David Appel

Lactic acidosis in severe asthma

Twelve patients with severe asthma in whom lactic acidosis developed are presented. All had an arterial blood pH level lower than that expected for the measured partial pressure of arterial carbon dioxide, all had an abnormally large anion gap, and the blood lactate level exceeded 2.8 mmol/liter. Respiratory acidosis subsequently developed in eight patients, and six required intubation. Lactic acidosis can develop in patients with severe asthma. Such patients are in danger of the development of respiratory failure and must be treated vigorously and observed closely.

Epinephrine improves expiratory flow rates in patients with asthma who do not respond to inhaled metaproterenol sulfate.

One hundred patients with acute asthma and peak expiratory flow rates (PEFR) less than 150 L/min were randomized and treated in a double-blind treatment protocol with either metaproterenol sulfate aerosol (MPA) inhalation and placebo injection or epinephrine injection (EPI) and inhaled placebo at entry and at 30 and 60 minutes, and then were treated with the crossover comparison regimen at 120, 150, and 180 minutes. The two groups had similar entry PEFRs and FEV1 (MPA, 112 L/min; 0.94 L, respectively; EPI, 111 L/min; 0.85 L, respectively) and similar plasma theophylline levels (MPA, 12.2 micrograms/ml; EPI, 13.8 micrograms/ml). PEFR and FEV1 were measured every 30 minutes for 4 hours. Mean expiratory flow rates among both groups were similar at entry and at 120 and 240 minutes. At 120 minutes, flow rates had improved in 28/46 MPA-treated patients (61%) and 48/54 EPI-treated patients (89%). Among these improved patients, flow rates were significantly higher in the MPA-treated group. At 120 minutes, 18/46 MPA-treated patients (39%) and 6/54 EPI-treated patients (11%) had PEFRs less than 120 L/min and PEFR and FEV1 less than 120% of baseline values (p less than 0.01). In 13 of these 18 MPA-treated patients who did not improve compared to 1/6 EPI-treated patients who did not improve, PEFRs were greater than 120 L/min, and PEFR and FEV1 had increased 20% or more above baseline values after treatment with the crossover comparison regimen (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of aminophylline when added to metaproterenol sulfate and beclomethasone dipropionate aerosol

Twenty-one patients with frequently recurrent severe asthma were treated for 2 wk with placebo capsules and metaproterenol sulfate aerosol therapy followed by beclomethasone dipropionate aerosol therapy sequentially inhaled every 4 to 6 hr and for 2 wk with the same aerosols and aminophylline therapy added. Treatment was double-blind, and the therapy regimens were administered in a random sequence. Patients measured their PEFR at home before and after aerosol inhalation three times a day. The mean PEFRs before inhalation of aerosol were significantly higher when patients were receiving aminophylline therapy. In 86% of the patients, the mean PEFR that was measured after inhalation of metaproterenol sulfate was 11% greater when they were also receiving aminophylline therapy, but this difference was not significant. In 14% of the patients, however, postaerosol inhalation PEFRs were significantly higher (50% to 80%) after aminophylline therapy was added to aerosol therapy. PEFRs were always lowest in the early morning, regardless of the therapy administered. Therapy regimens that contained aminophylline were associated with less dyspnea but produced more adverse side effects and were more costly. Thus in most patients the favorable effect that aminophylline therapy produced by raising baseline PEFRs and attenuating dyspnea should be balanced against the adverse effects this medication also produced, since in most patients aminophylline therapy did not significantly enhance postinhalation PEFRs.

Obstructive sleep apnea and world trade center exposure

Objectives: To describe the proportion of at-risk World Trade Center (WTC)-exposed rescue/recovery workers with polysomnogram-confirmed obstructive sleep apnea (OSA) and examine the relationship between WTC exposure, physician-diagnosed gastroesophageal reflux disease (GERD), and rhinosinusitis and OSA. Methods: A total of 636 male participants completed polysomnography from September 24, 2010, to September 23, 2012. Obstructive sleep apnea was classified as mild, moderate, or severe. Associations were tested using nominal polytomous logistic regression. Results: Eighty-one percent of workers were diagnosed with OSA. Using logistic regression models, severe OSA was associated with WTC exposure on September 11, 2001 (odds ratio, 1.91; 95% confidence interval, 1.15 to 3.17), GERD (odds ratio, 2.75; 95% confidence interval, 1.33 to 5.70), and comorbid GERD/rhinosinusitis (odds ratio, 2.31; 95% confidence interval, 1.22 to 4.40). Conclusions: We found significant associations between severe OSA and WTC exposure, and with diseases prevalent in this population. Accordingly, we recommend clinical evaluation, including polysomnography, for patients with high WTC exposure, other OSA risk factors, and a physician diagnosis of GERD or comorbid GERD and rhinosinusitis.