What impact will different puncture positions have on cesarean section anesthesia?

Up to now, cesarean section anesthesia is still mainly spinal anesthesia. Among them, combined spinal-epidural anesthesia occupies an important proportion due to its rapid onset, good muscle relaxation effect and low postoperative complications.

However, the effect of combined spinal-epidural anesthesia is affected by many factors, such as the ratio of spinal anesthesia drugs, the speed of drug injection, and the puncture position of the parturient.

Anesthesiologists who often perform combined spinal-epidural anesthesia have a lot of experience in the ratio of spinal anesthesia drugs and the speed of drug injection. However, some friends may not be too clear about the impact of puncture position.

The puncture position for cesarean section is significantly different from the anesthesia for general surgery because there is a common complication of anesthesia for cesarean section - supine hypotension syndrome.

In order to reduce the incidence of this syndrome, anesthesiologists often use the method of adjusting the operating table to a 30-degree left tilt. However, some anesthesiologists have found that the incidence of this syndrome can be reduced by puncturing in the right lateral position and maintaining the right tilt for 2 minutes and then adjusting the operating table to a 30-degree left tilt.

So, in addition to reducing supine hypotension syndrome, does this make a difference in the anesthetic effect?

Next, we will look at the detailed differences through a clinical study.

Anesthesia method: All puncture operations were performed by the same skilled attending physician. The L3-4 intervertebral space was selected as the puncture point. After the puncture was successful, the spinal anesthesia needle was opened toward the head, and after ensuring that the cerebrospinal fluid could flow out smoothly, the spinal anesthesia drug was injected at a uniform speed within 30 seconds. The anesthetic drug was heavy specific gravity.

The first group underwent right side decubitus puncture, while the second group underwent left side decubitus puncture. After the epidural catheter was fixed, the parturient was placed in a supine position with a 30-degree left tilt. The difference between the two groups was that in the right side decubitus puncture group, the patient needed to remain in a right tilt for 2 minutes after the puncture was completed and then adjust the operating table to a 30-degree left tilt. The operating table was leveled before the operation began.

The results show:

1. The final block plane of the parturients in the right lateral decubitus group was significantly lower than that in the left lateral decubitus group, and the time required to reach the final block plane was significantly shorter than that in the left lateral decubitus group.

2. The amount of ephedrine used in the right lateral decubitus group was significantly lower than that in the left lateral decubitus group.

3. The pH value of umbilical artery blood in the right lateral decubitus group was significantly higher than that in the left lateral decubitus group.

4. There was no statistically significant difference in the Apgar scores of newborns between the two groups.

Overall, right side decubitus puncture has advantages.

So, why is puncture more effective in the right side lying position?

The parturient takes the right side lying position for 2 minutes and then turns to the operating table with a 30-degree left tilt, so that the heavy specific gravity spinal anesthesia can be fully diffused to both sides. Since the drug is distributed on both sides, the anesthesia plane may be slightly lower. At the same time, it also avoids the occurrence of unilateral spinal anesthesia caused by heavy specific gravity.

Will it cause the anesthesia level to be too low?

In fact, the puncture plane in the right lateral decubitus position is only slightly lower than that in the left lateral decubitus position. However, this can also effectively lower the plane to thoracic 4. If the plane reaches thoracic 4, it can block the cardiac sympathetic nerves, causing bradycardia and decreased cardiac output.

Sympathetic blockage will not only cause nausea and vomiting in parturients, but the risk of cardiovascular depression is of greater concern to us. Therefore, is it better to choose right-side puncture? Welcome to leave a message to exchange ~

Qin Haiyan, Department of Anesthesiology, Binzhou People's Hospital

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