Respiratory Care

In recent years, there has been increased interest in respiratory intermediate inten-sive care units (RIICUs) as suitable environments when treating patients needing respiratory assistance. The aims of this study were to evaluate the dependence level of patients by use of a new scale, the Dependence Nursing Scale (DNS), for scoring the work activities of nurses and to compare the DNS score with accepted scores of illness severity, nursing work load, and clinical outcome.

The study was conducted in a 6-bed adult RIICU in an Italian respiratory rehabilitation department. Over 1 year, 111 consecutively admitted patients who required mechanical ventilation for acute on chronic respiratory failure (33 patients, Group 1), prolonged weaning from mechanical ventilation (33 patients, Group 2), or cardiopulmonary monitoring (45 patients, Group 3) were admitted to the study. At admission, demographic and anthropometric data, severity of disease (as determined by Acute Physi-ology and Chronic Health Evaluation [APACHE] II), nursing work load (as measured by the Nine Equivalents of Nursing Manpower Use Score, NEMS), and inspiratory muscle strength (maximal in-spiratory pressure) were recorded. The DNS score was determined at admission and at discharge. Mortality rate and days spent in the RIICU were also recorded. The DNS describes the dependence of patients needing increasing levels of nursing commitment, which is determined by scoring 13 tasks according to the amount of time spent on them by nursing staff. Scoring is done by use of a scale with a minimum of 0 (no dependence) and increasing by 1 to a maximum according to the number of activities for each task. Total score for the DNS ranges from 0 to 45.

At admission, the DNS score and the NEMS were significantly higher for patients in Group 2 than for patients in Groups 1 and 3. All tasks except tracheotomy care significantly improved, resulting in a significant decrease in the DNS score for all patients (from 18 ± 10 at admission to 10 ± 11 at discharge). At admission, the DNS score was significantly better correlated with the NEMS (r = 0.70) than with the APACHE II score, maximal inspiratory pressure, or the number of days spent in the RIICU.

Compared with scores for clinical illness severity and inspiratory muscle function, the DNS score can better predict the dependence level of patients and better reflect the nursing work load required for patients admitted to an RIICU.

The recent development of non-chlorofluorocarbon propellant formulations for pressurized metered-dose inhalers prompts the need for the comparative evaluation of dose delivery by small- versus large-volume holding chambers (HCs). The performance of 2 representative large- and small-volume HCs has been investigated with chlorofluorocarbon-formulated albuterol (Ventolin) and hydrofluoroalkane-formulated albuterol sulfate (Airomir) with the objective of studying the influence of chamber capacity on so-called "fine-particle" dose and total dose. Three Aero-Chamber and a similar number of Volumatic HCs were tested with each formulation.

An 8-stage Andersen cascade impactor was used to determine mass-weighted size distributions of drug delivered at the mouthpiece of each HC. The mass of albuterol (Ventolin) or albuterol sulfate (Airomir) collected in the impactor was assayed by high performance liquid chromatography with ultraviolet detection in order to measure both fine-particle dose (< 4.7-µm aerodynamic diameter) and total dose.

For Ventolin, the fine-particle and total doses were 45.4 ± 0.3 µg and 47.2 ± 0.1 µg, respectively, for the AeroChamber HC and 63.8 ± 2.3 µg and 66.1 ± 3.0 µg, respectively, for the Volumatic HC. For Airomir, the fine-particle and total doses expressed as albuterol base equivalent were 62.0 ± 2.9 µg and 64.2 ± 3.0 µg, respectively, for the AeroChamber HC and 67.9 ± 2.5 µg and 69.7 ± 3.4 µg, respectively, for the Volumatic HC.

There was a significant difference in both fine-particle and total dose between large- and small-volume HCs with Ventolin (unpaired t test, p < 0.001). However, both HCs performed similarly with Airomir (p = 0.056). In all cases, the available dose from the HCs comprised > 95% of fine particles.