Sedation with intravenous infusions of propofol or thiopentone. Effects on pain perception

The aim of this study was to investigate pain perception during thiopentone or propofol infusions for sedation. Thirty ASA 1 or 2 patients received a two step infusion of either thiopentone (step 1: 1.25 mg.kg-1 followed by 2.5 mg.kg-1.h-1; step 2: 1.25 mg.kg-1 and 12.5 mg.kg-1.h-1; n = 15) or propofol (step 1: 0.5 mg.kg-1, 1 mg.kg-1.h-1; step 2: 0.5 mg.kg-1, 5 mg.kg-1.h-1; n = 15) for sedation. At control and 10 min after the start of each infusion dosage, reaction times and thermal pain detection thresholds were determined. We found no clinically or statistically significant depression of thermal pain detection thresholds during propofol or thiopentone infusions and these are, therefore, unlikely to be associated with clinically relevant hyperalgesia.

Total intravenous anesthesia is best for neurological surgery

We believe that today balanced TIVA represents the best anesthetic technique for neurological surgery. Freely acknowledging that this point of view is unproven (36) with regard to the hard criterion of patient outcome on leaving the hospital, we submit that the intermediate or surrogate criteria discussed make a convincing case for preferring TIVA to volatile-based anesthetic techniques. Until a study demonstrating hard outcome differences between the two techniques is achieved, we will continue to encourage the use of TIVA in neuroanesthesia, based on its practical (anesthetic depth, neuromonitoring, surgical field) and theoretical (homeostasis, metabolism, antinociception, neuroprotection) advantages.

Epidural droperidol reduces the side effects and duration of analgesia of epidural sufentanil

The postoperative combination of epidural sufentanil and epidural droperidol was assessed in 40 patients with hip or knee arthroplasties. Patients were given a single intravenous (i.v.) bolus of sufentanil 50 micrograms with either droperidol 2.5 mg or placebo (0.9% NaCl) epidurally in a double-blind, randomized design at the first request for postoperative analgesia. Pain scores, side effects, and sufentanil plasma concentrations were regularly assessed for 5 h after injection. Heat pain thresholds were measured pre- and postoperatively. The incidence of nausea, emesis, and pruritus associated with epidural sufentanil was decreased by epidural droperidol (P < 0.01, P < 0.001, P < 0.05, respectively). More patients were sedated with epidural droperidol than with placebo (P < 0.02). The initial reduction in pain scores was similarly profound, but the duration of analgesia after sufentanil and droperidol was significantly shorter than after sufentanil and placebo (P < 0.02). Phasic and tonic heat pain thresholds were increased postoperatively 1 h after sufentanil and placebo (P < 0.01 and P < 0.0005, respectively). Only the tonic heat pain thresholds were increased 1 h after sufentanil and droperidol (P < 0.002). The addition of epidural droperidol significantly reduced the excitatory side effects of epidural sufentanil while diminishing the duration of analgesia. These interactions may be of clinical significance in reducing the toxicity of opioids, but the effect on duration of analgesia must be considered when repeated doses of opioids are prescribed.

Epidural-morphine-induced pruritus: propofol versus naloxone

In a prospective, randomized, double-blind clinical trial, we compared the efficacy of propofol and naloxone for the treatment of spinal-morphine-induced pruritus. Forty patients presenting with severe pruritus within 24 h of epidural morphine administration were allocated to receive either propofol 10 mg intravenously (i.v.) or naloxone 2 micrograms/kg. In the absence of a positive response, a second dose of the same treatment was given 5 min later. Pruritus and the level of post-operative pain were assessed every 5 min up to the end of the study period (45 min) using a verbal rating scale. The overall success rate in treating pruritus was similar in the two groups (80%). The rate of success after the first injection of the treatment drug was also similar (55%). The level of postoperative pain decreased after drug treatment in six patients (30%) in the propofol group versus none in the naloxone group (P < 0.05). Forty-five percent of the patients in the naloxone group had an increase in the level of postoperative pain versus none in the propofol group (P < 0.05). In conclusion, these results suggest that propofol and naloxone are equally effective in treating spinal-morphine-induced pruritus. However, the level of postoperative pain is significantly less in the propofol group.

[Pruritus associated with liver disease: propofol, a new therapeutic approach?]

Pruritus is a severe and troublesome symptom in patients with cholestasis and is often difficult to treat. Propofol was recently shown to be efficient in the treatment of pruritus secondary to spinal morphine administration. In a prospective, randomized, double-blind, cross-over and placebo controlled study, 20 patients received 1 dose of propofol (15 mg) and 1 dose of Intralipid (1.5 mg) during a 2-day study period. Pruritus was assessed by a visual analogue scale from 0 (no pruritus) to 10 (most severe pruritus imaginable). Treatment success was defined as a decrease in pruritus of at least 4 points on the scale in 80% of the patients receiving propofol and in 15% of those receiving intralipid (p < 0.05). Discomfort on injection was observed in 15% under propofol treatment. In conclusion this study shows that subhypnotic doses of propofol are effective for the short-term symptomatic relief of pruritus associated with liver disease. At the dose administered, side effects were rare and minor.

Propofol in the management of refractory status epilepticus: a case report

Status epilepticus is one of the most frequent neurological emergencies in the intensive care unit. Standard treatment includes intravenous barbiturates, benzodiazepines and phenytoin. However, drug coma is sometimes necessary to control refractory status epilepticus. We report such a case, successfully treated by intravenous propofol coma to EEG burst suppression.

Propofol improves patient comfort during cisplatin chemotherapy. A pilot study

20 consecutive patients with nausea and vomiting secondary to cisplatin chemotherapy uncontrolled by serotonin-antagonist and corticosteroid prophylaxis during their first cycle received adjuvant propofol. This new anesthetic agent was added at subhypnotic doses, i.e. 1 mg/kg/h, as a continuous intravenous infusion during the two subsequent chemotherapy cycles. In 85 and 90% of patients, nausea and vomiting were prevented in the first 24 h following the first and second propofol-supplemented chemotherapy cycles respectively. 24-72 h postchemotherapy, this side effect remained suppressed in 75 and 70% of patients, respectively. Patients' comfort and appetite were improved. All 20 subjects preferred the propofol-containing regimen.

Urinary serotonin metabolite excretion during cisplatin chemotherapy

BACKGROUND

Nausea and vomiting associated with cisplatin chemotherapy is a source of major morbidity that remains difficult to control. Acute phase (0-24 hours after induction of chemotherapy) nausea and vomiting parallels plasma serotonin release, which explains the effectiveness of 5HT3 antagonists; serotonin release in the delayed phase (24-48 hours after induction), during which consistent antiemetic control remains elusive, has not been investigated. The effect of propofol, a recent addition to the antiemetic armamentarium, on this serotonin release has not been studied.

METHODS

Ten women with nausea and vomiting refractory to ondansetron and dexamethasone prophylaxis in their first cisplatin chemotherapy cycle were studied. Serial urinary 5-hydroxyindoleacetic acid (5-HIAA) levels were determined during a 48-hour period in 30 subsequent cycles, conducted under ondansetron/dexamethasone prophylaxis together with a propofol infusion.

RESULTS

There was a significant urinary 5-HIAA peak 6 hours after induction of chemotherapy, with no peaks thereafter. Propofol did not inhibit serotonin release.

CONCLUSIONS

Cisplatin chemotherapy is associated with serotonin release in the acute phase. There is no serotonin release during the delayed phase. Thus the use of 5HT3 antagonists for delayed-phase nausea and vomiting would appear questionable.

Spontaneous excitatory movements during recovery from propofol anaesthesia in an infant: EEG evaluation

Spontaneous excitatory movements have been observed during recovery from propofol anaesthesia in children. Epilepsy has been postulated as a possible mechanism to explain these movements. We report the first case in which these spontaneous excitatory movements were studied using simultaneous multichannel EEG recordings.

Subhypnotic doses of propofol relieve pruritus associated with liver disease

BACKGROUND

Pruritus is a severe and troublesome symptom in patients with cholestasis and is often difficult to treat. Propofol was recently shown to be efficient in relieving pruritus secondary to spinal morphine administration. The efficacy of propofol was therefore investigated in patients with pruritus associated with liver disease.

METHODS

In a prospective, randomized, double-blind, crossover, placebo-controlled study, 10 patients received 2 doses of propofol (1.5 mL = 15 mg) and 2 doses of placebo (1.5 mL of Intralipid, Kabi-Pharm., Helsinki, Finland) during a 4-day study period. Pruritus was assessed by a verbal rating score from 0 (no pruritus) to 10 (most severe pruritus imaginable). Treatment success was defined as a decrease of pruritus of at least 4 points in the verbal rating score.

RESULTS

Treatment success was achieved in 85% of the patients receiving propofol and in 10% of those receiving Intralipid (P < 0.01). Discomfort on injection (15%) and slight dizziness (10%) were observed with propofol treatment.

CONCLUSIONS

This study shows that subhypnotic doses of propofol are effective for the short-term symptomatic relief of pruritus associated with liver disease. At the dose used, side effects were rare and minor.

Subhypnotic doses of propofol possess direct antiemetic properties

Propofol is associated with a low incidence of postoperative nausea and vomiting. In a prospective, randomized, double-blind, placebo-controlled study, we investigated the possible direct antiemetic properties of a subhypnotic dose of propofol. Fifty-two ASA physical status I or II patients, aged 15-60 yr with nausea and vomiting after minor gynecologic, orthopedic, or digestive tract surgery, were included in the study and received either propofol (10 mg = 1 mL) or placebo (1 mL Intralipid) intravenously in the postanesthesia care unit. Patients treated with propofol experienced a larger reduction in nausea and vomiting than patients treated with placebo (81% vs 35% success rate; P less than 0.05). Patients successfully treated had a similar incidence of relapse (propofol 28%; placebo 22%) within the first 30 min after therapy. Thirty-three percent of the propofol-treated patients and 44% of the placebo-treated patients showed a minor increase in sedation. The level of postoperative pain did not change in either group. Hemodynamic values remained unchanged in both groups. Pain on injection (7.6%) or dizziness (3.6%) only occurred in the propofol group. We conclude that propofol has significant direct antiemetic properties.

Subhypnotic doses of propofol relieve pruritus induced by epidural and intrathecal morphine

We investigated the efficacy of subhypnotic doses of propofol for spinal morphine-induced pruritus in a prospective, randomized, double-blind, placebo-controlled study. Fifty patients, ASA physical status 1-3, with spinal morphine-induced pruritus were allocated to receive either 1 ml propofol (10 mg) or 1 ml placebo (Intralipid) intravenously after gynecologic, orthopedic, thoracic, or gastrointestinal surgery. In the absence of a positive response, a second drug treatment was given 5 min later. The persistence of pruritus 5 min after the second treatment dose was considered a treatment failure. All failures then received, in an open fashion, a supplementary dose of propofol (10 mg) and were reevaluated 5 min later. Both groups were well matched. The success rate was significantly greater in the propofol group (84%) than in the placebo (16%) group (P less than 0.05). Ninety percent of the treatment failures in the placebo group were successfully treated by a supplementary dose of 10 mg propofol. Eight percent of the patients (4% in each group) were resistant to all treatments, including naloxone 0.08 mg intravenously. Three patients had a slight increase in sedation in the propofol group versus none in control (not significant). The beneficial effect of treatment was longer than 60 min in 85% of patients in the propofol group and in 100% of the controls (not significant). These results suggest that propofol in a subhypnotic dose is an efficient drug treatment for spinal morphine-induced pruritus. At the dose administered (10 mg), side effects were rare and minor.

Echocardiographic assessment of the haemodynamic effects of propofol: a comparison with etomidate and thiopentone

The haemodynamic effects of propofol (2 mg/kg), etomidate (0.2 mg/kg) and thiopentone (4 mg/kg) were studied in 30 ASA 1 and 2 patients in whom anaesthesia had been induced with midazolam 0.1 mg/kg, fentanyl 5 micrograms/kg, vecuronium 0.1 mg/kg and atropine 10 micrograms/kg, and maintained with nitrous oxide in oxygen. Arterial pressure was measured directly and left ventricular diameters were determined by transoesophageal echocardiography. Systolic blood pressure after propofol and thiopentone and the end-systolic quotient (systolic pressure/end-systolic diameter), a measure of inotropy, decreased. Fractional shortening (end-diastolic-end-systolic diameter/end-diastolic diameter) decreased only in the thiopentone group. Diastolic blood pressure and end-diastolic diameter (a measure of preload) did not change in any of the groups, and the etomidate group showed no changes in the haemodynamic variables measured. Propofol shows simultaneous negative inotropy and afterload reduction, while thiopentone is exclusively negatively inotropic.