摘要:

Ten nurses and 10 pharmacists or pharmacy technicians added hyperbaric potassium chloride (KCI) 20 mEq to four types of iv fluid filled with “one liter” of dextrose, 5 g/dl, in water. Mean potassium concentrations in 240 containers filled under controlled conditions varied more than 12.4% from the mean concentration in 95% of bags and bottles. Mixing was quite incomplete, especially in flexible polyvinylchloride bags. In Viaflex bags that were not purposefully mixed, KCI concentrations during discharge varied from 71 ± 21 (SEM) mEq/L at the beginning of fluid outflow to 11.8 ± 3 mEq/L at the end. In a few containers, the maximum KCI concentration was 1000 times greater than the minimum. KCI mixing was improved slightly by storage of the container for 0.5 or 8 h and was greatly improved with vigorous purposeful mixing. There was little inhomogeneity of KCI in glass containers and in semirigid polyolefin containers. When KCI was added to the container during the course of fluid outflow, the maximal KCI concentrations in the discharge fluid were 21 times greater than the expected well-mixed KCI concentrations. Inhomogeneity of mixing of additives to parenteral fluids is another variable in control of drug effects in critical care and this should be minimized by forceful mixing after addition.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Transcutaneous CO2tension (PtcCO2) was measured with heated and nonheated transcutaneous carbon dioxide electrode sensors during hypercarbia and standardized hypovolemic shock in anesthetized dogs. The 95% response times of the PtcCO2electrode, measured during step increases in FICO2at four electrode temperatures: 37, 39, 41, and 44°C, were 15, 7.5, 5, and 3.5 min, respectively. During experiments with normal cardiac output, the PtcCO2correlated well with PaCO2(r= 0.96).Three PtcCO2electrode temperatures were tested for response to hypovolemic shock. Data from all PtcCO2electrodes failed to correlate with PaCO2during shock. PtcCO2values rose as cardiac output decreased; there was a good negative correlation (r= −0.95). The 37 and 42° C electrodes were affected by shock at cardiac index values below 2 L/min M2; but the 44° C probe was not affected until a cardiac index of 1.5 L/min M2was reached. Values from the 44° C electrode rapidly returned to preshock values after fluid resuscitation. The response to resuscitation lagged in the 37 and 42° C electrodes and did not return the preshock values until the cardiac index had been normalized for more than 15 min.It was concluded that a PtcCO2electrode heated to 44° C would be more useful in adult patients because of its faster response to hypercarbia, shock, and resuscitation. The PtcCO2values are higher than the corresponding PaCO2values but they correlate well until the cardiac index (CI) falls below 1.5 L/min M2; then PtcCO2values have a strong negative correlation with the corresponding CI values.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Serum and pulmonary edema fluid samples of 26 patients with pulmonary edema were examined. The correlation coefficient comparing measured colloid osmotic pressure (COPm) to calculated colloid osmotic pressure (COPc) (Landis and Pappenheimer equation) was 0.84. Significant differences between COPmand COPcwere noted when total protein (TP) concentrations were less than or greater than 5 g/dl (p < 0.001 and p < 0.01, respectively). Twenty-one of 69 samples (30%) had a greater than 4 mm Hg difference between measured and calculated values. COP should be measured rather than calculated for accurate determinations.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Many authors have indicated that high FIO2(0.75–1.0) ventilation may increase pulmonary venous admixture. Reabsorption atelectasis is supposedly responsible for this adverse effect. The authors attempted to determine if increasing PEEP during high FIO2ventilation could eliminate the detrimental influence of the latter. In 17 patients in respiratory failure, hemodynamic and respiratory variables were measured during ventilation with FIO20.50, 0.75, and 1.0 and PEEP varying from −3 to +5 cm H2O from baseline.Before exposure to FIO2> 0.75, addition of PEEP resulted in a decrease of Qs/Qt from a mean of 26.6–21.9%. After exposure to FIO20.75–1.0, Qs/Qt remained at levels not different from baseline, even when PEEP 8 cm H2O above baseline was added.The authors conclude that ventilation with high FIO2is not useful in determining Qs/Qt, and may prevent the improvement in pulmonary venous admixture associated with PEEP therapy.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Hemodynamic function during spontaneous breathing (SB), IMV, IPPV, continuous positive airway pressure with 10 torr PEEP (CPAP10), IMV with 10 torr PEEP (IMV10), and continuous positive pressure ventilation with 10 torr PEEP (CPPV10) were studied in 13 normovolemic anesthetized dogs. Hemodynamic function was also studied during each type of ventilation after inducing acid aspiration with 0.1 molar HCl, 5 ml/kg, in these animals.In normal dogs, hemodynamic function during IMV and IPPV did not differ significantly from that observed in spontaneously breathing dogs. CPAP10had no effect on the hemodynamic function. IMV10decreased cardiac index, increased arterial-mixed venous O2content difference (avDO2) compared to SB and decreased stroke index compared to SB, IMV, and CPAP10. CPPV10significantly decreased cardiac and stroke indicies compared to SB, IMV, IPPV and CPAP10, and increased avDO2compared to SB. After acid aspiration, IMV did not affect the hemodynamic function, but IPPV caused a significant decrease in stroke index compared to SB. Again, CPAP10had no significant effect on the hemodynamic function. IMV10decreased cardiac index and increased systemic vascular resistance compared to SB and decreased stroke index compared to SB and IMV. CPPV10increased pulmonary vascular resistance and avDO2compared to SB, decreased cardiac index compared to SB and IMV, decreased stroke index compared to SB, IMV, and CPAP10and increased systemic vascular resistance compared to SB, IMV, IPPV, and CPAP10. Comparing percentage change of cardiac and stroke indices before and after aspiration indicated that the decrease in lung compliance caused by acid aspiration did not prevent the hemodynamic effects of different types of ventilation. Among different types of mechanical ventilation with PEEP, CPAP10caused the least cardiovascular depression.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Aggressive nutritional support has been advocated for critically ill patients. Ten patients in a medical ICU supported with mechanical ventilation, 3 on total parenteral nutrition (TPN) and 7 not on TPN, were studied over a 24-h period for oxygen uptake (Vo2), carbon dioxide production (Vco2), respiratory exchange ratio (R), and urinary urea nitrogen (UN). Indirect calorimetric formulas were used to calculate the caloric expenditure and this was compared to calories administered. The TPN group had a mean R of 1.23 which was significantly greater than the nonTPN group whose mean R was 0.88 (p< 0.001). The increased Vco2noted in the TPN group may have been secondary to high carbohydrate intake with fat synthesis and could play a role in patients who are difficult to wean from a ventilator.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

We propose a procedure for assessing the pulmonary airway resistance of patients under mechanical ventilation with a volume-cycled respirator having a sine-wave flow curve and inspiration/expiration (I/E) ratio of 1/2. This simplified procedure requires only the respirator's manometer and spirometer. The method is based on Ohm's Law, dividing the pressure difference (as shown on the manometer) between the peak value and that obtained by occluding the expiratory outlet by one-tenth of the minute volume (Vm). The relationship between the Vm and flow is obtained by calculating the height of the triangle formed by the sine wave, given that the area approximates total volume and the base is derived from the frequency and I/E ratio.This method was tested in 296 measurements on 106 patients using as a control the determination of resistance with a pneumotachograph and differential manometer placed between the patient and respirator. There was a high correlation (r= 0.96) between both procedures. To further facilitate bedside use, we have prepared a graph relating common values of Vm and pressure to resistance.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Infants with respiratory distress syndrome (RDS) have insufficient surfactant systems and decreased functional residual capacity (FRC). This study attempts to relate FRC with severity of disease course. Measurements were made on 36 newborn infants with clinically diagnosed RDS. All infants were intubated and breathing on continuous positive airway pressure (CPAP) at the time studied. Infant CPAP levels were adjusted to 10 cm H2O; then FRC and arterial blood gas measurements were made. The infants were grouped according to their FRC per birth weight (BW). Volumes ≥ 2 SD (≥ 42 ml/kg) of normal term infants not on CPAP were placed in the “large FRC” group. Volumes within ± 2 SD (15–41 ml/kg) were in the “medium FRC” group, and infants ≤ 2 SD (< 14 ml/kg) of normal were in the "small FRC" group. The severity of RDS disease course was judged by the time duration the infants were managed on CPAP and FIO2> 0.21 and by the maximum CPAP and FIO2levels used. Twelve infants (33%) had small FRC, 18 (50%) medium FRC, and 6 (17%) large FRC. The time duration the infants with large FRC were on CPAP was significantly less than infants with medium FRC and the medium FRC group time was less than the small FRC group. The time duration on increased FIO2and maximum FIO2level used on the large FRC group was less than the medium and small FRC groups. Thus, FRC/BW appears related to the severity of RDS disease course. It is possible that the infants with FRC/BW ≥ 42 ml/kg had pneumonia and were misdiagnosed as RDS. If so, FRC monitoring could have assisted in their diagnosis. BW and gestational ages of the groups were not different. Thus, variables other than these two play an important role in the degree of atelectasis occurring in infants with RDS. In patient management, where frequent changes in airway pressure and FIO2are made, knowing the FRC/BW as well as blood gas values could aid the clinician in his choice of CPAP and FIO2levels.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

In order to assess the usefulness of sighs in preventing deterioration of arterial PO2(PaO2), functional residual capacity (FRC), and compliance in hypoxemic patients, the authors studied 20 anesthetized and paralyzed dogs. The dogs were ventilated with either normal (11.5 ml/kg) or large (23 ml/kg) tidal volumes and their lungs were either normal or made edematous with oleic acid injection. Sighs (46 ml/kg) were administered periodically and PaO2, FRC, and compliance were measured at intervals between sighs. In dogs with normal lungs, regardless of tidal volume, sighs produced a transient increase in compliance and FRC but PaO2was not significantly affected. In dogs with pulmonary edema, sighs produced inconsistent effects on FRC and compliance and, interestingly, PaO2decreased after the sighs. The authors suggest that sighs may be unnecessary in patients with pulmonary edema, especially when they are already receiving large tidal volumes.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The concentration of fibrinogen/fibrin degradation products (FDP/fdp) was measured using a direct latex agglutination test in 40 critically ill patients with pulmonary arteriography and possible acute pulmonary embolism. All of them were admitted with signs of severe heart and/or respiratory insufficiency, and 12 (30%) of the patients required mechanical ventilation. The concentration of FDP/fdp was significantly higher in 28 of 29 patients with positive arteriography (mean 145 μg/ml), that in those whose arteriography was negative (in every cases the FDP/fdp level was lower than 10 μg/ml).To help differentiate pulmonary embolism from other acute heart or pulmonary diseases, the authors measured the FDP/fdp in 10 patients with bacterial pneumonia, 24 patients with acute myocardial infarction, 4 patients with extrinsic asthma, and 18 normal control subjects. The authors found high levels of FDP/fdp (more than 10 μg/ml) in only 2 patients with pneumonia and in 6 with myocardial infarction. In no case was the level of FDP/fdp higher than 40 μg/ml. On the other hand, in patients with pulmonary embolism, 23 (79%) had levels higher than 40 μg/ml.The study indicates that this test is a helpful screening method for pulmonary embolism, especially in situations where other emergency diagnosis tests are inconclusive or impractical; it also provides justification for beginning anticoagulant therapy and for recommending pulmonary arteriography.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID