Abstract:
OBJECTIVE:Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure functional residual capacity and ventilation homogeneity. The aim of the present study was to validate functional residual capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. DESIGN:Prospective laboratory and animal trial. SETTING:Animal laboratory in a university setting. SUBJECTS:Sixteen newborn piglets (age<12 hrs, median weight 1390 g [705-4200 g]) before and after surfactant depletion (Pao2<100 torr in Fio2=1.0) by lung lavage. INTERVENTIONS:Heptafluoropropane was measured with a new infrared mainstream sensor connected with the flow sensor of the Dräger Babylog 8000. Accuracy and precision of the measurement technique were tested in a mechanical lung model with a volume range from 11 to 35 mL. Reproducibility of the method and its sensitivity to detect changes of functional residual capacity were assessed in vivo by variation of ventilatory variables. MEASUREMENTS AND MAIN RESULTS:In vitro the absolute error of functional residual capacity was <1 mL (relative errors<3%) with a coefficient of variation<4%. The coefficient of variation of consecutive in vivo measurements was only slightly higher (<5.1%). Measurement of heptafluoropropane concentrations in blood showed no significant accumulation for repeated functional residual capacity measurements within short time periods. After lung lavage, the functional residual capacity decreased from 20.9 mL/kg to 14.5 mL/kg (p<.05) despite increased ventilatory pressures, and lung clearance index (p<.001) and moment ratios (p<.01) increased significantly due to uneven alveolar ventilation. In healthy lungs, the increase in peak inflation pressure and positive end-expiratory pressure by 3-4 cm H2O had only a moderate effect on functional residual capacity (20.9+/-8.6 vs. 26.0+/-11.9 mL/kg, p=.17) and no effect on ventilatory homogeneity, whereas in surfactant-depleted lungs the functional residual capacity increased from 14.5+/-6.7 mL/kg to 29.9+/-12.6 mL/kg (p<.001) and lung clearance index and moment ratios decreased significantly (p < .01). CONCLUSIONS:Heptafluoropropane is a suitable tracer gas for precise functional residual capacity measurements tested in vitro and allows for reproducible measurements in ventilated small lungs without any adverse effects on mechanical ventilation. The sensitivity of the method is sufficiently high to demonstrate the effect of changes in ventilatory settings on the functional residual capacity and ventilation homogeneity.
journal_name
Crit Care Medjournal_title
Critical care medicineauthors
Proquitté H,Kusztrich A,Auwärter V,Pragst F,Wauer RR,Schmalisch Gdoi
10.1097/01.CCM.0000220065.93507.ABsubject
Has Abstractpub_date
2006-06-01 00:00:00pages
1789-95issue
6eissn
0090-3493issn
1530-0293journal_volume
34pub_type
杂志文章abstract:OBJECTIVES:To evaluate the preload dependence of femoral maximal change in pressure over time (dP/dtmax) during volume expansion in preload dependent and independent critically ill patients. DESIGN:Retrospective database analysis. SETTING:Two adult polyvalent ICUs. PATIENTS:Twenty-five critically ill patients with a...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000004515
更新日期:2020-10-01 00:00:00
abstract:OBJECTIVE:To assess the impact of sepsis classification and multidrug-resistance status on outcome in patients receiving appropriate initial antibiotic therapy. DESIGN:A retrospective cohort study. SETTING:Barnes-Jewish Hospital, a 1,250-bed teaching hospital. PATIENTS:Individuals with Enterobacteriaceae sepsis, sev...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001013
更新日期:2015-08-01 00:00:00
abstract:OBJECTIVE:To test the hypothesis that hyperbaric oxygen therapy ameliorates delayed cognitive impairment after acute carbon monoxide poisoning by promoting neurogenesis through upregulating the brain-derived neurotrophic factor in the hippocampus. DESIGN:Laboratory animal experiments. SETTING:University/Medical cente...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001299
更新日期:2016-01-01 00:00:00
abstract:OBJECTIVE:To examine the pulmonary and cardiac function of children who survived an episode of acute hypoxemic respiratory failure. DESIGN:Descriptive cohort analysis. SETTING:Pediatric clinical research center of a university hospital. PATIENTS:Utilizing the criteria of PaO2 < 75 torr (< 10 kPa) with an FIO2 of > 0...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199601000-00024
更新日期:1996-01-01 00:00:00
abstract:OBJECTIVE:Sympathetic vasoconstriction regulates peripheral circulation and controls blood pressure, but sepsis is associated with hypotension. We evaluated whether apparent loss of sympathetic vasoconstrictor responsiveness relates to distended smooth muscles or to endotoxemia and/or hypoxia. DESIGN:Prospective descr...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000001486
更新日期:2016-04-01 00:00:00
abstract:OBJECTIVES:Ventilator-associated pneumonia diagnosis remains a debatable topic. New definitions of ventilator-associated conditions involving worsening oxygenation have been recently proposed to make surveillance of events possibly linked to ventilator-associated pneumonia as objective as possible. The objective of the...
journal_title:Critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1097/CCM.0000000000000674
更新日期:2015-01-01 00:00:00
abstract::There is an increasing evidence that survivors of critical illness suffer from impaired health-related quality of life. There are relatively few studies that have evaluated the effect of interventions in clinical trials to improve these long-term outcomes. Studies to improve long-term outcomes after critical illness f...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e3181922bb7
更新日期:2009-01-01 00:00:00
abstract::Intermittent Mandatory Ventilation (IMV) provides an alternative method of support to assisted and controlled mechanical ventilation in neonates with acute respiratory failure. Specific advantages include the use of only the level of mechanical support which is required on an individual basis. Because intrapleural pre...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-197701000-00004
更新日期:1977-01-01 00:00:00
abstract:OBJECTIVES:The Fragility Index, which represents the number of patients responsible for a statistically significant finding, has been suggested as an aid for interpreting the robustness of results from clinical trials. A small Fragility Index indicates that the statistical significance of a trial depends on only a few ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000003527
更新日期:2019-03-01 00:00:00
abstract:OBJECTIVE:To test the short-term physiologic effects (indexes of respiratory effort, ventilation, and gas exchange), leaks, patient-ventilator asynchrony, and comfort of four noninvasive ventilation (NIV) facial, oronasal, or oral interfaces with major differences in internal volume. DESIGN:Prospective, short-term, cr...
journal_title:Critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1097/CCM.0b013e31819b575f
更新日期:2009-03-01 00:00:00
abstract:OBJECTIVE:Our goal was to demonstrate explicitly that lower-frequency positive-pressure ventilation not only preserves adequate oxygenation and acid-base status in hemorrhagic states, but also that "normal" or higher respiratory rates significantly compromise hemodynamics, even with moderate degrees of hemorrhage. DES...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000134264.88332.37
更新日期:2004-09-01 00:00:00
abstract::Nine ventilator-dependent patients were successfully weaned from mechanical ventilatory support by high-frequency jet ventilation. All patients had been on ventilatory support for at least 2 wk, and had not responded to attempts at weaning by intermittent mandatory ventilation. ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198409000-00021
更新日期:1984-09-01 00:00:00
abstract:OBJECTIVES:To test whether hospital-based physicians made different intensive care unit and life-sustaining treatment decisions for otherwise identical black and white patients with end-stage cancer and life-threatening hypoxia. DESIGN:We conducted a randomized trial of the relationship between patient race and physic...
journal_title:Critical care medicine
pub_type: 杂志文章,随机对照试验
doi:10.1097/CCM.0b013e3182186e98
更新日期:2011-07-01 00:00:00
abstract:OBJECTIVE:Cocaine, which first made its appearance >1,000 yrs ago, is now widely used throughout the world. The physiologic responses to cocaine may cause severe pathologic effects. This review highlights the many critical care challenges resulting from these effects. DESIGN:Historical vignettes, epidemiologic factors...
journal_title:Critical care medicine
pub_type: 杂志文章,评审
doi:10.1097/01.CCM.0000063258.68159.71
更新日期:2003-06-01 00:00:00
abstract:OBJECTIVE:To determine the efficacy of supplemental 25% albumin in reducing morbidity and mortality rates in the surgical intensive care unit (ICU). DESIGN:Prospective, randomized, unblinded clinical study. SETTING:Surgical ICU in a community hospital. PATIENTS:Two hundred nineteen patients with admission circulatin...
journal_title:Critical care medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00003246-199404000-00017
更新日期:1994-04-01 00:00:00
abstract::The educational objectives in use in our Pediatric ICU are described. These have importance for educational programs in critical care medicine, in particular, where patient care needs can easily overwhelm educational needs. It is important not to overlook our role as teachers in the development of proper attitudes and...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-197705000-00008
更新日期:1977-05-01 00:00:00
abstract::Sepsis and resulting multiple system organ failure are the leading causes of mortality in intensive care units. Although it is generally appreciated that rampant, deregulated inflammatory pathways play a major role in sepsis, a comprehensive understanding based on the integrated response of multiple signal transductio...
journal_title:Critical care medicine
pub_type: 杂志文章,评审
doi:10.1097/00003246-200301001-00001
更新日期:2003-01-01 00:00:00
abstract:OBJECTIVE:To investigate the effect of norepinephrine on static (right atrial pressure, pulmonary artery occlusion pressure ) and dynamic (pulse pressure variation and arterial systolic pressure variation) preload indicators in experimental hemorrhagic shock. DESIGN:Prospective controlled experimental study. SETTING:...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000182801.48137.13
更新日期:2005-10-01 00:00:00
abstract:OBJECTIVE:Increasing evidence, including publication of the Transfusion Requirements in Critical Care trial in 1999, supports a lower hemoglobin threshold for RBC transfusion in ICU patients. However, little is known regarding the influence of this evidence on clinical practice over time in a large population-based coh...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0b013e31828e9a49
更新日期:2013-10-01 00:00:00
abstract:OBJECTIVE:Although it is established that septic shock induces immunosuppression, the mechanisms for this phenomenon remain poorly understood. Human leukocyte antigen-G exerts strong inhibitory effects that are directed at different arms of the immune system. The main objective of the current study was to measure human...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.CCM.0000277039.84372.1C
更新日期:2007-08-01 00:00:00
abstract::Malaria is one of the most common infectious diseases in the world, and severe respiratory complications have been described mainly in association with Plasmodium falciparum. We describe a case of acute respiratory distress syndrome complicating infection with P. vivax in the setting of relatively low parasitemia in a...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-200103000-00037
更新日期:2001-03-01 00:00:00
abstract::A portable video image-processor unit used to evaluate bedside digital subtraction angiography yields sufficient information on the major arterial vessels and the heart, using standard x-ray equipment at fluoroscopic energy levels. This unit should contribute to the evaluation of the critically ill patient in the ICU....
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198412000-00014
更新日期:1984-12-01 00:00:00
abstract::Foreign-body aspiration in adults is usually associated with asphyxiation after aspiration of food particles. The present report documents a case of foreign-body aspiration that resulted from poor tracheostomy care in an alcoholic patient, and caused fulminant pneumonitis. ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198408000-00020
更新日期:1984-08-01 00:00:00
abstract:OBJECTIVES:Our goal was to "reverse translate" the human response to surgical sepsis into the mouse by modifying a widely adopted murine intra-abdominal sepsis model to engender a phenotype that conforms to current sepsis definitions and follows the most recent expert recommendations for animal preclinical sepsis resea...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/CCM.0000000000003926
更新日期:2019-11-01 00:00:00
abstract::The aim of this study was to assess prospectively the variations of serum phosphorus concentration (P) after onset of mechanical ventilation (MV) in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory acidosis. In 14 COPD patients, we measured P, PaCO2, and pH, immediately before MV (H0), ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198911000-00005
更新日期:1989-11-01 00:00:00
abstract::We compared the degree of complement activation in 15 patients receiving massive blood transfusions and 21 patients with the septic syndrome and examined its association with other risk factors for adult respiratory distress syndrome (ARDS). Patients with massive transfusion (n = 8) as their only risk factor for ARDS ...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-198612000-00001
更新日期:1986-12-01 00:00:00
abstract::With the thermodilution technique, repeated determination of cardiac index (CI) has become a rapid, easily accomplished, safe procedure. We paired 77 CI determinations measured by direct Fick and thermodilution techniques in 21 patients who underwent myocardial revascularization. Commercially available thermistor-tipp...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-197509000-00002
更新日期:1975-09-01 00:00:00
abstract:OBJECTIVE:To describe a postpartum patient who presented with fulminant hepatic failure and hepatic coma as a result of unrecognized peripartum cardiomyopathy. DESIGN:Case report. SETTING:Medical intensive care unit of a tertiary care academic medical center. PATIENT:A 35-yr-old woman 5 wks postpartum from an uneven...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/01.ccm.0000158517.25962.8e
更新日期:2005-04-01 00:00:00
abstract::Severe complications sometimes occur in critically ill patients during intrahospital transport. Possible causes may be inadequate ventilation, insufficient monitoring, interrupted application of vasoactive drugs, or disconnections and accidental extubation. We constructed a transport unit equipped with a respirator; c...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199012000-00024
更新日期:1990-12-01 00:00:00
abstract:OBJECTIVE:To determine if autopsies performed on patients who die in the medical intensive care unit (ICU) provide clinically important new information. DESIGN:Retrospective review. SETTING:A 16-bed medical-coronary ICU. PATIENTS:Patients who underwent autopsy during a 1-yr period. INTERVENTIONS:Pre mortem diagnose...
journal_title:Critical care medicine
pub_type: 杂志文章
doi:10.1097/00003246-199808000-00015
更新日期:1998-08-01 00:00:00