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Biomedical subjects

S L Krachman

Publications and source records attributed to S L Krachman.

4 recordsLinked to original sources

Sleep in the intensive care unit.

The most critically ill patients in the hospital are located in the ICU. Due to intensive individualized care and monitoring, these patients often suffer from severe sleep deprivation. The amount and continuity of sleep as well as normal sleep architecture are all affected. Moreover, by impairing protein synthesis, cell division, and cellular immunity, sleep deprivation can affect the healing process and thus contribute to an increased morbidity and mortality. Reasons for sleep deprivation appear to be multifactorial and include the following: the patient's chronic underlying illness, an acute superimposed illness or surgical procedure, medications used in treatment of the primary illness, and the ICU environment itself. Therapeutic interventions need to address each of these potential causes, with an emphasis placed on providing an environment that is both diurnal and focused on the importance of uninterrupted sleep.

Chronic Disease

Obstructive sleep apnea: a multisystemic disorder.

Obstructive sleep apnea is a multisystemic disorder with pathologic sequelae that become apparent after a number of years. Patients with obstructive sleep apnea generally present with hypersomnolence, and diagnosis is eventually established through observation of the patient during sleep. Patients with obstructive sleep apnea snore loudly and experience nocturnal oxygen desaturation and repetitive disruptions from sleep that eventually lead to daytime hypersomnolence. Numerous complex interactive pathophysiologic events occur during each obstructive episode, and it is important for the clinician to be aware of the cardiopulmonary, neurologic, and anatomic abnormalities associated with this condition. The anatomic configuration of the pharynx and the physiologic response to occlusion of the upper airway have a major role in the pathogenesis of this disorder. Alveolar ventilation during an apneic episode is immediately reduced to zero, and the metabolic demands for oxygen must be met by oxygen stores within the body. With repetitive episodes of obstruction, the oxygen stores within the lungs are diminished and the rate of arterial oxyhemoglobin desaturation increases. During apneic episodes, the systemic blood pressure increases while heart rate and cardiac output decrease. Bradydysrhythmias have been noted with the obstructive apneic episodes, and ventricular dysrhythmias are associated with episodes of severe oxyhemoglobin desaturation. Coexisting cardiopulmonary or neuromuscular disease in patients with obstructive sleep apnea contributes to the development of hypoventilation, serious gas exchange derangement, and general cardiovascular instability.

Female

Effects of dobutamine on oxygen transport and consumption in the adult respiratory distress syndrome.

OBJECTIVE: To determine if oxygen consumption (VO2) in patients with adult respiratory distress syndrome (ARDS) is dependent on, and thus limited by, oxygen transport (TO2) rather than O2 demand. DESIGN: Prospective study. SETTING: Intensive care unit of a tertiary referral center. PATIENTS: 12 patients with ARDS and sepsis syndrome. INTERVENTIONS: Routine intensive care unit monitoring including pulmonary and radial artery catheters. MEASUREMENTS: Dobutamine was used to increase cardiac output, thereby directly varying TO2 under conditions of constant O2 demand. After baseline measurements of TO2 and VO2, dobutamine was infused intravenously at progressively increasing doses of 5, 10, 15 and 20 micrograms/kg/min and measurements of TO2 and VO2 were repeated after 30 min at each dose. RESULTS: Dobutamine increased TO2 in 8 of the 12 patients, by 29% at 5 micrograms/kg/min and by 45% (net) at 10 micrograms/kg/min, but not at higher doses. In these 8 patients dobutamine also increased VO2 by 15% at 5 micrograms/kg/min, but did not further increase VO2 at higher doses. There was no correlation between baseline blood lactate concentration and the response of either TO2 or VO2 to dobutamine. CONCLUSIONS: In some but not all patients with ARDS and sepsis syndrome, short-term infusion of low-dose dobutamine can increase both TO2 and VO2. Achievement of a TO2-independent level of VO2 could not be convincingly demonstrated in any individual patient. The response of TO2 and VO2 to dobutamine could not be predicted from baseline blood lactate concentration. Determination of the impact on patient outcome of a more prolonged infusion of dobutamine requires further study.

Adult

Diagnosis and management of asthma: a brief review of two asthma expert panel reports.

During the past decade, asthma morbidity and mortality have increased noticeably. Although the reasons for the increase are not clear, the prevalence of asthma has been reported to be increasing not only in the United States but also in other countries throughout the world, including the United Kingdom, New Zealand, and Australia. Asthma mortality rates and morbidity trends are increasing despite what appears to be major scientific advances in our understanding of asthma and in the face of a multitude of new therapeutic modalities. This article presents a brief overview of the pathogenesis and diagnosis of asthma, and highlights the major management recommendations of two expert panel reports.

Algorithms