摘要:

ObjectiveTo determine the extent to which postpyloric feeding reduces gastroesophageal regurgitation and pulmonary microaspiration in critically ill patients.DesignRandomized trial.SettingA medical/surgical intensive care unit at a tertiary care hospital.ParticipantsIntensive care unit patients were expected to remain ventilated >72 hrs. We excluded patients with esophageal, gastric, or small bowel surgery in the last week and patients with overt or clinically significant gastrointestinal bleeding. We studied 33 patients; 42.4% were female, mean age (sd) was 59.2 (± 16.8) yrs, and mean Acute Physiology and Chronic Health Evaluation II score was 22.5 (7.8).InterventionsPatients were randomized to gastric or postpyloric enteral feeds. Technetium 99-sulphur colloid was added to the feeds for 6 hrs of each of the first 3 days on study.Measurements and ResultsWe sampled the oropharynx and trachea hourly for the 6 hrs per day that patients received radioisotope-labeled enteral feeds, and the level of radioactivity in these specimens was measured. We defined an episode of gastroesophageal regurgitation and microaspiration as an increase in radioactivity >100 counts per minute/g. Patients fed into the stomach had more episodes of gastroesophageal regurgitation (39.8% vs. 24.9%,p= .04) and trended toward more microaspiration (7.5% vs. 3.9%,p= .22) compared with patients fed beyond the pylorus. When the logarithmic mean of the radioactivity count was compared across groups, there was a trend toward an increase in gastroesophageal regurgitation (3.7 vs. 2.9 counts/g,p= .22) and a trend toward increased microaspiration (1.9 vs. 1.4 counts/g,p= .09) in patients fed into the stomach. Patients who had gastroesophageal regurgitation were much more likely to aspirate than patients who did not have gastroesophageal regurgitation (odds ratio: 3.2; 95% confidence interval: 1.36, 7.77).ConclusionsFeeding beyond the pylorus is associated with a significant reduction in gastroesophageal regurgitation and a trend toward less microaspiration.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo answer the following questions: Can the digital chest roentgenogram (CXR) be used to differentiate patients’ volume status? Do clinical data alter radiologists’ accuracy in interpreting the digital CXR?DesignProspective cohort study.SettingNine adult intensive care units of a tertiary care medical center.PatientsOne hundred thirty-five consecutive patients with pulmonary artery catheters, of whom 35 were excluded because of unacceptable pulmonary artery occlusion pressure (PAOP) tracings.MethodsEach patient had a portable, anteroposterior, supine digital CXR. Clinicians evaluated volume status and then measured hemodynamic data within 1 hr of the CXR. Digital CXRs were independently interpreted on two separate occasions (with and without clinical information) by three experienced chest radiologists, and these interpretations were compared with hemodynamic data.ResultsOf the 100 patients, 39 had PAOP >18 mm Hg, whereas 61 had PAOP <18 mm Hg. Radiologists’ accuracy in differentiating volume status increased with incorporation of clinical data (56% without vs. 65% with clinical data,p= .009). Using objective receiver operating characteristic–derived cutoffs of 70 mm for vascular pedicle width and 0.55 for cardiothoracic ratio, radiologists’ accuracy in differentiating PAOP >18 mm Hg from PAOP <18 mm Hg was 70%. The intrareader and the inter-reader correlation coefficients were very high. The likelihood ratio of the CXR in determining volume status using the objective vascular pedicle width and cardiothoracic ratio measures was 3.1 (95% confidence interval, 1.9–6.0), significantly higher than subjective CXR interpretations with and without clinical data (p< .001).ConclusionsDifferentiating intravascular volume status with portable, supine, digital CXRs may be improved by using objective cutoffs of vascular pedicle width >70 mm and cardiothoracic ratio >0.55 or by incorporating clinical data.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectivePyruvate has been shown to be protective in numerousin vitroandin vivomodels of oxidant-mediated cellular or organ system injury. Unfortunately, the usefulness of pyruvate as a therapeutic agent is abrogated by its very poor stability in solution. In an effort to take advantage of the ability of pyruvate to scavenge reactive oxygen species while avoiding the problems associated with the instability of pyruvate in solution, we sought to determine whether a simple derivative, ethyl pyruvate, would be protective in an animal model of reactive oxygen species-mediated tissue injury, namely mesenteric ischemia and reperfusion in rats.DesignProspective, randomized trial.SettingAnimal research center.SubjectsMale Sprague-Dawley rats.InterventionsUnder general anesthesia, rats were subjected to 60 mins of mesenteric ischemia followed by 60 mins of reperfusion. Controls (n = 6) received intravenous lactated Ringer’s solution according this dosing schedule: 1.5 mL/kg bolus before ischemia, 3.0 mL/kg bolus before resuscitation, and 1.5 mL·kg−1·hr−1by continuous infusion. Two experimental groups received similar volumes of either pyruvate (n = 6 each) or ethyl pyruvate (n = 9) solution made up exactly like lactated Ringer’s solution except for the substitution of eitherpyruvate or ethyl pyruvate for lactate, respectively.Measurements and Main ResultsTo obtain tissues for assessing mucosal permeability and histology, five 10-cm long segments of small intestine were obtained at the following time points: baseline, after 30 and 60 mins of ischemia, and after 30 and 60 mins of reperfusion. Mucosal permeability to fluorescein isothiocyanate dextran (molecular weight 4000 Da) was assessedex vivoby using an everted gut sac method. Compared with controls, treatment of rats with either pyruvate solution or ethyl pyruvate solution significantly ameliorated the development of intestinal mucosal hyperpermeability during the reperfusion. Treatment with ethyl pyruvate solution also significantly decreased the extent of histologic mucosal damage after mesenteric reperfusion.ConclusionsTreatment with Ringer’s ethyl pyruvate solution ameliorated structural and functional damage to the intestinal mucosa in a rat model of mesenteric ischemia/reperfusion. Ethyl pyruvate solution warrants further evaluation as a novel therapeutic agent for preventing oxidant-mediated injury in various disease states.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo investigate the impact of dobutamine and enoximone on hepatosplanchnic perfusion and function in fluid-optimized septic patients.DesignProspective, randomized, double-blinded interventional study.SettingIntensive care unit of a university hospital.PatientsForty-eight septic shock patients were examined within 12 hrs after onset of septic shock. Patients were conventionally resuscitated, achieving an optimal pulmonary artery occlusion pressure at which the left ventricular stroke work was on the maximal plateau. Liver blood flow was estimated by venous suprahepatic catheterization using the continuous indocyanine green infusion technique. Microsomal liver function was assessed by the plasma appearance of monoethylglycinexylidide, and release of hepatic tumor necrosis factor-&agr; (TNF-&agr;) was measured to estimate the severity of hepatic ischemia-reperfusion syndrome.InterventionsPatients were randomly treated with dobutamine or enoximone. Within the first 10 hrs after baseline measurements, the dosage was increased until no further increase in the left ventricular stroke work index occurred. Then, positive inotropes were kept constant throughout the study.Measurements and Main ResultsMeasurements were performed at baseline and after 12 and 48 hrs after baseline measurements. Cardiac index, systemic oxygen delivery, systemic oxygen consumption, and liver blood flow increased significantly in both groups during treatment (p< .01) without a significant difference between groups. Fractional liver blood flow (liver blood flow/cardiac index) did not change in the enoximone group and showed a significant but only minor (median, 10%) decrease in the dobutamine group (p< .05 after 12 hrs andp< .01 after 48 hrs vs. baseline). After 12 hrs of enoximone treatment, monoethylglycinexylidide kinetics and hepatosplanchnic oxygen consumption demonstrated a significant increase (p< .05). The release of hepatic TNF-&agr; after 12 hrs of dobutamine treatment was twice as high (p< .05) as during enoximone.ConclusionThe increase in hepatosplanchnic oxygen consumption, together with an increased lignocaine metabolism and decreased release of hepatic TNF-&agr;, indicates improved hepatosplanchnic function and antiinflammatory properties after 12 hrs of enoximone treatment. Therefore, if the inflammatory response should be attenuated in high-risk patients, administration of enoximone in fluid-optimized septic shock patients may be favorable compared with dobutamine.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo determine whether low-dose dopamine administration reduces the incidence or severity of acute renal failure, need for dialysis, or mortality in patients with critical illness.Data Sources and Study SelectionWe performed a MEDLINE search of literature published from 1966 to 2000 for studies addressing the use of dopamine in the prevention and/or treatment of renal dysfunction.Data ExtractionData were abstracted regarding design characteristics, population, intervention, and outcomes. Results of individual randomized clinical trials were pooled using a fixed effects model and a Mantel-Haenszel weighted chi-square analysis.Data SynthesisWe identified a total of 58 studies (n = 2149). Of these, outcome data were reported in 24 studies (n = 1019) and 17 of these were randomized clinical trials (n = 854). Dopamine did not prevent mortality, (relative risk, 0.90 [0.44–1.83];p= .92), onset of acute renal failure (relative risk, 0.81 [0.55–1.19];p= .34), or need for dialysis, (relative risk, 0.83 [0.55–1.24];p= .42). There was sufficient statistical power to exclude any large (>50%) effect of dopamine on the risk of acute renal failure or need for dialysis.ConclusionsThe use of low-dose dopamine for the treatment or prevention of acute renal failure cannot be justified on the basis of available evidence and should be eliminated from routine clinical use.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveWe have reported that initial distribution volume of glucose indicates the central extracellular fluid volume in the presence of fluid gain or loss. The purpose of this study was to describe changes in initial distribution volume of glucose, plasma volume determined by the indocyanine green dilution method (PV-ICG), and thoracic fluid content by thoracic electrical bioimpedance in patients with or without apparent thoracic fluid accumulation in the absence of pleural effusion. We also sought to test whether initial distribution volume of glucose rather than PV-ICG mirrors thoracic fluid content.DesignProspective, clinical study.SettingGeneral intensive care unit.PatientsEleven consecutive patients with apparent thoracic fluid accumulation as judged by thoracic fluid content >0.05/ohm and underlying pathology and 20 consecutive acute myocardial infarction patients within 24 hrs after its onset were selected for study. None of the acute myocardial infarction patients had thoracic fluid content >0.05/ohm.InterventionsFive grams of glucose and 25 mg of indocyanine green were administered simultaneously to calculate initial distribution volume of glucose and PV-ICG daily for the fluid-accumulated patients, and the same dosages were administered to the acute myocardial infarction patients immediately after their admission to the intensive care unit after percutaneous coronary angioplasty. Only the data on the day of the maximal and minimal thoracic fluid content in the fluid-accumulated patients were used for the study. The relationship between these two fluid volumes and thoracic fluid content was evaluated in the two patient groups.Measurements and Main ResultsInitial distribution volume of glucose and thoracic fluid content rather than PV-ICG and thoracic fluid content moved together in the same direction in each fluid-accumulated patient. Neither pulmonary artery occlusion pressure, central venous pressure, nor PV-ICG produced a better correlation with cardiac index when compared with initial distribution volume of glucose in patients with or without thoracic fluid accumulation.ConclusionsWe suggest that initial distribution volume of glucose rather than PV-ICG is a better indicator of the intrathoracic blood volume status, even although intravenously administered glucose cannot stay in the intravascular compartment.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo determine quality of life after severe bacterial peritonitis and infected necrotizing pancreatitis treated with open management of the abdomen and planned re-operations.DesignRetrospective chart review.SettingUniversity hospital intensive care unit, general wards, and outpatient department.PatientsForty-one patients who survived severe bacterial peritonitis and infected necrotizing pancreatitis treated with open management of the abdomen and planned re-operations.InterventionsNone.Measurements and Main ResultsOver a period of 7 yrs, 95 patients underwent open management of the abdomen and planned re-operations for severe bacterial peritonitis and infected necrotizing pancreatitis. Thirty-nine patients died during the initial intensive care unit stay and 12 as a result of nonperitonitis-related systemic diseases after discharge. Four patients were lost or excluded from final analysis. Long-term morbidity and quality of life using Karnofsky and Rankin scores at discharge and at follow-up at least 1 yr after discharge (mean: 4 yrs) and the Sickness Impact Profile (SIP) were determined. The remaining 41 patients reviewed showed significant long-term morbidity, including dysfunction of the abdominal wall resulting from herniation, persistent polyneuropathy, and mental disorders needing psychiatric support. Patients having persistent polyneuropathy and, to a lesser extent, mental disorders, showed significantly lower Karnofsky, higher Rankin, and higher SIP scores. After discharge, performance status of patients improved significantly, as shown by higher Karnofsky and lower Rankin scores, and, because Karnofsky and Rankin scores are closely related to SIP scores, higher SIP scores. Especially in measuring quality of life in terms of social and role management, assessment of the SIP proved to have additional value.ConclusionsAbout three-quarters of patients who survive open management of the abdomen and planned re-operations for severe bacterial peritonitis and infected necrotizing pancreatitis regain a good quality of life. Some patients, especially those who suffer from persistent polyneuropathy and mental disorders, show restrictions in daily life.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThe selection of the optimal method for assessing renal function relies on the accuracy of the technique. Plasma clearance of nonradioactive iodine contrast media (i.e., iohexol or iopromide) has been suggested as a reliable alternative to the renal clearance of inulin for estimating glomerular filtration rate (GFR). The accuracy of this method when used with critically ill patients displaying different levels of renal function in an intensive care unit (ICU) has not, until now, been examined.DesignThe accuracy of double- and multiple-point iohexol or iopromide plasma clearances was compared with that of already established techniques for measuring GFR (creatinine clearance, formula clearance by Cockcroft and Gault) and with that of inulin clearance, which is regarded as the gold standard for the measurement of GFR.PatientsValues were obtained from 31 ICU patients who exhibited a wide range of renal function (serum creatinine: 0.6–6.7 mg/dL).MeasurementsInulin clearance was performed using the constant-infusion technique. Creatinine clearance was determined from 24-hr urine samples. The clearance formula was calculated according to Cockcroft and Gault’s formula. Iohexol or iopromide were applied as a single intravenous dose, and blood samples were taken up to 6 hrs after the injection. Iodine concentrations were determined by radiographic fluorescence.ResultsPlasma clearance of iohexol/iopromide measured after the single injection of contrast media and that of the conventional inulin clearance was almost identical (y = 0.971x + 7.65,r2= .96; n = 31). Two-point clearance of iohexol/iopromide (double sampling technique) was as reliable as the three-point clearance (three-slope-intercept method, y = 0.995x + 0.62,r2= .999; n = 18). With respect to inulin clearance, GFR measurements determined by creatinine clearance or according to the formula given by Cockcroft and Gault revealed errors that increased proportionally (y = 1.03x,r2= .88; n = 27; and y = 0.93x,r2= .62; n = 31, respectively). It could also be shown that the accuracy of GFR measurements involving plasma clearance of iohexol was not greatly affected by the degree of renal insufficiency or the route by which contrast media were applied.ConclusionThese findings indicate that the determination of plasma clearance of iohexol/iopromide is a simple, rapid, and accurate method that can indeed be used for estimating GFR in ICU patients with normal renal function or even different degrees of renal insufficiency.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ContextThe incidence of acute cor pulmonale (ACP), a frequent and usually lethal complication of acute respiratory distress syndrome (ARDS) during traditional respiratory support, has never been re-evaluated since protective ventilation gained acceptance.ObjectiveWe performed a longitudinal transesophageal echocardiographic (TEE) study to determine whether this incidence, and its severe implications for prognosis, might have changed in our unit as we altered respiratory strategy.DesignProspective open clinical study.SettingMedical intensive care unit of a university hospital.PatientsSeventy-five consecutive ARDS patients given respiratory support with airway pressure limitation (plateau pressure ≤30 cm H2O).InterventionsACP was defined as a ratio of right ventricular end-diastolic area to left ventricular end-diastolic area in the long axis >0.6 associated with septal dyskinesia in the short axis during TEE examination.ResultsNormal right ventricular function was present in 56 patients, whereas right ventricular dysfunction was observed in 19 patients after 2 days of respiratory support. ACP was associated with pulmonary artery hypertension, increased heart rate, and decreased stroke index. Significant impairment of left ventricular diastolic function was also seen. All echo-Doppler abnormalities were reversible in patients who recovered, and the mortality rate was the same in both groups (32%). However, ACP patients who recovered required a longer period of respiratory support. A multivariate analysis individualized Paco2 level as the sole factor independently associated with ACP, suggesting that ACP development in ARDS is influenced by the severity of lung damage and/or the respiratory strategy.ConclusionEvaluation of right ventricular function by TEE in a group of 75 ARDS patients submitted to protective ventilation revealed the persistence of a 25% incidence of ACP, resulting in detrimental hemodynamic consequences associated with tachycardia. However, ACP was reversible in patients who recovered and did not increase mortality.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectivesThere is recent experimental evidence that caspase-1 activation plays an instrumental role in the pathomechanism of severe acute pancreatitis. Besides interleukin-1&bgr;, interleukin-18, a recently described proinflammatory cytokine, is cleaved into its biologically active form by caspase-1 as well. Interleukin-18 is known to have potent properties concerning the activation of the Th1-lymphocyte subset via costimulation of interferon-&ggr; production. In contrast to interleukin-1&bgr;, little is known about the clinical impact of interleukin-18 in the course of acute pancreatitis.DesignCohort study comparing patients with mild and severe acute pancreatitis associated with local and systemic complications during the course of the disease.SettingSurgical and anesthesiological intensive care unit as well as wards of the department of general surgery.PatientsWe included 68 patients with acute pancreatitis in the present study. In terms of local complications, pancreatic necrosis was present in 37 patients, of whom 21 developed pancreatic infections. Systemic complications included pulmonary, renal, or cardiocirculatory insufficiency and were observed in 40, 18, and 25 patients, respectively. Severe multiple-organ dysfunction syndrome involving all three organ systems occurred in 18 patients, all suffering from pancreatic necrosis.InterventionsSerum samples were collected over 14 consecutive days after study inclusion. Ascites or peripancreatic exudate was obtained by ultrasound-guided fine needle aspiration in 14 cases. Sera and local aspirates were stored at −70°C until analysis.Measurements and ResultsInterleukin-18 and interferon-&ggr; were measured by commercially available enzyme-linked immunosorbent assays. Interleukin-18 concentrations were significantly increased after the fourth day of disease onset until the end of the observation period in patients who developed pancreatic necrosis and systemic complications such as pulmonary, renal, and cardiocirculatory failure as well as severe multiple-organ dysfunction syndrome. However, no correlation was found between the development of pancreatic infections and interleukin-18 concentrations. In contrast with interleukin-18, interferon-&ggr; concentrations did not show any significant difference with respect to the presence or absence of either systemic or local complications. Local interleukin-18 concentrations in ascites or peripancreatic exudate were up to 20-fold higher than systemic concentrations, whereas interferon-&ggr; concentrations did not differ.ConclusionsSerum interleukin-18 concentrations are significantly elevated in patients with acute pancreatitis complicated by pancreatic necrosis and remote organ failure. The present data suggest an important role of caspase-1 dependent cytokine activation in the pathomechanism of severe acute pancreatitis beyond the experimental setting. In this context, interleukin-18 may serve as a potential target for new therapeutic approaches.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID