Spinal anaesthesia: local anaesthetics and adjuncts in the ambulatory setting

Pudendal nerve block (PNB): a safe, simple and effective approach in surgical proctological patients

BACKGROUND

Pudendal nerve block (PNB) is commonly used in pudendal neuralgia (PN) and as an anaesthesiological technique in obstetrical and urological procedures. The purpose of this retrospective study was to compare the efficacy of PNB with other anaesthesiolocal techniques in proctological surgery.

METHODS

A total of 362 patients were seen from a 22 months time interval. Surgical indication was placed after a conservative therapy. 78 patients underwent surgery: 42 with spinal anaesthesia with PNB and 36 with PNB alone according to their anatomical characteristics. All the patients underwent PNB in lithotomy position and with a perirectal approach. The success rate of PNB was evaluated in post operative pain control with the VAS score, after the first and the second evacuation. The follow up also included a third check on the seventh day after surgery.

RESULTS

In post operative period, the mean VAS score found after the first evacuation in patients undergoing PNB was 2.66, after the second evacuation was 1.55, while the VAS score on the seventh day was 0.38. The mean VAS score in the group who underwent spinal anaesthesia and PNB were respectively 3.71 and 1.80 after the first and second evacuation. The VAS score calculated on the seventh day was 0.50. There were no statistically significant differences in the VAS score between the 2 groups (P >0.05).

CONCLUSIONS

PNB may be a valid alternative to spinal anaesthesia in proctological patients. PNB has proven to be both safe and effective technique.

[Spinal anaesthesia in day-case surgery. Optimisation of procedures]

BACKGROUND

Since prilocaine is being increasingly used for day case surgery as a short acting local anaesthetic for spinal anaesthesia and because of its low risk for transient neurological symptoms, we compared it to bupivacaine.

PATIENTS AND METHODS

Patients (n=88) who were scheduled for lower limb surgery with spinal anaesthesia randomly received 15 mg hyperbaric bupivacaine 0.5% or 60 mg hyperbaric prilocaine 2% (administered in a sitting position). Onset time, intensity, duration of the sensomotoric block, vital parameters and time of spontaneous miction were recorded and patients were questioned on satisfaction with the anaesthesia procedure and the occurrence of adverse side-effects after 24 h.

RESULTS

Bupivacaine caused a significantly higher sensory block than prilocaine (T6 vs. T8). Both groups were similar in reaching an analgesic level of at least T12, block intensity and onset times. Median analgesic levels at T12 were maintained for 60 min with prilocaine versus 120 min with bupivacaine, regression of the motor block was 135 min versus 210 min, sensory block S1 was 240 min versus 360 min, and time for spontaneous miction was 306 min versus 405 min, respectively (differences for all comparisons were statistically significant).

CONCLUSION

Under the present study conditions, hyperbaric prilocaine 2% was superior to hyperbaric bupivacaine 0.5% due to a shorter effect profile but otherwise equivalent quality of block. However, puncture in a sitting position and positioning with elevated torso for restriction of the cranial expansion of block spread might cause an enhanced sacral block with delayed recovery of bladder function.

Regional Anaesthesia in the Elderly

The number of elderly patients presenting for anaesthesia and surgery has increased exponentially in recent years. Regional anaesthesia is frequently used in elderly patients undergoing surgery. Although the type of anaesthesia (general versus regional anaesthesia) has no substantial effect on perioperative morbidity and mortality in any age group; it intuitively makes sense that elderly patients would benefit from regional anaesthesia because they remain minimally sedated throughout the procedures and awaken with excellent postoperative pain control. However, a multitude of factors influence the outcome, such as the type, duration and invasiveness of the operation, co-existing medical and mental status of the patient and the skill and expertise of the anaesthesiologist and surgeon. These factors make it difficult to decide if and when one technique is equivocally better than another. Thus, it is more important to optimise the overall management of the patient during the perioperative period and, in most cases, it is the quality of the anaesthetic administered rather than the type of anaesthetic which is most important. Sedatives used for regional anaesthesia in the elderly should be short acting, easy to administer, have a low adverse effect profile and high safety margin. Midazolam, lorazepam, ketamine, propofol and low-dose opioids have been successfully used for sedation in the elderly. Aging affects the pharmacokinetics and pharmacodynamics of local anaesthetics, composition and characteristics of tissues and organs within the body, and physiological functions of the body. Changes in the systematic absorption, distribution and clearance of local anaesthetics lead to an increased sensitivity, decreased dose requirement and a change in the onset and duration of action in the elderly. Decreases in neural population, neural conduction velocity and inter-Schwann cell distance can lead to an increased sensitivity to local anaesthetics in the elderly. The addition of an opioid and epinephrine (adrenaline) has been shown to be useful in central neuraxial blockade. Epinephrine also can prolong the duration of peripheral nerve blocks. However, caution must be exercised as epinephrine has the potential for causing ischaemic neurotoxicity in peripheral nerves. Regional anaesthesia appears to be safe and beneficial in elderly patients; however, every anaesthetic administered must be assessed on a case-by-case basis and particular consideration should be given to the health status of the patient, the operation being performed and the expertise of the anaesthesiologist.

Regional anaesthesia in ambulatory surgery

PURPOSE OF REVIEW

The purpose of this review is to present recent research into the clinical use of regional anaesthesia techniques in ambulatory surgery. Further, to put into an ambulatory perspective some of the issues recently discussed on the basis and practice of regional anaesthesia in general.

RECENT FINDINGS

Early discharge with long-acting peripheral nerve blockade seems safe, and discharge of patients who have not voided after surgery is possible under specified terms. The spinal anaesthesia technique may be improved in terms of better and faster recovery characteristics if the dose of local anaesthesia is reduced by adding a small dose of opioid.

SUMMARY

Loco-regional techniques are well suited for ambulatory surgery due to less postoperative nausea and pain and possibly less cognitive dysfunction. The different techniques are continuously being refined in order to provide fast discharge readiness, while still maintaining the benefits.