Percutaneous radial artery cannulation. (A) The wrist is positioned and the artery identified by palpation. (The catheter-over-needle assembly is introduced through the skin and advanced toward the artery. (C) Entry of the needle tip into the artery is identified by the flash of arterial blood in the needle hub reservoir. (D) Needle-catheter assembly is advanced at a lower angle to assure entry of the catheter tip into the vessel. (E) If blood flow continues into the needle reservoir, the catheter is advanced gently over the needle into the artery. (F) The catheter is attached to pressure monitoring tubing while maintaining proximal occlusive pressure on the artery. See text for greater detail.
Salvaging arterial cannulation. (A) When blood flow into the needle reservoir ceases, the needle tip has exited the vessel lumen. (The needle tip is withdrawn several millimeters so that the catheter tip becomes the leading edge of the needle-catheter assembly and arterial blood flow reappears in the collection reservoir. (C) When arterial blood flow is reestablished, the catheter is advanced into the arterial lumen.
Salvaging arterial cannulation (II). (A) When blood flow into the needle reservoir ceases, both the needle tip and catheter tip may have exited the vessel lumen. (The needle tip is withdrawn several millimeters so that the catheter tip becomes the leading edge of the needle-catheter assembly. (C) If arterial blood flow does not reappear in the collection reservoir, the entire needle catheter assembly is now withdrawn, allowing the catheter tip to reenter the vessel as the leading edge. This is confirmed by the reappearance of arterial blood flow in the collection reservoir. (D) When arterial blood flow has been reestablished, the catheter is advanced into the arterial lumen.
Using a guide wire to aid arterial cannulation. (A) A catheter may not thread into a tortuous artery. (The needle is removed from the catheter, and a guide wire is advanced through the catheter into the artery. (C) The catheter is advanced over the guide wire into the arte-rial lumen.
Arterial cannulation using an integrated needle–guide-wire–catheter assembly. (A) The artery is identified by a flash of arterial blood into the collection reservoir as the needle tip enters the vessel. (The guide wire is advanced through the needle into the vessel lumen. (C) The catheter is advanced over the guide wire.
股动脉桡动脉在CPB中的比较
Arterial pressure gradients following cardiopulmonary bypass. (A) Femoral and radial artery pressure traces recorded 2 minutes after bypass (2 min postbypass), when radial artery pressure underestimates the more centrally measured femoral artery pressure and 30 minutes later (30 min postbypass), when radial and femoral arterial pressures have been equalized and radial pressure has assumed a more typical morphology. Note that dicrotic notch (arrows) is visible in the femoral pressure trace after bypass, but not initially in the radial pressure trace. (Femoral and radial artery pressure traces recorded before cardiopulmonary bypass (prebypass), two minutes following bypass (2 min postbypass), and 30 minutes following bypass (30 min postbypass). Note changing relationship between femoral and radial artery pressure measurements at these different times. See text for greater detail.