Intrathecal morphine and sleep apnoea severity in patients undergoing hip arthroplasty: a randomised, controlled, triple-blinded trial
BRITISH JOURNAL OF ANAESTHESIA
Authors: Albrecht, Eric; Bayon, Virginie; Hirotsu, Camila; Al Ja'bari, Aboud; Heinzer, Raphael
Abstract
Background: Intrathecal morphine prolongs analgesia after surgery, but has been implicated in postoperative respiratory depression or apnoeic episodes. However, this has not been investigated in a prospective trial using respiratory polygraphy. This randomised controlled triple-blinded trial tested the hypothesis that intrathecal morphine increases sleep apnoea severity, measured using respiratory polygraphy. Methods: Sixty subjects undergoing hip arthroplasty under spinal anaesthesia received either 15 mg isobaric bupivacaine 0.5% with 0.5 ml normal saline 0.9% (control group) or 15 mg isobaric bupivacaine 0.5% with 0.5 ml intrathecal morphine 100 mu g (intrathecal morphine group). Respiratory polygraphy was performed before surgery and on the first and third postoperative nights. The primary outcome was the apnoea-hypopnoea index in the supine position (supine AHI) on the first postoperative night. Secondary outcomes included supine AHI on the third postoperative night, oxygen desaturation index (ODI), and ventilatory frequency during the first and third postoperative nights. Results: On the first postoperative night, mean (95% confidence interval) values for supine AHI were 20.6 (13.9-27.3) and 21.2 (12.4-30.0) events h(-1)in the control and intrathecal morphine groups, respectively (P=0.90). There were no significant between-group differences for any of the secondary outcomes, except for a significantly higher central and mixed apnoea index preoperatively and significantly lower mean SpO(2) on the third postoperative night in the control group. Conclusions: Intrathecal morphine did not increase sleep apnoea severity when measured using respiratory polygraphy. Of note, all patients had an increased number of apnoeic episodes on the third postoperative night.
Single exercise stress reduces central neurotrophins levels and adenosine A(1)and A(2)receptors expression, but does not revert opioid-induced hyperalgesia in rats
INTERNATIONAL JOURNAL OF DEVELOPMENTAL NEUROSCIENCE
Authors: Medeiros, Liciane Fernandes; Nunes, Ellen Almeida; Lopes, Bettega Costa; de Souza, Andressa; Cappellari, Angelica Regina; de Freitas, Joice Soares; de Macedo, Isabel Cristina; Kuo, Jonnsin; Cioato, Stefania Giotti; Battastini, Ana Maria de Oliveira; Caumo, Wolnei; Torres, Iraci L. S.
Abstract
Background This study assessed the effects of an acute stress model upon the long-term hyperalgesia induced by repeated morphine administration in neonatal rats. We also evaluated neurotrophins and cytokines levels; expressions of adenosine and acetylcholine receptors, and acetylcholinesterase enzyme at the spinal cord. Material and methods Male Wistar rats were subjected to morphine or saline administration from P8 to P14. Thermal hyperalgesia and mechanical hyperesthesia were assessed using the hot plate (HP) and von Frey (vF) tests, respectively, at postnatal day P30 and P60. After baseline measurements, rats were subjected to a single exercise session, as an acute stress model, at P30 or P60. We measured the levels of BDNF and NGF, interleukin-6, and IL-10 in the cerebral cortex and the brainstem; and the expression levels of adenosine and muscarinic receptors, as well as acetylcholinesterase (AChE) enzyme at the spinal cord. Results A stress exercise session was not able to revert the morphine-induced hyperalgesia. The morphine and exercise association in rats induced a decrease in the neurotrophins brainstem levels, and A(1), A(2A), A(2B)receptors expression in the spinal cord, and an increase in the IL-6 cortical levels. The exercise reduced M2 receptors expression in the spinal cord of naive rats, while morphine prevented this effect. Conclusions Single session of exercise does not revert hyperalgesia induced by morphine in rats; however, morphine plus exercise modulate neurotrophins, IL-6 central levels, and expression of adenosine receptors.