Monitoring the respiratory rate by miniature motion sensors in premature infants: a comparative study.

OBJECTIVE: Existing respiratory rate (RR) monitors suffer from inaccuracy. The study assesses the accuracy of a novel modality that monitors lung ventilation with miniature motion sensors. STUDY DESIGN: RR was measured by three methods: impedance technology, motion sensors and visual count, in babies (n=9) that breathed spontaneously or with respiratory support and babies (n=12) that received high-frequency oscillatory ventilation (HFOV). RESULTS: A line close to equality (slope=0.96, r(2)=0.83) was obtained between the motion sensor and the visual count of the RR with narrow 95% limits of agreements (<14.0 b.p.m.). The relationship between the impedance and the visual count showed a lower correlation (r(2)=0.65) and wider 95% limits of agreements (21.4 b.p.m.). The motion sensor- and the ventilator-determined RRs demonstrated a good agreement during HFOV, whereas the impedance failed to measure the RR during HFOV. CONCLUSION: Monitoring RR with motion sensors is more accurate compared with the impedance, in infants, in all ventilation modes.

A comparison of inhaled ipratropium, oral theophylline plus inhaled beta-agonist, and the combination of all three in patients with COPD.

To evaluate the role of inhaled ipratropium bromide alone vs oral theophylline plus inhaled beta-agonist or the combination of all three in patients with stable COPD, the following double-blind, placebo-controlled study was conducted. Forty-eight patients with stable COPD (mean age, 61.8 years, with mean baseline FEV1 < 1.0 L) were randomized on four separate days to receive the following drug regimens: (1) theophylline tablets (dose previously determined to result in blood level of 12 to 18 mg/L), followed by inhaled albuterol (2 puffs via metered-dose inhaler [MDI]), followed by inhaled placebo (2 puffs via MDI); (2) oral placebo followed by ipratropium (2 puffs via MDI; 36 micrograms), followed by inhaled placebo; (3) oral theophylline, followed by albuterol, followed by ipratropium; or (4) oral placebo followed by two inhaled placebos. On study days, spirometry and heart rate were measured at time 0, 30 min, 60 min, and hourly for 6 h. The FEV1 peak change (liters) and area under the curve (liter x hours) for the treatment groups were compared. Ipratropium was more effective than placebo (p = 0.001 and p = 0.0078, respectively). The combination of albuterol and theophylline was superior to ipratropium alone (p = 0.001 and p = 0.0001, respectively), and all three drugs together were superior to the combination of albuterol and theophylline (p = 0.0373 and p = 0.0289), respectively; one-sided test of hypotheses). Peak heart rates were significantly higher for treatment groups compared with placebo groups (p = 0.0001). However, theophylline and albuterol and the combination of all three drugs resulted in greater peak heart rates than did ipratropium alone (p = 0.001). These data suggest that for patients with stable COPD, combination therapy with ipratropium (two puffs), theophylline, and albuterol (two puffs) is superior to ipratropium alone or the combination of theophylline and albuterol.

A comparison of the effects of ipratropium bromide and metaproterenol sulfate in acute exacerbations of COPD.

Thirty-two patients presenting with acute exacerbations of chronic obstructive pulmonary disease were entered into the following double-blind, crossover study. First (time 0), patients inhaled either ipratropium bromide (54 micrograms) or metaproterenol sulfate (1.95 mg) via a metered dose inhaler (MDI) attached to a device (Inspirease) (phase 1). After 90 minutes, they inhaled whichever of the two medications they had not received in phase 1. This is referred to as phase 2. Pulmonary function (FEV1 and FVC) was measured at time 0, and at 30, 60, and 90 minutes following phase 1 treatment, and at 30, 60, and 90 minutes following phase 2 treatment (120, 150, and 180 minutes from the start of the study). Arterial blood gas samples (n = 20) were obtained at entry into the study and 30 and 90 minutes after phase 1 medication. The groups did not differ in age, degree of airway obstruction, hypoxemia, or theophylline usage at the start of the study. In phase 1, at 90 minutes, pulmonary function in both groups significantly and similarly improved. For ipratropium, FEV1 improved from 0.62 +/- 0.08 L to 0.88 +/- 0.11 L (p less than 0.01) and for metaproterenol FEV1 improved from 0.69 +/- 0.06 to 0.92 +/- 0.09 L (p less than 0.01). There was no further improvement with phase 2 treatment for either group. Thirty minutes after inhaling ipratropium, there was a small but significant rise in PO2 (5.8 +/- 3.0 mm Hg; p less than 0.05) while metaproterenol inhalation resulted in a 6.2 +/- 1.2 mm Hg decline in PO2 (p less than 0.05). These changes were not sustained at 90 minutes. We concluded that for acute exacerbations of COPD, both ipratropium and metaproterenol are effective medications when administered via an MDI attached to a device (Inspirease). However, ipratropium may be a safer choice as it initially did not cause a decline in blood oxygenation.