ABSTRACT
BACKGROUND: C-type natriuretic peptide (CNP) and its co-product N-terminal proCNP (NTproCNP) have been associated with beneficial effects on the cardiovascular system. In prevalent dialysis patients, however, a relation between NTproCNP and mortality has not yet been investigated. Furthermore, as a middle molecular weight substance, its concentration might be influenced by dialysis modality. METHODS: In a cohort of patients treated with haemodialysis (HD) or haemodiafiltration (HDF), levels of NTproCNP were measured at baseline and 6, 12, 24 and 36 months. The relation between serum NTproCNP and mortality and the relation between the 6-month rate of change of NTproCNP and mortality were analysed using Cox regression models. For the longitudinal analyses, linear mixed models were used. RESULTS: In total, 406 subjects were studied. The median baseline serum NTproCNP was 93 pmol/L and the median follow-up was 2.97 years. No relation between baseline NTproCNP or its rate of change over 6 months and mortality was found. NTproCNP levels remained stable in HD patients, whereas NTproCNP decreased significantly in HDF patients. The relative decline depended on the magnitude of the convection volume. CONCLUSIONS: In our study, levels of NTproCNP appear strongly elevated in prevalent dialysis patients. Second, while NTproCNP remains unaltered in HD patients, its levels decline in individuals treated with HDF, with the decline dependent on the magnitude of the convection volume. Third, NTproCNP is not related to mortality in this population. Thus NTproCNP does not seem to be a useful marker for mortality risk in dialysis patients.
ABSTRACT
We present the case of a 67-year-old male patient, who was admitted to the intensive care unit for hypoxemic respiratory failure due to severe COVID-19 pneumonitis, requiring mechanical ventilation. Despite close monitoring using transpulmonary pressure measurements and interventions to pursue lung-protective ventilation, the patient developed extensive barotrauma including a right-sided pneumothorax, subcutaneous emphysema and pneumomediastinum while on pressure support ventilation. We hypothesize that the high respiratory drive that COVID-19 patients seem to exhibit, combined with diffuse alveolar injury and increased alveolar pressure, resulted in gross barotrauma. CONCLUSION: The respiratory characteristics that COVID-19 patients seem to exhibit might expose those on mechanical ventilation to an increased risk of developing ventilation-induced lung injury. This case emphasizes that caution should be taken in the respiratory treatment of patients with COVID-19 pneumonitis.
