Retrospective investigation of pulmonary resection in patients with high total pulmonary vascular resistance during preoperative unilateral pulmonary artery occlusion.

PURPOSE: The aim of this study was to evaluate the indications for pulmonary resection (lobectomy) in patients with increased total pulmonary vascular resistance (TPVR) during a preoperative unilateral pulmonary artery occlusion (UPAO) test. According to our previous report, the feasibility of performing lobectomy in patients with a high risk of cardiopulmonary complications is determined on the basis of the increase in TPVR after 15 min of obstruction during the UPAO test (occluded TPVR). METHODS: A total of 19 high-risk [occluded TPVR > or =700 dynes/s/cm(-5)/m(2) (dynes)] patients who underwent lobectomy or pneumonectomy were studied and a detailed analysis of postoperative cardiopulmonary complications was performed. The subjects were divided into four groups based on the occluded TPVR (700-799 dynes, 800-899 dynes, 900-999 dynes, or > or =1000 dynes) to compare the incidence of postoperative complications. RESULTS: Two patients died after surgery. One of them had an occluded TPVR >1000 dynes and died 313 days after right upper lobectomy; the other had an occluded TPVR of 783 dynes and died 20 days after right pneumonectomy. Postoperative cardiopulmonary complications occurred in 6 of 19 patients (31.6%), and all three patients with an occluded TPVR > or =900 dynes developed cardiopulmonary complications. CONCLUSION: Limited surgery should be performed in patients with an occluded TPVR > or =900 dynes.

Changes in A-type natriuretic peptide and its receptors induced by a neutral endopeptidase inhibitor in a rat model of sepsis.

PURPOSE: Elevated plasma A-type natriuretic peptide (ANP) levels in sepsis cause fluid transfer into extravascular spaces. We investigated the changes in ANP concentrations and natriuretic peptide receptor (NPR) expression induced by thiorphan, a neutral endopeptidase (NEP) inhibitor, in a rat model of sepsis. METHODS: Fifteen male rats were divided into three groups: a control group (n = 5), a lipopolysaccharide (LPS) group (n = 5), and an LPS-thiorphan group (n = 5). We measured ANP concentrations in the plasma and lung, and NPR mRNA expression in the lung 4 h after administering LPS, and compared the values with those in the control group. RESULTS: Plasma and lung ANP levels in the LPS group were significantly higher than those in the control group (P < 0.05), but were significantly decreased by thiorphan administration (P < 0.05). NPR-A mRNA levels did not differ significantly among the groups. NPR-C mRNA levels in the LPS-thiorphan group were significantly higher than those in the other groups (P < 0.05). CONCLUSIONS: Elevated ANP levels were decreased by thiorphan administration, which increased NPR-C mRNA levels in the lung. Thus, thiorphan might be effective for reducing elevated ANP levels in sepsis.

Long-term recovery of exercise capacity and pulmonary function after lobectomy.

OBJECTIVE: The objective of the present study was to perform longitudinal objective evaluations of recovery of exercise capacity based on expired gas analysis during exercise testing up to 1 year after pulmonary resection. METHODS: The study included 18 patients who underwent lobectomy. Expired gas analysis during exercise testing was conducted 1 week before surgery and 2 weeks, 1 month, 3 months, 6 months, and 1 year after surgery. The parameters studied included maximum exercise capacity based on expired gas analysis during exercise testing (maximum oxygen uptake per minute per square meter of body surface area) and assessment of moderate exercise capacity (anaerobic threshold per square meter of body surface area). The changes in postoperative data relative to the preoperative values (baseline) were assessed, including the percent changes from baseline data, which were arbitrarily given a value of 100. RESULTS: Maximum oxygen uptake per minute per square meter of body surface area decreased significantly to 78.6% +/- 14.2% of the baseline value at 2 weeks after surgery and was 80.3% +/- 12.7%, 90.9% +/- 15.9%, 90% +/- 19.7%, and 97% +/- 4.8% of the baseline value at 1, 3, and 6 months, and 1 year, respectively. Anaerobic threshold per square meter of body surface area reached 91.1% +/- 17.5% of the baseline value even 2 weeks after surgery and was 87.1% +/- 17.3%, 97.5% +/- 28.0%, 84.3% +/- 13.2%, and 104% +/- 16.2% of the baseline value at 1, 3, and 6 months, and 1 year, respectively. CONCLUSION: The extent of recovery of exercise capacity at 1 year after surgery was approximately 95%. Furthermore, the anaerobic threshold per square meter of body surface area was restored to the preoperative level by 1 year after surgery.