Inaccuracy of radial artery pressure measurement after cardiac operations

Accuracy of radial arterial pressure measurement during surgery under controlled hypotension

“…Previous studies, in other clinical conditions, have found a significant difference between central and peripheral arterial pressures. An aorto‐radial blood pressure gradient has been demonstrated after cardiopulmonary bypass in patients undergoing cardiac surgery (7–9). This has been explained by an intense vasodilation of the upper extremities and by an inadequate filling of the low peripheral arterial tree induced by hypovolemia, hemodilution and thermoregulatory mechanisms (7, 13, 14).…”

“…An aorto‐radial blood pressure gradient has been demonstrated after cardiopulmonary bypass in patients undergoing cardiac surgery (7–9). This has been explained by an intense vasodilation of the upper extremities and by an inadequate filling of the low peripheral arterial tree induced by hypovolemia, hemodilution and thermoregulatory mechanisms (7, 13, 14). A similar femoral‐to‐radial pressure gradient has also been found in sceptic shock (10), during cardiopulmonary resuscitation (11) and in human volunteers during thermoregulatory vasodilation (12).…”

“…A similar femoral‐to‐radial pressure gradient has also been found in sceptic shock (10), during cardiopulmonary resuscitation (11) and in human volunteers during thermoregulatory vasodilation (12). In all these clinical conditions, it has been suggested that radial arterial pressure measurement may not be adequate for efficient clinical management (7–12).…”

“…However, radial arterial pressure may underestimate the pressure in the aorta and in the proximal arteries. A central‐to‐radial blood pressure gradient has been documented after cardiopulmonary bypass (7–9), in septic shock (10), during cardiopulmonary resuscitation (11) and in human volunteers during thermoregulatory vasodilation (12). The difference between aortic and radial pressures was attributed to active vasodilation and increased flow of blood through arteriovenous shunts in the hand (8, 12–14).…”

The effect of haemodynamic and peripheral vascular variability on cardiac output monitoring: thermodilution and non‐invasive pulse contour cardiac output during cardiothoracic surgery

“…Non‐invasive arterial pressure CO was compared with invasive arterial pressure CO to determine whether the non‐invasive method introduced variability (some notes on assessing the agreement of methodologies are given in Data S3, section ‘Considerations on comparison of cardiac output methods’). The data after extracorporeal circulation (‘after pump’) were considered to contain additional variability, since peripheral arterial pressure may be less representative of central pressure . Moreover, the temperature drift caused by the rewarming of the subject may render thermodilution CO erratic.…”