[Use of 2 % hyperbaric prilocaine for spinal anesthesia : sensitivity analysis in outpatient surgery].

Background: Hyperbaric prilocaine 2 % has been available for spinal anesthesia in Germany for 2 years and is characterized by a short duration of action, a lack of postspinal urine retention and a reduction of transient neurological syndromes. However, desirable pharmacological properties are contrasted by higher pharmacological costs compared to hyperbaric bupivacaine 0.5 %.
Materials and Methods: This paper deals with a sensitivity analysis for the use of hyperbaric prilocaine 2 % versus hyperbaric bupivacaine 0.5 % in Germany and investigates the financial break-even point up to which time a shorter patient stay in the recovery area compensates for the higher costs for the use of prilocaine 2 % for ambulatory spinal aaesthesia. A sensitivity analysis is an instrument of investment appraisal. It is a model to reduce a complex system with numerous variables to a straightforward calculation by assuming a framework requirement and systematically changing only one or two variables. In this paper additional costs for spinal anesthesia have been neglected, only the time a nurse spends with the patient in the recovery area and the costs for each vial of drug have been taken into account.
Results: For the assumption of 75 min time until leaving the recovery area and being discharged after spinal anesthesia with hyperbaric prilocaine 2 % versus 150 min (recovery of motor competence) or 405 min (voiding) with hyperbaric bupivacaine 0.5 % the calculation shows a cost benefit for hyperbaric prilocaine 2 % of EUR 11.64 or EUR 64.76 compared to hyperbaric bupivacaine 0.5 % and EUR 13.32 or EUR 66.44 compared to isobaric bupivacaine 0.5 %. Under the assumption that all patients who have received spinal anesthesia with hyperbaric bupivacaine 0.5 % can be discharged from the recovery area after 150 min, the use of hyperbaric prilocaine 2 % remains more economical as long as the patient is discharged from the recovery area within 130 min. If 405 min recovery time is assumed for hyperbaric bupivacaine 0.5 % the costs compared with hyperbaric prilocaine 2 % will be compensated after 300 min. To be more economical compared to patients with hyperbaric prilocaine 2 % those who received hyperbaric bupivacaine 0.5 % must be discharged from the recovery area within at least 100 min. However, a time of less than 160 min for discharge from the recovery area is not published anywhere in the literature. In summary, the use of hyperbaric prilocaine 2 % for 60 min operation time is cheaper than the use of bupivacaine 0.5 % as long as patients do not stay in the recovery area for longer than 120 min and are discharged from the recovery area.
Conclusions: For German framework conditions the use of hyperbaric prilocaine 2 % can provide an economical advantage compared to the use of hyperbaric bupivacaine 0.5 % if staff assignment can be flexible.