The three biological gaps and hyperoxaluria in ethylene glycol poisoning: case presentation and review.

Ethylene glycol is a toxic alcohol which may induce significant toxicity when ingested accidentally or intentionally. The main clinical complications of EG poisoning include central nervous system depression, cardiorespiratory instability and renal failure, which may be lethal if improperly treated. Although the demonstration of high plasma levels of ethylene glycol confirms the intoxication, such measurements are generally not obtained in the acute setting and can be misleading due to the rapid metabolism of EG. This implies the need for alternative, indirect, diagnostic methods, which reflect the metabolic fate of EG. These include an early and transient osmolar gap, followed by an anion gap metabolic acidosis and hyperoxaluria. Another frequent finding is a lactate gap between various methods of lactate measurements. An appropriate knowledge of these laboratory findings is essential for the diagnosis of EG poisoning, and for the initiation of antidote therapy (fomepizole) and hemodialysis in selected cases. These features are illustrated by the presentation of a prototypical case of EG poisoning, in which an incomplete diagnostic workup on hospital admission resulted in an unnecessary laparotomy and a significant delay in the management of the intoxication.

Video fluoroscopy for pulmonary artery catheter insertion in high-risk situation of knotting or misplacement.

Pulmonary artery catheter (PAC) insertion in patients with severe pulmonary hypertension, right heart dilation and failure, is very challenging. Misplacement and knotting are rare but could be serious complications leading to a delay of the monitoring and sometimes an emergent not expected intervention. Here we report a case of a patient admitted to Intensive Care Unit (ICU) with an acute hypoxemic respiratory failure. She had a history of chronic respiratory failure with pulmonary hypertension and right heart failure. We decided to monitor her cardiac output and pulmonary pressure with a PAC. Repeated attempts to reach the pulmonary artery (PA) were unsuccessful and the PAC was knotted and blocked at the distal tip of the introducer. Under fluoroscopy the knot was released by radiologist. Few days later, a monitoring of PA pressure was needed to guide a PA vasodilator treatment. Under fluoroscopic guidance with the supervision of radiologist, the catheter was successfully placed in the PA at the first attempt. Despite some limitations (patient displacement and radiation), this technique is more accurate than waveform guidance. We suggest in specific situations (low cardiac output, severe pulmonary hypertension, and severe tricuspid regurgitation) to consider first fluoroscopy.