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Biomedical subjects

J Varon

Publications and source records attributed to J Varon.

At least 55 records · Page 3Linked to original sources
PubMed1998

The obese patient in the ICU.

Data from recent surveys indicate that a staggering 34.9% of US adults are overweight. Obese adults are at in increased risk for many chronic medical conditions, and this increases the likelihood of admission to an ICU. The critically ill obese patient presents the ICU team with many unique problems. Obesity may result in significant alterations of pulmonary and cardiac function, as well as the handling of many drugs. An appreciation of these and other changes is essential in the management of the obese ICU patient. The purpose of this article is to review some of the basic concepts related to the treatment of obese patients in the ICU.

Adult↗
PubMed1998

The hemodynamic derangements in sepsis: implications for treatment strategies.

The incidence of the sepsis syndrome has increased dramatically in the last few decades. During this time, we have gained new insights into the pathophysiologic mechanisms leading to organ dysfunction in this syndrome. Yet, despite this increased knowledge and the use of novel therapeutic approaches, the mortality associated with the sepsis syndrome has remained between 30% and 40%. Appropriate antibiotic selection and hemodynamic support remain the cornerstone of treatment of patients with sepsis. Recent studies have failed to demonstrate a global oxygen debt in patients with sepsis. Furthermore, therapy aimed at increasing systemic oxygen delivery has failed to consistently improve patient outcome. The primary aim of the initial phase of resuscitation is to restore an adequate tissue perfusion pressure. Aggressive volume resuscitation is considered the best initial therapy for the cardiovascular instability of sepsis. Vasoactive agents are required in patients who remain hemodynamically unstable or have evidence of tissue hypoxia after adequate volume resuscitation.

Fluid Therapy↗
PubMed1997

Automated external versus blind manual defibrillation by untrained lay rescuers.

INTRODUCTION: sudden cardiac death is an important cause of mortality in the United States today. A major determinant of survival from sudden cardiac death is rapid defibrillation. Communities with high rates of bystander cardiopulmonary resuscitation (CPR) and early defibrillation enjoy the highest survival rates from out-of-hospital cardiac arrest. First responders and emergency medical technicians (EMTs) have been trained to use external defibrillators (AEDs). The period of instruction for successful use of the AED remains to be determined. It was the purpose of this study to compare AED versus blind manual defibrillation (BMD) by untrained lay rescuers using a simple instruction sheet and following a 20-min training period. METHODS: 50 employed volunteers were confronted with a stimulated cardiac arrest and asked to attempt defibrillation using either AED or BMD by following a written instruction sheet. Success was defined as delivery of three countershocks during the simulated resuscitation. Time to first and third shocks were recorded. RESULTS: 24 of 25 volunteers (96%) were successful in operating the AED compared to none in the BMD group. Time to delivery of first shock averaged 119.5 +/- 45.0 s and time to third shock averaged 158.7 +/- 46.3 s. A 95% confidence interval for time to first shock for untrained lay rescuers was 100.5-138.4 s. CONCLUSIONS: untrained lay rescuers demonstrated a very high success rate using the AED during simulated cardiac arrest. Success with BMD by untrained rescuers is poor. This study suggests that prehospital personnel can be successfully trained in the use of AED in a substantially shorter period of time than in current practice. Strategic placement of AEDs like fire hoses and pool-side life preservers could result in improved survival from sudden cardiac death.

Ambulatory Care↗
PubMed1996

In-hospital resuscitation among the elderly: substantial survival to hospital discharge.

The appropriateness of aggressive resuscitation in many clinical settings has been questioned. Survival rates from cardiac arrest in the elderly are generally reported as poor, and satisfactory results from resuscitation attempts prolonged beyond 15 minutes are said to be rare. It was the purpose of this study to examine success rates for resuscitation in a cohort of elderly inpatients suffering cardiac arrest. We retrospectively reviewed 213 consecutive cardiac arrests occurring during a 12-month period in a large tertiary private hospital. Patient age, presenting rhythm, and survival to hospital discharge were recorded. Elderly was defined as 70 years or older. Cardiac arrests in the elderly totaled 89. Average age in this cohort was 76.2 +/- 4.5 years. Eighteen patients (20.2%) had return of spontaneous circulation and 8 patients survived to hospital discharge (44.4% of those with return of spontaneous circulation). No significant difference in age or presenting rhythm of survivors versus nonsurvivors could be demonstrated, although a trend to more frequent ventricular fibrillation or ventricular tachycardia was seen (P = .059, Fisher's exact). Time for resuscitation averaged 25.75 +/- 9.2 minutes for survivors and 32.6 +/- 22.1 minutes for nonsurvivors. Survival to hospital discharge occurs in 9% of in-hospital cardiac arrests in the elderly following average CPR times substantially in excess of 15 minutes.

Age Factors↗
PubMed1996

Hypertensive crises. The need for urgent management.

Although hypertensive crises are now relatively uncommon, they often are life-threatening when they do occur and demand early recognition and management to minimize morbidity and mortality. Most patients have essential hypertension, and withdrawal from an antihypertensive drug is the most common cause of acute elevation of blood pressure. Short-acting parenteral agents are generally recommended for management of hypertensive crises. In most patients with hypertensive emergencies, the mean arterial pressure is lowered 25% over 2 to 4 hours. Both cerebral and coronary hypoperfusion must be avoided.

Acute Disease↗
PubMed1995

CPAP machine performance and altitude.

UNLABELLED: STUDY RATIONALE AND OBJECTIVE: Sleep-disordered breathing is commonly treated with nasally applied continuous positive airway pressure (CPAP). Typically, pressures are titrated to pneumatically splint the airway to prevent its collapse in response to negative inspiratory pressure. This investigation was prompted by several patient complaints of sleep-related breathing difficulty associated with travel to high altitudes. CPAP devices create pressure with fan-generated airflow; therefore, CPAP performance should behave according to collective fan laws. MEASUREMENTS AND RESULTS: In the present study, we examined the effect of simulated altitude change on four commercially available CPAP machines. Machines were tested using anatomic airway mannequins in an altitude chamber. We made three simulated ascents to 12,000 feet with machines set at 5, 10, and 12 cm H2O sea level pressure equivalents. We measured pressure using water manometers at 2,000-foot increments during ascent and descent. Mask pressures varied systematically with changing altitude in three machines. One machine, equipped with a pressure regulation feature, maintained pressure within 1 mm H2O at all pressure and altitude combinations. CONCLUSIONS: Altitude significantly alters delivered pressure according to predictions made by the fan laws, unless a unit has pressure-compensating features. Clinicians should consider this factor when CPAP is prescribed for patients who live or travel to places located at significantly higher or lower elevations than the titration site.

Altitude↗
PubMed1994

Emergency department procedures and length of stay for critically ill medical patients.

STUDY OBJECTIVE: To date, the study of critical illness in the emergency department has been limited. The purpose of this study was to determine the ED length of stay and procedures performed in medical critical care patients. DESIGN: Descriptive study of a prospective single cohort. SETTING: Large urban public hospital. TYPES OF PARTICIPANTS: Fifty consecutive ED patients subsequently admitted to the medical ICU. MEASUREMENTS AND MAIN RESULTS: The study population consisted of 24 women and 26 men. The mean ED stay was 284.5 +/- 212.6 minutes (median, 255 minutes; interquartile range [IQR], 115 to 355 minutes). Patients remained in the ED after administrative transfer of their care to the medical ICU an average of 75 +/- 71.4 minutes (range, 10 to 375 minutes; median, 50 minutes; IQR, 25 to 105 minutes). Forty-one of these patients (82%) received one or more critical care procedures. The mean time to performance of first procedure was 92.8 +/- 180.6 minutes (median, 23 minutes; IQR, 11 to 82 minutes) from ED arrival. Death after ICU admission occurred in 11 patients. Mean ED length of stay was 291 +/- 269.8 minutes (range, 35 to 980 minutes; median, 135 minutes; IQR, 85 to 467 minutes) in nonsurvivors, and 91% of them received procedures in the ED. Survivors averaged 282.4 +/- 193.4 minutes (range, 15 to 230 minutes; median, 263 minutes; IQR, 126 to 355 minutes) (P = NS) and 79.5% (P = NS) received ED procedures. CONCLUSION: Critically ill patients spend a substantial amount of time in the ED before transfer to the ICU. Typical ICU procedures are commonly performed. Further study of the impact on patient outcome of ED stay and the procedures performed in critically ill medical patients should be conducted.

Adult↗
PubMed1994

Acute exacerbations of obstructive lung disease. What to do when immediate care is crucial.

Obstructive lung disease is a major cause of morbidity and mortality in the United States, and the mortality rate is rising. Successful treatment of acute exacerbations begins with appropriate assessment and intervention. Supplemental oxygen is appropriate for all patients with hypoxemia, and mechanical ventilation should be considered in those with clouded consciousness, profound acidosis, or severe hypoxemia. Inhaled beta 2 agonists are the first line of therapy in acute exacerbations. Anticholinergics, methylxanthines, and corticosteroids may also be useful. Alternative therapies (eg, magnesium, glucagon, calcium channel blockers, clonidine, helium) are receiving increased attention and are undergoing investigation.

Acute Disease↗
PubMed1993

Discrepancy in resuscitation beliefs among physicians at various levels of training.

Having previously described some of the attitudes of health care providers toward resuscitation for themselves, based on an individual's beliefs about the likelihood of success of cardiopulmonary resuscitation (CPR), the differences among attitudes of physicians at different levels of training have now been assessed. A multi-question survey was sent to medical students, house officers, and attending physicians at two university medical centers. Sociodemographic information, questions regarding beliefs about outcome after CPR, and personal desires were included. Respondents were asked to identify the clinical condition carrying the worst prognosis during cardiac arrest from among: metastatic cancer (MC), end-stage renal disease (ESRD), acquired immunodeficiency syndrome (AIDS), sepsis, and myocardial infarction (MI), and to specify their resuscitation desires should they be affected by these conditions. The preferences of each group regarding resuscitation given their least favored diagnosis were assessed using chi 2 analysis of trends for binomial proportions. Approximately 186 questionnaires were evaluated and consisted of 90 by medical students (MS), 67 by house officers (HOs), and 29 by attending physicians (APs). Resuscitation desires for each diagnosis were MC, 7 of 40; ESRD, 8 of 34; AIDS, 10 of 74; sepsis, 10 of 15; and MI, 20 of 23. chi 2 test for trend of desire to be resuscitated from the self-selected worst prognostic category by level of training demonstrated no significant decrease in desire to be resuscitated with increasing level of training. Physician's beliefs about CPR may be influenced by their experiences with particular patients and events.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMed1993

Cardiopulmonary resuscitation. New and controversial techniques.

Primary care physicians may need to perform cardiopulmonary resuscitation (CPR) from time to time. Knowledge regarding CPR has become extensive, and it is hoped that greater success will be achieved in the future with the advent of new methods. A number of techniques and devices have received attention in the lay and professional press. If appropriate care is to be delivered, practicing physicians must be aware of what is proven technology and what is investigational.

Cardiopulmonary Bypass↗