Remifentanil Propofol

Salengros J-C, Velghe-Lenelle C-E, Bollens R, Engelman E, Barvais L. Lactic acidosis during propofol-remifentanil anesthesia in an adult. Anesthesiology 2004 101 243-5. 

O Hare R, Reid J, Breslin D, Hayes A, Mirakhur RK. Propofol-remifentanil interaction influence onrecovery. BrJAnaes (1999) 83, 180P. 

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... 

Shen X, Hu CB, Ye M, Chen YZ. Propofol-remifentanil intravenous anesthesia and spontaneous ventilation for airway foreign body removal in children with preoperative respiratory impairment. Paediatr Anaesth 2012 22 1166-70. 

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. 

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. 

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. 

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 ... 

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. 

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... 

Servin FS, Raeder JC, Merle JC, Wattwil M, Hanson AL, Lauwers MH, Aitkenhead A, Marty J, Reite K, Martisson S, Wostyn L. Remifentanil sedation compared with propofol during regional anaesthesia. Acta Anaesthesiol Scand 2002 46(3) 309-15. 

A four-year-old patient developed a nodal bradycardia while receiving propofol 6 mg/kg/hour + remifentanil 0.25 microgram/kg/minute (17). The bradycardia responded to atropine 0.3 mg. 

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

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). 

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. 

Burmeister MA, Brauer P, Wintruff M, Graefen M, Blanc I, Standi TG. A comparison of anaesthetic techniques for shock wave lithotripsy the use of a remifentanil infusion alone compared to intermittent fentanyl boluses combined with a low dose propofol infusion. Anaesthesia 2002 57(9) 877-81. 

Grewal K, Samsoon G. Facilitation of laryngeal mask airway insertion effects of remifentanil administered before induction with target-controlled propofol infusion. Anaesthesia 2001 56(9) 897-901. 

Krenn H, Deusch E, JeUinek H, Oczenski W, Fitzgerald RD. Remifentanil or propofol for sedation during carotid endarterectomy under cervical plexus block. Br J Anaesth 2002 89(4) 637-. ... 

Davis PJ, Lerman J, Suresh S, McGowan EX, Cote CJ, Landsman I, Henson LG. A randomized multicenter study of remifentanil compared with alfentanil, isoflurane, or propofol in anesthetized pediatric patients undergoing elective strabismus surgery. Anesth Analg 1997 84(5) 982-9. 

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. 

Crankshaw DP, Chan C, Leslie K, Bjorksten AR. Remifentanil concentration during target-controlled mfusion of propofol. Anaesth Intensive Care 2002 30(5) 578-83. 

Klemola UM, Mennander S, Saarnivaara L. Tracheal intubation without the use of muscle relaxants remifentanil or alfentanil in combination with propofol. Acta Anaesthesiol Scand 2000 44(4) 465-9. 

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... 

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

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. 

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. 

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. 

---