Clinical pharmacology of opioids: basic pharmacology
Nigel Sykes, Michael I Bennett, Chun-Su Yuan in Clinical Pain Management, 2008
The existence of different types of opioid receptors, i.e. the mu, delta, and kappa receptors, makes the concept of an agonist–antagonist possible. These compounds are agonists to one type of opioid receptor, while an antagonist to another type. As an example, drugs in this class antagonize mu receptors, but act as agonists at kappa receptors. Semisynthetic: – phenanthrene derivatives: nalbuphine;– thebaine derivatives: buprenorphine.Synthetic: – benzomorphan derivatives: pentazocine, dezocine;– morphinan derivatives: butorphanol.
Advantages and feasibility of intercostal nerve block in uniportal video-assisted thoracoscopic surgery (VATS)
Published in Postgraduate Medicine, 2023
Analgesic drugs commonly used after chest surgery include NSAIDs, opioid analgesics, and acetaminophen. NSAIDs inhibit the synthesis of cyclooxygenase (COX) and prostaglandin (PG). Ketorolac tromethamine is a nonselective COX inhibitor administered intravenously. While it can reduce opioid dosage and related adverse effects such as nausea, vomiting, and excessive sedation, its main side effects include gastrointestinal bleeding and an increased risk of postoperative bleeding. In contrast, acetaminophen inhibits PG synthesis by acting on the central nervous system and has fewer side effects than NSAIDs. Acetaminophen is effective for mild to moderate pain and can enhance the analgesic effects of opioids or NSAIDs when used in combination, but high doses may lead to liver damage [25]. Opioids activate opioid receptors in the peripheral and central nervous systems, producing analgesia. Dezocine, an opioid receptor agonist, has a similar analgesic effect to morphine, but has a ceiling effect on both analgesic and side effects [26]. Dose escalation beyond a certain point does not increase analgesia but may increase the risk of side effects, such as respiratory depression. Combining dezocine with other types of analgesic drugs can have a synergistic effect. Ropivacaine is an amide local anesthetic that can enhance postoperative analgesia when combined with epinephrine. However, accidental injection into the bloodstream may cause immediate acute systemic toxicity. Therefore, caution must be exercised during administration to prevent iatrogenic collateral injury.
Three cases of retained cuff related infection after manual pull removal of peritoneal dialysis catheter
Published in Renal Failure, 2021
Suojian Zhang, Xu Zhang, Haitao Li, Zhiqiang Wei, Juan Cao
Compared with open surgery, this technique is simple to perform, causes less surgical trauma, and requires less time. However, the PD catheter may rupture, and patients may experience acute pain when using the technique. The silicone PD catheters were hard enough, and there have been no cases of rupture at our center. Dezocine was administered intravenously and lidocaine was injected around the cuff to relieve the pain. A serious possible complication of this technique is retained cuff-related infection. The retained cuff is a foreign body in the abdominal wall, which may cause infection. Previous reports have indicated inconsistent incidence of retained cuff-related infection. For example, none of the 17 patients reported by Hakim et al. [1] exhibited infection, whereas only one patient exhibited retained cuff-related infection among the 31 patients reported by Quiroga et al. [2] and 46 patients reported by Grieff et al. [3]. However, Elkabir et al. [4] reported that the ‘pull technique’ was used in 62 PD patients, of whom 15 (24.2%) developed retained cuff-related infection. From the beginning of 2018 to the end of March 2020, a total of 30 PD catheters were removed by the ‘pull technique’ and 3 cases of retained cuff-related infections occurred, with an incidence rate of 10% at our center. Additionally, it is unclear whether there is an association between peritonitis and retained cuff-related infection. Some scholars may fear soft tissue infection caused by the outflow of infected fluid in patients with peritonitis. Except Case 3, the other two patients did not have peritonitis when the PD catheter was removed. Bacterial culture of secretions was different from the original peritonitis infection bacteria in Case 3. In addition, 8 PD patients who discontinued PD treatment owing to refractory peritonitis did not have retained cuff-related infection after PD catheter removal by the ‘pull technique’ at our PD center, suggesting that retained cuff-related infection is not related to the presence of peritonitis during PD catheter removal. Some scholars may be afraid that deep cuff was the source of the infection; however, we found that all the infections were related to superficial cuff. In Case 2, conservative anti-infective treatment alone was attempted for retained cuff-related infection, but it was ineffective. All three patients were cured after surgical resection together with anti-infective treatment. Therefore, we suggest that the basic principle is excision of the fistula canal, which can be the source of permanent infection and peritoneal content leakage. Moreover, all three patients had superficial cuff-related infections. Wang et al. [5] improved the ‘pull technique’ by isolating the superficial cuff and then using the ‘pull technique’ for PD catheter removal. He used the improved ‘pull technique’ in 24 patients and no cuff-related infection occurred. Superficial cuff separation is not difficult and it may be a better ‘pull technique’. In addition, the original exit site of PD catheter may be a site of bacterial invasion, which should be stitched.
Related Knowledge Centers
- Intramuscular Injection
- Pain Management
- Partial Agonist
- Pain
- Opioid
- Intravenous Therapy
- Opioid Receptor
- Receptor Modulator
- Μ-Opioid Receptor
- Κ-Opioid Receptor