Respiratory Care

During a 12-week period, 204 consecutive patients admitted to the multidisciplinary intensive-care unit of a children's hospital were prospectively studied for complications of mechanical ventilation. METHOD: A respiratory therapist completed a standardized data form at the end of each shift for each ventilated patient. Patient age, sex, length of ventilation, diagnosis, and complications were noted. Complications were classified as relating to the endotracheal tube (ETT), the ventilator, or the patient's medical management, and were analyzed according to incidence (number per 100 patients or per 100 ventilator days) and to associated mortality. RESULTS: Patients ranged in age from newborn to 24 years. Sixty-three percent were male. Twenty-one percent of patients were managed by the medical staff, 11% by the general surgical staff, and 68% by the cardiac surgical staff. Average length of ventilation was 5.2 days. Overall survival rate was 91.7%. ETT complications reported as number per 100 patients were: pre-necrosis (13.0 [4/ 57 orally intubated patients and 23/147 nasally intubated patients]), ETT retaping complications (6.0), ETT plugging (1.0), and self-extubation (3.0). Ventilator complications reported as number per 100 ventilator days were: alarm failures (6.5), ventilator failures (0.7), and circuit problems (7.0). Medical complications reported as number per 100 patients were: massive gastric distension (8.8), right-upper-lobe collapse (4.4), pneumothorax (4.4), subcutaneous air (1.5), and pneumoperitoneum (1.0). ETT and ventilator complications showed no association with mortality. The large number of cardiac infants less than 24 months of age (n = 101) led us to further analyze this group for survival rate. We found that the survival rate was 93% for those requiring < 7 days mechanical ventilation and 89.3% for those requiring ≥ 1 days. As the study progressed, the respiratory therapists independently noted that their attentiveness to both patient and machine increased as did their awareness of complications. The incidence of alarm failure, circuit problems, and pre-necrosis was higher among the first 103 patients compared to the 101 patients entered into the study subsequently.

Because little information has been available regarding common respiratory care practices in neonatology and pediatrics, it has been difficult to develop departmental standards of care. We therefore conducted a national survey of current practices, hoping to establish whether any de facto standards exist in the U.S. METHODS: A 47-item multiple-choice survey instrument was mailed in 1988 to 689 U.S. hospitals that included all neonatal and perinatal high-risk centers. RESULTS: Response was received from 323 hospitals, for a 47% response rate. Some de facto standards do seem to exist, notably (1) q 2 h ventilator checks, (2) continuous measurement of oxygen concentration in oxygen hoods and ventilator circuits, (3) staffing ratio of four ventilator patients to one respiratory care practitioner, and (4) changing of ventilator circuits q 48 h. CONCLUSION: While we do not claim that such de facto standards have a scientific basis, we suggest that respiratory care services whose practices vary from the de facto standards should investigate why their own practices differ and whether they can be justified.

The use of insufflating suction catheters that deliver an oxygen flow either simultaneously or alternately with suction may have definite benefits. However, the potential exists for any inflating flow to cause barotrauma, and this risk has not been addressed. MATERIALS & METHOD: We tested a commercially available single-lumen insufflating suction catheter (VenTech) to determine the factors that affect the insufflating pressures within a test lung, using a variety of flowrates, suction-catheter and endotracheal-tube sizes, and suction pressures. We also attempted to determine the factors that affect the pressure-relief-activation point on the insufflating catheter. RESULTS: Pressure-relief-valve-activation values in this catheter are higher (86-1196 cm H2O) than clinically acceptable and are dependent on flowrate but independent of catheter size. We found that the factors affecting pressures within the test lung include insufflating flowrate and the ratio of the cross-sectional area of the suction catheter to the cross-sectional area of the endotracheal tube (SC:ETT) and the length of time the lung is exposed to the flow (ie, the absolute gas volume added to the lung). CONCLUSIONS: Although our bench study does not allow us to draw specific conclusions applicable to human subjects, we believe that clinicians should assure an SC:ETT of approximately 0.5 and avoid excessive insufflating flows and prolonged insufflating intervals.

Listings and Reviews of Books and Other Media

Note to publishers: Send review copies of books, films, tapes, and software to RESPIRATORY CARE, l 1030 Ables Lane, Dallas TX 75229.

Notices of competitions, scholarships, fellowships, examination dates, new education programs, and the like will be listed here free of charge. Items for the Notices section must reach the Journal 60 days before the desired month of publication (January l for the March issue, February l for the April issue, etc). Include all pertinent information and mail notice to RESPIRATORY CARE Notices Dept, 11030 Ables Lane, Dallas TX 75229.

Not-for-profit organizations are offered a free advertisement of up to eight lines to appear, on a space available basis, in Calendar of Events in RESPIRATORY CARE. Ads for other meetings are priced at $5.50 per line and require an insertion order. Deadline is the 20th of month two months preceding the month you wish the ad to run. Submit copy and insertion orders to: Calendar of Events, RESPIRATORY CARE, 11030 Ables Lane, Dallas TX 75229.

News releases about new products and services will be considered for publication in this section. There is no charge for these listings. Send descriptive release and glossy black and white photographs to RESPIRATORY CARE Journal, New Products and Services Dept, 11030 Ables Lane, Dallas TX 75229.