Prognostic role of minute ventilation/carbon dioxide production slope for perioperative morbidity and long-term survival in resectable patients with nonsmall-cell lung cancer: a prospective study using propensity score overlap weighting.

BACKGROUND: The role of minute ventilation/carbon dioxide production ( / CO 2 ) slope, a ventilation efficiency marker, in predicting short-term and long-term health outcomes for patients with nonsmall-cell lung cancer (NSCLC) undergoing lung resection has not been well investigated. MATERIAL AND METHODS: This prospective cohort study consecutively enrolled NSCLC patients who underwent a presurgical cardiopulmonary exercise test from November 2014 to December 2019. The association of / CO 2 slope with relapse-free survival (RFS), overall survival (OS), and perioperative mortality was evaluated using the Cox proportional hazards and logistic models. Covariates were adjusted using propensity score overlap weighting. The optimal cut-off point of the E/ CO 2 slope was estimated using the receiver operating characteristics curve. Internal validation was completed through bootstrap resampling. RESULTS: A cohort of 895 patients [median age (interquartile range), 59 (13) years; 62.5% male] was followed for a median of 40 (range, 1-85) months. Throughout the study, there were 247 relapses or deaths and 156 perioperative complications. The incidence rates per 1000 person-years for relapses or deaths were 108.8 and 79.6 among patients with high and low E/ CO 2 slopes, respectively [weighted incidence rate difference per 1000 person-years, 29.21 (95% CI, 7.30-51.12)]. A E/ CO 2 slope of greater than or equal to 31 was associated with shorter RFS [hazard ratio for relapse or death, 1.38 (95% CI, 1.02-1.88), P =0.04] and poorer OS [hazard ratio for death, 1.69 (1.15-2.48), P =0.02] compared to a lower / CO 2 slope. A high E/ CO 2 slope increased the risk of perioperative morbidity compared with a low E/ CO 2 slope [odds ratio, 2.32 (1.54-3.49), P <0.001]. CONCLUSIONS: In patients with operable NSCLC, a high E/ CO 2 slope was significantly associated with elevated risks of poorer RFS, OS, and perioperative morbidity.

Respiratory morbidity, healthcare utilisation and cost of care at school age related to home oxygen status.

UNLABELLED: The aim of the study was to determine whether respiratory morbidity, lung function, healthcare utilisation and cost of care at school age in prematurely born children who had bronchopulmonary dysplasia (BPD) were influenced by use of supplementary oxygen at home after neonatal intensive care unit discharge. Healthcare utilisation and cost of care in years 5 to 7 and respiratory morbidity (parent-completed respiratory questionnaire) and lung function measurements at least at age 8 years were assessed in 160 children. Their median gestational age was 27 (range 22-31) weeks and 65 of them had received supplementary oxygen when discharged home (home oxygen group). The home oxygen group had more outpatient attendances (p = 0.0168) and respiratory-related outpatient attendances (p = 0.0032) with greater related cost of care (p = 0.0186 and p = 0.0030, respectively), their cost of care for prescriptions (p = 0.0409) and total respiratory related cost of care (p = 0.0354) were significantly greater. There were, however, no significant differences in cough, wheeze or lung function results between the two groups. CONCLUSION: Prematurely born children who had BPD and supplementary oxygen at home after discharge had increased healthcare utilisation at school age. Whether such children require greater follow, in the absence of excess respiratory morbidity, merits investigation.

Lung gas transfer in children with sickle cell anaemia.

The impact of sickle cell anaemia (SCA) on respiratory function of children must be determined if their management is to be optimised. Pulmonary diffusing capacity (DL(CO)), corrected for haemoglobin (DL(COc)), therefore was assessed in 24 children with SCA and 24 ethnic matched controls, mean age 11 (range 7-16) years. To determine if any differences found correlated with other measures of lung function, spirometry was undertaken and lung volumes assessed. The SCA children compared to the controls had lower weight (p=0.01), body mass index (p=0.002), DL(CO) (p<0.0001), K(CO) (p=0.003), V(CSB) (p=0.01), FEV(1) (p<0.0001) and FVC (p<0.0001), but greater K(COc) (p=0.001). K(COc) results correlated significantly with PEF (r=-0.58, p=0.02), but not TLC(pleth) (p=0.36), FEV(1) (0.39) or FVC (p=0.36). In conclusion, when corrected for haemoglobin levels, the SCA children compared to controls of similar age had elevated gas transfer per unit lung volume results. Our results suggest this abnormality is independent of other lung function abnormalities.