Clinical pharmacology: opioids
Pamela E Macintyre, Suellen M Walker, David J Rowbotham in Clinical Pain Management, 2008
Remifentanil is a μ-opioid receptor agonist with an analgesic potency similar to that of fentanyl.106 It is a fentanyl derivative which is broken down by blood and tissue esterases.106 Its speed of onset is similar to that of alfentanil.107 It has a short and predictable half-life which is not affected by hepatic or renal function108 or plasma cholinesterase (butyrylcholinesterase or pseudocholinesterase) deficiency. The main metabolic product of ester hydrolysis is a carboxylic acid derivative (GI-90291) which is excreted by the kidneys (elimination half-life approximately 100 minutes).109 Although its elimination is delayed in renal failure, significant pharmacological effects are unlikely as its potency relative to remifentanil is only 0.1–0.3 percent.110
Anesthesia and analgesia in pregnancy
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
In the general patient population, PCA has been found to provide better pain relief than intermittent, nurse-administered analgesia (29). Nalbuphine has been shown to provide better labor analgesia when administered in a PCA mode, while PCA administration of meperidine does not demonstrate any significant improvement (30,31). Opioids that are shorter acting may lend themselves well to PCA administration. Fentanyl has been used in a PCA mode, but neonatal depression has been reported. In one retrospective study, the total dose of fentanyl received by mothers of infants who required naloxone was significantly higher than the group of mothers whose infants did not require naloxone (32). Remifentanil is a synthetic opioid with a very short duration of action. It is rapidly metabolized by blood esterases with a half-life of 3.5 minutes. There are no active metabolites, no drug accumulation, and metabolism is not organ dependent (33). Remifentanil has been administered in a PCA mode successfully for labor analgesia. Problems have been reported with respect to maternal respiratory depression and decreasing oxygen saturation, but adverse neonatal effects are few (34–38). Remifentanil administered via PCA may be the best opioid analgesic alternative when epidural analgesia is contraindicated.
Head, Neck, Maxillo-Facial And Dental Surgery
Elizabeth Combeer in The Final FRCA Short Answer Questions, 2019
Drugs: Maintenance via intravenous or inhalational route.Remifentanil useful to minimise need for further muscle relaxant and to achieve a degree of hypotension that will improve surgical field.Vasopressor, e.g. phenylephrine, may be useful to achieve normotension towards the end of surgery to test haemostasis.High risk of nausea and vomiting: give antiemetics. Dexamethasone has added effect of reducing airway oedema.Plan for postoperative analgesia: important for blood pressure control postoperatively. Intravenous morphine towards end of surgery, regular paracetamol, NSAIDs if not contraindicated, oral morphine for breakthrough pain usually sufficient in addition to local anaesthetic plus adrenaline infiltration by surgeon. Superficial cervical plexus blocks may also be used.
How Integrated Anesthesia Communication Leads to Dependable IONM Data
Published in The Neurodiagnostic Journal, 2021
Veronica O. Busso, John J. McAuliffe
Despite adequate hypnosis with propofol, when an incision is made the patient may still move. The addition of opioids helps prevent movement with surgery and avoids the potential cardiac depression associated with increasing the propofol infusion alone (Ferenets et al. 2007). Typically, remifentanil is the opioid of choice when providing care for complex anesthesia and surgical patients. This combination allows for the fastest wake-up if a wake-up test is initiated intraoperatively. Sufentanil is also an appropriate adjunct however wake up is significantly slower. It is also important to be cognizant of drug shortages and patient costs when developing an anesthesia plan. Obviously, a safe patient care model is the priority. If performing a posterior spinal fusion in a complex neuromuscular spine and the surgeon is anticipating changes, performing osteotomies, remifentanil may prove a better choice as you are anticipating the need for a wake-up test. However, if the patient is an idiopathic spine with a low degree of curvature and the surgeon is confident of the outcome, remifentanil is on drug shortage, perhaps sufentanil is an appropriate choice as an adjunct (Table 4).
Comparison of effectiveness of epidural analgesia and monitored anesthesia care for high-intensity focused ultrasound treatment of adenomyosis
Published in International Journal of Hyperthermia, 2018
Chang-Soon Lee, Jae Young Lee, Soohan Ro, Seungeun Choi, Jee Youn Moon
In the MAC group, intravenous remifentanil was administered with target-controlled infusion to a target site concentration of 3 ng/mL (Injectomat TIVA Agilia; Fresenius Kabi GmbH, Graz, Austria) in accordance with patient discomfort. In the EA group, 6 ml of 0.5% ropivacaine was administered epidurally prior to HIFU treatment to achieve spinal sensory block at the level of T9–12. Preservation of sensation at the lumbar and lumbosacral plexus was assessed with alcohol swab in both lower extremities and if muscle power in both hip flexors was assessed as ≥ grade 4 (movement against external resistance with less strength than usual) or 5 (normal strength) [21]. An additional 4 ml of ropivacaine was administered every 1 h if the procedure took more than 2 h. When the patient complained of insufficient analgesia despite epidural sensory block, intravenous remifentanil was administered with target-controlled infusion to a target site concentration of 3 ng/mL. Intravenous midazolam was administered with a bolus dose of 1–2 mg when patients in either group asked to be sedated because of pain or anxiety. At the end of HIFU treatment, fentanyl 20 µg was injected in the operating room if the patient complained of moderate to severe pain.
Different effects of intravenous and local anesthesia in patients undergoing ultrasound-guided radiofrequency ablation of thyroid nodules: a prospective cohort study
Published in International Journal of Hyperthermia, 2022
Shuhang Gao, Yalin Zhu, Mengying Tong, Lina Wang, Shuangsong Ren, Liu Rui, Fang Yang, Zhiqing Lian, Ying Che
Major and minor complications occurred with both methods of anesthesia. Although there is no evidence to prove that the incidence of adverse events is different due to the small number of cases, we observed slightly different types of complications in both groups. Patients with IV have specific symptoms of post-procedural nausea and intra-procedural snoring. These conditions are considered to be caused by the application of intravenous anesthetics. The most common side effects of propofol and remifentanil are gastrointestinal reactions, such as nausea and vomiting. Snoring may be caused by excessive sedation or obesity (body mass index, 28.1 kg/m2). This suggests that individualized medication dosage and close anesthesia care are significantly important during IV induction.
Related Knowledge Centers
- Cardiac Surgery
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- General Anaesthesia
- Sedation
- Craniotomy
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- Opioid
- Analgesic
- Medication
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