Fentanyl postoperative

This type of pain management is used for postoperative pain, labor pain, and cancer pain. The most serious adverse reaction associated with the administration of narcotics by the epidural route is respiratory depression. The patient may also experience sedation, confusion, nausea, pruritus, or urinary retention. Fentanyl is increasingly used as an alternative to morphine sulfate because patients experience fewer adverse reactions. 

Remifentanil (Ultiva) is used for induction and maintenance of general anesthesia and for continued analgesia during the immediate postoperative period. This drug is used cautiously in patients witii a history of hypersensitivity to fentanyl. 

Opioids maybe administered in a variety of routes including oral (tablet and liquid), sublingual, rectal, transdermal, transmucosal, intravenous, subcutaneous, and intraspinal. While the oral and transdermal routes are most common, the method of administration is based on patient needs (severity of pain) and characteristics (swallowing difficulty and preference). Oral opioids have an onset of effect of 45 minutes, so intravenous or subcutaneous administration maybe preferred if more rapid relief is desired. Intramuscular injections are not recommended because of pain at the injection site and wide fluctuations in drug absorption and peak plasma concentrations achieved. More invasive routes of administration such as PCA and intraspinal (epidural and intrathecal) are primarily used postoperatively, but may also be used in refractory chronic pain situations. PCA delivers a self-administered dose via an infusion pump with a preprogrammed dose, minimum dosing interval, and maximum hourly dose. Morphine, fentanyl, and hydromorphone are commonly administered via PCA pumps by the intravenous route, but less frequently by the subcutaneous or epidural route. 

Opioids play an important role in anesthetic practice. Opioid analgesics potentiate the efficacy of anesthetics. They can be given as part of the premedication as well as during the operation. Examples of short acting agents with high potency are fentanyl, sufentanyl, alfentanil and remifentanil. Because of their hemodynamic stability these agents can be used for patients with compromised myocardial function. Respiration must be maintained artificially and may be depressed into the postoperative period. They are usually supplemented with inhalation anesthetic, benzodiazepines or propofol. 

In developing protein and peptide trans-dermal delivery systems, one must be mindful of the high interindividual variation in drug absorption across the skin. Large variations in bioavailability have been demonstrated with fentanyl patches, initially intended for postoperative pain relief but later abandoned due to unacceptable variability among individuals receiving the same dose [9]. Response in postoperative patients to the application of a fentanyl patch ranged from ineffective pain relief to severe respiratory depression, and effects were correlated with variations in plasma fentanyl levels [9]. 

Recovery is sufficiently rapid with most intravenous drugs to permit their use for short ambulatory (outpatient) surgical procedures. In the case of propofol, recovery times are similar to those seen with sevoflurane and desflurane. Although most intravenous anesthetics lack antinociceptive (analgesic) properties, their potency is adequate for short superficial surgical procedures when combined with nitrous oxide or local anesthetics, or both. Adjunctive use of potent opioids (eg, fentanyl, sufentanil or remifentanil see Chapter 31) contributes to improved cardiovascular stability, enhanced sedation, and perioperative analgesia. However, opioid compounds also enhance the ventilatory depressant effects of the intravenous agents and increase postoperative emesis. Benzodiazepines (eg, midazolam, diazepam) have a slower onset and slower recovery than the barbiturates or propofol and are rarely used for induction of anesthesia. However, preanesthetic administration of benzodiazepines (eg, midazolam) can be used to provide anxiolysis, sedation, and amnesia when used as part of an inhalational, intravenous, or balanced anesthetic technique. 

Dosages and routes of administration For acute (postoperative) pain and for anesthesia, fentanyl is given by the intravenous route. For pre-medication in anesthesia and for break-through pain the compound can also been given as an oral-transmucosal formulation (Ashburn and Streisand, 1994). A transdermal patch has been developed for chronic pain treatment (Jeal and Benfield, 1997 O Siordin, 1998). The intravenous doses for premedication are 50-100 pg, oral-transmucosal systems contain 200-400 pg and patch formulations have a delivery rate of 25-100 pg/h. 

Transdermal systems with electrophoretic release of the active substance are under development, e.g. ETRANS by ALZA with fentanyl for postoperative pain in clinical phase III. By virtue of the electrical field administration of the active substance is faster and on demand, e.g. similar to PCA therapy. 

Clinical use The indications for levobupivacaine include wound infiltration (0.25 % solution), nerve conduction block (0.25 - 0.5 %), spinal analgesia (0.5 %) and epidural anesthesia (0.5 to 0.75 %). For labour analgesia, lower concentrations of levobupivacaine are recommended when administered as epidural injection (0.125 to 0.25 % up to 25 mg) or infusion (0.25 %). The maximum dose for ilioinguinal or iliohypogastric block in children is 1.25 mg/kg/side (0.25 to 0.5 % solutions). For postoperative pain management, levobupivacaine can be applied epidurally in combination with the opioids fentanyl or morphine or with the a2-agonist clonidine. 

Scott, D. A., Blake, D., Buckland, M, Etches, R., Halliwell, R., Marsland, C., Merridew, G., Murphy, D., Paech, M., Schug, S. A., Turner, G., Walker, S., Huizar, K., Gustafsson, U.. A comparison of epidural ropivacaine infusion alone and in combination with 1.2 and 4 pg/mL fentanyl for seventy-two hours of postoperative analgesia after major abdominal surgery, Anesth. Analg. 1999, 88, 857-864. 

Aygun S, Kocoglu H, Goksu S, et al. Postoperative patient-controlled analgesia with intravenous tramadol, intravenous fentanyl, epidural tramadol and epidural ropivacaine + fentanyl combination. EurJ Gynaecol Oncol. 2004 25 498-501. 

ChellyJE, Grass J, Houseman TW, et al. The safety and efficacy of a fentanyl patient-controlled transder-mal system for acute postoperative analgesia a multicenter, placebo-controlled trial. Anesth Analg. 2004 98 427-433. 

Paech MJ, Lim CB, Banks SL, Rucklidge MW, Doherty DA. A new formulation of nasal fentanyl spray for postoperative analgesia a pilot study. Anaesthesia. 2003 58 740-744. 

Viscusi ER, Reynolds L, Chung F, et al. Patient-controlled transdermal fentanyl hydrochloride vs intravenous morphine pump for postoperative pain a randomized controlled trial. JAMA. 2004 291 1333-1341. 

ChellyJE. An iontophoretic, fentanyl HC1 patient-controlled transdermal system for acute postoperative pain management. Expert Opin Pharmacother. 2005 6 1205-1214. 

Koo PJ. Postoperative pain management with a patient-controlled transdermal delivery system for fentanyl. Am J Health Syst Pharm. 2 00 5 62 1171-1176. 

Furthermore, high intravenous doses of opioids can cause chest wall rigidity, thereby acutely impairing ventilation, as well as postoperative respiratory depression requiring prolonged assisted ventilation and the administration of opioid antagonists (eg, naloxone). Low doses of fentanyl have been used as premedication and as an adjunct to both intravenous and inhaled anesthetics. 

A pre-emptive analgesic, using a subcutaneous injection of 50 ug/kg fentanyl can be given immediately postoperative as indicated. This may be given q4h 2x, followed by a Tylenol elixir added to the drinking water (1 ml elixir per 100 ml water) in a rodent drinking bottle for 2-3 days post procedure. 

Sinatra, R. (2005), The fentanyl FI Cl patient-controlled transdermal system (PCTS) An alternative to intravenous patient-controlled analgesia in the postoperative setting, Clin. Pharmacokinet., 44(Suppl 1), 1-6. 

The addition of droperidol 2.5 mg to fentanyl 0.4 mg in 40 ml of 0.125% bupivacaine lowered the incidence of postoperative nausea and vomiting compared with a solution without droperidol or with butorphanol added instead in patients undergoing anorectal surgery in a prospective randomized, single-blind study (28). 

A 26-year-old woman with a history of multiple substance abuse required emergency caesarean section at 30 weeks of gestation as a result of crack cocaine-induced placental abruption and fetal distress (251). Her admission blood pressure was 145/95 mmHg, heart rate 95/minute and respiratory rate 20/minute. The fetal heart rate was 130/minute and non-reactive, with late and variable decelerations and no response to maternal oxygen administration. Spinal block with bupivacaine, fentanyl, and morphine was performed with the patient in a sitting position. No maternal or neonatal postoperative complications were reported. 

Lately, the nasal route is receiving attention for the management of postoperative pain. Mucosal administration requires only a 1.1-1.5 times higher dose of fentanyl than the intravenous dose. ° For this new application field, called PCINA (patient-controlled-intranasal-analgesia), the pharmaceutical industry demands safety precautions of the delivery device, which can be fulfilled through implementation of intelligent microelectronic features. 

Toussaint, S. Maidl, J. Schwagmaier, R. Striebel, H.W. Patient controlled intranasal analgesia (PCINA) with fentanyl for the treatment of postoperative pain. Int. Monitor 1998, 10, 63. 

Holley, F.O. van Steennis, C. Postoperative analgesia with fentanyl pharmacokinetics and pharmacodynamics of constant-rate IV and transdermal delivery. Br. J. Anaesthesia. 1988, 60, 608-613. 

---