摘要:

This study examines our current perioperative fluid regimen in relation to body fluid compartments, intravascular volumes, and early kidney function in 17 kidney transplant recipients and their living related donors. Donors were given 0.5 g/kg of 10% dextran-40 during surgery and electrolyte solutions averaging 3032 ml/24 h. Recipients were randomized to receive albumin or dextran-40 infusions and given 0.5 g/kg during surgery. Electrolyte and 5% glucose infusions averaged 5580 ml/ 24 h, to match the urinary output. Total intravascular albumin (TIA) and total intravascular dextran (TID) were calculated from the plasma concentrations and plasma volume (PV).Mean preoperative PV in the donors was 44.5 ml/kg. The TIA loss of 0.37 g/kg was balanced by a TID of 0.27 g/kg, and PV increased to 46 and 49 ml/kg at 3 and 34 h after surgery, respectively. In recipients, the preoperative volume of extracellular water correlated linearly to the total body water and PV, as well as to the urine flow the first 24 h after transplantation. No difference was found in urine volume, serum creatinine, or PV expansion between recipient patients receiving albumin or dextran-40. Twelve patients with immediate urinary onset had blood volume (BV) and PV of more than 70 and 45 ml/kg, respectively, in sharp contrast to five patients with delayed urinary onset, who had lower BV and PV values. A fall in TIA of 0.9 g/kg at 3 h corresponded to a PV loss of 18 ml/kg and was only partially replaced by the 0.5 g/kg of intraoperative colloids.We conclude that BV and PV of more than 70 and 45 ml/kg, respectively, are associated with immediate kidney function in living related transplant recipients. Immediate kidney function may be induced by colloid infusions in a dose of about 1 g/kg, in addition to electrolyte solutions and blood transfusions.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Resting energy expenditure (EE) is often used as the basis of nutritional support for critically ill patients but whether resting EE is representative of total daily EE is not known. EE was measured for 24 h in ten mechanically ventilated, critcally ill patients (average Acute Physiology and Chronic Health Evaluation II score 23) to determine EE, resting EE, and the energy expended during various ICU activities. Although activities, such as weighing the patient on a sling-type bed scale, repositioning, and chest physiotherapy resulted in dramatic EE increases above resting levels (36%, 31%, and 20%, respectively), the actual contribution of these activities to total EE was small (1.1%, 2.1%, and 3.6%, respectively). The mean measured resting EE was 47.3 ± 22.3% above mean predicted EE based on the Harris and Benedict equation, and the mean total 24-h EE was 6.9 ± 2.6(SD)% above the mean measured resting EE. In this group of mechanically ventilated, critically ill patients, an activity factor of no greater than 10% above resting EE is appropriate.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Group BStreptococcus(GBS) sepsis in humans may cause the persistent pulmonary hypertension syndrome. Infusions of GBS in animals elevate pulmonary artery pressure (PAP) and resistance and are associated with elevated thromboxane levels. We investigated the hemodynamic effects of the specific thromboxane synthesis inhibitor, dazmegrel, in a piglet model of GBS-induced pulmonary hypertension. PAP rose from 22 ± 6 to 42 ± 11 (SD) mm Hg during infusion of heat-killed GBS; pulmonary vascular resistance increased from 1440 ± 400 to 4000 ± 1040 dyne sec/cm5. No significant changes in cardiac output, mean arterial pressure, or left atrial pressure were noted. Treatment with 1 mg/ kg of dazmegrel resulted in a rapid return of PAP and resistance to control values. No other hemodynamic effects of either bacteria or drug were observed despite continued infusion of GBS.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Clinical and echocardiographic data were evaluated in 46 patients after acute myocardial infarction (AMI). M-mode echocardiogram was performed 24 and 72 h and 5 days after AMI. Early acute pericarditis (EAP) was clinically recognized in 19 (41%) patients. Pericardial effusion (PE) was detected in 29 (63%) patients. In 23 (50%) patients both anterior and posterior PE was observed, while in six (13%) patients PE was only posterior. An echocardiographic pattern consistent with localized fibrinous pericarditis was detected in 11 (24%) patients. Eighteen (95%) of 19 patients with EAP had PE, and only 11 (40%) of the patients without EAP had PE (p< .001). We conclude that PE is observed frequently after AMI and that the echocardiographic study can help in the diagnosis of EAP after AMI.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

In 13 patients without tricuspid incompetence, we compared the values of right ventricular ejection fraction (RVEF) and right ventricular end-diastolic volume (RVEDV) obtained with biplane angiography and thermodilution at end-inspiration. A modification of Simpson's rule was used to measure angiographic volumes, and a new pulmonary artery catheter equipped with a rapid response thermistor was used to measure the ejection fraction by the Holt plateau method. The correlation between the two methods was acceptable (r = 0.83 for RVEF, r = 0.71 for RVEDV) despite the limitations of both angiography and thermodilution. Thermodilution underestimated RVEF and overestimated RVEDV when compared to angiography. The variation coefficient with thermodilution for five measurements of the RVEF per patient was 12 ± 5%. In addition to pressure and cardiac output measurements, monitoring of RVEF and RVEDV in the ICU should be possible with such a catheter. Further work is needed to assess the clinical relevance of these added data and their use for optimizing the therapy of right ventricular failure in acutely ill patients.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The effects of dimethyl sulfoxide (DMSO) infusion on cerebral blood flow (CBF) and systemic hemodynamics were studied in a canine model of myocardial ischemia. Immediately after ligation, cardiac output dropped from 2.09 ± 0.11 (SEM) in the control group and 1.79 ± 0.13 in the DMSO group to 1.07 ± 0.21 and 1.0 ± 0.08 L/min, respectively; there were no significant differences for 2 h. By the third hour and thereafter, the DMSO group had a significantly (p< .05) higher cardiac output (1.65 ± 0.08 L/min) than the control group (1.15 ± 0.10 L/min). The cardiac output increase at 3 h was accompanied by significantly (p <.05) lower systemic vascular resistance (SVR) in the DMSO group (5315 ± 248 dyne · sec/cm5) as compared to the control group (7892 ± 442 dyne · sec/cm5). There were no significant differences in heart rate, mean arterial pressure, pulmonary artery wedge pressure, or cerebral or pulmonary resistances in the control as compared to the DMSO group. Higher CBF values were noted at one hour and thereafter in the DMSO as compared to the control group (p< .05). Low-dose DMSO given as an iv bolus improved cardiac output and CBF and lowered SVR in this canine model of experimental myocardial ischemia.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Because determining cardiac output is difficult in premature infants, little is known about the hemodynamic effects of PEEP in this age group. We used pulsed-wave Doppler echocardiography to assess the hemodynamic effects of PEEP increments in ten premature infants with respiratory distress syndrome. At a PEEP of 4 cm H2O, the systemic and pulmonary blood flow and the right (SVRV) and left (SVLV) ventricular stroke volume decreased slightly, while the systemic vascular resistance (Rs) increased slightly. At a PEEP of 8 cm H2O, cardiac performance was impaired significantly, with a profound decrease of the systemic and pulmonary blood flow, SVRV and SVLV and a reflectory increase of the Rs. Surprisingly, the heart rate and mean arterial BP remained constant. The effective left ventricular afterload, which takes into account the changing intrathoracic pressure, increased slightly with increasing PEEP.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Minimizing work of breathing (WOB) during intermittent mandatory ventilation (IMV) and continuous positive airway pressure (CPAP) is important as it facilitates weaning from mechanical ventilation. To minimize WOB, we devised a simple, continuous-flow CPAP-IMV system that uses a weighted, partially filled reservoir bag and operates efficiently at low fresh gas flow (FGF). We compared both the pattern and WOB of our system (FGF at 15 L/min) with a conventional continuous-flow CPAP/IMV system (FGF at 15 and 30 L/min) as well as with two relatively efficient demand-value systems, the Servo 900 B and 900 C. Six healthy male subjects were studied; tidal volumes (VT), flow, mouth pressure, and pleural pressure (Ppl) were measured. Ten breaths, matched for VT, from each subject on each system were selected for analysis. Mechanical WOB was estimated by integrating Ppl with respect to VT. The conventional continuous-flow system was associated with a high work/breath relative to the other systems (p< .001). The weighted reservoir system was associated with a significantly lower work/breath (p< .001), its performance approaching that of the Servo 900B. Work/breath was least with the Servo 900C (p<.001) (p<.001). As breathing frequency was higher with the demand valve than continuous-flow systems(p< .001), the difference in work/time was minimal between the weighted reservoir bag and demand-valve systems. These systems were all associated with significantly (p<.001) lower work/time than the conventional system at both FGF. We conclude that the weighted reservoir system is advantageous since it is associated with relatively low WOB and disturbance of breathing pattern, functions efficiently at low FGF, is less costly than demand-valve systems, and is adaptable to any ventilator circuit.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Last year, five critically ill children with acute renal failure were treated by continuous arteriovenous hemofiltration. Mean treatment duration was 326 ± 89 (SD)h, for a total of 1632 h. Mean ultrafiltration rates of 5.4 ±1.7 ml/min m2achieved mean serum urea levels of 150 ± 25 mg/dl and a decline of mean prehemofiltration serum creatinine level of 3.5 ± 3.6 to 2.9 ± 2.0 mg/dl posthemofiltration. Continuous arteriovenous hemofiltration allowed adequate parenteral nutrition with a mean caloric intake of 79.6 ± 9.2 kcal/kg day. In the four surviving patients, urinary output started between 12 and 42 days after the onset of acute renal failure. Continuous arteriovenous hemofiltration is a very effective extracorporeal therapeutic system to control azotemia, fluid, and electrolyte balance in critically ill children with acute renal failure and hemodynamic instability.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Hypervolemic, normovolemic and hypovolemic patients with PEEP values less than 10 cm H2O were studied during brief discontinuance of mechanical ventilation to determine whether blood volume status would affect on-off ventilator pulmonary artery pressure (PAP) readings. There were no appreciable hemodynamic effects in patients with blood volume deficits less than one liter. Discontinuance for 1 min decreased Pao2from 121 ± 8 (SD) to 77 ± 7 torr (p.001) and increased Paco2 from 32 ± 1 to 35 ± 1 torr (p< .01). The decreased Pao2persisted up to one hour after return to mechanical ventilation. Our data reveal that brief discontinuance of ventilation in the normovolemic or hypervolemic patient with physiologic levels of PEEP does not increase the accuracy of PAP measurements. However, with severe hypovolemia, marked reductions in PAP may occur with discontinuance of mechanical ventilation. The practice of recording PAP off the ventilator and frequent suctioning of patients should be abandoned when interruption of mechanical ventilation has little utility and can result in persistent hypoxemia.

ISSN:0090-3493    

出版商:OVID    

年代:1987

数据来源: OVID