摘要:

PEEP is widely accepted as a therapy for some forms of acute respiratory failure (ARF). PEEP increases functional residual capacity (FRC), decreases intrapulmonary shunt fraction, and improves arterial oxygenation. The time required for FRC and arterial oxygen tension (Pao2) to stabilize after an adjustment in the level of PEEP is not clearly established. Therefore, to determine the temporal relationship between PEEP, FRC, and Pao2after adjusting the level of PEEP, aspiration pneumonitis was produced in swine. The FRC and the Pao2decreased within seconds after intratracheal instillation of 0.1 N HCl; FRC of all animals was restored to its control value after the application of PEEP, 5 cm H2O, but Pao2remained low. It was necessary to increase PEEP to 20 cm H2O and FRC to twice the control value to return arterial oxygenation to control levels. After PEEP was applied, an average of 15 sec was required to increase FRC; the less compliant the lung, the more rapid the change. After PEEP was removed, FRC stabilized within an average of 22 sec. When PEEP, 25 cm H2O, was removed, arterial oxygenation decreased suddenly and substantially which suggests that PEEP, especially at higher levels, should not be discontinued, even momentarily, for nonessential maneuvers.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Fifty-seven postoperative cardiac surgical patients receiving intra-aortic balloon pump (IABP) support were selected for detailed hemodynamic and renal function measurements on the basis of depressed cardiac and/or renal function. Eleven patients developed acute renal failure while receiving maximal IABP support and 10 during, or after withdrawal of IABP support. To define further the relationship between IABP support and renal function, 17 patients underwent simultaneous assessment of hemodynamic and renal function under varying conditions of IABP support. These studies, performed just before IABP withdrawal, demonstrated slight, clinically insignificant, improvement in hemodynamic and renal function with increased IABP support. Arterial pressure recordings, performed above and below the intra-aortic balloon in 8 patients, revealed no significant pressure gradient across the balloon whether single- or double-chambered. In addition, the balloon pulse waveform was always evident in the femoral artery. Importantly, the intra-aortic balloon did not interfere demonstrably with renal function, nor did it decrease renal perfusion pressure, in spite of its suprarenal position. Therefore, improvement in systemic perfusion from IABP support in the early postoperative period will result in improved renal perfusion.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Starling's hypothesis of forces governing fluid movement across capillary membranes suggests that any unopposed decrease in intracapillary colloid oncotic pressure (COP) or increase in capillary permeability should result in increased interstitial fluid. Iso-oncotic increase in pulmonary artery wedge (PAW) causes pulmonary dysfunction. Isobaric reduction of COP with normal capillary permeability does not result in pulmonary interstitial edema. Because sepsis is a frequent antecedent of clinical pulmonary dysfunction, the question was asked: does reduction in the COPPAW gradient in the presence of sepsis result in increased pulmonary dysfunction? Twenty baboons were studied: group 1—control, group 2—4-h constant infusion ofE. coli, group 3—plasmapheresis alone, group 4—plasmapheresis followed by sepsis. Ringer's lactate was infused to keep PAW constant. Arterial and mixed venous blood gases were drawn and the intrapulmonary shunt (QS/QT) was calculated. The data were compared using Tukey's HSD test and one way analysis of variance. Plasmapheresis alone resulted in a 68% reduction in COP (15 ± 2.9 (SD) torr to 4.6 ± 0.6 in group 3 and 16.5 ± 4.3 to 5.7 ± 0.9 in group 4,p< 0.05). Sepsis resulted in an increase in QS/QTin all septic animals. There was no increased QS/QTin those animals that had sepsis added to plasmapheresis, group 4 (p< 0.05). These data indicate that sepsis leads to pulmonary dysfunction but that this dysfunction appears to be independent of colloid oncotic forces.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

It was found that, during 1974, it cost an average of ±8842 (±12,909 in 1979) to care for a survivor of severe respiratory distress syndrome (RDS) who required mechanical ventilation in this ICU compared to ±2448 (±3574 in 1979) for nonsurvivors. Death in 15 out of the 16 nonsurvivors was accompanied by grade III-IV intraventricular hemorrhage. This complication also accounted for moderate to severe neurological impairment in two of the three survivors so affected. The cost of care prorated for life expectancy was ±0.42 (±0.61 in 1979) per day of life. These data are compared with similar data generated from adult intensive care patients from the same institution.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Manometric central venous pressure (CVP) measurements are still routinely used as indicators of intravascular volume, particularly during surgery and when cardiorespiratory function is assumed to be normal. The difference between manometric measurements of CVP, from a 16-gauge polyvinylchloride catheter, and those obtained electronically from the level of the right atrium through the proximal port of a pulmonary artery catheter was studied in 40 patients admitted to the ICU. Despite correct position of the catheter tips and adequate respiratory oscillations, manometric measurements differed considerably from right atrial mean pressure determinations. The discrepancy was largest and the direction of change not predictable when the CVP catheters were inserted via an antecubital or right subclavian vein. When catheters were inserted from the left subclavian vein or the internal jugular, on the other hand, manometric CVP was consistently 4–6 cm H2O higher than the electronic pressure determination. If a manometric CVP catheter is to be used, the internal jugular or left subclavian routes appear preferable.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

It has been shown experimentally that irreversible brain injury and death may follow after 5–7 nun of cerebral ischemia and that even brief periods, 2 min or less, can produce focal damage to the nervous system. All published studies demonstrating a protective effect of barbiturates have been performed in animals.A patient is presented who recovered full neurological function after 13 min of hypovolemic hypertension. This remarkable outcome may have been due to the rapid institution of high-dose barbiturate therapy. The extent to which such therapy affected his outcome is unclear, but does add to the growing body of evidence suggesting a favorable effect from this type of barbiturate therapy.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Iatrogenic barbiturate coma for the control of intracranial hypertension is a relatively new addition to the neurosurgeon's therapeutic armamentarium. Although initial studies are quite promising, the induction of coma, especially for prolonged periods (ranging from days to weeks), is a major therapeutic endeavor which requires sophisticated monitoring of both neurological and physiological function. A multidisciplinary approach prevents many possible complications of this form of therapy and facilitates treatment when untoward physiological complications do occur. The following case report illustrates one such complication.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To minimize respiratory effort, continuous positive airway pressure (CPAP) must be applied in a manner that maintains a constant airway pressure. Conventional CPAP circuits depend on relatively high fresh gas flows (FGF) to maintain circuit pressure during inspiration. The authors describe a CPAP circuit employing a “weighted bellows.” This simple modification of the conventional gas reservoir allows the FGF to be significantly reduced. In fact, minimal changes in circuit pressure can be achieved Hvith FGF that barely exceeds the patient's minute ventilation. The modified system is compact, mechanically uncomplicated, and simply constructed.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A new CPAP device is described which is simple, lightweight, easily constructed, and not functionally dependent on gravity or valves. The device consists of a conventional T-piece into which a small nozzle is placed opposite, but projecting towards, the patient connection. When a flow of oxygen is delivered through the nozzle, continuous positive pressure within the airway results. The device was evaluated with a mechanical lung model, in human volunteers using various breathing patterns and in intubated patients requiring transport within the hospital. In all three situations, the device provided 7–15 torr endexpiratory pressure and an FIO2of 0.40–0.90 using oxygen flow rates of 10–30 L/min. The device is safe, reliable, and can be easily adapted to provide IMV when required. Clinical applications are discussed.

ISSN:0090-3493    

出版商:OVID    

年代:1981

数据来源: OVID