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Biomedical subjects

J Varon

Publications and source records attributed to J Varon.

At least 37 records · Page 2Linked to original sources
PubMed1999

Automatic external defibrillators: lessons from the past, present and future.

Coronary artery disease remains the leading cause of death in the United States and most developed countries. Many of the victims die from sudden cardiac arrests, resulting from dysrhythmias-most commonly ventricular fibrillation. Since most cardiac arrests occur outside the hospital, implementing emergency services in the field will have a great impact on survival. With the development of the modern automatic external defibrillator (AED), early recognition and correction of these dysrhythmias by lay rescuers can significantly improve outcome from sudden death. This paper reviews the past, present and future development and applications of AEDs.

Electric Countershock↗
PubMed1999

Physicians' own preferences to the limitation and withdrawal of life-sustaining therapy.

While limiting and forgoing therapy at the end of life is now accepted on medical, ethical, moral and legal grounds, many Americans continue to die with heroic measures being taken to prevent their death. Recent studies have demonstrated that physicians frequently attend to their patients without knowledge of their preferences with regards to end-of-life issues. It is postulated that a physician's personal preferences with regard to the limitation and withdrawal of life support and active euthanasia would effect the discussion they had with their patients. The purpose of this study was to analyze end-of-life preferences of a diverse group of practicing physicians. The participants were active attending physicians at a community hospital, a rural referral center, a large tertiary care referral academic complex, and a specialized tertiary care referral center all within the United States. A questionnaire was developed which was mailed to attending physicians at the four participating medical centers. The respondents provided basic demographic data, do-not-resuscitate (DNR) preferences under various clinical circumstances as well as responses to a number of case vignettes. Six hundred and forty physicians responded to the survey. The mean age of the respondents was 46 years; 72% were male. In the event of a cardiac arrest less than 20% of respondents would want to undergo cardiopulmonary resuscitation in the setting of chronic end stage organ failure; the positive response rate was 5% for metastatic cancer and 2% for Alzheimer's disease. If death was imminent, 87% of physicians indicated they would want treatment withdrawn. Similarly, 95% of respondents indicated that they would want treatment withdrawn should they be in a persistent vegetative state. Only 1% of respondents believed that health care providers should never remove or withhold life-sustaining therapy. Should they have advanced motor neuron disease, 38% of physicians indicated they would request that their life be ended. The majority of physicians surveyed volunteered that they would want life-sustaining measures to be limited at the end of their life. A significant number were in favor of active euthanasia. This study suggests that it is unlikely that physicians' personal beliefs in regards to end-of-life care result in the failure to discuss these issues with their patients.

Attitude of Health Personnel↗
PubMed1999

Critical care and the World Wide Web.

The Internet was created in 1969, when the Advanced Research Projects Agency of the United States Department of Defense fired up an experimental network consisting of only four computers. Over the past five years there has been an exponential explosion in the number of computers added to this network. It is estimated that Internet traffic doubles every 100 days with more than 100 million people worldwide now on-line. The Internet is so vast that practically every aspect of human interest is represented is some form or fashion. From recreation to applied science and technology, and from Critical Care Medicine case scenarios to digitized radiology images and pathology specimens, the Internet has become increasingly useful for critical care practitioners. To date, no resource is better equipped to assist critical care providers in many of their daily tasks. This article presents some of the historical developments of the Internet as well as common applications that are useful for critical care practitioners.

Critical Care↗
PubMed1999

Severity scoring and outcome assessment. Computerized predictive models and scoring systems.

Severity of illness scoring systems and standardized death ratios are being used with increasing frequency as markers of quality of care and to compare and contrast the performance of ICUs. However, numerous factors unrelated to the quality of care delivered may impact the severity of illness score and standardized death ratios. This article reviews the commonly used severity scoring systems and factors that affect their predictive performance.

Computer Simulation↗
PubMed1999

The ex vivo antimicrobial activity and colonization rate of two antimicrobial-bonded central venous catheters.

OBJECTIVE: Catheter-related sepsis is an important complication associated with the use of central venous catheters. Recent studies have suggested that antimicrobial-bonded catheters may reduce catheter colonization and catheter-related sepsis. The aim of this study was to determine the relationship between the antimicrobial activity and the colonization rate of two commercially available antimicrobial-bonded central venous catheters. DESIGN: Prospective, randomized, controlled, nonblinded study. SETTING: Medical intensive care unit of a university-affiliated teaching hospital. PATIENTS: One hundred twenty consecutive medical intensive care unit patients requiring new central venous catheters (fresh stick). INTERVENTIONS: Patients were randomized to receive a) a Standard Arrow; b) an ARROWgard; or c) a Cook Bio-Guard Spectrum central venous catheter. Central venous catheters were removed when they were no longer required or when catheter-related sepsis was suspected. Under aseptic conditions, the distal 12 cm of the removed catheters were cut into six 2-cm segments. Semiquantitative culture was performed (by roll technique) on the distal segment. Colonization was defined as >15 colony-forming units. Using a modified Kirby-Bauer technique, the zone of inhibition of the remaining five segments was determined against the following organisms: methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Enterococcus faecalis, Acinetobacter baumannii, and Candida albicans Catheters that were removed within 24 hrs of insertion were excluded from the analysis. MEASUREMENTS AND MAIN RESULTS: Seven patients were not assessable. The baseline clinical and demographic characteristics were similar among the three groups of patients. Eleven Standard Arrow (28%), seven ARROWgard (19%), and four Bio-Guard (11%) catheters were colonized (p = .05 for Bio-Guard vs. control). Staphylococci were the most common colonizing organisms. Two patients with Standard Arrow catheters (5%) and one patient with an ARROWgard catheter (3%) developed catheter-related sepsis. Antibiotic-coated catheters significantly inhibited the growth of all test organisms except C. albicans (p < or = .05). Zones of inhibition were significantly larger for the Bio-Guard compared with the ARROWgard catheter when tested against MRSA, S. epidermidis, and E. faecalis (p < or = .002). CONCLUSION: The Bio-Guard central venous catheter had greater ex vivo antimicrobial activity against MRSA, S. epidermidis, and E. faecalis compared with the ARROWgard catheter, and this was associated with a significantly lower rate of catheter colonization.

APACHE↗
PubMed1999

The effect of acidified enteral feeds on gastric colonization in critically ill patients: results of a multicenter randomized trial. Canadian Critical Care Trials Group.

OBJECTIVE: To evaluate the effect of acidified enteral feeds on gastric colonization in critically ill patients compared with a standard feeding formula. DESIGN: Randomized, double-blind, multicenter trial. SETTING: Eight mixed intensive care units at tertiary care hospitals. PATIENTS: We recruited mechanically ventilated critically ill patients expected to remain ventilated for >48 hrs. We excluded patients with gastrointestinal bleeding, acidemia, and renal failure requiring dialysis. We enrolled 120 patients; 38% were female, age (mean +/- SD) was 57.6+/-19.3 yrs, and Acute Physiology and Chronic Health Evaluation II score (mean +/- SD) was 21.6+/-7.6. INTERVENTIONS: Vital High Nitrogen (Abbott Laboratories, Ross Products Division, Columbus, OH) was used as the standard feeding formula for the control group (pH = 6.5). Hydrochloric acid was added to Vital High Nitrogen to achieve a pH of 3.5 in the experimental group. MEASUREMENTS AND MAIN RESULTS: The main outcome measure was gastric colonization. Secondary outcomes included gastric pH, pneumonia, and mortality. The mean gastric pH in patients receiving acid feeds was lower (pH = 3.3) compared with controls (pH = 4.6; p<.05). One patient (2%) on acid feeds was colonized in the stomach with pathogenic bacteria, compared with 20 patients (43%) in the control group (p<.001). There was no difference in the incidence of pneumonia (6.1% in the acid feeds group vs. 15% in the control group; p = .19). Overall, there were 15 deaths in the acid feeds group and seven in the control group (p = .10); four patients in the acid feeds group and three in the control group died during the study period (p not significant). CONCLUSIONS: Acidified enteral feeds preserve gastric acidity and substantially reduce gastric colonization in critically ill patients. Larger studies are needed to examine its effect on ventilator-associated pneumonia and mortality.

Bacteria↗
PubMed1998

Cardiopulmonary resuscitation: a review for clinicians.

Attempts at cardiopulmonary resuscitation (CPR) date from antiquity, but it is only in the last 50 years that a scientifically-based methodology has been developed. External chest compressions is the standard method for managing circulatory arrest, however, numerous alterations of this technique have been proposed in attempts to improve outcome from CPR. Defibrillation is the single most important therapy for the management of ventricular fibrillation or pulseless ventricular tachycardia. Adrenergic agents used to improve myocardial and cerebral perfusion are also the subject of considerable investigation with new agents entering clinical study. This paper reviews the history, current techniques and pharmacotherapy as well as controversial issues in the management of patients with cardiac arrest.

Cardiopulmonary Resuscitation↗
PubMed1998

Should a cancer patient be resuscitated following an in-hospital cardiac arrest?

OBJECTIVE: Previous reports from general hospitals and cancer centers have identified the presence of malignancy as a poor prognostic indicator for successful cardiopulmonary resuscitation (CPR) for an in-hospital cardiac arrest. The purpose of this study was to evaluate the initial success of CPR as determined by return of spontaneous circulation (ROSC), patient survival to hospital discharge, and 1-year survival of this group as compared to previous studies in non-oncological centers. In addition, the charges incurred in caring for these patients were analyzed. MATERIALS AND METHODS: All cardiac arrests occurring between 1 January 1993 and 31 December 1994 were identified from a centralized morbidity and mortality database and reviewed retrospectively. Cardiac arrest was defined as the absence of a palpable pulse and initiation of CPR. Patients suffering pure respiratory arrest or shock without loss of pulse were excluded. Age, gender, primary site of malignancy, initial and ultimate outcome, including Zubrod's functional status (ZFS), and total hospital charges following cardiac arrest were recorded. Computerized billing records were used to tabulate total charges. RESULTS: 83 cardiac arrests occurred during the study period (42 women, 41 men). Mean age was 56.2 years. Forty-two percent of the patients had hematologic malignancies, 19% lung, 15% gastrointestinal, 5% head and neck cancers and 19% other malignancies. Sixty-six percent of the patients had ROSC. Only eight (9.6%) patients survived to hospital discharge: three died within 6 weeks under hospice care, two died within 6 months of discharge and only three (3.6%) patients survived to 1 year. Functional status follow-up of these three patients revealed two with ZFS 1 and one with ZFS 2. Total hospital charges for these 83 patients were US$ 2,959,740. CONCLUSIONS: Although ROSC after cardiac arrest in our patients was better than that reported for most series in general hospitals, their ultimate survival and hospital discharge was extremely poor.

Cardiopulmonary Resuscitation↗
PubMed1998

Feasibility of noninvasive mechanical ventilation in the treatment of acute respiratory failure in postoperative cancer patients.

PURPOSE: Patients with cancer who require mechanical ventilation have high mortality rates. Although oncological patients have multiple clinical problems, including nutritional and immunological deficiencies, added complications from mechanical ventilation by themselves may be life-threatening and may further compromise the ability of these patients to recover from an episode of acute respiratory failure (ARF). Noninvasive mechanical ventilatory support (NIMV) using positive-pressure-ventilation delivered through a mask has gained popularity for the treatment of ARF and may limit some mechanical ventilation complications. The purpose of this study was to prospectively evaluate NIMV in cancer patients with ARF. MATERIALS AND METHODS: All patients admitted to the surgical intensive care unit (SICU) at The University of Texas M.D. Anderson Cancer Center from August 1, 1994, to April 15, 1996, with hypoxemic or hypercapnic ARF were eligible for this study. NIMV was delivered with the BiPAP S/T-D (Respironics, Murrysville, PA) device. The initial settings were adjusted to achieve a tidal volume of 5 to 7 mL/kg and a SaO2 greater than 0.90. Demographic data, duration of therapy, and need for endotracheal intubation were recorded for each patient. RESULTS: Sixty patients were included in this study. There were 21 women (35%) and 39 men. The primary cancer sites of these patients were gastrointestinal (25 patients), genitourinary (15), hematological (8), lung (6), sarcoma (4), and skin (2). Fifty-three patients (88%) had hypoxemic ARF and 7 had hypercapnic ARF. The mean duration of NIMV was 1.83 days (range, 1 to 5 days) with a median of 2 days. Forty-two patients (70%) were weaned from NIMV and were spared endotracheal intubation. The remaining 18 patients deteriorated and ultimately required intubation and assisted mechanical ventilation. No complications related to the use of NIMV were seen in this study population. CONCLUSIONS: NIMV was effective in the treatment of ARF in cancer patients at our institution substantially decreasing the need for intubation. This ventilatory technique is a viable option for cancer patients with ARF.

Acute Disease↗
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↗