tailieunhanh - Oxford Handbook of Critical Care - part 3

Ngộ độc xyanua nặng có một khởi đầu cực kỳ nhanh chóng và xảy ra ở một số trường hợp hít phải khói. Survival có thể được kết hợp với tổn thương não thiếu ôxy. Chẩn đoán phải được thực hiện cl inically từ một mức độ máu cyanide có 3 giờ để thực hiện. | Pulmonary artery catheter insertion Insertion 1. Insert 8Fr central venous introducer sheath under strict aseptic technique. Pulmonary artery catheterisation is easier via internal jugular or subclavian veins. 2. Prepare catheter pre-insertion 3-way taps on all lumens flush lumens with crystalloid inflate balloon with air and check for concentric inflation and leaks place transparent sleeve over catheter to maintain future sterility pressure transduce distal lumen and zero to a reference point usually mid-axillary line . Depending on catheter type other pre-insertion calibration steps may be required . oxygen saturation. 3. Insert catheter 15cm . beyond the length of the introducer sheath before inflating balloon. Advance catheter smoothly through the right heart chambers. Pause to record pressures and note waveform shape in RA RV and PA. When a characteristic PAWP waveform is obtained stop advancing catheter deflate balloon and ensure that PA waveform reappears. If not withdraw catheter by a few cm. 4. Slowly re-inflate balloon observing waveform trace. The wedge recording should not be obtained until at least of air has been injected into the balloon. If not withdraw catheter 1-2cm and repeat. If overwedged pressure continues to climb on inflation catheter is inserted too far and balloon has inflated forward over distal lumen. Immediately deflate withdraw catheter 1-2cm and repeat. 5. After insertion a CXR is usually performed to verify catheter position and to exclude pneumothorax. Con traindica tions cautions Coagulopathy Tricuspid valve prosthesis or disease Complica tions Problems of central venous catheterisation Arrhythmias especially when traversing tricuspid valve Infection including endocarditis Pulmonary artery rupture Pulmonary infarction Knotting of catheter Valve damage do not withdraw catheter unless balloon deflated Troubleshooting Excessive catheter length in a heart chamber causes coiling and a risk of knotting. No more .