow (CBF) with conventional closed-chest cardiopulmonary resuscitation (CCPR) has been measured at only 2% to 11% of prearrest values. The purpose of our study was to determine whether the peripheral administration of higher doses of epinephrine than currently recommended during CCPR following a prolonged cardiac arrest improves CBF compared to CCPR using a standard dose of epinephrine. Fifteen swine were randomized to receive CCPR plus 0.02 mg/kg, 0.2 mg/kg, or 2.0 mg/kg epinephrine through a peripheral IV line following a ten-minute cardiopulmonary arrest and three minutes of CCPR. Regional CBF measurements were made by radionuclide microsphere technique during normal sinus rhythm (NSR), CCPR, and following epinephrine administration. The adjusted regional blood flows (in mL/min/100 g) following epinephrine administration for the 0.02-, 0.2-, and 2.0-mg/kg groups were, respectively, left cerebral cortex (3.3, 13.1, 11.8); right cerebral cortex (3.9, 13.8, 12.2); cerebellum (9.2, 32.0, 33.1); midbrain/pons (9.9, 32.1, 32.3); medulla (10.6, 61.5, 54.2); and cervical spinal cord (12.2, 53.8, 35.8). In this swine model, 0.2 mg/kg and 2.0 mg/kg epinephrine significantly increased regional CBF over that seen with standard doses. Because neuronal survival is dependent on flow rates of 10 to 15 mL/min/100 g, this preliminary evidence suggests that these higher doses of epinephrine may help improve neurological outcome in CCPR.

Animals↗
PubMed1986

White blood cell count and differential count.

Current methods for performing the white blood cell count and differential count along with recent technologic advances are discussed. Sources of error and variation in these tests are presented. The use of the white blood cell count and the differential count in a variety clinical situations is reviewed.

Adolescent↗
PubMedDate not supplied

One-way neonatal transports: a new approach to increase effective utilization of air medical resources.

INTRODUCTION: High-risk neonates often require significant stabilization and preparation time for transport. The purpose of this study was to determine whether the institution of a formal neonatal transport policy would increase the effective utilization of air medical resources and to determine whether such a policy would be useful to other air medical transport programs. METHODS: A descriptive review of flight data from time periods before and after the institution of the policy, combined with a telephone survey of 20 other rotor-wing transport programs. RESULTS: After implementation of the policy, the total number of neonatal transports decreased (85 in 13 months vs 60 in 17 months) as did the number of two-way transports per month (4.6 vs 1.3). In addition, average mission time for all neonatal transports decreased. Fifteen of 20 transport programs in this Association of Air Medical Resources region perform neonatal transports. Only one of the 15 has a formal policy to determine the use of one-way versus two-way neonatal transports. CONCLUSION: The neonatal team transport policy has increased the effective utilization of air medical resources in this program. This policy could have wider application for other programs as well.

Air Ambulances↗