ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo determine the relationship between gastric intramucosal pH and several other indices of splanchnic perfusion in patients undergoing cardiopulmonary bypass.DesignProspective, single-arm study.SettingUniversity Hospital.MethodsElective cardiac surgery patients (n = 8), free of hepatic disease, were studied. Before anesthetic induction, a triple-lumen, heparin-bonded fiberoptic catheter was inserted into the hepatic vein under fluoroscopic guidance. An identical catheter was inserted into the pulmonary artery. After endotracheal intubation, a nasogastric tube modified to permit measurement of gastric intramucosal pH was inserted into the stomach. Systemic oxygen delivery (&U1E0A;o2), and arterial, mixed venous, hepatic venous, and femoral venous blood gases and lactate concentrations were recorded at the following times: immediately before induction of anesthesia (time 1); during atrial cannulation (time 2); after 30 mins of hypothermic cardiopulmonary bypass (time 3); 15 mins after termination of cardiopulmonary bypass (time 4); and 1 hr after arrival in the ICU (time 5). Hepatic venous hemoglobin saturation (So2) and mixed venous hemoglobin saturation (S&OV0456;o2) were monitored continuously from times 1 to 5. Gastric intramucosal pH was recorded at times 2, 3, 4, and 5. The hepatic catheter was removed as soon as the last samples were collected in the ICU.ResultsThe square of the weighted mean correlation coefficients (rw)2for gastric intramucosal pH vs. hepatic venous lactate concentrations, gastric intramucosal pH vs. hepatic venous Po2, and gastric intramucosal pH vs. hepatic venous pH were (rw)2= .50, (rw)2= .58, and (rw)2= .32, respectively. Systemic &U1E0A;o2, hepatic venous lactate concentrations, hepatic venous Po2, and hepatic venous pH were significant determinants in the multiple regression model for gastric intramucosal pH (r2= .89). There were significant differences between S&OV0456;o2and hepatic venous So2at times 4 and 5.ConclusionGastric intramucosal pH may provide a minimally invasive way to monitor the adequacy of splanchnic &U1E0A;o2in patients undergoing cardiopulmonary bypass. Additional data are necessary to determine whether low gastric intramucosal pH is truly a marker of supply-dependent oxygen uptake across the hepatosplanchnic vascular bed under these conditions.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo evaluate the feasibility of airway pressure release ventilation (APRV) in providing ventilatory support to patients with acute lung injury of diverse etiology and mild-to-moderate severity.DesignProspective, multicenter, nonrandomized crossover trial.SettingICUs in six major referral hospitals.PatientsFifty adult patients with respiratory failure requiring mechanical ventilation and positive end-expiratory airway pressure.InterventionsAfter optimization of continuous positive airway pressure (CPAP), conventional ventilation and APRV were administered sequentially for 30 mins. During APRV, the CPAP level and airway pressure release level were adjusted to prevent hypoxemia, while the degree of ventilatory support was adjusted by altering the frequency of pressure release.Measurements and Main ResultsCirculatory and ventilatory pressures, arterial blood gases and pH, heart rate, and respiratory rate were measured. Alveolar ventilation was augmented adequately in 47 of 50 patients by APRV. Adjustment of APRV required an increase in mean CPAP from 13 ± 3 (SD) to 21 ± 9 cm H2O and a release pressure of 6 ± 5 cm H2O. This airway pressure pattern produced a mean airway pressure comparable to that pressure achieved during conventional ventilation. Failure of APRV in three patients could be attributed to an inadequate level of CPAP or an inadequate APRV rate. While maintaining oxygenation of arterial blood and circulatory function, APRV allowed a substantial (55 ± 17%;p< .0001) reduction in peak airway pressure compared with conventional positive pressure ventilation adjusted to deliver a comparable or lower level of ventilatory support.ConclusionsAPRV is a feasible alternative to conventional mechanical ventilation for augmentation of alveolar ventilation in patients with acute lung injury of mild-to-moderate severity.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo compare the effects of two different antibiotic regimes on the colonization and infection rates of critically ill pediatric patients.DesignA prospective randomized trial.SettingA pediatric ICU in a university hospital.PatientsFifty critically ill pediatric patients who required intensive care for at least 4 days were randomly allocated to either the selective parenteral and enterai antisepsis regimen (treatment group, n = 25) or the control group (n = 25).InterventionsThe treatment group received oral nonabsorbable antimicrobial agents (polymyxin E, gentamicin, and amphotericin B) and parenteral cefotaxime, whereas the control group received either perioperative antibiotic prophylaxis or antibiotic therapy according to clinical or microbiological evidence of infection.ResultsBoth groups were comparable for age, body weight, sex, and severity of illness. Colonization with Gram-negative microorganisms and yeasts in the oropharynx, and digestive and respiratory tracts increased rapidly up to 52% in the control group, whereas there was no colonization with these microorganisms in the treatment group. The occurrence rates of acquired secondary infections in the control and treatment groups were 36% and 8%, respectively (p< .025). There were no differences between groups in the duration of intensive care or mortality rate.ConclusionSelective oropharyngeal and gastrointestinal decontamination combined with systemic cefotaxime application allows for a significant reduction of the colonization rate with Gram-negative bacteria and yeasts in critically ill pediatric patients undergoing prolonged intensive care. In addition, it significantly reduces the Gram-negative infection rate of the respiratory system. However, this therapeutic approach does not alter ICU length of stay or mortality rate.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectivesTo prospectively document the occurrence of ionized hypocalcemia in infants and children treated with extracorporeal membrane oxygenation (ECMO), to determine if the type of calcium salt (calcium chloride or gluconate) used in priming the ECMO circuit affected ionized calcium, to determine if ionized calcium concentrations correlate with total calcium, protein, albumin, or total magnesium values, and to determine if the hypotension usually observed after ECMO initiation correlates with low circulating ionized calcium concentrations.DesignProspective study.SettingPediatric ICU and neonatal ICU.PatientsSixteen neonatal and three pediatric patients who were started on ECMO for cardiopulmonary support.InterventionsThe ECMO circuit was primed in a standardized manner, 100 mg of calcium gluconate was added in group 1 patients and 100 mg of calcium chloride was added in group 2 patients.MeasurementsIonized calcium was measured from the circuit before initiation of ECMO and from the patient before, and then 5, 10, 15, 30, 60, 120, and 240 mins after initiation of ECMO. Total calcium and ionized calcium concentrations were measured simultaneously every 6 hrs. Serum total protein, albumin, magnesium, and ionized calcium values were measured from blood samples collected simultaneously twice daily.ResultsA significant decrease in the mean serum ionized calcium value occurred 5 mins after the initiation of ECMO in both groups,p<. 001. The ionized calcium value remained significantly decreased until 30 mins after the initiation of ECMO. There were no differences between the ionized calcium concentrations obtained during priming with calcium gluconate vs. those concentrations obtained with calcium chloride priming (p=.79). Throughout the course of ECMO, the serum ionized calcium concentrations ranged from 0.60 to 1.86 mmol/L. Poor correlations existed between circulating ionized calcium values and total calcium (r2=.30), total protein (r2=.20), albumin (r2=.20), and magnesium concentrations (r2=.10). There was a good correlation between the patients' BP and ionized calcium concentrations after bypass was initiated (r2=.87).ConclusionOur data demonstrate that ionized hypocalcemia is a frequent occurrence after the initiation of ECMO. Since there is a poor correlation between ionized calcium and total calcium, ionized calcium concentrations should be measured directly in these patients.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo examine the effects of associated injuries on death, disability, rehabilitation needs, and cost in patients with blunt traumatic brain injury.DesignA retrospective case series analysis of 1,709 patients with blunt traumatic brain injury, or 37.2% of 4,590 consecutive blunt trauma patients, was combined with a prospective study of a subset of 202 of the 1,709 braininjured patients obtained during the same time period with regard to need for rehabilitation services, residual disability, and costs at 1 yr after discharge from the acute trauma center.SettingA level I regional trauma center that is also the statewide neurotrauma and multiple trauma unit serving a population of more than 3 million persons.ResultsContingency table analysis showed the Glasgow Coma Scale to be highly predictive (p< .0001) of likelihood of mortality, need for postacute inpatient rehabilitation, or discharge home. Of the blunt traumatic brain injury patients, 40.4% (691) had an isolated brain injury and 59.6% (1,018) had brain plus at least one other systemic injury. The mortality rate of the isolated brain injury group was 11.1% compared with 21.8% in all brain plus systemic injury groups (p< .0001). Spine, lung, visceral, pelvis, or extremity injuries in blunt traumatic brain injury all increased mortality rate to >25% (all simultaneously significant,p< .0001). Analysis of the interaction of brain injury (quantified by Glasgow Coma Scale) with blood replacement in the initial 24 hrs showed that at any Glasgow Coma Scale range, percent mortality increased as the volume of blood increased. Hypovolemic shock increased the mortality rate from 12.8% to 62.1% (p< .0001). The need for postacute inpatient rehabilitation in survivors also increased as blood replacement increased, and shock increased the percent of patients requiring post-acute inpatient rehabilitation from 39.7% to 60.3%. In 202 consecutive surviving brain trauma patients followed for 1 yr, isolated brain-injured patients with moderate brain injuries had a 4% need for posttrauma, postacute inpatient rehabilitation with a total cost per case of $12,489 compared with the brain plus extremity injury group, who had a 23% postacute inpatient rehabilitation rate and a total cost per case of $36,177 at 1 yr. With severe brain injury, isolated brain injury increased postacute inpatient rehabilitation to 29% and 1-yr cost to $59,274, but with the brain plus extremity injury group, postacute inpatient rehabilitation increased to 49% and cost to $84,950.ConclusionsIn blunt traumatic brain injury, the addition of major visceral or extremity injuries, with need for blood replacement or shock, increases the risk of death, the need for rehabilitation, and the costs of disability.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo determine cardiac output from measurements of CO2production (&OV0312;co2), and arterial (Sao2) and mixed venous (S&OV0456;o2) oxygen saturations, using a modified Fick equation, in which cardiac output = &OV0312;co2/[k (Sao2– S&OV0456;o2)], where k represents a constant.DesignA metabolic measurement cart was used to measure &OV0312;co2and oxygen consumption (&OV0312;o2) at 3-min intervals. Sao2and S&OV0456;o2were measured via a pulse oximeter and a fiberoptic right heart catheter, respectively. The initial value of k for each study was determined from initial simultaneous measurements of thermodilution cardiac output, &OV0312;co2, Sao2, and S&OV0456;o2via the equation k = &OV0312;co2/[cardiac output (Sao2– Svo2)]. The value of k was assumed to remain constant for the entire study period. Thereafter, cardiac outputs calculated from k and the measurements of &OV0312;co2, Sao2, and S&OV0456;o2were compared with the simultaneously obtained cardiac outputs determined by thermodilution. Similarly, cardiac outputs calculated from the traditional oxygen Fick equation, where cardiac output = &OV0312;o2/[13.4 × hemoglobin (Sao2– S&OV0456;o2)], were compared with the simultaneously acquired cardiac outputs determined by thermodilution.SettingSurgical ICU in a Veterans Affairs Medical Center.PatientsSeven postoperative patients, mechanically ventilated using the intermittent mandatory ventilation mode, were studied over a mean period of 4 hrs.ResultsCardiac output (obtained from &OV0312;co2and oximetry saturations) was closely related to thermodilution cardiac output: with linear regression showing r2= .96 and standard error of the estimate = 0.59 L/min, n = 21; and, with bias and precision = 0.17 and 0.68 L/min, respectively. The traditional oxygen Fick cardiac output was also closely related to the thermodilution cardiac output (r2= .81, standard error of the estimate = 1.46 L/min, n = 22; bias and precision = 0.31 and 1.46 L/min, respectively).ConclusionThe proposed method for calculating cardiac outputs solely from &OV0312;co2and oximetry saturations yields results that correspond closely to thermodilution determined cardiac outputs. The method is simple and avoids the difficulties in the Fick method associated with accurate &OV0312;o2measurement. This approach may be suitable for continuous cardiac output monitoring in critically ill patients.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo test the hypothesis that a formal interdisciplinary team approach to managing ICU patients requiring mechanical ventilation enhances ICU efficiency.DesignRetrospective review with cost-effectiveness analysis.SettingA 20-bed medical-surgical ICU in a 450-bed community referral teaching hospital with a critical care fellowship training program.PatientsAll patients requiring mechanical ventilation in the ICU were included, comparing patients admitted 1 yr before the inception of the ventilatory management team (group 1) with those patients admitted for 1 yr after the inception of the team (group 2). Group 1 included 198 patients with 206 episodes of mechanical ventilation and group 2 included 165 patients with 183 episodes of mechanical ventilation.InterventionA team consisting of an ICU attending physician, nurse, and respiratory therapist was formed to conduct rounds regularly and supervise the ventilatory management of ICU patients who were referred to the critical care service.Measurements and Main ResultsThe two study groups were demographically comparable. However, there were significant reductions in resource use in group 2. The number of days on mechanical ventilation decreased (3.9 days per episode of mechanical ventilation [95% confidence interval 0.3 to 7.5 days]), as did days in the ICU (3.3 days per episode of mechanical ventilation [90% confidence interval 0.3 to 6.3 days]), numbers of arterial blood gases (23.2 per episode of mechanical ventilation;p< .001), and number of indwelling arterial catheters (1 per episode of mechanical ventilation;p< .001). The estimated cost savings from these reductions was $1,303 per episode of mechanical ventilation.ConclusionWe conclude that a ventilatory management team, or some component thereof, can significantly and safely expedite the process of “weaning” patients from mechanical ventilatory support in the ICU.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Background and MethodsNosocomial pneumonia is frequent after hemorrhage and trauma, and often contributes to multiple organ system failure, morbidity, and mortality in this setting. Although the percentages and numbers of resting pulmonary B cells (clonal precursors) able to be stimulated to produce antibodies to bacterial antigens are markedly decreased after hemorrhage, the effects of hemorrhage on the pulmonary plasma cells actually producing antibody to bacterial antigens have not been examined. To investigate this question, mice were bled 30% blood volume, then resuscitated with the shed blood 1 hr later. At predetermined times after hemorrhage, the mice were intranasally immunized with liposomes containing the bacterial polysaccharide antigen levan (fromAerobacter levanicum). One week later, lung lavages were performed to measure bacterial antigen-specific secretory immunoglobulin A (slgA) titers and the numbers of intraparenchymal pulmonary plasma cells producing antibody against the bacterial antigen were determined.ResultsReduced numbers of pulmonary plasma cells producing antibody against the immunizing bacterial polysaccharide antigen were found between 1 and 14 days after blood loss, and titers of bacterial antigen-specific secretory IgA were decreased for >2 wks after hemorrhage. The importance of these abnormalities in pulmonary B-cell function was demonstrated by an increased susceptibility toPseudomonas aeruginosapneumonia in mice infected 4 days after hemorrhage, when bacterial antigen-specific pulmonary plasma cell numbers were at their lowest point. Resuscitated mice showed the same increased susceptibility toP. aeruginosapneumonia as did hemorrhaged but unresuscitated animals.ConclusionsHemorrhage, even if resuscitated, results in alterations in bacterial antigen-specific pulmonary B-cell function and secretory IgA production that are profound, long lasting, and associated with increased susceptibility to infection at this mucosal surface. Because these effects on pulmonary B-cell function do not occur immediately after hemorrhage, immunization techniques able to enhance bacterial antigen-specific secretory IgA titers at pulmonary surfaces may be able to increase resistance to nosocomial pneumonia if administered shortly after injury and blood loss.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID