Deceptive jugular manometry, blood colour and Po2 in the presence of an ipsilateral upper extremity arteriovenous fistula: a report of two cases

Manometry, blood gas analysis and colour of blood are often used as adjuncts to verify central venous access and rule out inadvertent arterial puncture. Several clinical scenarios may make these techniques unreliable. Two cases are presented involving patients with mature upper arm arteriovenous fistulas in which techniques to confirm correct central venous access contradicted ultrasound imaging findings.