Pigs are commonly used in biomedical research, often subjected to complicated and invasive surgical procedures. The knowledge of appropriate analgesia and anaesthesia in pigs however is limited. Therefore, the general aim of the present thesis was to establish and evaluate opioid analgesia suitable for abdominal surgery in growing pigs. Isoflurane minimal alveolar concentration (MAC) was determined in growing pigs using claw pinching. Thereafter, each pig was randomly studied thrice to determine the MAC values in the following treatments: induction of anaesthesia with medetomidine and tiletamine/zolazepam given intramuscularly (MTZ); MTZ followed by epidural morphine (MTZ/M); and MTZ followed by intramuscular buprenorphine (MTZ/B). Pigs were subjected to abdominal surgery during isoflurane anaesthesia and physiological and behavioural effects of MTZ/M and MTZ/B compared to MTZ were evaluated. Transdermal fentanyl was applied and the effects were evaluated for 60 h in conscious pigs and in pigs treated with MTZ/M. Opioid serum concentrations were monitored up to 72 h after drug administration. Behaviour was analysed utilizing videotape recordings of pigs’ activity level before and after surgery. Induction of anaesthesia with MTZ reduced the isoflurane MAC in pigs by 68%. Additional epidural morphine and systemic buprenorphine decreased MTZ isoflurane MAC by 33% and 50%, respectively. Pigs treated with epidural morphine or systemic buprenorphine prior to abdominal surgery attained surgical anaesthetic depth with reduced isoflurane requirement. Induction of anaesthesia with MTZ improved arterial blood pressure and oxygenation compared to isoflurane induction. Epidural morphine did not influence the cardiorespiratory functions during anaesthesia but systemic buprenorphine affected the respiratory response in spontaneously breathing pigs. The postoperative activity level after epidural morphine was lower but the pigs gained weight and the feed intake was similar compared to before surgery. Combining epidural morphine and transdermal fentanyl resulted in initial return to regular activity levels and weight gain after surgery. Twelve hours after surgery these pigs showed decreased activity but still gained weight. Transdermal fentanyl alone in conscious pigs did not cause inactivity or sedation but resulted in inter-individual variations in fentanyl serum concentrations. Systemic buprenorphine caused unpredictable activity levels with postoperative decrease in weight and feed consumption. The analgesic properties of MTZ contributed to a substantial reduction in concentration of isoflurane required for maintenance of inhalation anaesthesia. Additional preoperative opioid analgesia further reduced the requirements of isoflurane needed to maintain an adequate anaesthetic depth. The opioids evaluated resulted in different behaviour postoperatively. Pigs treated with epidural morphine with or without transdermal fentanyl had good appetite and gained weight after abdominal surgery indicating improved postoperative recovery.

The aims of the present thesis (I-V) were to evaluate the analgesic and adverse effects of manual acupuncture for low-back and pelvic pain during pregnancy (I) and for labour pain (II-III), and also to study the effects of low-frequency electro acupuncture (EA) on clinical physiological responses to skin incision in anaesthetized patients (IV-V). Acupuncture in obstetric patients (I-III) Manual acupuncture in obstetric patients was found to relieve pain in one prospective randomised (I) and two retrospective (II-III) studies. Low-back and pelvic pain intensity during pregnancy was decreased by acupuncture (I), and parturients receiving acupuncture required fewer of the other analgesic modalities than the women in the control group (II-III). Neither patients in the acupuncture group nor their infants suffered from substantial adverse effects (I-III). These findings are in agreement with results obtained by other research groups investigating acupuncture during pregnancy and labour, but future studies are desirable to establish the role of acupuncture in obstetrics. Acupuncture in anaesthetized patients (IV,V) In contrast to the beneficial effects of acupuncture referred above (I-III), two prospective, randomised, placebo-controlled and double-blind studies (IV,V) revealed that low-frequency EA in anaesthetized patients did not attenuate but instead facilitated clinical physiological response to skin incision. Patients given EA required a higher steady state concentration of sevoflurane to abolish physiological reactions to skin incision (IV). Furthermore, when exposed to the same steady state concentration of sevoflurane, more acupuncture than control patients responded to surgery with movements of head or limbs, dilation of pupils or divergence of eye axes (V). Similar results have not been reported elsewhere, although combined high- and low-frequency EA in anaesthetized volunteers was recently reported to have no effect on the response to painful stimulation. In our study, the depth of anaesthesia was not influenced by acupuncture, since the A-line ARX index reflecting AEP activity was found to be similar in the two groups (V). Future studies of the possible mechanisms underlying this effect of EA under general anaesthesia are desirable.