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Biomedical subjects

B Honigman

Publications and source records attributed to B Honigman.

35 records · Page 2Linked to original sources
PubMed1987

Cardiac dysrhythmias in the acute setting: pathophysiology or anyone can understand cardiac dysrhythmias.

Cardiac dysrhythmias are easy. Unlike the lung (which has formidable neuroendocrine, metabolic, and respiratory responsibilities), the heart is simple. It is an innervated muscular pump. A resting Purkinje or ventricular muscle cell membrane maintains a charge of about 90 millivolts. The five phases of a cardiac action potential are similar to the action potential in skeletal muscle, however, the cardiac action potential lasts a hundred times longer. When sodium specific "fast" channels and calcium specific "slow" channels open, positive ions rush into the myocardial cell, thus causing rapid membrane depolarization. In order to produce an action potential, some stimulus must decrease the membrane potential from -90 millivolts to "threshold" or -60 millivolts. Purkinje fibers do not have a stable phase for diastolic potential. These fibers continuously depolarize during diastole. Hypoxemia or hypokalemia may exacerbate this diastolic depolarization, thus promoting "hyperexcitability" or "automatic" ectopy. When myocardium is damaged, characteristically with myocardial ischemia, rapid conduction of cardiac impulses may be slowed dramatically. Very slow impulses may course through muscle such that by the time the activation wave front returns to the initiating site, this origin has had a chance to repolarize. This is the basis for re-entrant dysrhythmias. All cardiac dysrhythmias are automatic, re-entrant or both.

Arrhythmias, Cardiac↗
PubMed1987

Cardiac dysrhythmias in the acute setting: recognition and treatment or anyone can treat cardiac dysrhythmias.

The two primary goals in dysrhythmia therapy are: to control the ventricular rate (between 70 and 100 beats per minute) and to maintain sinus rhythm. Maintenance of sinus rhythm is definitely secondary. If a patient is hemodynamically unstable, but has a ventricular rate between 60 and 100 beats per minute, the trouble is almost certainly not due to the cardiac rhythm. Normal conduction velocity is fast. An impulse is transmitted by healthy Purkinje fibers at 2 to 3 meters per second. This means that the entire ventricle, when activated by the Purkinje system, is activated in 80 milliseconds. When a superventricular impulse is transmitted to the ventricles via the A-V node, the ventricle should be activated (depolarized) in less than 80 milliseconds. Conversely, if an impulse is generated at an ectopic ventricular site, it does not access the high velocity Purkinje system as rapidly. A ventricular origin beat (PVC) thus, takes longer to activate the entire ventricle. The QRS is, therefore, longer (or wider). A wide QRS signifies aberrant ventricular conduction. When a dysrhythmia originates above the A-V node, the therapy is pharmacologic A-V nodal blockade (verapamil). When a dysrhythmia originates below the A-V node, therapy is pharmacologic (Lidocaine) or electrical (cardioversion). If uncertain or a patient is unstable, cardioversion is always acceptable. Thus; with an unstable patient, proceed immediately to cardioversion; with a narrow complex tachycardia (superventricular) proceed to verapamil; and with a wide complex (ventricular) tachycardia give Lidocaine and proceed to cardioversion.

Arrhythmias, Cardiac↗
PubMed1987

Prehospital advanced trauma life support for critical blunt trauma victims.

The ability of paramedics to deliver advanced trauma life support (ATLS) in an expedient fashion for victims of trauma has been strongly challenged. In this study, the records of 114 consecutive victims of blunt trauma who underwent laparotomy or thoracotomy were reviewed. Prehospital care was rendered by paramedics operating under strict protocols. The mean response time (minutes +/- SEM) to the scene was 5.6 +/- 0.27. On-scene time was 13.9 +/- 0.62. The time to return to the hospital was 8.0 +/- 0.4. On-scene time included assessing hazards at the scene, patient extrication, spine immobilization (n = 98), application of oxygen (n = 94), measurement of vital signs (n = 114), splinting of 59 limbs, and the following ATLS procedures: endotracheal intubation (n = 31), IV access (n = 106), ECG monitoring (n = 69), procurement of blood for tests including type and cross (n = 58), and application of a pneumatic antishock garment (PASG) (n = 31). On-scene times were analyzed according to the number of ATLS procedures performed: insertion of one IV line (n = 46), 14.8 +/- 1.03 minutes; two IV lines (n = 28), 13.4 +/- 0.92; one IV line plus intubation (n = 7), 14.0 +/- 2.94; two IV lines plus intubation (n = 9), 17.0 +/- 2.38; and two IV lines plus intubation plus PASG (n = 13), 12.4 +/- 1.36. Of the 161 IV attempts, 94% were completed successfully. Of 36 attempts at endotracheal intubation, 89% were successful.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency Medical Services↗
PubMed1985

Prehospital advanced trauma life support for critical penetrating wounds to the thorax and abdomen.

The role of advanced trauma life support (ATLS) in the prehospital care of the critically injured is highly controversial. This study analyzes the efficacy of ATLS in the management of critical penetrating wounds of the thorax and abdomen. In the 2 1/2-year period ending July 1984, 203 consecutive patients underwent emergency laparotomy or thoracotomy for gunshot and stab wounds. All patients were treated in the field by advanced paramedics (EMT-P). For gunshot wounds the mean time (+/- S.E.M.) responding to the scene was 4.5 (+/- 0.29) minutes, on the scene 10.1 (+/- 0.41) minutes, and returning to the hospital 6.4 (+/- 0.32) minutes. For stab wounds the mean time responding to the scene was 4.8 (+/- 0.21) minutes, on the scene 9.5 (+/- 0.37) minutes, and returning to the hospital 5.7 (+ 0.30) minutes. The number of intravenous lines started averaged 1.8 per patient. Eighty-one patients had PASG applied and 28 patients underwent endotracheal intubation (21 orally, seven nasally). Thirty-three patients had no obtainable blood pressure, of whom six survived (18%). One hundred sixty (94%) of the remaining 170 patients who had any initial blood pressure survived. One hundred nine (55%) patients had an increase in BP greater than or equal to 10 mm Hg (average, 35.6 mm Hg), 64 (32%) had no significant change, and 25 (13%) had a fall greater than or equal to 10 mm Hg (average, 24.2 mm Hg) from the field to the emergency department. Twenty (80%) of the 25 patients with a fall in blood pressure survived.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1985

A comparison of PTV and endotracheal ventilation in an acute trauma model.

Percutaneous transtracheal ventilation (PTV) is an active airway management technique that may be an alternative to cricothyroidotomy in critically injured patients. A canine trauma model was devised to compare the ventilatory capacity and hemodynamic effects of PTV to endotracheal intubation. Mongrel dogs (25-37 kg), splenectomized 14 days previously, were anesthetized with pentobarbital and bled to a mean arterial pressure (MAP) of 20 mm Hg. Animals were maintained at this MAP for 1 hour, then resuscitated with simultaneous: a) aortic crossclamping via left thoracotomy, b) Ringer's lactate infusion, and c) active airway support. Control animals (N = 5), intubated with a cuffed endotracheal tube, were ventilated at a rate of 12 per minute, a tidal volume of 500 cc and an FIO2 of 60%. In study animals (N = 5), PTV, for a duration of 1 second, was instituted at the same rate and FIO2. There was no statistically significant difference between the two groups with regard to pO2, pCO2, pH, and hemodynamic parameters. PTV was also performed in the emergency department on four patients unresponsive to resuscitative thoracotomy for postinjury cardiac arrest. PTV rate was 12/minute; duration, 1 second; and FIO2, 100%. Mean values (+/- SEM) for pH, pO2, and pCO2 obtained after 15 minutes of PTV were 7.14 +/- 0.03, 322 +/- 49.5 torr, and 21.5 +/- 4.7 torr, respectively. PTV is comparable to endotracheal intubation with respect to oxygenation, ventilation and hemodynamic response (p greater than 0.05). Our preliminary clinical study corroborates its efficacy in the acute trauma setting and supports further clinical investigation.

Animals↗
PubMed1984

Percutaneous transtracheal ventilation in a canine shock model with an open thorax.

This study evaluates the effectiveness of percutaneous transtracheal ventilation (PTV) in a canine shock model. Five mongrel dogs (25 to 35 kg), splenectomized two weeks prior to study, were anesthetized (pentobarbital, 22 mg/kg) and bled to and sustained at a mean arterial pressure (MAP) of 20 mm Hg for 60 minutes. Ringer's lactate was infused and the descending thoracic aorta was cross-clamped. Simultaneously, PTV was begun with 60% O2 through the cricothyroid membrane. Hemodynamic measurements and arterial blood gases were obtained at 0, 5, 15, and 30 minutes following the initiation of PTV. Orotracheal ventilation was then instituted in place of PTV and continued for 30 minutes, and measurements were repeated. Auto-transfusion was also begun at this time. During PTV, PO2 and PCO2 were adequate in all dogs at each interval. We conclude that PTV provides effective oxygenation and ventilation in dogs subjected to profound shock, thoractomy, and thoracic aortic cross-clamp.

Animals↗
PubMed1981

The chronic emergency department patient.

The chronic emergency department visitor presents a common but largely unstudied problem. Using the criterion of one or more visits per month for a six-month period, a population of 16 frequent or chronic visitors was identified at our institution. These chronic visitors were predominantly single (94%), men (81%), with an average age of 48.5 years. Alcoholism was present in 87.5% and 56% were suffering from a chronic psychiatric condition. The majority were dependent on government support (75%) and lived alone (69%). Ambulance transport was used for 84% of the visits, but in only 6% of the visits was hospital admission required. We concluded that these patients became the responsibility of the ED by default because alcoholism or mental illness prevented their compliance with any therapeutic program. Furthermore, this group is at high risk for medical and traumatic illness, and the physician must not let familiarity lead to careless evaluation. Several suggestions for disposition are provided, for the diversion of one such patient to an alternate and more appropriate source of care creates enormous savings in medical time and expense.

Adult↗
PubMed1981

Acute organic brain syndrome: a review of 100 cases.

A retrospective review of 100 admissions to Denver General Hospital with a diagnosis of acute organic brain syndrome was conducted. A total of 44% of the patients were found to have a chronic organic brain syndrome with a superimposed acute insult which caused decompensation. The other 56% of patients developed acute organic brain syndromes de novo for a variety of reasons. The most common etiologic factors producing decompensation of the chronic OBS were infections (in 23%) and environmental changes (in 17%). The most common etiologic factor causing AOBS de novo was drug-related. In most cases, a toxicologic screen, lumbar puncture, and CT scan of the brain should be a part of the investigation of any patient with AOBS.

Acute Disease↗
PubMedDate not supplied

Reemergence of self-induced abortions.

Two cases of adolescent females attempting self-induced abortions are presented. Many ramifications and complications of illegal abortions are discussed as they affect the patient and society. In addition, we discuss the future of medical education as well as the economic aspects of health care in relationship to illegal abortions.

Abortion, Illegal↗
PubMedDate not supplied

Emergency thoracotomy: comparison of medical student, resident, and faculty performances on written, computer, and animal-model assessments.

OBJECTIVE: In clinical practice, thoracotomy and other critical emergency procedures are rarely required. Consequently, medical students and residents have difficulty acquiring procedural competency in these critical procedures. The authors developed objective written, computer, and animal-model assessments of thoracotomy procedural competency to permit comparison of the reliability and validity of these three procedural assessment modalities. METHODS: Thoracotomy procedural competency was evaluated for 18 persons at three levels of training (medical student, resident, faculty), using written, computer, and animal-model assessments. A prospective, sequential assessment design was used, with the examinees serving as their own controls. Procedural competency was defined in terms of performance time (animal time scale) and performance accuracy (written accuracy, computer accuracy, and animal accuracy scales) for three thoracotomy procedures (opening the chest, pericardiotomy, and aortic cross-clamping). Level of training was the independent variable, and procedural competency scores were the outcome measures. Confounding variables included previous thoracotomy and computer experience. RESULTS: Computer and animal-model assessments produced reliable results (Chronbach's alpha > 0.50). The animal time scale and computer accuracy scale best reflected the expected skill differences among levels of physician training, providing support for construct validity. In contrast, written and animal accuracy scale scores did not significantly differ by level of physician training. Moreover, previous thoracotomy experience (i.e., number of procedures previously performed) was not a significant predictor of procedural competency. CONCLUSIONS: This study demonstrates that critical emergency medicine procedures can be evaluated reliably and validly using computer simulation and animal-model assessments. Neither previous thoracotomy experience nor knowledge of procedure content adequately predicts thoracotomy competency.

Animals↗
PubMedDate not supplied

Using computerized data to identify adverse drug events in outpatients.

OBJECTIVE: To evaluate the use of a computer program to identify adverse drug events (ADEs) in the ambulatory setting and to evaluate the relative contribution of four computer search methods for identifying ADEs, including diagnosis codes, allergy rules, computer event monitoring rules, and text searching. DESIGN: Retrospective analysis of one year of data from an electronic medical record, including records for 23,064 patients with a primary care physician, of whom 15,665 actually came for care. MEASUREMENT: Presence of an ADE; sensitivity and specificity of computer searches for ADE. RESULTS: The computer program identified 25,056 incidents, which were associated with an estimated 864 (95 percent confidence interval [CI], 750-978) ADES. Thus, the ADE rate was 5.5 (CI, 5.2-5.9) per 100 patients coming for care. Furthermore, in 79 (CI, 68-89) ADEs, the patient required hospitalization, resulting in an estimated rate of 3.4 (CI, 2.7-4.3) admissions per 1,000 patients. The sensitivity of the search methods for identifying ADEs was estimated to be 58 (CI, 18-98) percent, and the estimated specificity was 88 (CI, 87-88) percent. The positive predictive value was 7.5 (CI, 6.5-8.5) percent, and the negative predictive value was 99.2 (CI, 95.5-99.98) percent. Compared with age and gender-matched controls with no positive screen, patients with ADEs had twice as many outpatient visits and were taking nearly three times as many drugs. Antihypertensives, ACE-inhibitors, antibiotics, and diuretics were associated with 56 (CI, 47-65) percent of ADES. Among ADEs, 23 (CI, 16-32) percent were life-threatening or serious, and 38 (CI, 29-47) percent were judged preventable. CONCLUSION: Computerized search programs can detect ADEs, and free-text searches were especially useful. Adverse drug events were frequent, and admissions were not rare, although most hospitals today do not identify them. Thus, such detection programs demonstrate "value-added" for the electronic record and may be useful for directing and assessing the impact of quality improvement efforts.

Adverse Drug Reaction Reporting Systems↗