Drug-induced pulmonary arterial hypertension: a review.

Pulmonary arterial hypertension (PAH) is a subgroup of PH patients characterized hemodynamically by the presence of pre-capillary PH, defined by a pulmonary artery wedge pressure (PAWP) ≤15 mmHg and a PVR >3 Wood units (WU) in the absence of other causes of pre-capillary PH. According to the current classification, PAH can be associated with exposure to certain drugs or toxins such as anorectic agents, amphetamines, or selective serotonin reuptake inhibitors. With the improvement in awareness and recognition of the drug-induced PAH, it allowed the identification of additional drugs associated with an increased risk for the development of PAH. The supposed mechanism is an increase in the serotonin levels or activation of serotonin receptors that has been demonstrated to act as a growth factor for the pulmonary artery smooth muscle cells and cause progressive obliteration of the pulmonary vasculature. PAH remains a rare complication of several drugs, suggesting possible individual susceptibility, and further studies are needed to identify patients at risk of drug-induced PAH.

Heparin dosing in critically ill patients undergoing therapeutic hypothermia following cardiac arrest.

PURPOSE: To determine the effects of anticoagulation with intravenous unfractionated heparin (IVUH) during therapeutic hypothermia (TH) post-cardiac arrest. METHODS: Single-center, retrospective, observational trial in the intensive care units of two hospitals within the Detroit Medical Center. Unresponsive survivors of cardiac arrest, receiving treatment doses of IVUH during TH were included. Patients were required to have at least 1 measured activated partial thromboplastin time (aPTT) during TH. Coagulation parameters were collected at 3 distinct temperature phases: baseline, TH, and post-re-warming (±37 °C) target aPTT defined as 1.5-2 times baseline. RESULTS: Forty-six patients received IVUH during TH, with 211 aPTTs. Heparin starting rate was 13±4 units/kg/h. Average baseline, TH and post-TH aPTT were 34±12, 142±48, and 56±17 s, respectively. Using standard dosing strategies, initial aPTT was above the target range in 89% of patients. After re-warming, aPTT significantly decreased (142±48s vs. 56±17 s, p=0.005), and heparin dose significantly increased (7.9±3 vs. 9±4 units/kg/h, p<0.001). There was a significant difference between aPTT among all three groups, and heparin dose between TH and post-TH even after correcting for age, sex, body mass index, heparin rate, and APACHE II score (p<0.001). Three patients experienced a major bleeding event. CONCLUSIONS: Current dosing protocols for IVUH should not be utilized during TH. Heparin requirements are drastically reduced during TH and prolonged interruptions may be required to allow for adequate clearance of UH.

Distance saturation product predicts health-related quality of life among sarcoidosis patients.

BACKGROUND: Sarcoidosis is a chronic disease with different phenotypic manifestations. Health-related quality of life is an important aspect in sarcoidosis, yet difficult to measure. The objective of this study was to identify clinical markers predictive of poor quality of life in sarcoidosis patients that can be followed over time and targeted for intervention. METHODS: We assessed the quality of life of 162 patients with confirmed sarcoidosis in a prospective, cross-sectional study using the Sarcoidosis Health Questionnaire (SHQ) and Short Form-36 Health Survey (SF-36). We evaluated the validity of these questionnaires and sought to identify variables that would best explain the performance scores of the patients. RESULTS: On multivariate regression analyses, the very best composite model to predict total scores from both surveys was a model containing the distance-saturation product and Borg Dyspnea Scale score at the end of a 6-min walk test. This model could better predict SF-36 scores (R² = 0.33) than SHQ scores (R² = 0.24). Substitution of distanced walked in 6 min for the distance-saturation product in this model resulted in a lesser ability to predict both scores (R² = 0.26 for SF-36; R² = 0.22 for SHQ). CONCLUSIONS: Both the SHQ and SF-36 surveys are valuable tools in the assessment of health-related quality of life in sarcoidosis patients. The best model to predict quality of life among these patients, as determined by regression analyses, included the distance-saturation product and Borg score after the 6-min walk test. Both variables represent easily obtainable clinical parameters that can be followed over time and targeted for intervention.