Propofol-induced anaesthesia. Double-blind comparison of recovery after anaesthesia induced by propofol or thiopentone

Propofol-Related Infusion Syndrome: A Bibliometric Analysis of the 100 Most-Cited Articles

Propofol-related infusion syndrome (PRIS) is a rare, yet life-threatening sequelae to prolonged administration of the anesthetic propofol in mechanically intubated patients. The condition is characterized by progressive multi-system organ failure and eventual mortality; of note, the predominant characteristics of PRIS involve but are not limited to cardiovascular impairment and collapse, metabolic and lactic acidosis, rhabdomyolysis, hyperkalemia, and acute renal failure. While potent or extended doses of propofol have been found to be the primary precipitating factor of this condition, others such as age, critical illness, steroid therapy, and hyperlipidemia have been discovered to play a role as well. This bibliometric analysis was done to reflect the current relevance and understanding of PRIS in recent literature. The SCOPUS database was utilized to conduct a search for articles with keywords "propofol infusion syndrome" and "propofol syndrome" from February 24, 2001, until April 16, 2023, with parameters for article title, citation number, citation per year, author, institution, publishing journal, and country of origin. PRIS was first defined in 1990, just a year after its approval by the Food and Drug Administration for use as a sedative-hypnotic. Since then, interest in PRIS slowly rose up to 13 publications per year in 2013. Seven papers on the topic were published in Critical Care Medicine, six in Neurocritical Care, and four in Anesthesia. The most common institutions were Mayo Clinic, Northeastern University, and Tufts Medical Center. To our knowledge, this is the first bibliometric analysis to evaluate the most influential publications about PRIS. A majority of the research is case-based, possibly owing to the rarity of the condition. Our research suggests that confounding factors outside the precipitating dosage of propofol may be implicated in the onset and progression of PRIS. This study could therefore bring renewed interest to the topic and lead to additional research focused on fully understanding the pathophysiology of PRIS in order to promote the development of novel diagnostics and treatment.

Neurocognitive Impairment After Propofol With Relevance for Neurosurgical Patients and Awake Craniotomies-A Prospective Observational Study

Background: Short-acting anesthetics are used for rapid recovery, especially for neurological testing during awake craniotomy. Extent and duration of neurocognitive impairment are ambiguous.

Methods: Prospective evaluation of patients undergoing craniotomy for tumor resection during general anesthesia with propofol (N of craniotomies = 35). Lexical word fluency, digit span and trail making were tested preoperatively and up to 24 h after extubation. Results were stratified for age, tumor localization and hemisphere of surgery. Results in digit span test were compared to 21 patients during awake craniotomies.

Results: Word fluency was reduced to 30, 33, 47, and 87% of preoperative values 10, 30, 60 min and 24 h after extubation, respectively. Digit span was decreased to 41, 47, 55, and 86%. Performances were still significantly impaired 24 h after extubation, especially in elderly. Results of digit span test were not worse in patients with left hemisphere surgery. Significance of difference to baseline remained, when patients with left or frontal lesions, i.e., brain areas essential for these tests, were excluded from analysis. Time for trail making was increased by 87% at 1 h after extubation, and recovered within 24 h. In 21 patients undergoing awake craniotomies without pharmacological sedation, digit span was unaffected during intraoperative testing.

Conclusion: Selected aspects of higher cognitive functions are compromised for up to 24 h after propofol anesthesia for craniotomy. Propofol and the direct effects of surgical resection on brain networks may be two major factors contributing (possibly jointly) to the observed deficits. Neurocognitive testing was unimpaired in patients undergoing awake craniotomies without sedation.

A comparison of propofol and thiopentone use in electroconvulsive therapy: cognitive and efficacy effects

OBJECTIVE

The purpose of this study was to compare thiopentone and propofol administration for electroconvulsive therapy (ECT) in terms of associated efficacy and cognitive side effects in the immediate and medium term.

METHOD

Participants comprised 30 depressed patients who were administered either propofol or thiopentone as an anesthetic agent for ECT. Clinical rating scales and a battery of neuropsychological tests were administered at baseline, after 6 treatments, 1 to 3 days after treatment end point, and at 1-month follow-up.

RESULTS

Thiopentone administration was associated with advantages in efficacy and cognitive side effects compared with propofol administration.

CONCLUSIONS

This study reports some serendipitous findings regarding the comparative effects of the anesthetic agents, propofol and thiopentone. Although limited by small sample size, results suggest that thiopentone has advantages for use as an anesthetic agent with ECT compared with propofol. It also highlights the need for further investigation of the impact of anesthetic agents on the cognitive side effects and efficacy of ECT.

Propofol-thiopentone admixture: recovery characteristics

We have investigated, in a prospective double-blind study, recovery from anaesthesia induced by two admixtures of propofol and thiopentone and compared it with a third group of patients who received propofol and lignocaine. Ninety unpremedicated ASA 1 or 2 patients scheduled for elective gynaecological laparoscopy as a daycase procedure were randomly allocated to receive one of three different mixtures for induction of anaesthesia as part of a standardized anaesthetic: Group P50: propofol 1% 10 ml/thiopentone 2.5% 10 ml, Group P75: propofol 1% 15 ml/thiopentone 2.5% 5 ml, Group P100: propofol 1% 20 ml/lignocaine 1% 4 ml. Recovery from anaesthesia was assessed for up to four hours post-induction by critical flicker fusion threshold and best post-box toy completion time. Comparison was made with preoperative baseline performance. There was no significant difference in postoperative recovery between the three groups with either assessment but no group returned to their mean preoperative performance levels within the first four hours post-induction. Nor was there any difference between the groups with respect to postoperative analgesia or anti-emetic administration. Utilizing the most sensitive end-point, a sample of nearly 1000 patients in each group would be required to confirm the observed difference with a power of 0.8 based on the data from this study. In comparison with lignocaine, the addition of thiopentone to propofol does not delay recovery from anaesthesia and does not increase postoperative analgesic or anti-emetic requirements.

Patient evaluation and comparison of the recovery profile between propofol and thiopentone as induction agents in day surgery

The patient's subjective perception of the quality of his/her recovery after day case anaesthesia with propofol or thiopentone as induction agents is still controversial. The authors investigated the perception and quality of awakening after anaesthesia during the recovery period and at 24 hours and 72 hours, in outpatients undergoing anaesthesia induced either with propofol or thiopentone and maintained with a volatile anaesthetic. In a double-blind study in adults undergoing knee arthroscopy in a day surgery unit, propofol and thiopentone were compared as induction agents in 60 randomized outpatients. A Critical Flicker Fusion Threshold test (CFFT), verbal test for anxiety, visual analog scale for anxiety and pain, and questionnaires were used to assess objectively and subjectively the quality of anaesthesia and awakening during the postoperative period. Demographic data and mean duration of anaesthesia were similar. In the propofol group, patients awoke more rapidly (9.2 +/- 5.8 vs 12.3 +/- 5.8 min) (P < 0.05); however, the CFFT measurements did not show any significant difference between the groups, except at time = 0 min, when 17 patients in the propofol group were able to perform the test versus only 10 patients in the thiopentone group (P < 0.05). At 4, 24, and 72 hours postoperatively, the authors were unable to detect any difference between the two groups. Except for early recovery, there were no differences between the intermediate and late recovery profiles, when propofol or thiopentone was used as the anaesthetic induction agent in day surgery.

The laboratory assessment of daytime sleepiness in childhood

Excessive daytime sleepiness is a disabling symptom of diverse etiologies. This article reviews the various, currently available diagnostic techniques that can be applied in the evaluation of childhood hypersomnolence, along with their merits and limitations. Normal polysomnographic data of children differ from those of adults. Serial studies may be required in evolving childhood narcolepsy for establishing a definitive diagnosis.

Recovery characteristics following induction of anaesthesia with a combination of thiopentone and propofol

The purpose of this study was to determine the rate and quality of recovery when general anaesthesia was induced with a mixture of thiopentone and propofol, compared with thiopentone or propofol alone. Sixty ASA class I and II women scheduled for out-patient laparoscopic surgery underwent induction of anaesthesia with either (i) thiopentone, (ii) propofol, or (iii) a mixture of the two, in a randomized, double-blind fashion. Anaesthesia was then maintained using nitrous oxide, isoflurane and fentanyl. A psychometric test was administered before and after surgery, and the time taken to reach a series of recovery milestones was noted. Patients were discharged as soon as they were ambulant and had satisfactory control of pain and nausea with oral agents. They were telephoned at 24-48 hr later, and asked to rate their experience of a list of side effects on an ordinal scale. Patient groups were demographically comparable and underwent surgery of the same duration. Those receiving thiopentone were discharged after a mean time of 3 hr 25 +/- 58 min (SD). The corresponding figures for propofol and the thiopentone/propofol mixture were 2 hr 40 min (+/- 49) and 2 hr 48 min (+/- 68) respectively. The recovery time between thiopentone and the other two regimes was different (P < 0.05). All three groups experienced equally frequent and severe nausea, headache, tiredness and other side effects during the next 24 hr. It is concluded that induction with a mixture of thiopentone and propofol leads to a similar rate and quality of recovery to that of propofol above.(ABSTRACT TRUNCATED AT 250 WORDS)

The subjective effects of low-dose propofol. A double-blind study to evaluate dimensions of sedation and consciousness with low-dose propofol

In this study the subjective effects (sedation and mood) of subanaesthetic doses of propofol were examined in 28 healthy male volunteers. A computer model was used to predict the infusion profiles necessary to obtain steady state propofol plasma concentrations of 0.3 microgram.ml-1, 0.6 microgram.ml-1, 0.9 microgram.ml-1. Objective measures of sedation from saccadic eye movement and choice reaction time gave significant dose responses at each level but a battery of psychometric tests failed to show dose-related subjective responses. Of particular note in the subjective data is the lack of a difference between groups or even of a consistent trend within the data. This suggests that a low concentration of propofol in plasma does not induce euphoria or a sense of well-being. The anecdotal evidence available for mood changes with propofol therefore remains unsubstantiated.

Anxiety levels following anaesthesia for day-case surgery. A comparison of state anxiety levels following induction of anaesthesia with propofol or thiopentone

The effect of different induction agents on postoperative state anxiety levels was investigated. Propofol produces statistically significant lower levels when compared with thiopentone. This finding suggests that propofol should remain the drug of choice for short duration anaesthesia.

Recovery characteristics using isoflurane or propofol for maintenance of anaesthesia: a double-blind controlled trial

We studied 114 female patients (ASA 1 or 2) who were within 20% of ideal body weight and who were scheduled to undergo gynaecological laparoscopy which required supplementation with an opioid (groups IA and PA), or dental procedures which did not require opioid supplementation (groups IO and PO). A computerised package of psychomotor tests was performed before surgery. Anaesthesia was induced with propofol 2.5 mg.kg-1 and all patients received atracurium 0.3 mg.kg-1 and 67% nitrous oxide in oxygen. Patients in group IA received isoflurane 1% (inspired), and alfentanil 10 micrograms.kg-1 as a bolus and 10 micrograms.kg-1.h-1 as an infusion. Patients in group PA received propofol 9 mg.kg-1.h-1 as an infusion, decreasing to 6 mg.kg-1.h-1 after 15 min, together with alfentanil 10 micrograms.kg-1.h-1. Patients in groups IO and PO received isoflurane and propofol in the regimens described for groups IA and PA, but without alfentanil. Recovery was assessed by a blinded observer who recorded times to awakening (eye opening) and orientation (giving date of birth), and who repeated the psychomotor tests at 1, 3 and 5 h. Linear analogue scales of mood, nausea and pain were obtained and other side effects were noted in the succeeding 48 h. A matched control group of 25 females (who were not anaesthetised) underwent psychomotor testing on four occasions in order to assess the 'learning effect' of repeated recovery testing. The analysis of recovery tests did not assume a normal distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-blind comparison of patient recovery after induction with propofol or thiopentone for day-case relaxant general anaesthesia

Postoperative recovery after induction with either propofol or thiopentone has been compared in forty ASA I unpremedicated day surgery patients undergoing surgical extraction of third molar teeth under relaxant general anaesthesia. Mean recovery times in the propofol group, required for patients to sit out of bed (44.8 minutes; SD 18.6) and meet discharge criteria (113.1 minutes; SD 34.5) were significantly (P less than 0.05) shorter than those in the thiopentone group (59.7 minutes; SD 21.4 and 133.5 minutes; SD 34.5). Fewer patients in the propofol group were treated in the recovery room for nausea and vomiting and the incidence of mild nausea not requiring treatment was less in the propofol group, but these differences were not statistically significant. Postoperative mental performance, measured by the FAST index, a new test of mental speed, was reduced on average by 1.7% of preoperative levels, during the recovery period tested, with no significant difference between the groups.