Characteristics and predictors of mortality of patients with hematologic malignancies requiring invasive mechanical ventilation.

RATIONALE: Acute respiratory failure (ARF) may complicate the course of hematologic malignancies (HMs). Our objective was to study the characteristics, outcomes and predictors of mortality of patients with HMs who required intubation for ARF. METHODS: This retrospective cohort study evaluated all patients with HMs who were admitted to the Intensive Care Unit (ICU) of King Abdul-Aziz Medical City-Riyadh between 2008 and 2013 and required invasive mechanical ventilation. We noted their baseline characteristics, treatments and different outcomes. Multivariable logistic regression analysis was performed to evaluate predictors of hospital mortality. RESULTS: During the 6-year period, 190 patients with HMs were admitted to the ICU and 122 (64.2%) required intubation for ARF. These patients had mean age of 57.2 ± 19.3 years and Acute Physiology and Chronic Health Evaluation II score of 28.0 ± 7.8 and were predominantly males (63.4%). Lymphoma (44.3%) and acute leukemia (38.5%) were the most common hematologic malignancy. Noninvasive ventilation (NIV) was tried in 22 patients (18.0%) but failed. The code status was changed to "Do-Not-Resuscitate" for 39 patients (32.0%) during ICU stay. Hospital mortality was 70.5% and most deaths (81.4%) occurred in the ICU. The mortality of patients with "Do-Not-Resuscitate" status was 97.4%. On multivariable logistic regression analysis, male gender (odds ratio (OR), 6.74; 95% confidence interval (CI), 2.24-20.30), septic shock (OR, 6.61; 95% CI, 1.93-22.66) were independent mortality predictors. Remission status, non-NIV failure and chemotherapy during ICU stay were not associated with mortality. CONCLUSIONS: Patients with HMs requiring intubation had high mortality (70.5%). Male gender and presence of septic shock were independent predictors of mortality.

Calcified small cell carcinoma of the lung.

Calcification within pulmonary lesions usually signifies a benign entity, but depending on the specific pattern of calcification it can also represent malignancy. The authors report a case of calcified small cell lung cancer in a patient with end-stage renal disease. The calcification was unrelated to renal failure and not the result of metastatic calcification, and the pattern of calcification and tissue pathology excluded other causes of calcification within this mediastinal mass.

Impact of adherence with positive airway pressure therapy on hypercapnia in obstructive sleep apnea.

BACKGROUND: Daytime hypercapnia is common in morbidly obese patients with obstructive sleep apnea and is associated with serious complications. Our objective was to quantify the effect of adherence with positive airway pressure on hypercapnia and hypoxia in these patients. METHODS: We performed a retrospective cohort study of 75 patients using a multivariable general linear model analysis to identify variables that predicted changes in PaCO2 and PaO2 after therapy. Bootstrap resampling methods were used to calculate confidence intervals for the effects of significant predictors and to internally validate the predictive models. RESULTS: The variables that predicted the change in PaCO2 were average daily hours of positive pressure therapy, FEV1 percentage of predicted, and baseline PaCO2 (model R(2) = 0.70). The PaCO2 dropped 1.84 mm Hg per hour of adherence and plateaued at 7 hours of average daily use. The PaO2 improved by approximately 3 mm Hg per hour of adherence and plateaued after 4.5 hours of therapy (model R2 = 0.48). Patients who used therapy for more than 4.5 hours per day experienced significant improvements in PaCO2 and PaO2 compared with less-adherent patients (APaCO2 7.7+/-5 vs 2.4+/-4 mm Hg, p < .001; delta PaO2 9.2+/-11 vs 1.8+/-9 mm Hg, p < .001). For adherent patients, the need for daytime home oxygen therapy decreased from 30% to 6% (p = .02). CONCLUSION: In hypercapnic patients with obstructive sleep apnea, adherence with positive airway pressure is an important modifiable predictor of improvements in PaCO2 and PaO2, and its benefit plateaus between 5 and 7 hours of daily therapy.