Hemodynamic Monitoring In The Cardiac Surgical Patient: Comparison of Three Arterial Catheters

Abstract

ObjectiveSystemic systolic (SAP) and mean (MAP) arterial pressure monitoring is the cornerstone in hemodynamic management of the cardiac surgical patient and the radial artery is the most common site of catheter placement. The present study compares three different arterial line procedures. It is hypothesized that a 20-G 12.7cm catheter inserted in the radial artery will be equal to 20-G 12.7cm angiocath placed in the brachial artery, and superior to a 20-G 5.0cm angiocath placed in the radial artery. DesignA prospective randomized control was performed. SettingSingle Academic University Hospital ParticipantsAdult patients ≥ 18 years old undergoing non-emergent cardiac surgery utilizing cardiopulmonary bypass. InterventionsAfter approval by the Rhode Island Hospital institutional review board, a randomized prospective control study to evaluate three different peripheral intra-arterial catheter systems was performed: 1) Radial Short (RS). 20-G 5cm catheter, 2) Radial Long (RL): 20-G 12cm catheter, 3) Brachial Long (BL): 20-G 12cm catheter. Measurements&ResultsGradients between central aortic and peripheral catheters (CA-P) were compared and analyzed prior to CPB, and 2 and 10 minutes after separation from CPB. The placement of femoral arterial lines, and administration of vasoactive medications were recorded. After exclusions 67 BL, 61 RL, and 66 RS patients were compared. Prior to CPB CA-P SAP and MAP gradients were not significant among the three groups. Two minutes after CPB the CA-P SAP gradient was significant for the RS group (p=0.005) and insignificant for BL (p=0.47) and RL (p=0.39). Two-group analysis reveal that CA-P SAP gradients are similar between BL and RL (p=0.84), both of which were superior to RS (p=0.02 and p=0.04 resp.). At 10 minutes after CPB, the CA-P SAP gradient for RS remained significant (p=0.004) and similar to the gradient at 2 minutes. The CA-P SAP gradients increased from 2 to 10 minutes for BL (p=0.13) and RL (p=0.06). Two minutes after CPB the CA-P MAP gradients are significant for BL(p=0.003), RL(p< 0.0001), and RS(p< 0.0001) groups. Two-group analysis reveal that the CA-P MAP gradients were lower for the BL group compared to RL (p=0.054) and RS (p< 0.05) groups. Ten minutes after CPB, the CA-P MAP gradients in the RL and RS groups remained significant (p< 0.0001) and both greater than the BL group (p=0.002). A femoral arterial line was placed more frequently in the RS group (8/66=12.1%), than RL group (3/61=4.9%), and the BL group (2/67=3.0%). Vasopressin was administered significantly more frequently in the RS group… ConclusionRegarding CA-P SAP gradients, the RL group performed equally to the BL group, both being superior to RS. Regarding CA-P MAP gradients BL was superior to RL and RS. Clinically, femoral line placement and vasopressin administration was less for the BL and RL groups when compared to the RS group. This study demonstrates the benefits of a long (12.7cm) 20 G angiocath placed in the radial artery.