ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Airway pressure release ventilation (APRV) delivers continuous positive airway pressure (CPAP) and may support ventilation simultaneously. This investigation tested whether, after acute lung injury (ALI), APRV promotes alveolar ventilation and arterial oxygenation without increasing airway pressure (Paw) above the CPAP level and without depressing cardiac function. Ten anesthetized dogs randomly received either intermittent positive-pressure ventilation (IPPV) or APRV. APRV was delivered with a continuous-flow CPAP system. Expiration occurred when a switch in the expiratory limb opened and Paw decreased to near-ambient, which decreased lung volume. After baseline data collection, ALI was induced by infusing oleic acid iv. Two hours later, IPPV and APRV were administered randomly, and data were collected.With normal lungs, APRV and IPPV achieved similar gas exchange and hemodynamic function. During ALI, arterial oxygenation was improved, and peak Paw which did not exceed the CPAP level, was lower during APRV. Similar minute ventilations were delivered by both modes but resulted in lower Paco2with APRV. Thus, APRV decreased physiologic deadspace ventilation. Hemodynamic status was similar during both modes. Therefore, APRV is an improved method of oxygenation and ventilatory support for patients with ALI that will allow unrestricted spontaneous ventilation and may decrease the incidence of barotrauma.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The frequent and severe nosocomial infections in ICU patients suggest that these patients are immunodeficient. We studied the phagocytic activity of granulocytes and monocytes isolated from the blood of 32 ICU patients with nosocomial pneumonia (19 male, 13 female; age 41 ± 4 yr). Cells were tested in standard medium and in the presence of patients' serum. Blood granulocytes and monocytes were purified and separately exposed to opsonized zymosan (to test C3 receptor function), immunoglobulin-coated erythrocytes (to test Fc receptor function), and glutaraldehyde-treated erythrocytes (to test nonspecific binding structures). Phagocytosis and superoxide anion production were measured. Granulocytes of patients exhibited a substantial decrease of zymosan ingestion (p< .05), whereas phagocytosis of other particles was normal. Monocytes from the patients displayed an unselective overall decrease of phagocytic ability for the three particle types (p< .05). Patients' sera were at least as efficient as a pool of normal sera in opsonizing zymosan. Further, no phagocytic inhibitor was found in the tested patients. In conclusion, we point out a deficiency of membrane receptors of neutrophils and monocytes in ICU patients with nosocomial infection.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Plasma fibronectin may be of critical importance for the septic patient through its proposed function as the major opsonin for macrophage clearance of circulating, noncellular debris. As a rule, critically ill, septic patients are depleted of fibronectin. In earlier uncontrolled studies, infusion of fibronectin-rich cryoprecipitate had resulted in improved renal and pulmonary functions and changes in peripheral hemodynamics. In this controlled study, 32 septic ICU patients (mean initial fibronectin level = 60% of normal) received cryoprecipitate or control infusions. Although the fibronectin level was significantly elevated to the normal range in the cryoprecipitate group, no effects were seen in hemodynamics, oxygen metabolism, or lung and kidney functions. Our results indicate that this form of fibronectin therapy does not influence the impaired organ function in septic shock.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Arterial blood lactate is regarded as a very good indicator of the severity and prognosis of circulatory shock. Accordingly, the practical issue of whether such measurements might be equally valid on blood sampled from the right atrium or superior vena cava or from the pulmonary artery was investigated.In blood sampled prospectively on SO occasions in 12 patients (group 1), arterial blood lactate ranged from 0.39 to 9.71 mmol/L. A very high correlation (r = .995) was observed between blood sampled simultaneously from an arterial and central venous catheter. The maximum absolute difference was 0.5, and mean difference 0.029 mmol/L. Comparable correlations were obtained between arterial and simultaneously sampled pulmonary artery blood (r = .994).We analyzed retrospectively the results of lactate analyses on 104 paired blood samples from the pulmonary artery and peripheral artery in 23 critically ill and injured patients (group 2) whose arterial blood lactates ranged from 0.46 to 12.99 mmol/L. We also found a high correlation (r = .998) between arterial and simultaneously sampled pulmonary artery blood lactate. The maximum absolute difference was 0.82, and the mean difference 0.03 mmol/L.These data demonstrate that lactate measurements in venous blood sampled either from a pulmonary artery or from a central venous catheter yield lactate concentrations essentially equivalent to those in arterial blood.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The influence of PEEP during controlled mechanical ventilation (CMV) on plasma levels of alpha-atrial natriuretic peptide (alpha-ANP) was examined in seven patients suffering from acute respiratory failure. The majority of patients were volume-expanded. Samples were drawn from the superior vena cava, right atrium, pulmonary artery, and radial artery. All alpha-ANP levels were significantly depressed by 15 cm H2O PEEP for one hour, when compared to CMV without PEEP. During the PEEP period, cardiac index, creatinine clearance, urinary flow and urinary sodium excretion were decreased. CMV with PEEP of 20 cm H2O depressed peripheral venous plasma levels of alpha-ANP in six volume-expanded healthy volunteers, too. The decreased release of alpha-ANP could be a consequence of atrial compression by the distended lungs and of reduced venous return. We suggest that the decline in plasma alpha-ANP levels contributes to fluid retention and renal dysfunction, which occur frequently during CMV with PEEP. More detailed studies are necessary to confirm our hypothesis.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

We compared the partial pressure of oxygen directly via a continuous intra-arterial probe (Piao2) and indirectly using a transcutaneous device (Ptco2) with simultaneously obtained arterial blood Pao2. The Piao2values were measured using a bipolar oxygen sensor placed through an 18-ga arterial catheter. The Ptco2values were measured using a transcutaneous O2-CO2sensor placed on the abdomen. Seven critically ill, hemodynamically stable, ventilator-dependent adult patients were studied. Measurements were obtained at varying concentrations (0.25 to 1.0) of inspired oxygen after a 10-min stabilization. A total of 78 simultaneous values were obtained; by linear regression: Piao2= 0.91 Pao2+ 1.39 (r = .98, standard errors of the estimate [SEE] = 18.6); Ptco2= 0.39 Pao2+ 36.2 (r = .89, SEE = 14.1).To assess these instruments as trend monitors, we compared the changes in simultaneous Pao2, Piao2, and Ptco2values; by linear regression: APiao2= 0.90 APao2+ 3.88 (r = .96, SEE = 27.7); APtco2= 0.43 APao2+ 5.6 (r = .94, SEE = 15.2). We conclude that, although these instruments correlate highly with the Pao2, the SEE was substantial and therefore may limit their clinical reliability in adults. Any acute or clinically significant change in Piao2or Ptco2should be confirmed with a blood gas Pao2.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A total of 250 consecutive admissions to an open-plan respiratory ICU were analyzed prospectively to identify the incidence of secondary hospital-acquired infections and possible predisposing factors. Despite preventative measures and a restricted antibiotic policy, 23.6% of patients developed secondary infections. Patients admitted after multiple trauma were the only diagnostic category of patients who showed a significantly increased incidence of secondary infections. The length of hospitalization and number of patients who had intubations or tracheostomies was higher in the group with secondary infection; the causal relationship was difficult to establish. Patients who were not intubated or tracheostomized did not develop secondary infection. Prior administration of antibiotics did not appear to influence the incidence of secondary infection. There was a significant increase in secondary infections in patients with a higher therapeutic intervention scoring system score. The predominant pathogens cultured were highly resistant Gram-negative organisms, particularly Acinetobacter sp. andPseudomonassp.Staphylococcus aureuswas the most common Gram-positive pathogen. The ICU course was probably prolonged by the complication of nosocomial infection, which may have contributed to the deaths.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Eighty-seven pulmonary artery catheters (PACs) with sterile protective sleeves were placed into 69 surgical ICU patients by one of the following two methods: through an introducer placed in a new, percutaneous site or by exchanging an indwelling catheter for an introducer. On removal, 5-cm catheter segments from the catheter tip and from within the introducer and sleeve, peripheral blood, and blood drawn from the PAC distal port were cultured quantitatively. Sleeve segment cultures were sterile if catheterization was less than 48 h and had been accomplished through a new percutaneous site. The risk of growing greater than 103 colonies on the tip and introducer segment increased to greater than 30% when PACs were left in over 96 h. The incidence of catheter-related bacteremia (CRB), defined as the simultaneous growth of identical organisms from the blood and the PAC tip, was 5.3% but may have been underestimated. CRB was associated with the use of corticosteroids (p= .009) and with cultures from any PAC segment growing more than 103colonies (p< .01). Although our data suggest that the use of the sterile protective sleeve is associated with a low risk of colonization, further study will be required to delineate the relationship between the use of protective sleeves and CRB.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Intramuscular (im) pentamidine isethionate can cause substantial local pain and inflammation at the injection site. This drug is being used more frequently in recent years to treatPneumocystispneumonia, particularly in patients with acquired immunodeficiency syndrome. Ginicians began administering it iv despite warnings that iv administration might cause severe hypotension.We investigated the safety of im and iv pentamidine, monitoring hemodynamics after each dose in 11 patients with intra-arterial lines. Results showed only a small (but statistically significant) fall in mean arterial pressure after both im and slow (60 min) iv administration. A concomitant decrease in pulse occurred, but no change in cardiac output, pulmonary capillary occlusion pressure or systemic vascular resistance was noted. These results suggest that it may be safe to infuse pentamidine slowly intravenously. This route is more comfortable to patients than im administration.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID