Anaesthetic and haemodynamic effects of continuous spinal versus continuous epidural anaesthesia with prilocaine:

Prilocaine spinal anesthesia for ambulatory surgery: A review of the available studies

Transient neurologic symptoms (TNS) led to the abandonment of intrathecal lidocaine. We reviewed the published literature for information about the duration of action and side effects of intrathecal prilocaine, which has been recently reintroduced in Europe. Medline and EMBASE databases were searched for the time period from 1966 to 2015. Fourteen prospective and one retrospective study were retrieved. The duration of the surgical block can be adjusted using doses between 40 and 80mg. Hyperbaric prilocaine in doses as low as 10mg can be used for perianal procedures. Four cases of TNS in 486 patients were reported in prospective studies, and none in 5000 cases in a retrospective data set. Spinal prilocaine appears to be safe and reliable for day case anesthesia. However, as chloroprocaine has a shorter duration and a lower risk of TNS and urinary retention, the indications for prilocaine remain to be defined.

Spinal anesthesia with low-dose bupivacaine-fentanyl combination: a good alternative for day case transurethral resection of prostrate surgery in geriatric patients

BACKGROUND AND OBJECTIVE

We evaluated the effectiveness, block duration, postanesthesia care unit stay and adverse effects of using intrathecal low dose bupivacaine and fentanyl combination and compared with conventional dose prilocaine and fentanyl combination for day case transurethral resection of prostate surgery in geriatric patient population.

MATERIALS AND METHODS

Sixty patients were randomized into two groups with Group B receiving 4 mg bupivacine 0.5%+25 μg fentanyl and Group P receiving 50 mg prilocaine 2%+25 μg fentanyl intrathecal. Block quality and duration, postanesthesia care unit stay and adverse effects were compared.

RESULTS

Block durations and postanesthesia care unit stay were shorter in Group B than in Group P (p<0.001 in both). Hypotension and bradycardia were not seen in Group B which was significantly different than in Group P (p=0.024 and p=0.011 respectively).

CONCLUSION

Intrathecal 4 mg bupivacaine + 25 μg fentanyl provided adequate spinal anesthesia with shorter block duration and postanesthesia care unit stay with stable hemodynamic profile than intrathecal 50 mg prilocaine + 25 μg fentanyl for day case transurethral resection of prostate surgery in geriatric patients.

A prospective, double-blinded, randomized, clinical trial comparing the efficacy of 40 mg and 60 mg hyperbaric 2% prilocaine versus 60 mg plain 2% prilocaine for intrathecal anesthesia in ambulatory surgery

BACKGROUND

In this prospective, double-blind, randomized trial we compared 60 mg and 40 mg of 2% hyperbaric prilocaine with 60 mg of 2% plain prilocaine for spinal anesthesia in terms of sensory block onset in outpatients undergoing elective short-duration (<60 minutes) surgery under spinal anesthesia.

METHODS

Ninety patients were enrolled and randomly allocated to receive 1 of the 3 treatments. Times to sensory and motor block onsets, time to the maximum sensory block level, readiness for surgery, time to first urinary voiding, time to Bromage's score 0, and side effects were registered blindly. A blinded observer also questioned patients about transient neurological symptoms 24 hours and 7 days after spinal anesthesia.

RESULTS

Mean times to achieve a T10 level of sensory block were comparable in the 3 groups. However, 20% of patients receiving plain prilocaine did not achieve a T10 level. The 2 hyperbaric dosages (60 mg and 40 mg) showed significantly faster times to motor block onset (P = 0.0091, P = 0.0097), to the maximum sensory block level (P = 0.0297, P = 0.0183), to motor block offset (P = 0.0004, P < 0.0001), and to first urinary voiding (P = 0.0013, P = 0.0002, respectively) than did plain prilocaine. No major adverse reactions or transient neurological symptoms were observed in the study.

CONCLUSIONS

Spinal anesthesia with 60 mg or 40 mg of 2% hyperbaric prilocaine is comparable to 60 mg of 2% plain prilocaine in terms of onset of sensory block at T10. The hyperbaric solution showed faster times to motor block onset and shorter duration of surgical block, suggesting its superiority for the ambulatory setting.

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.