Critical care clinics
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Critical care clinics · Jul 2008
Common sleep problems in ICU: heart failure and sleep-disordered breathing syndromes.
Ventilation during sleep is under tight metabolic control, and can be destabilized by upper airway obstruction leading to snoring or obstructive apneas, inadequate respiratory pump muscle activity leading to hypoventilation, and central control instability leading to changes in metabolic feedback and loop gain. These three physiologic disturbances can lead to obstructive sleep apnea hypopnea syndrome (OSAHS), hypoventilation syndromes, and periodic breathing. OSAHS places a strain on the cardiac output by virtue of hypoxemia, large negative intrathoracic pressures, and high swings in systemic blood pressure. Periodic breathing, also known as central sleep apnea with Cheyne-Stokes pattern of respiration, is likely to be a product of advanced heart failure.
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Achieving restorative sleep in the ICU remains a challenge for most patients. Various environmental and nonenvironmental factors affect sleep patterns in the ICU. This article discusses the effects and relative importance of these factors on sleep patterns in the critical care setting. In addition, the implications of sleep pattern alteration on human physiology and homeostatic mechanisms are considered.
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Critical care clinics · Apr 2008
ReviewSepsis and septic shock: selection of empiric antimicrobial therapy.
This article is a brief overview of empiric antibiotic selection for sepsis and septic shock. The article includes a differential diagnosis of the mimics of sepsis and stresses a strategy for avoiding problems associated with antibiotic resistance. Although early appropriate empiric therapy is the cornerstone of sepsis and septic shock therapy, nonantibiotic interventions are critical as well. ⋯ Empiric monotherapy for sepsis and septic shock is preferred. Multiple-drug therapy is more expensive, has an increased potential for drug-drug interactions, has a higher likelihood of side effects, and does not decrease the resistance potential of the antibiotics being used. For these reasons, early empiric monotherapy is optimal and de-escalation is not necessary if initial mono therapy was wisely selected.
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The emergence of gram-negative bacteria resistant to most available antibiotics has led to the readministration of polymyxins B and E (colistin) as "salvage" therapy in critically ill patients. Recent studies demonstrated acceptable effectiveness and considerably less toxicity than reported in older studies of polymyxins. These old antibiotics may be administered for the treatment of intensive care unit-acquired infections of various types, including ventilator-associated pneumonia, urinary tract infections, bacteremia, and meningitis caused by multidrug resistant gram-negative pathogens, such as Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Enterobacter species. Randomized controlled trials are urgently needed to further clarify various issues regarding the effectiveness and safety of polymyxins, however.
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Seizures represent stereotypic electroencephalographic (EEG) and behavioral paroxysms as a consequence of electrical neurologic derangement. Seizures are usually described as focal or generalized motor convulsions; however, nonconvulsive seizures that occur in the absence of motor activity may escape clinical detection. ⋯ For optimal treatment, early diagnosis of the seizure type and its cause is important to ensure appropriate therapy. Convulsive status epilepticus requires emergent treatment before irreversible brain injury and severe metabolic disturbances occur.