摘要:

ObjectivesRecent studies in animal models of sepsis-induced acute respiratory distress syndrome (ARDS) have shown that a low-carbohydrate, high-fat diet combining the anti-inflammatory and vasodilatory properties of eicosapentaenoic acid (EPA; fish oil), gamma-linolenic acid (GLA; borage oil) (EPA + GLA), and antioxidants improves lung microvascular permeability, oxygenation, and cardiopulmonary function and reduces proinflammatory eicosanoid synthesis and lung inflammation. These findings suggest that enteral nutrition with EPA + GLA and antioxidants may reduce pulmonary inflammation and may improve oxygenation and clinical outcomes in patients with ARDS.DesignProspective, multicentered, double-blind, randomized controlled trial.SettingIntensive care units of five academic and teaching hospitals in the United States.PatientsWe enrolled 146 patients with ARDS (as defined by the American-European Consensus Conference) caused by sepsis/pneumonia, trauma, or aspiration injury in the study.InterventionsPatients meeting entry criteria were randomized and continuously tube-fed either EPA + GLA or an isonitrogenous, isocaloric standard diet at a minimum caloric delivery of 75% of basal energy expenditure x 1.3 for at least 4-7 days.Measurements and Main ResultsArterial blood gases were measured, and ventilator settings were recorded at baseline and study days 4 and 7 to enable calculation of PaO2/FIO2, a measure of gas exchange. Pulmonary neutrophil recruitment was assessed by measuring the number of neutrophils and the total cell count in bronchoalveolar lavage fluid at the same time points. Clinical outcomes were recorded. Baseline characteristics of 98 evaluable patients revealed that key demographic, physiologic, and ventilatory variables were similar at entry between both groups. Multiple bronchoalveolar lavages revealed significant decreases ([similar]2.5-fold) in the number of total cells and neutrophils per mL of recovered lavage fluid during the study with EPA + GLA compared with patients fed the control diet. Significant improvements in oxygenation (PaO (2/FIO)2) from baseline to study days 4 and 7 with lower ventilation variables (FIO2, positive end-expiratory pressure, and minute ventilation) occurred in patients fed EPA + GLA compared with controls. Patients fed EPA + GLA required significantly fewer days of ventilatory support (11 vs. 16.3 days; p = .011), and had a decreased length of stay in the intensive care unit (12.8 vs. 17.5 days; p = .016) compared with controls. Only four of 51 (8%) patients fed EPA + GLA vs. 13 of 47 (28%) control patients developed a new organ failure during the study (p = .015).ConclusionsThe beneficial effects of the EPA + GLA diet on pulmonary neutrophil recruitment, gas exchange, requirement for mechanical ventilation, length of intensive care unit stay, and the reduction of new organ failures suggest that this enteral nutrition formula would be a useful adjuvant therapy in the clinical management of patients with or at risk of developing ARDS. (Crit Care Med 1999; 27:1409-1420)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo identify the organisms, their antibiotic susceptibility, and the associated focus on infection causing nosocomial bacteremia in patients in an adult intensive care unit (ICU) between 1971 and 1995.DesignProspective observational study.SettingA 12-bed general adult ICU in a 1,000-bed tertiary referral teaching hospital.PatientsFour hundred eighty-six episodes of bacteremia involving 570 organisms in 425 patients.Measurements and Main ResultsBlood cultures taken from patients with suspected nosocomial infection were analyzed. Isolated organisms were identified, and their susceptibility to commonly used antibiotics was determined. Clinical details, including antibiotic treatment, were recorded for all patients. From 1986 to 1995, culture results of samples obtained from other sites were used to help identify the focus of infection causing bacteremia. All results were collected prospectively by clinical microbiologists. Between 1971 and 1990, the number of bacteremias and the relative frequency of isolation of individual organisms changed little, with Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella species predominating. During 1991 to 1995, the number of bacteremias increased two-fold, largely attributable to increased isolation of Enterococcus species, coagulase-negative staphylococci, intrinsically antibiotic-resistant Gram-negative organisms (particularly P. aeruginosa), and Candida species. The most commonly used antibiotics for the treatment of bacteremic patients throughout the 1970s were amoxicillin and gentamicin. After the introduction of cephalosporins in the early 1980s, their use increased progressively to equal that of gentamicin in the 1990s, whereas amoxicillin use decreased. Since the introduction of cephalosporins, increases in the antibiotic resistance of Gram-negative organisms have been largely confined to an outbreak of gentamicin- and ceftazidime-resistant organisms caused by contaminated arterial pressure monitors during 1992 and 1993 and a two-fold increase in ceftazidime resistance of the Pseudomonas species. Gentamicin resistance of Gram-negative aerobes remained unchanged (excluding the arterial pressure monitor outbreak), despite gentamicin being one of the most frequently prescribed antibiotics throughout the 25-yr period. Between 1986 and 1995, two thirds of all bacteremic organisms were cultured from intravascular catheters, which were designated as the focus of infection, 7% were secondary to gastrointestinal pathology, but only [similar]3% were secondary to wound, respiratory tract, or urinary tract infections.ConclusionsBacteremias have become more frequent in the ICU, probably because of the increased use of intravascular catheters, which are the most frequent foci for bacteremic infection. The spectrum of organisms has changed, and this can be temporally related to the changes in the antibiotics prescribed. Gentamicin resistance of Gram-negative organisms has not increased during a 25-yr period, despite being one of the most frequently prescribed antibiotics in the ICU. (Crit Care Med 1999; 27:1421-1428)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveNitric oxide (NO[middle dot]) derived from exogenous donors has been shown to increase the permeability of cultured intestinal epithelial monolayers, an effect that is augmented by mildly acidic conditions. Because interferon-gamma (IFN-gamma) also increases intestinal epithelial permeability, at least partly by an NO[middle dot]-dependent mechanism, we sought to determine whether IFN-gamma-induced hyperpermeability is increased under acidic conditions.MethodsHuman intestinal epithelial (Caco-2BBe) cells were grown as monolayers on permeable supports in bicameral chambers. Permeability was assessed by measuring transepithelial electrical resistance (TER) or the transepithelial passage of fluorescein disulfonic acid. Inducible nitric oxide synthase (iNOS) messenger RNA expression was determined by northern blot analysis. Concentrations of nitrite and nitrate (NO (2)-/NO3-), stable oxidation products of NO[middle dot], were determined using the Greiss reaction. Cellular adenosine triphosphate (ATP) levels were determined using the luciferin/luciferase method.Measurements and Main ResultsIncubation of Caco-2BBemonolayers with INF-gamma (1000 units/mL) at an extracellular pH (pHo) of 7.4 increased permeability to fluorescein disulfonic acid and decreased TER. However, incubation of monolayers with IFN-gamma under mildly acidic conditions (i.e., pHo7.0-6.6) accelerated the decrease in TER and augmented the increase in permeability induced by the cytokine. IFN-gamma-induced iNOS messenger RNA expression and NO2-/NO3-accumulation in medium were unaffected by acidic conditions. At pHo7.4, incubation of Caco-2BBemonolayers with IFN-gamma (1000 units/mL) for 72 hrs had no effect on intracellular ATP content compared with monolayers simultaneously incubated under the same conditions but in the absence of the cytokine. However, when the cells were incubated for 72 hrs with the same concentration of IFN-gamma under mildly acidic conditions (i.e., pHo7.0 or 6.6), ATP levels were significantly decreased. At pHo7.0, IFN-gamma-induced increases in permeability were ameliorated by addition of the following agents: 2-phenyl-4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide (a NO[middle dot] scavenger), NG-monomethyl-L-arginine(a iNOS inhibitor), dimethyl sulfoxide (a hydroxyl radical scavenger), and ascorbate (a peroxynitrous acid scavenger).ConclusionMild acidosis augments IFN-gamma-induced intestinal epithelial hyperpermeability and ATP depletion, possibly by fostering the formation of peroxynitrous acid and/or hydroxyl radical. (Crit Care Med 1999; 27:1429-1436)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveThe purpose of this study is to present an unusual respiratory and cardiovascular course after intoxication and near drowning in a river contaminated with kerosene.DesignCase reports and review of the literature.SettingIntensive care unit of a university-affiliated hospital.PatientsFour patients after near drowning.InterventionSupportive only.ResultsThe four patients developed acute respiratory failure. Cardiomyopathy was present in three patients and a persistent hypokalemia in two patients. The onset of the symptoms was delayed, which led to underestimation of the severity of their illness. Two of the four patients died. The diagnosis of hydrocarbon intoxication was based on bronchoalveolar lavage results, neutrophilic alveolitis with the presence of lipid-laden macrophages, and evidence of lipoid pneumonia from the autopsy performed on one victim. One patient who clinically deteriorated and another who developed a severe restrictive pulmonary disorder were treated with corticosteroids, which were effective only in the latter patient.ConclusionsAcute kerosene intoxication in a near-drowning event often results in severe respiratory and cardiac failure, with a high fatality rate. Treatment with corticosteroids may lead to a rapid improvement in lung function. (Crit Care Med 1999; 27: 1437-1440)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveThe aim of this study was to investigate the direct influence of lung contusion on pulmonary surfactant in multiple trauma patients.DesignProspective, nonrandomized study.SettingUniversity hospital, trauma intensive care unit.Patients19 were studied prospectively.InterventionsBronchoalveolar lavage was performed daily until either day 7 or extubation. Samples from the side of lung contusion (n = 62) and the contralateral, uninjured side (n = 62) were obtained at the same time in 14 patients. Total phospholipids, total phospholipid classes, and surfactant apoprotein A were quantified. Additionally, surfactant function was measured with a pulsating bubble surfactometer in four patients. All data are presented as mean +/- SEM. Statistical analyses were performed using programs of SPSS for Windows 6.1.3 (SPSS Inc., Chicago, IL) (Student's t-test; p < .05).Measurements and Main ResultsTotal phospholipids were significantly increased on the side of lung contusion (contusion side, 40 +/- 7 [micro sign]g/mL; contralateral side, 21 +/- 3 [micro sign]g/mL; p = .004). The percentage contents of phosphatidylcholine (contusion side, 87.1% +/- 1.0%; contralateral side, 84.3% +/- 1.0%; p = .04) and sphingomyelin (contusion side, 2.9% +/- 0.3%; contralateral side, 1.9% +/- 0.2%; p = .004) were significantly higher. In contrast, the percentage content of phosphatidylglycerol was significantly decreased (contusion side, 4.1% +/- 0.1%; contralateral side, 6.9% +/- 0.6%; p = .001). No alterations were found for the relative contents of phosphatidylethanolamine (contusion side, 2.4% +/- 0.2%; contralateral side, 2.2% +/- 0.2%; p = .47), phosphatidylinositol (contusion side, 3.5% +/- 0.4%; contralateral side, 4.6% +/- 0.5%; p = .06), and surfactant apoprotein A (contusion side, 7177 +/- 1404 ng/mL; contralateral side, 4513 +/- 787 ng/mL, p = .10). There was no statistical difference for minimal surface tension measured with the pulsating bubble surfactometer after 5 mins of oscillation (contusion side, 29.5 +/- 2.3 mN/m; contralateral side, 23.7 +/- 2.1 mN/m; p = .08).ConclusionsDirect damage of lung parenchyma by lung contusion alters the composition of surfactant. No additional changes in surfactant function were observed that would argue in favor of functional compensation. (Crit Care Med 1999; 27:1441-1446)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo evaluate the frequency of gastrointestinal complications (GICs) in a prospective cohort of critically ill patients receiving enteral nutrition and to assess its effect on nutrient administration and its relationship to the patient's outcome.DesignMulticenter, prospective cohort study.SettingThirty-seven multidisciplinary intensive care units (ICUs) in Spain.PatientsProspective cohort of 400 consecutive patients admitted to the ICU and receiving enteral nutrition.InterventionsNoninterventional, follow-up study.Measurements and Main ResultsEnteral nutrition-related GICs and their management were defined by consensus before data collection. A set of variables related to enteral nutrition administration and the presence of GICs was recorded. During the 1-month study period, 400 patients were enrolled, and a total of 3,778 enteral feeding days were analyzed. The mean time of enteral nutrition was 9.6 +/- 0.4 days. Mean elapsed time from ICU admission to the start of enteral feeding was 3.1 +/- 0.2 days. A total of 265 patients (66.2%) received a standard polymeric formula, and 132 (33.8%) received a disease-specific one. Enteral feeds were administered mainly through a nasogastric tube (91%). One or more GICs were presented by 251 patients (62.8%) during the feeding course. The frequency of each particular GIC was as follows: high gastric residuals, 39%; constipation, 15.7%; diarrhea, 14.7%; abdominal distention, 13.2%; vomiting, 12.2%; and regurgitation, 5.5%. Enteral nutrition withdrawal as a consequence of noncontrollable GICs occurred in 15.2% of patients. The volume ratio (expressed as the ratio between administered and prescribed volumes) was calculated daily and was used as an index of diet administration efficacy. Patients with GICs had a lower volume ratio than did patients without GICs (63.1 +/- 1.2% vs. 93.3 +/- 0.3%) (p < .001), a longer length of stay (20.6 +/- 1.2 vs. 15.2 +/- 1.3 days) (p < .01), and higher mortality (31% vs. 16.1%) (p < .001).ConclusionsThe frequency of enteral nutrition-related GICs in critically ill patients is high. High gastric residuals is the most frequent GIC. These complications decreased nutrient intake and, if persistent, could expose the patients to undernutrition. Enteral feeding gastrointestinal intolerance seems to have an evolutive effect in prolonging the ICU stay and increasing patient mortality. (Crit Care Med 1999; 27:1447-1453)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveCardiopulmonary bypass (CPB) is associated with abnormalities of lung function characterized by an increase in static elastance of the respiratory system. We examined the following: a) the effects of CPB on the total inspiratory volume-pressure (V-P) relationship of the respiratory system; b) the relative contribution of the chest wall and lung to the impairment of respiratory system mechanics; and c) the time-course of such impairment.DesignProspective, interventional study.SettingSurgical and medical intensive care units in a teaching hospital.PatientsEight adult patients scheduled for elective open heart surgery to correct valvular dysfunction.InterventationsV-P curves (interrupter technique) of the respiratory system were partitioned between the chest wall and lung by measurements of esophageal pressure. Measurements were obtained before sternotomy (control), immediately after, 4 hrs after, and 7 hrs after separation from CPB.Measurements and Main ResultsControl V-P relationships of the respiratory system and lung showed lower inflection points (Pflex) at pressure values of 5.9 +/- 2.3 and 4.3 +/- 2.5 cm H2O, respectively. Immediately after and 4 hrs after separation from CPB, both curves had sigmoid shapes because of lower Pflexand formation of upper inflection (UIP) points. The pressures corresponding to the Pflexincreased significantly (p < .001) by 56% +/- 3% and 78% +/- 4%, whereas the UIP corresponded to a pressure value of 42.34 +/- 8.5 and 35.6 +/- 7.8 cm H2O in the respiratory system and lung, respectively. A linear V-P relationship of the chest wall was observed during the control condition and after separation from CPB. Four hours later, no further increases in the pressure values corresponding to Pflexwere observed on the inspiratory V-P curves of the respiratory system and lung, whereas the UIP occurred at a pressure of 35.6 +/- 9.1 and 29.7 +/- 8.4 cm H2O, respectively. A UIP was present on the V-P curve of the chest wall at a volume of 0.77 +/- 0.02 L. Seven hours after separation from CPB, the inspiratory V-P curves of the respiratory system, chest wall, and lung returned to normal.ConclusionsSternotomy and CPB produced immediate changes in lung mechanics. Chest wall mechanics were affected only 4 hrs after sternotomy. Seven hours after disconnection from CPB, all mechanics had returned to normal. (Crit Care Med 1999; 27:1454-1460)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo evaluate the effectiveness of lorazepam and midazolam for long-term sedation of critically ill, mechanically ventilated patients.DesignDouble-blind, randomized, controlled study.SettingMedical intensive care unit in a university teaching hospital.Patients3 days.InterventionsPatients were randomized to receive blinded solutions of either lorazepam or midazolam by continuous infusion. The lowest dose that achieved an adequate sedation was infused. The maximum dose allowed for each drug was 60 mg/hr for midazolam and 4 mg/hr for lorazepam. Sedation was assessed initially and at least every 8 hrs thereafter on a seven-point scale if the sedation was adequate and every 2 hrs if it was not.Measurements and Main ResultsMeasurements included the score on the sedation scale, the time between determination of the desired level of sedation and the achievement of that level, and plasma concentrations. It is significantly easier to reach a desired level of sedation with lorazepam than with midazolam. No difference in recovery was found in the 24 hrs after discontinuation of therapy. The fact that there are many factors influencing midazolam pharmacokinetics may explain the more difficult management of desired sedation levels. The equipotent dose of 10 mg of midazolam proved to be 0.7 mg of lorazepam in long-term sedation. The average cost for therapy with midazolam was approximately ten times more than that with lorazepam.ConclusionsLorazepam is a useful alternative to midazolam for the long-term sedation of patients in the medical intensive care unit and provides easier management of the sedation level. Sedation with lorazepam offers a significant cost-savings. (Crit Care Med 1999; 27:1461-1465)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID