7.蛛网膜下腔麻醉的坐姿方法

Sitting approach for spinal anesthesia. The patient is instructed to sit on the edge of the stretcher or operating table with the feet supported on a stool or bench that allows for more flexion of the lumbar spine. The shoulders are hunched forward, again contributing to increased flexion of the spine. Frequently, an assistant is needed to help the patient maintain this position and to monitor and provide support for the patient who has been given some sedation. This approach is particularly useful in the patient who is overweight in whom the midline is difficult to appreciate in a standard lateral decubitus position.

8.蛛网膜下腔麻醉折刀状卧位

Spinal anesthesia in the jackknife position. The patient is placed in the prone position on the operating table. The table is then flexed to a maximum degree and turned in a slight head-down direction. The flexion point of the table should be directly under the patient's hips. The use of a pillow under the hips helps accentuate the flexion. The needle then can be introduced using the standard midline or paramedian approaches. Spinal fluid pressure is often negative in this area, and gentle aspiration may be needed to confirm identification of the subarachnoid space. Injection of a hypobaric location anesthetic solution produces excellent anesthesia for rectal procedures.

9.通过钝化的硬膜外注射针标记的硬膜外导管的螺化

A marked epidural catheter being threaded through an etched epidural needle ( A and

. This

arrangement enables one to determine the distance a catheter is threaded into the epidural space. The distance at which loss of resistance is achieved is noted on the epidural needle, thus determining the distance between the skin and the epidural space. The epidural catheter is then threaded through the needle until a length of 4 to 5 cm is advanced into the epidural space. After removal of the epidural needle, the catheter is withdrawn until 2 to 4 cm of catheter length remains within the epidural space. This measurement is determined by adding 2 to 4 cm to the number of centimeters representing the skin-to-epidural space distance. For example, if loss of resistance is attained at 5 cm and the epidural catheter is withdrawn to the 8-cm mark, then 3 cm of catheter remains within the epidural space.