Inhaled Nebulised S(+)-Ketamine for Postoperative Analgesia
Status:
Withdrawn
Trial end date:
2020-12-01
Target enrollment:
Participant gender:
Summary
Ketamine has been administrated via the intravenous, intramuscular, subcutaneous, rectal,
oral, transdermal, intranasal, sublingual, transmucosal, epidural, intrathecal, and
intra-articular routes. Pharmacokinetic properties of inhaled ketamine have not been studied
officially, but one of the investigators researchers has tested nebulized ketamine on himself
with repeated painful stimulus and monitoring applied. Based on this experiment, analgesic
effect is roughly estimated to begin in 3 minutes.Ketamine has been used successfully to
treat acute pain in intranasal form. The primary purpose of this study is to evaluate whether
nebulised S(+)-ketamine carries potential as a an analgesic bypassing first pass metabolism
and without the need for intravenous access. Secondary aim is to assess the duration of
analgesia obtained by nebulized S-ketamine. Thirdly, the aim is to evaluate whether inhaled
nebulized ketamine decreases the need for rescue analgesia during PACU care. The subjects are
recruited among patients coming in for a surgical intervention (orthopedic, gastrointestinal,
plastic or urologic surgery) and needing further observation in postoperative care unit
(PACU).
It was calculated that sample size of 8 subjects per group would be required to achieve
statistical power of 80% and detect a difference of 3 units in NRS-values with standard
deviation of 2 units and type I error of 5%. To prepare for possible dropouts, total of 20
subjects will be recruited (10 in each group).
Patients will receive either nebulized placebo (i.e. saline) or ketamine (Ketanest-S) when
they require pain alleviation in the PACU. Dosage of ketamine is 1 mg/kg. Patients will be
randomized into two groups so that other group's first inhalation contains ketamine and
second inhalation placebo and in the opposite order.