Abstract:
OBJECTIVES:To understand when the use of high-frequency ventilation would be advantageous, we formulated the problem of achieving adequate alveolar ventilation at minimal pressure cost by dividing it into two simpler problems: a) the pressure cost per unit of convective oscillatory flow; and b) the convective flow cost necessary to achieve a unit of alveolar ventilation. METHODS:Simple solutions for each of these cost functions were formulated using established models of gas exchange and lung mechanics, including the effects of lung inflation tidal volume and respiratory frequency in alveolar ventilation, nonlinear lung tissue compliance, and alveolar recruitment and derecruitment. Solutions to these models were combined to assess the total pressure cost of high-frequency ventilation as a function of the ventilatory settings and the pathophysiologic variables of the patient. MAIN RESULTS:The model predicted that for variables applicable to an infant with respiratory distress syndrome, the selection of positive end-expiratory pressure (PEEP) becomes critical because the penalties in pressure cost are amplified for both high and low values of PEEP. The selection of frequency is not as critical for frequencies > 10 Hz, although it is more important than in the normal neonatal lung. CONCLUSIONS:This analysis illustrates the importance of using high-frequency ventilation in infant respiratory distress syndrome and of optimizing the amount of PEEP. It also points out the danger of barotrauma in the derecruited lung. When the lungs are in a derecruited state, the combinations of frequency, PEEP, and tidal volume that yield adequate ventilation with safe distention of recruited alveoli are severely limited.
journal_name
Crit Care Medjournal_title
Critical care medicineauthors
Venegas JG,Fredberg JJdoi
10.1097/00003246-199422091-00004subject
Has Abstractpub_date
1994-09-01 00:00:00pages
S49-57issue
9 Suppleissn
0090-3493issn
1530-0293journal_volume
22pub_type
杂志文章,评审abstract:OBJECTIVE:In the ICU, discussions between clinicians and surrogate decision makers are often accompanied by conflict about a patient's prognosis or care plan. Trust plays a role in limiting conflict, but little is known about the determinants of trust in the ICU. We sought to identify the dimensions of trust and clinic...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001957
更新日期:2016-12-01 00:00:00
abstract::Critically ill patients who fear impending death may die suddenly. We studied prospectively the incidence of death in critically ill surgical patients who articulated the fear that they were about to die. Physiologic, environmental, and behavioral correlates which might influence perceptions of impending death were ex...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198607000-00005
更新日期:1986-07-01 00:00:00
abstract:OBJECTIVE:To determine the effects of accidental injury of varying severity on interleukin (IL)-1 alpha, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and endotoxin release. DESIGN:Prospective, multi-unit, longitudinal study. SETTING:Emergency Departments and intensive care units of two university hospitals. ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199306000-00010
更新日期:1993-06-01 00:00:00
abstract:OBJECTIVES:To assess trends in the use of extracorporeal membrane oxygenation for poisoning in the United States. DESIGN:Retrospective cohort study. SETTING:The National Poison Data System, the databased owned and managed by the American Association of Poison Control Centers, the organization that supports and accred...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000004401
更新日期:2020-08-01 00:00:00
abstract::Computerized gamma scintigraphy revealed a significant (p less than 0.001) rising lung:heart radioactivity ratio, which has been called "slope of injury" or "slope index", with both 99mTechnetium-tagged human serum albumin (99mTc-HSA) and 99mTechnetium-tagged red blood cells (99Tc-RBC) after 0.05 or 0.2 ml/kg iv oleic...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198201000-00008
更新日期:1982-01-01 00:00:00
abstract:OBJECTIVE:Therapeutic hypothermia has been used to attenuate the effects of traumatic brain injuries. However, the required degree of hypothermia, length of its use, and its timing are uncertain. We undertook a comprehensive meta-analysis to quantify benefits of hypothermia therapy for traumatic brain injuries in adult...
journal_title:Critical care medicine
pub_type: 杂志文章,meta分析,评审
doi:10.1097/CCM.0000000000002205
更新日期:2017-04-01 00:00:00
abstract:OBJECTIVE:Tea has been around for centuries, and its medicinal properties have been purported in the literature but never fully confirmed. Interleukin-8 is a principle neutrophil chemoattractant and activator in humans. We determined the effects of theaflavin, a black tea-derived polyphenol, on tumor necrosis factor-al...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000142661.73633.15
更新日期:2004-10-01 00:00:00
abstract:BACKGROUND:Neurologic dysfunction, coma, and seizures are common in obstetric patients in the intensive care unit. OBJECTIVE:To review common neurologic disorders resulting in critical illness in pregnancy. REVIEW:Obstetric disorders causing coma and seizures include eclampsia, acute fatty liver of pregnancy, and amn...
journal_title:Critical care medicine
pub_type: 杂志文章,评审
doi:10.1097/01.ccm.0000182790.35728.f7
更新日期:2005-10-01 00:00:00
abstract:OBJECTIVES:To compare usual care with a proactive case-finding approach for critically ill patients with terminal dementia using an inpatient palliative care service. DESIGN:Prospective comparison to historical control. SETTING:Urban, university-affiliated hospital. PATIENTS:Total of 52 men and women with end-stage ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000138560.56577.88
更新日期:2004-09-01 00:00:00
abstract:BACKGROUND:Extravascular lung water is a quantitative marker of the amount of fluid in the thoracic cavity besides the vasculature. Indexing to both predicted and actual body weight have been proposed to compare different individuals and provide a uniform range of normal. OBJECTIVE:We explored extravascular lung water...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e318275cd75
更新日期:2013-04-01 00:00:00
abstract:OBJECTIVES:Maintenance of mean arterial pressure>65 mm Hg has been associated with improved clinical outcomes in many studies of critically ill patients. Current guidelines for the management of septic shock and guidelines for managing other critical illnesses suggest intra-arterial blood pressure measurement is prefer...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e3181fa057f
更新日期:2010-12-01 00:00:00
abstract:BACKGROUND:Millions of patients are discharged from intensive care units annually. These intensive care survivors and their families frequently report a wide range of impairments in their health status which may last for months and years after hospital discharge. OBJECTIVES:To report on a 2-day Society of Critical Car...
journal_title:Critical care medicine
pub_type: 杂志文章,评审
doi:10.1097/CCM.0b013e318232da75
更新日期:2012-02-01 00:00:00
abstract:OBJECTIVE:To determine whether clinically relevant airspace concentrations of beta2-adrenergic agonists stimulated maximal alveolar fluid clearance rates and to determine whether beta2 agonist therapy decreased pulmonary edema in experimental acute lung injury. DESIGN:Prospective randomized laboratory investigation. ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000129489.34416.0e
更新日期:2004-07-01 00:00:00
abstract:OBJECTIVES:Reviews of patient safety efforts suggest that technical/administrative change must be augmented by global factors such as organizational culture and climate. The objective was to outline a comprehensive model for healthcare climate and test one of its elements, the nursing subclimate, in terms of several pa...
journal_title:Critical care medicine
pub_type: 杂志文章,多中心研究
doi:10.1097/01.CCM.0000262404.10203.C9
更新日期:2007-05-01 00:00:00
abstract::The authors determined the correction factor (Ct) for three sizes of commonly available central venous catheters. These catheters are used as the injectate catheter when a 2.5 Fr transthoracic thermistor is used to determine cardiac output by thermodilution. The valves for Ct were highly reproducible. These determinat...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198112000-00014
更新日期:1981-12-01 00:00:00
abstract:OBJECTIVE:To date, no study has systematically investigated the impact of drowning-induced asphyxia on hemostasis. Our objective was to test the hypothesis that asphyxia induces bleeding by hyperfibrinolytic disseminated intravascular coagulation. DESIGN:Observational study. SETTING:A 2,100-bed tertiary care facility...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001273
更新日期:2015-11-01 00:00:00
abstract::A new quantitative method for measuring the prognosis and severity of illness in terms of probability of survival was developed from 224 studies in an index population of 220 critically ill surgical patients. Patients were selected preoperatively to eliminate pre-existing cardiac disease, cirrhosis, nutritional debili...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198502000-00007
更新日期:1985-02-01 00:00:00
abstract:OBJECTIVES:Most knowledge related to the pathophysiology of microcirculation in ischemic stroke comes from experimental research. Unfortunately, data on microcirculation in the human brain are limited, partially as a result of the lack of appropriate investigational techniques. The objective of our study was to test th...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e31820ead5e
更新日期:2011-05-01 00:00:00
abstract:OBJECTIVE:To evaluate the frequency and clinical correlates of ultrafilterable hypomagnesemia in neonates admitted to the neonatal intensive care unit (ICU). DESIGN:Prospective, observational study. SETTING:Massachusetts General Hospital and Mount Auburn Hospital. PATIENTS:A total of 117 patients (84 neonatal ICU pa...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199405000-00017
更新日期:1994-05-01 00:00:00
abstract:OBJECTIVE:To determine whether the absence or presence of clinical pharmacists in intensive care units (ICUs) results in differences in mortality rates, length of ICU stay, and ICU charges for Medicare patients with nosocomial-acquired infections, community-acquired infections, and sepsis. DESIGN, SETTING, AND PATIENT...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e31818f2269
更新日期:2008-12-01 00:00:00
abstract:OBJECTIVES:To evaluate the use of multifrequency bioelectrical impedance analysis to predict creatinine/urea clearance based on 24 hours urine collection. A practical formula was developed, and its performance was compared with that of established formulas such as Cockcroft-Gault, Modification of Diet in Renal Disease,...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000004033
更新日期:2019-12-01 00:00:00
abstract:OBJECTIVES:To define the hemodynamic and gastric intramucosal PCO2 (PiCO2) changes during the first 48 hrs after burn trauma and to analyze their relationship with outcome. DESIGN:Prospective, observational study in a cohort of consecutively admitted critically ill burn patients. SETTING:Intensive care burn unit in a...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-200006000-00005
更新日期:2000-06-01 00:00:00
abstract::Recorded values (SpO2) of oxygen saturation from six noninvasive pulse oximeters were compared to each other and to the value from a cooximeter. Simultaneous measurements were obtained from each instrument in eight healthy nonsmoking volunteers rendered hypoxic greater than 70% SpO2. Functional arterial oxygen saturat...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198907000-00016
更新日期:1989-07-01 00:00:00
abstract::Arterial and transcutaneous O2 (PtcO2) and CO2 (PtcCO2) tensions, arterial O2 saturations (SaO2) and P50 values were measured in 47 patients before extubation. In order to unmask ventilation to perfusion (VA/Q) inequality, all variables were obtained without CPAP and with FIO2 of 0.40 as well as with CPAP of 5 cm H2O ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198309000-00007
更新日期:1983-09-01 00:00:00
abstract:OBJECTIVES:This report examines the frequency, type, and prognostic factors of medical (nonneurologic) complications after subarachnoid hemorrhage in a large, prospective study. The influences of contemporary neurosurgical, neurological, and critical care practice on mortality and morbidity rates after aneurysmal subar...
journal_title:Critical care medicine
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1097/00003246-199506000-00004
更新日期:1995-06-01 00:00:00
abstract:OBJECTIVE:To determine whether blood lactate, base deficit, or oxygen-derived hemodynamic variables correlate with morbidity and mortality rates in a clinically-relevant LD50 model of penetrating trauma. DESIGN:Prospective, controlled study. SETTING:University research laboratory. SUBJECTS:Anesthetized, mechanically...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199901000-00044
更新日期:1999-01-01 00:00:00
abstract:OBJECTIVES:A cuffed tracheostomy tube facilitates prolonged mechanical ventilation and weaning but usually leads to prolonged voicelessness, which can be one of the most negative experiences of hospitalization. No randomized trials have examined the effects of targeted early communication intervention for the restorati...
journal_title:Critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1097/CCM.0000000000001610
更新日期:2016-06-01 00:00:00
abstract:OBJECTIVES:Anaphylactic shock is associated with severe hypotension. Potassium channel blockers, such as 4-aminopyridine, induce vasoconstriction. The objective of this study was to test the ability of 4-aminopyridine to restore blood pressure and increase survival in anaphylactic shock. DESIGN:Experimental study. SE...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001822
更新日期:2016-11-01 00:00:00
abstract:OBJECTIVE:To investigate if prone position delays the progression of experimental ventilator-induced lung injury, possibly due to a more homogeneous distribution of strain within lung parenchyma. DESIGN:Prospective, randomized, controlled trial. SETTING:Animal laboratory of a university hospital. SUBJECTS:Thirty-fiv...
journal_title:Critical care medicine
pub_type: 评论,杂志文章
doi:10.1097/01.ccm.0000150660.45376.7c
更新日期:2005-02-01 00:00:00
abstract:BACKGROUND:Although survival is traditionally modeled using Cox proportional hazards modeling, this approach may be inappropriate in sepsis, in which the proportional hazards assumption does not hold. Newer, more flexible models, such as Gray's model, may be more appropriate. OBJECTIVES:To construct and compare Gray's...
journal_title:Critical care medicine
pub_type: 杂志文章,多中心研究
doi:10.1097/01.ccm.0000114819.37569.4b
更新日期:2004-03-01 00:00:00