Remifentanil and propofol

Bagshaw O. TIVA with propofol and remifentanil. Anaesthesia 1999 54(5) 501-2. 

In eight subjects the concentration of remifentanil was significantly increased when therapeutic concentrations of propofol were present in the body (41). The combination of propofol and remifentanil can cause cardiovascular depression. As with other opioids, remifentanil competes with propofol for hydrophobic binding in the lungs and heart. 

EFFECT OF ANAESTHESIA WITH PROPOFOL AND REMIFENTANIL ON WHOLE BLOOD CHEMILUMINESCENCE DISCRIMINANT ANALYSIS OF THE DATA... 

Many papers describe dose-related in-vitro effects of propofol and remifentanil on different neutrophil (PMN) functions, while in-vivo effects seem to be less clearly evident. ... 

In the present study the effect of a short-time intravenous anaesthesia with propofol and remifentanil on PMN chemiluminescence (CL) activity is measured in a group of young patients undergoing surgery for strabismus. 

Drover DR, Litalien C, Wellis V, Shafer SL, Hammer GB. Determination of the pharmacodynamic interaction of propofol and remifentanil during esophagogastroduodenoscopy in children. Anesthesiology (2004) 100,1382-6. 

Bouillon TW, Bruhn J, Radulescu L, Andresen C, Shafer TJ, Cohane C, Shafer L. Miarma-codynamic interaction between propofol and remifentanil regardii hypnosis, tolerance of laryngoscopy, bispectral index and electroencephalographic approximate txtSropy.Ams si-... 

Ludbrook GL, Upton RN. Pharmacokinetic drug interaction between propofol and remifentanil (2003) 97, 924-5. 

Bouillon T, Bruhn J, Radu-Radulescu L, Bertaccini E, Park S, Shafer S. Ncn-stea(ty state analysis of the pharmacokinetic interaction between propofol and remifentanil Anes siol-ogy (2002) 97, 1350-62. 

Chandler JR, Myers D, Mehta D, Whyte E, Groberman MK, Montgomery CJ, et al. Emergence delirium in children a randomized trial to compare total intravenous anesthesia with propofol and remifentanil to irthalational sevoflurane anesthesia. Pediatr Anaesth April 2013 23(4) 309-15. 

Na HS, Hwang JW, Park SH, Oh AY, Park HP, Jeon YT, et al. IJrug-adrriinistration sequence of target-controUed propofol and remifentanil influences the onset of rocuronium. A double-blind, randomized trial. Acta Anaesthesiol Scand 2012 56 558-64. 

TIVA has become feasible thanks to the introduction of agents with a suitably short duration of action, including the injectable anesthetics propofol and etomidate, the analgesics alfentanil und remifentanil, and the muscle relaxant mivacurium. These drugs are eliminated within minutes after being adminster-ed, irrespective of the duration of anesthesia. 

In addition to the medicines mentioned above, a number of opiate- and non-opiate-based analgesics, including COX-2 inhibitors, anaesthetics (e.g. propofol, desflurane, sevoflurane, ropivacaine, levobupivacaine and remifentanil), neuromuscular blockers (e.g. rocuronium bromid, zemuron, cisatracuiium, doxacurium. 

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. 

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. 

Operationally, anaesthetics can be classified as inhalational or intravenous. The most used compounds of this last group are thiopental, propofol and ketamine recently, new synthetic opioids related to phenylpiperidines (phentanyl and its congeners, sufentanil, alfentanil, remifentanil) are also used. 

Nine patients (age 7-12 years) were anaesthetised for strabismus surgery with 3 mg kg propofol and 0.3 pg kg min remifentanil for induction phase and 100-200 pg kg min propofol and 0.3-0.5 pg kg min remifentanil for maintenance phase. Peripheral blood was drawn before, at the end of anaesthesia, 3 and 24 h after surgery. 

General anesthesia - Remifentanil is not recommended as the sole agent in general anesthesia because loss of consciousness cannot be assured and because of a high incidence of apnea, muscle rigidity, and tachycardia. Remifentanil is synergistic with other anesthetics and doses of thiopental, propofol, isoflurane, and midazolam have been... 

Cough reflex Exercise caution when using narcotic analgesics postoperatively and in patients with pulmonary disease because cough reflex is suppressed. Intraoperative awareness Intraoperative awareness has been reported in patients younger than 55 years of age when remifentanil has been administered with propofol infusion rates of 75 mcg/kg/min or less. 

An anxious 5-year-old child with chronic otitis media and a history of poorly controlled asthma presents for placement of ventilating ear tubes. General anesthesia is required for this short elective ambulatory surgery procedure. What preanesthetic medication should be administered Which of the three commonly used anesthetic techniques would you choose to use in this situation (1) inhalational anesthesia with sevoflurane for induction and maintenance in combination with nitrous oxide, (2) intravenous anesthesia with propofol for induction and maintenance of anesthesia in combination with remifentanil, or (3) balanced anesthesia using propofol for induction of anesthesia followed by a combination of sevoflurane and nitrous oxide for maintenance of anesthesia ... 

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... 

In two randomized, double-blind, controlled comparisons of anesthetic techniques for extracorporeal shock wave lithotripsy remifentanil infusion had no advantage over the combination of fentanyl bolus plus propofol infusion, but caused more adverse effects (nausea and vomiting) (10). In another study remifentanil infusion provided comparable analgesia and caused less respiratory depression and fewer gastrointestinal symptoms than intravenous boluses of sufentanil (11). 

The respiratory depressant and gastrointestinal adverse effects of remifentanil have been observed in a randomized, single-blind study of 125 patients undergoing elective orthopedic and urological surgery under spinal or brachial plexus anesthesia (16). They were randomized to either remifentanil (a bolus of 0.5 micrograms/kg plus an infusion of 0.1 micrograms/kg/minute) or propofol... 

In a prospective study in 12 men undergoing elective coronary artery bypass grafting, remifentanil 0.5 and 2.0 micrograms/kg/minute combined with propofol preserved hemodynamic stability and reduced myocardial blood flow and metabolism to a similar extent (24). Asystole has been attributed to remifentanil (25). 

Hogue CW Jr, Bowdle TA, O Leary C, Duncalf D, Miguel R, Pitts M, Streisand J, Kirvassilis G, Jamerson B, McNeal S, Batenhorst R. A multicenter evaluation of total intravenous anesthesia with remifentanil and propofol for elective inpatient smgery. Anesth Analg 1996 83(2) 279-85. 

Estimates of target remifentanil clinical concentrations were obtained by scaling the alfentanil concentration-response relationship for clinical responses (e.g., analgesia, surgery with low-dose propofol) by the relative potency estimate (30-fold) obtained in the EEG trial. The concordance between the observed therapeutic remifen-tanil concentration estimated from Phase 2/3 clinical trials and predicted therapeutic concentrations is depicted in Figure 31.6. In every case the predicted range... 

Fechner J, Hering W, Ihmsen H, Palmaers T, Schuttler J, Albrecht S. Modelling the pharmacodynamic interaction between remifentanil and propofol by EEG-controlled dosir. EurJ Anaesthesiol (2003) 20, 373-9. 

In a double-blind, multicenter, randomized study in 20 ASA I-III patients aged 18-69 years and scheduled for elective surgery lasting at least 120 minutes, anesthesia was induced with remifentanil and rocuronium and maintained with sevoflurane or propofol remifentanil was used for... 

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