Does propofol interact with D2 dopamine receptors?

Propofol-based total intravenous anesthesia decreases the incidence of postoperative nausea and vomiting without affecting flap survival in free flap breast reconstruction

Background

Postoperative nausea and vomiting (PONV) may cause undesirable effects after microsurgical breast reconstruction. Although total intravenous anesthesia (TIVA) with propofol has been demonstrated to be effective in reducing PONV, it has not been assessed in autologous free flap breast reconstruction. The purpose of this study was to investigate the antiemetic prophylaxis effect and safety of TIVA in microvascular breast reconstruction.

Methods

Eighty-three patients undergoing microsurgical breast reconstruction with propofol (31 patients) or sevoflurane (52 patients) were retrospectively reviewed. The incidence of PONV was assessed at 2, 6, and 24 hours after surgery. Mean arterial blood pressure (MAP) was compared at T₁ (after flap elevation but before transfer), T₂ (15 minutes after revascularization), and T₃ (at the end of surgery).

Results

The incidence of nausea was significantly reduced in the TIVA group over 0 to 2 hours period (P=0.017), and over 2 to 6 hours period (P=0.033). The incidence of vomiting was significantly reduced in the TIVA group over 0 to 2 hours period (P=0.006), and over 2 to 6 hours period (P=0.005). MAP was higher in the TIVA group at T₁ (P=0.018), T₂ (P=0.005), and T₃ (P=0.007). The incidence of flap failure was similar between the two groups (P=0.373).

Conclusions

Compared with sevoflurane maintaining anesthesia, propofol-based TIVA improves PONV with less fluctuation of MAP, and did not affect flap survival.

A Comparison of the Recovery Characteristics between Propofol-remifentil and Sevoflurane-remifentail Anesthesia for Total Thyroidectomy

ObjectivesThis study was investigated the recovery characteristics of propofol-remifentanil and sevoflurane-remifentanil anesthesia for total thyroidectomy MethodsEighty patients in ASA physical status 1 and 2 scheduled for total thyroidectomy were allocated randomly to either group P (n = 40) or group S (n = 40). Anesthesia was maintained with remifentanil effect site concentration (Ce) 1-3 ng/mL and propofol Ce 2-4 μ g/mL in the group P, and was maintained with remifentanil Ce 1-3 ng/mL and sevoflurane 1.5-2% in the group S. Blood pressure, heart rate, and bispectral (BIS) index were measured during perioperative period. The times from discontinuance of anesthetic agent to eye opening, to extubation, and to stating name were measured. Postoperative complications were evaluated. ObjectivesThis study was investigated the recovery characteristics of propofol-remifentanil and sevoflurane-remifentanil anesthesia for total thyroidectomy MethodsEighty patients in ASA physical status 1 and 2 scheduled for total thyroidectomy were allocated randomly to either group P (n = 40) or group S (n = 40). Anesthesia was maintained with remifentanil effect site concentration (Ce) 1-3 ng/mL and propofol Ce 2-4 μ g/mL in the group P, and was maintained with remifentanil Ce 1-3 ng/mL and sevoflurane 1.5-2% in the group S. Blood pressure, heart rate, and bispectral (BIS) index were measured during perioperative period. The times from discontinuance of anesthetic agent to eye opening, to extubation, and to stating name were measured. Postoperative complications were evaluated. ResultsThere were no significant differences between group P and S on the blood pressure, heart rate, and recovery time. BIS index of group P showed lower than that of group S during operation (P < 0.05). The incidences of side effects were similar in the two groups, though the incidence of nausea was higher in the group S (P < 0.05). ConclusionsPropofol-remifentanil anesthesia was more advantageous than sevoflurane-remifentanil anesthesia for thyroidectomy in view of side effect incidences.

Total intravenous anesthesia with propofol reduces postoperative nausea and vomiting in patients undergoing robot-assisted laparoscopic radical prostatectomy: a prospective randomized trial

PURPOSE

We investigated the effect of total intravenous anesthesia (TIVA) with propofol on postoperative nausea and vomiting (PONV) after robot-assisted laparoscopic radical prostatectomy (RLRP) in patients at low risk of developing PONV, in comparison to balanced anesthesia with desflurane.

MATERIALS AND METHODS

Sixty two patients were randomly assigned to the Des or TIVA group. Propofol and remifentanil were used for induction of anesthesia in both groups and for maintenance of the anesthesia in the TIVA group. In the Des group, anesthesia was maintained with desflurane and remifentanil. In both groups, postoperative pain was controlled using fentanyl-based intravenous patient controlled analgesia, and ramosetron 0.3 mg was administered at the end of surgery. The incidence of PONV, severity of nausea and pain, and requirements of rescue antiemetics and analgesics were recorded.

RESULTS

The incidence of nausea in the post-anesthetic care unit was 22.6% in the Des group and 6.5% in the TIVA (p=0.001) group. The incidence of nausea at postoperative 1-6 hours was 54.8% in the Des group and 16.1% in the TIVA group (p=0.001). At postoperative 6-48 hours, there were no significant differences in the incidence of nausea between groups.

CONCLUSION

In order to prevent PONV after RLRP in the early postoperative period, anesthesia using TIVA with propofol is required regardless of patient-related risk factors.

Postoperative nausea and vomiting after endoscopic thyroidectomy: total intravenous vs. balanced anesthesia

BACKGROUND

Endoscopic thyroidectomy was recently introduced and has been rapidly accepted by surgeons and patients. The present study was conducted to estimate and compare the incidences of postoperative nausea and vomiting (PONV) after endoscopic thyroidectomy using two different anesthetic methods: sevoflurane based balanced anesthesia; total intravenous anesthesia (TIVA).

METHODS

Ninety nine female patients that were scheduled to undergo elective endoscopic thyroidectomy under general anesthesia were enrolled. These patients were randomly allocated to receive sevoflurane based balanced anesthesia (BA group) or propofol-remifentanil anesthesia (TIVA group). PONV was evaluated using a 4-point Likert scale, and pain using a visual analogue scale (VAS; range 0 to 100) for 0-2, 2-6, and 6-24 hours postoperatively. At 24 hours postoperatively, overall patient satisfaction regarding PONV and pain were recorded.

RESULTS

The incidence of PONV was 14.6% in the TIVA group and 51.3% in the BA group. The incidence of nausea at 0-2 and 2-6 hours postoperatively was lower in the TIVA group than in the BA group (4.2% vs. 35.9%, 6.3% vs. 23.1%, respectively), but no between-group difference was observed at 6-24 hours postoperatively (8.3% vs. 5.1%). Antiemetic usage at 0-2 and 2-6 hours was lower in the TIVA than the BA group (4.2% vs. 38.5%, 6.3% vs. 23.1%), but no between-group difference was observed for 6-24 hours (6.3% vs. 7.7%). There were no differences in pain or in patient satisfaction.

CONCLUSIONS

After endoscopic thyroidectomy, total intravenous anesthesia with propofol-remifentanil is associated with less PONV during the early postoperative period (0-6 hours) than sevoflurane based balanced anesthesia.

Vomiting after a pediatric adenotonsillectomy: comparison between propofol induced sevoflurane-nitrous oxide maintained anesthesia and TIVA with propofol-remifentanil

BACKGROUND

Anesthesia methods and drugs affect postoperative nausea and vomiting. Propofol is known to have antiemetic effects. We compared the incidence of postoperative vomiting (POV) in children undergoing an adenotonsillectomy; anesthesia in one group was induced with propofol and maintained with sevoflurane and nitrous oxide, and the other group received total intravenous anesthesia (TIVA) with propofol-remifentanil.

METHODS

Ninety children, ASA physical status I, were assigned randomly to one of two groups. In the PSN group, anesthesia was maintained with 2-3 vol% sevoflurane and 50% nitrous oxide. In the PR group, anesthesia was maintained with 10 mg/kg/h propofol and 0.25 µg/kg/min remifentanil. In both groups, anesthesia was induced with 0.5 µg /kg remifentanil and 2 mg/kg propofol. The incidence of POV and the need for rescue antiemetics were assessed in the postanesthesia care unit at 6, 12, and 24 hours postoperatively.

RESULTS

The total incidence of POV was not significantly different between the groups; POV occurred in eight (17.7%) and three (6.7%) children in the PSN and PR groups, respectively. Postoperative frequency of retching in the recovery room was significantly higher in the PSN group, with four children (8.9%) in the PSN group compared to none (0%) in the PR group (P = 0.041). The frequency of POV 24 hrs after exiting the recovery room tended to be higher in the PSN group than the PR group, but no statistically significant difference was observed.

CONCLUSIONS

If the development of POV in the early anesthetic recovery phase of children undergoing adenotonsillectomy is adequately prevented, propofol-induced anesthesia maintained with sevoflurane-nitrous oxide is as safe as TIVA with propofol-remifentanil.

Comparative study of the antiemetic efficacy of ondansetron, propofol and midazolam in the early postoperative period

BACKGROUND AND OBJECTIVE

To compare the antiemetic efficacy of ondansetron with two different hypnotic drugs (propofol 15 mg, midazolam 1 and 2 mg) for the treatment of established postoperative nausea and vomiting (PONV).

METHODS

Four-hundred-and-fifty-three patients scheduled for elective gynaecological or abdominal surgery were enrolled. One-hundred-and-twenty patients (26%) experienced postoperative emesis, and when nausea scores reached 2 or greater on a five-point scale, they were randomized to receive intravenously: propofol 15 mg (1.5 mL) in Group P, midazolam 1 mg in Group M1, midazolam 2 mg in Group M2 and ondansetron 4 mg in Group O.

RESULTS

Four patients (13.3%) in Group P, 13 patients (43.3%) in Group M1, five patients (16.6%) in Group M2 and one patient (3.3%) in Group O required a second dose of the study drug. After administration of the study drugs, nausea scores were significantly lower in all groups than before these drugs were given. No patient had a sedation score over 3 (the patients remained awake and/or responded to verbal contact). The sedative effects of midazolam and propofol lasted for a much shorter time than the antiemetic effects of these drugs.

CONCLUSIONS

Propofol and midazolam used in subhypnotic doses were as effective as ondansetron in treating PONV in patients undergoing abdominal or gynaecological surgery without untoward sedative or cardiovascular effects.

Management of postoperative nausea and vomiting in children

In spite of improvements in anesthesia techniques, the 'big little problem' of postoperative nausea and vomiting (PONV) still exists. PONV can prolong recovery room stay and hospitalization, and is one of the most common causes of hospital readmission after day surgery. While there is little evidence to support prophylactic administration of antiemetics in patients at low risk of PONV, the higher risk population could benefit from the use of adequate antiemetic drugs. A wide variety of pharmacological approaches have been reported to be effective, as well as some nonpharmacological approaches. Antiemetic drugs available to treat or prevent PONV include phenothiazines, antihistamines, anticholinergics, benzamides, butyrophenones and 5-HT(3) antagonists. Since available drugs still present undesired adverse effects and are not completely able to control PONV, clinical investigations are ongoing for more effective and better tolerated agents; indeed, the ideal antiemetic drug might be cost-effective for routine use.

Rett syndrome: investigation of nine patients, including PET scan

BACKGROUND

We describe nine females with Rett Syndrome (RS), aged 14 to 26 years. All had had developmental delay before the end of their first year and had subsequently regressed to profound dementia with apraxia, ataxia, irregular respirations and often also seizures.

METHODS

The Revised Gesell developmental assessment and Alpern-Boll Developmental Profile were used in modified form. Volumetric measurements of basal ganglia using MRI were compared with the findings in nine age-matched volunteer females. Positron emission scans with [18F]-6-fluorodopa and [11C]-raclopride were performed under light anesthesia with intravenous Propofol, and the findings were compared with those in healthy control girls. Bidirectional sequencing of the coding regions of the MECP2 gene was investigated in blood samples for mutational analyses.

RESULTS

The RS females functioned at a mental age level ranging from about 4 to 15 months. The scores correlated with height, weight and head circumference. Magnetic resonance scans of basal ganglia showed a significant reduction in the size of the caudate heads and thalami in the Rett cases. Positron emission scans demonstrated that the mean uptake of fluorodopa in RS was reduced by 13.1% in caudate and by 12.5% in putamen as compared to the controls, while dopamine D2 receptor binding was increased significantly by 9.7% in caudate and 9.6% in putamen. Mutations in the coding regions of the MECP2 gene were present in all nine patients. No significant correlation between type and location of mutation and volumetric changes or isotope uptake was demonstrable.

CONCLUSIONS

Our findings suggest a mild presynaptic deficit of nigrostriatal activity in Rett syndrome.

The effect of anaesthetic technique on postoperative nausea and vomiting after day-case gynaecological laparoscopy

Gynaecological surgery is of high emetogenic potential and both total intravenous anaesthesia (TIVA) and prophylactic antiemetic therapy may reduce the incidence of postoperative nausea and vomiting (PONV). We studied 144 patients scheduled for day-case gynaecological laparoscopy in a randomized trial comparing balanced inhalational anaesthesia and prophylactic dolasetron (group I+D) with propofol TIVA and dolasetron (group T+D) or TIVA alone (group T). The primary outcome of "complete response" (no vomiting, no treatment for PONV) was not significantly different among groups (34%, 51%, 32%; groups I+D vs T+D vs T, P=0.12). During the first hour after surgery, group I+D had nausea of greater severity (P<0.03). During hospital admission, group T had more vomiting (P<0.03). From discharge until 24 hours postoperatively, 55% of group I+D experience nausea and 38% vomited. The incidence and severity of nausea were significantly lower in the TIVA groups (P<0.04 and <0.05 respectively). There were no significant differences between groups T+D and T, although comparing all groups the complete response rate was highest and the post-discharge incidence and severity of nausea lowest in group T+D. In conclusion, propofol TIVA, with or without dolasetron, reduced postoperative nausea, but not perioperative vomiting or antiemetic requirement, when compared with inhalational anaesthesia plus dolasetron.

Combination therapy for postoperative nausea and vomiting - a more effective prophylaxis?

The problem of postoperative nausea and vomiting (PONV) remains far from being resolved. Despite the introduction of new classes of antiemetics and a vast amount of published research, there is a general impression that there has been little progress in this area. The multifactorial etiology of PONV might be better addressed using a combination of drugs acting at different receptor sites. This approach of balanced antiemesis may be the answer towards achieving a significant improvement in the management of PONV. This article will cover the different strategies used to prevent PONV with particular emphasis on combination antiemetics. A review of the currently available methods to manage PONV as well as the physiological and pharmacological basis of combination therapy is presented.

Propofol anesthesia increases dopamine and serotonin activities at the somatosensory cortex in rats: a microdialysis study

We sought to estimate the activities of dopamine and serotonin in animals receiving propofol anesthesia. The in vivo microdialysis technique was used in Sprague-Dawley rats (n = 6) to measure the major metabolites of dopamine and serotonin, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (4-hydroxy-3-methyphenylacetic acid; HVA) and 5-hydroxy indole acetic acid (5-HIAA) in the somatosensory cortex. We also measured the levels of propofol in the brain and blood by microdialysis sampling in another group of rats (n = 6). During the experiment, the rat was infused intravenously (IV) with propofol at a rate of 10 mg x kg(-1) x h(-1) for 60 min and 60 mg x kg(-1) x h(-1) for 40 min. We found that IV infusion of propofol at a rate of 60 mg x kg(-1) x h(-1) significantly increased DOPAC, HVA, and 5-HIAA. We also determined that these changes correlated well with propofol levels in the brain and blood. We concluded that anesthetic doses of propofol increased the functional activities of dopamine and serotonin in the cortex. These increases correlate well with propofol levels in the cortex and blood.

Metoclopramide reduces the induction dose of propofol

BACKGROUND

Metoclopramide has been shown to reduce the dose of thiopentone required for induction of anaesthesia. When propofol is used, there have been conflicting results with one small study showing a reduction in the anaesthetic dose and one study failing to demonstrate any effect.

METHODS

Two groups of 30 patients were studied. The patients were randomised to receive either saline 0.03 ml/mg or metoclopramide 0.15 mg/kg 5 min before a manual injection of propofol at a set rate.

RESULTS

This study shows a reduction in the dose of propofol required for the induction of general anaesthesia following an intravenous dose of metoclopramide. The induction dose of propofol was reduced by 24%.

CONCLUSION

The mechanism of reduction of propofol dose by metoclopramide is unknown; it may involve GABA or result from a more complex interaction involving dopamine blockade by metoclopramide.

Subhypnotic doses of propofol do not possess antidopaminergic properties

In order to investigate the possible interactions of propofol with the dopaminergic system, a prospective, randomized, double-blind, placebo-controlled study was performed on the profile of prolactin secretion, since prolactin blood levels are known to increase when dopaminergic receptors are blocked. Ten fasting female patients scheduled to receive cancer chemotherapy were allocated to receive either propofol at a rate of 1 mg.kg-1.h-1 or Intralipid 0.1 ml.kg-1.h-1. The study included two consecutive chemotherapy cycles; each patient received in a random order propofol or Intralipid. The infusions were started 4 h prior to induction of chemotherapy; prolactin blood levels were determined at time 0, 30, 60, 120, and 240 min (end of the study period). The basal prolactin blood levels were 14.2 +/- 4.3 vs 12.8 +/- 2.7 and 10.7 +/- 1.7 vs 14.0 +/- 3.6 ng/mL at the end of the study for propofol and Intralipid, respectively. These results suggest that the antiemetic properties of propofol are not mediated via interactions with the dopaminergic system.

Propofol in terminal care

In advanced cancer patients close to death, delirium, multifocal myoclonus, and restlessness may occur. Multi-organ failure and related metabolic changes are mostly responsible for these symptoms. A pharmacologic approach to manage the delirium is necessary in the majority of cases. Benzodiazepines, neuroleptics, and barbiturates are the most common drugs used. In the case reported, propofol administered at very low doses provided good control of neuropsychiatric symptoms. After a loading dose of 20 mg, an infusion of 50-70 mg per hr was started. The patient died peacefully after 8 hr of propofol infusion, without requiring opioids. Propofol seems to be a promising drug in treating the terminal agitated state that can be associated with the dying process.

Prolonged myoclonus and meningism following propofol

The purpose of this report is to describe a new complication of propofol administration. A previously fit patient underwent intravenous anaesthesia with propofol for removal of dental wires. Postoperatively he developed myoclonic jerking of his limbs. On regaining consciousness he complained of an occipital headache, neck stiffness and photophobia, and was found to have nuchal rigidity on examination. These clinical features resolved over the following week. Subsequent investigations failed to explain the aetiology of the symptoms of meningeal irritation, which suggests that propofol was the causative agent. While prolonged myoclonus has been previously described with propofol administration, this is the first report of meningism occurring with its use.