Clinical Pearls

Often, the little things necessary to carry out effective spinal anesthesia are unstated because they somehow seem less important than the broader issues, such as the incidence of neurologic complications after spinal anesthesia. Nevertheless, the little things often spell the difference between successful use of the technique and failure.

The successful integration of neuraxial blocks into an anesthesia practice requires that anesthesiologists be willing to supplement their blocks with CNS depressants.^[108] A concept has developed that a regional anesthetic should need no supplementation, and if it does, it should be considered a failed block. This reasoning needs rethinking. For example, an anesthesiologist would not be expected to pick an arbitrary concentration of an inhaled agent before a general anesthetic and, on discovering that the concentration needs to be altered during the anesthetic, consider the technique a failure! Likewise, supplementation of a spinal or epidural anesthetic contributes to its comprehensive use and should not be a marker of failed blocks. After this concept is accepted, neuraxial blocks can be adapted to many more situations, allowing an anesthesiologist's experience and confidence with the techniques to grow.

To prevent prolongation of a patient's recovery room stay and therefore unnecessarily introduce institutional inefficiency, inpatients should be allowed to leave the recovery room after spinal anesthesia after it can be demonstrated that their block is receding appropriately (at least four dermatomes' regression or a spinal level of less than T10), they are hemodynamically stable, and they are comfortable. After spinal anesthesia, outpatients should be able to ambulate without orthostatic changes and void before their discharge (see Chapter 68 ).

Intraoperatively, during high spinal anesthesia, patients occasionally complain excessively about dyspnea. This is not a result of significantly decreased inspiratory capacity but most often seems related to loss of chest wall sensation, which does not allow patients to experience the reassurance of a deep breath. This impediment to patient acceptance can often be overcome by instructing the patients to raise a hand near the mouth and exhale forcefully. The tactile appreciation of the deep breath seems to provide reassurance.

If a neurologic complication is identified after an operation performed with spinal anesthesia, it is useful to obtain neurologic consultation early, so that an unbiased consultant can examine the patient and determine whether the "new" neurologic finding was preexistent, related to a peripheral neuropathy, or more rarely, potentially related to the spinal anesthetic. The latency in electromyographic alterations associated with denervation due to neurologic injury takes time (14 to 21 days) to develop in the lower extremities. The physician should obtain electromyographic studies early and serially after a potential spinal anesthetic-related lesion. In this manner, it is possible to document whether the lesion was preexisting or provide evidence that it is a peripheral rather than central lesion.

Probably more important than any single factor for the success of spinal anesthesia in the day-to-day use of anesthesia is that it must be time efficient. It cannot add measurably to the surgical day if nurses and surgeons are to be coadvocates of the technique. The physician should plan ahead to maximize time efficiency. Often overlooked is that the patient preparation for surgery can begin almost as soon as the block is administered if patient sedation is at an appropriate level.