Dialysis catheter malposition: blood gas analysis provides a clue

Correspondence to Dr Hannah Victoria Reynolds; hannah.reynolds@health.qld.gov.au Description Following surgical debridement for Fournier’s gangrene, a morbidly obese man (250 kg, Body Mass Index 87 kg/m2) was admitted to the intensive care unit (ICU) in septic shock and multiorgan failure. With the advent of bedside ultrasound and improved training, malposition of a central venous access device has been reduced but not eliminated.1 Confirming the position (or detecting malposition) of a central venous catheter may involve a conventional chest radiograph, transducing pressures or blood gas analysis on a sample from the catheter. In the literature, the incidence of partial anomalous pulmonary venous connections (PAPVC) are reported to be between 0.4% and 0.7%.2 3 Although dependent on the shunt fraction, the presence of a PAPVC is usually asymptomatic and its diagnosis is usually incidental during other investigations.4 In the critical care setting, incidental diagnosis of a partial anomalous pulmonary venous connections during dialysis catheter insertion has been well described5–7 but the utility of blood gas analysis to provide early insight to the diagnosis less so.8 Furthermore, this case highlights the benefits of accessing interventional radiology to both clarify the exact position and relocation for patients with limited other access sites.