摘要:

The maximum inspiratory force (MIF) that children and adults can generate has been shown to be one of the parameters that correlates positively with their ability to be weaned from mechanical ventilation. The purpose of this study was to determine if the MIF might also be useful in judging the ability of neonates to be weaned from mechanical ventilation.The relationships among MIF, PaCO2, spontaneous respiratory rate (SRR), and patient outcome were studied in 20 neonates receiving ventilator support (babybird). A Boehringer inspiratory force meter was used to obtain MIF daily and just before extubation. At each measurement, the patient was given 3–4 trials to achieve MIF with 6 inspiratory attempts during airway occlusion. An attempt was made always to occlude the airway at FRC. Two variable regressions with a level of significance ofp< 0.05 showed: (1) MIF did not correlate with PaCO2or SRR, or change significantly on a daily basis to the value at the time of extubation in the entire group or when the patients were compared by gestational age; (2) MIF did not correlate with reintubation (N = 4, mean 29 ± 13 cm H2O) versus no reintubation (N = 16, mean 33 ± 15 cm H2O). This lack of correlation may be due to the timing difficulties of occluding the infant airway exactly at FRC. The timing difficulties in neonates are caused by a rapid respiration rate (l/sec), small tidal volume (5–20 ml), irregular respiratory pattern, and paradoxical chest movement.

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Over a 12-month period, 27% of patients in a new ICU grew bacterial pathogens from sputum or tracheal cultures. The commonest isolates werePseudomonas aeruginosaandKlebsiellaspecies. Endotracheal intubation, the length of time intubated, and antimicrobial therapy all predisposed to the isolation of organisms from sputum.No patient developed a gram-negative pneumonia, and there was no case of septicemia associated with a positive sputum culture. The presence of epithelial or pus cells in sputum was unrelated to the culture results. It was concluded that the growth of colonic bacteria from sputum or tracheal aspirates was of little prognostic or clinical significance.No significant common environmental site or cross-infection pathway was identified: sinks were contaminated by patients rather than vice versa. Most sputum isolates were probably endogenous in origin.

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The ratio of arterial oxygen tension to inspired oxygen concentration (PaO2/FIO2) as an index of respiratory function was evaluated in 22 patients with body surface area burns of 15–80%. These results indicate that this ratio is limited in its applicability because extrapulmonary factors, such as cardiac output, oxygen consumption, and arterial oxygen content, can affect this index by alterations in the amount of venous desaturation. Useful estimates of intrapulmonary right to left shunt (Qs/Qt) from PaO2/FIO2were obtained only when arteriovenous oxygen content differences (aQDO2) were between 3–5 ml/dl. There were aVDO2values above and below 3–5 ml/dl in at least 35% of the observations. Under these circumstances, PaO2/FIO2did not correctly reflect changes in Qs/Qt. Blood gases from central venous catheters did not mirror changes in true mixed venous blood and, thus, can lead to erroneous estimations of Qs/Qt. Rational therapy of reduced arterial oxygen saturation requires measurement of both extra- and intrapulmonary factors contributing to arterial desaturation. Measurement of PaO2/FIO2alone will not estimate these factors.

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Five mechanically ventilated patients were studied during hemodialysis. The aim was to determine if hypoxemia would develop, and to identify the causes. Respiratory variables (dynamic compliance, peak airway pressure, CO2production); oxygen uptake, and transport variables (alveolar and arterial PO2, pulmonary venous admixture, oxygen consumption); respiratory quotient; pulmonary vascular resistances and white blood cells (WBC) were measured. PaO2decreased during dialysis, as did PaO2. However, the fall in alveolar oxygen tension failed to explain the hypoxemia. Lung volume did not change significantly, because dynamic compliance, peak airway pressure, and pulmonary vascular resistance were not modified. CO2losses through the dialysis coil were of little clinical significance. WBC count fell significantly. The authors conclude that ventilation/perfusion and diffusion abnormalities related to leuko-agglutination are responsible for hypoxemia during dialysis.

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1979

数据来源: OVID