Propofol Fentanyl

The inhalational anaesthetics increase the effects of the neuromuscular blockers to differing extents, but nitrous oxide appears not to interact significantly. Ketamine has been reported to potentiate the effects of atracurium. Propofol does not appear to interact with mivacurium or vecuronium. Xenon is reported not to interact with mivacurium or rocuronium, and has less effect than sevoflurane on vecuronium neuromuscular blockade. Bradycardia has been seen in patients given vecuronium with eto-midate or thiopental. Propofol can cause serious bradycardia if it is given with suxamethonium (succinylcholine) without adequate antimuscarinic premedication, and asystole has been seen when fentanyl, propofol and suxamethonium were given sequentially. 

Egan TD, Brock-Utne JG. As3rstole after anesthesia induction with a fentanyl, propofol, and... 

NERVOUS SYSTEM A case report describes a healthy male patient who developed involxmtary movements of the arms and head after exposure to fentanyl [31 ]. In a randomised controlled trial of 112 children undergoing anaesthesia, 14.9% experience emergence delirium after fentanyl/propofol anaesthesia as compared to 38.9% receiving sevoflurane [32 j. 

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. 

A 77-year-old man is admitted to the hospital for a coronary artery bypass. He has been treated with a (3-blocker (Tenormin 100 mg per day), which he took every morning. He is induced with propofol 1 mg/kg, fentanyl 5 jjig/kg and vecuronium 8 mg for muscle relaxation. After 3 minutes a decreasing heart rate becomes a worry for the anesthesiologist. The heart rate continues to fall until it reaches 38 BPM. At this point the patient s blood pressure is 80/60 and the anesthesiologist gives atropine 0.4 mg and ephedrine 10 mg. This treatment results in a stable patient. What effects were most likely produced by the anesthesia procedure Could this have been avoided ... 

Answer This feature of bradycardia is typical of patients who take (3-blockers, which should be continued so they result ultimately in better anesthetic management. The drugs given could have been modified (i.e., etomidate instead of propofol, which does not raise or may cause a slower heart rate). The potent opioids in the fentanyl family all cause vagal transmitted bradycardia. The muscle relaxant vecuronium (norcuron) has no effect on heart rate and could have been replaced by pancuronium, which has a vagolytic effect and will counter bradycardia in the usual induction bolus doses. 

Unlike isoflurane, desflurane may stimulate the sympathetic nervous system at concentrations above 1 MAC. Sudden and unexpected increases in arterial blood pressure and heart rate have been reported in some patients, accompanied by increases in plasma catecholamine and vasopressin concentrations and increased plasma renin activity. These pressor effects may increase morbidity or mortality in susceptible patients. The mechanism of sympathetic activation is unclear but does not appear to be baroreceptor-mediated. Clonidine, esmolol, fentanyl and propofol partially block the response but lignocaine (lignocaine) is ineffective. 

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. 

A relatively large number of studies have investigated the effects of opioids on tests requiring focused attention. Morphine (2.5 to 10 mg, IV)185 and propofol (70 mg, IV)193 impaired an auditory simple reaction time test, and fentanyl (1 to 2.5 ng/ml, IV)182 impaired a visual choice reaction time test. Jenkins et al.197 reported that IV (3 to 20 mg) and smoked (2.6 to 10.5 mg) heroin impaired performance on a simple visual reaction time task. However, other studies reported no effect of butorphanol (0.5 to 2.0 mg, IV),186 fentanyl (25 to 100 pg, IV),191 meperidine (0.25 to 1.0 mg, IV),192 and nalbuphine (2.5 to 10 mg, IV)189 on an auditory simple reaction time test. It may be... 

Numerous studies have reported that performance on the DSST was impaired by various opioids, including morphine (2.5 to 10 mg),185,198 fentanyl (1 to 2.5 ng/ml),182 pentazocine (30 mg),184 butorphanol (0.5 to 2 mg),186 dezocine (2.5 to 10 mg),187 propofol (22 to 70 mg),193,199 nalbuphine (2.5 to 10 mg, IV),189 and the combination of fentanyl (50 pg) plus propofol (35 mg).194 In contrast, meperidine was found to have no effect on the DSST.192 Because the DSST is a timed test, it would appear that opioids slow speeded responses in a fairly consistent manner in opioid-naive subjects. However, in opioid abusers or opioid-dependent persons, Preston and colleagues have reported no effect on DSST performance of several opioids, including morphine (7.5 to 30 mg, IM),200 hydro-morphone (0.125 to 3 mg, IM),201 buprenorphine (0.5 to 8 mg, IM),202 pentazocine (7.5 to 120 mg, IM),203 butorphanol (0.375 to 1.5 mg, IV),204 and nalbuphine (3 to 24 mg, IM).205... 

A 61-year-old woman undergoing mitral valve surgery received fentanyl, midazolam, nitrous oxide, and propofol infusion 3 mg/kg/hour during a 5-hour anesthetic. She developed lactic acidosis soon after the completion of surgery and required reintubation and ventilation. The peak lactate concentration, which occurred 1 day later, was 14.3 mmol/1. There was also mild disturbance of liver function. She eventually recovered. 

Several drugs are used intravenously, alone or in combination with other drugs, to achieve an anesthetic state (as components of balanced anesthesia) or to sedate patients in intensive care units who must be mechanically ventilated. These drugs include the following (1) barbiturates (thiopental, methohexital) (2) benzodiazepines (midazolam, diazepam) (3) opioid analgesics (morphine, fentanyl, sufentanil, alfentanil, remifentanil) (4) propofol (5) ketamine and (6) miscellaneous drugs (droperidol, etomidate, dexmedetomidine). Figure 25-2 shows the structures of... 

All patients are ventilated and sedated (for sedation use fentanyl and propofol). 

A 44-year-old woman developed atropine-resistant but isoprenaline-sensitive bradycardia (36 beats/minute), thought to be due to sinus node dysfunction related to lithium, fentanyl, and propofol (120). 

Sinus bradycardia (36/minute) developed in a 44-year-old woman taking lithium who received fentanyl and propofol (120). 

In 113 patients undergoing general anesthesia, intravenous midazolam 15 mg slowed recovery of the twitch height after vecuronium and atracurium compared with diazepam. The recovery index was not altered (162). However, in another study in 20 patients, midazolam 0.3 mg/kg did not affect the duration of blockade, recovery time, intensity of fasciculations, or adequacy of relaxation for tracheal intubation produced by suxamethonium 1 mg/kg, nor the duration of blockade and adequacy of relaxation for tracheal intubation produced by pancuronium 0.025 mg/kg in incremental doses until 99% depression of muscle-twitch tension was obtained (161). Furthermore, in 60 patients undergoing maintenance anesthesia randomly assigned to one of six regimens (etomidate, fentanyl, midazolam, propofol, thiopental plus nitrous oxide, or isoflurane plus nitrous oxide), midazolam did not alter rocuronium dosage requirements (165). 

Olkkola KT, Tammisto T. Quantifying the interaction of rocuronium (Org 9426) with etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane using closed-loop... 

Usually intravenous pre-oxygenation followed by a small dose of an opioid, e.g., fentanyl or alfentanil to provide analgesia and sedation, followed by propofol or, less commonly, thiopental or etomidate to induce anaesthesia. Airway patency is maintained with an oral airway and face-mask, a laryngeal mask airway (LMA), or a tracheal tube. Insertion of a tracheal tube usually requires paralysis with a neuromuscular blocker and is undertaken if there is a risk of pulmonary aspiration from regurgitated gastric contents or from blood. 

Sedation in critical care units is used to reduce patient anxiety and improve tolerance to tracheal tubes and mechanical ventilation. Whenever possible, patients are sedated only to a level that allows them to open their eyes to verbal command oversedation is harmful. Commonly used drugs include propofol and midazolam, and opioids such as fentanyl, alfentanil, or morphine. 

A 7-year-old boy with trisomy 21 (Down syndrome) had explosive coughing, 30 seconds after fentanyl 50 pg (2 pg/kg) had been injected and flushed through an intravenous cannula. The cough was unproductive and persisted in spasmodic bursts for a further 2-3 minutes until anesthesia was induced with propofol 60 mg and atracurium 15 mg intravenously. The coughing immediately ceased. A petechial rash in the conjuncti-vae and periorbital regions was subsequently noted and disappeared by the end of the first postoperative day. 

Bragonier R, Bartle D, Langton-Hewer S. Acute dystonia in a 14-yr-old following propofol and fentanyl anaesthesia. Br J Anaesth 2000 84(6) 828-9. 

Kazama T, Ikeda K, Morita K. The pharmacodynamic interaction between propofol and fentanyl with respect to the suppression of somatic or hemodynamic responses to skin incision, peritoneum incision, and abdominal wall retraction. Anesthesiology 1998 89(4) 894-906. 

The incidence of adverse events related to an endoscopy sedation regimen that included propofol (in addition to midazolam and fentanyl), delivered by specially trained general practitioners, has been examined in a prospective audit (8) 28 472 procedures were performed over 5 years. There were 185 sedation-related adverse events, 107 with airway or ventilation problems 123 interventions were necessary to maintain ventilation. No patients required tracheal intubation and there were no deaths. The authors concluded that appropriately trained general practitioners encountered a low incidence of adverse events and could safely use propofol for sedation during endoscopy. It should be noted that aU the general practitioners had some experience in anesthesia or intensive care and were individually trained by the Director of Anesthesia. 

The characteristics of sevoflurane anesthesia have been compared with those of target-controlled infusion of propofol in 61 day-case adults undergoing surgery (25). All received nitrous oxide 50% and fentanyl 1 pg/kg. After insertion of a laryngeal mask airway the propofol target concentration was reduced from 8 to 4 pg/ml and the... 

In a placebo-controUed study of induction of anesthesia with a combination of propofol -f fentanyl in 90 patients aged over 60 years, prophylactic intravenous ephedrine 0.1 or 0.2 mg/kg given 1 minute before induction of anesthesia significantly attenuated the fall in blood pressure and heart rate that is usually observed (14). Prophylactic use of ephedrine may be useful in preventing the occasional instances of cardiovascular collapse recorded after induction of anesthesia using these agents in elderly people. 

The effects of giving calcium chloride 10 mg/kg after induction of anesthesia with propofol, fentanyl, and pancuronium have been investigated in 58 patients undergoing elective coronary artery bjq)ass grafting (16). Calcium chloride reduced the fall in arterial blood pressure and prevented the reductions in heart rate, stroke volume index, cardiac index, and cardiac output, compared with placebo. Propofol reduces the availabihty of calcium to the myocardial cells, and calcium chloride effectively minimizes the hemodynamic effects of... 

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