Guilty, or not guilty?: a short story of propofol abuse

Development of a highly sensitive gas chromatography-mass spectrometry method preceded by solid-phase microextraction for the analysis of propofol in low-volume cerebral microdialysate samples

To date, the commonly used intravenous anesthetic propofol has been widely studied, and fundamental pharmacodynamic and pharmacokinetic characteristics of the drug are known. However, propofol has not yet been quantified in vivo in the target organ, the human brain. Here, cerebral microdialysis offers the unique opportunity to sample propofol in the living human organism. Therefore, a highly sensitive analytical method for propofol quantitation in small sample volumes of 30 μL, based on direct immersion solid‐phase microextraction was developed. Preconcentration was followed by gas chromatographic separation and mass spectrometric detection of the compound. This optimized method provided a linear range between the lower limit of detection (50 ng/L) and 200 μg/L. Matrix‐matched calibration was used to compensate recovery issues. A precision of 2.7% relative standard deviation between five consecutive measurements and an interday precision of 6.4% relative standard deviation could be achieved. Furthermore, the permeability of propofol through a cerebral microdialysate system was tested. In summary, the developed method to analyze cerebral microdialysate samples, allows the in vivo quantitation of propofol in the living human brain. Additionally the calculation of extracellular fluid levels is enabled since the recovery of the cerebral microdialysis regarding propofol was determined.

Recent Insights Into Molecular Mechanisms of Propofol-Induced Developmental Neurotoxicity: Implications for the Protective Strategies

Mounting evidence has demonstrated that general anesthetics could induce developmental neurotoxicity, including acute widespread neuronal cell death, followed by long-term memory and learning abnormalities. Propofol is a commonly used intravenous anesthetic agent for the induction and maintenance of anesthesia and procedural and critical care sedation in children. Compared with other anesthetic drugs, little information is available on its potential contributions to neurotoxicity. Growing evidence from multiple experimental models showed a similar neurotoxic effect of propofol as observed in other anesthetic drugs, raising serious concerns regarding pediatric propofol anesthesia. The aim of this review is to summarize the current findings of propofol-induced developmental neurotoxicity. We first present the evidence of neurotoxicity from animal models, animal cell culture, and human stem cell-derived neuron culture studies. We then discuss the mechanism of propofol-induced developmental neurotoxicity, such as increased cell death in neurons and oligodendrocytes, dysregulation of neurogenesis, abnormal dendritic development, and decreases in neurotrophic factor expression. Recent findings of complex mechanisms of propofol action, including alterations in microRNAs and mitochondrial fission, are discussed as well. An understanding of the toxic effect of propofol and the underlying mechanisms may help to develop effective novel protective or therapeutic strategies for avoiding the neurotoxicity in the developing human brain.

Effects of propofol with midazolam verus lidocaine during gastroscopy in elderly patients

AIM: To compare the effects of propofol with midazolam versus lidocaine during endoscopy in elderly patients.

METHODS: Ninety-seven ASA-Ⅱ class patients were used as an experimental group. They were treated with propofol with midazolam for painless gastroscopy between July 2008 and July 2013 at our hospital. Eighty-two ASA-Ⅱ level patients who used traditional lidocaine gel pulp in painless gastroscopy were used as a control group. Age, weight, baseline blood pressure between two groups had no significant differences (P > 0.05 for all). Professional medical personnel recorded the changes in blood pressure, heart rate, oxygen saturation and adverse reactions in the examination process.

RESULTS: After the painless gastroscopy procedure, blood pressure and heart rate in the experimental group were significantly lower than those in the control group (blood pressure: 90.2 mmHg ± 2.5 mmHg vs 131.2 mmHg ± 3.4 mmHg; heart rate: 70.2 ± 1.5 vs 85.0 ± 6.4, P < 0.05). During the examination process, blood pressure and heart rate dropped initially and then rose to a stable level in the experimental group, while in the control group, blood pressure and heart rate initially increased and then decreased to a stable level. The differences were statistically significant (P < 0.05) within the two groups. Oxygen saturation between groups and within groups showed no significant differences (P > 0.05). Compared with the control group, adverse reactions in the experimental group were significantly reduced (χ² = 12.991, 142.482, 55.838, 179.000, P < 0.05). Times to wake up from anesthesia and drug elimination were relatively short in the experimental group (1.51 s ± 0.17 s, 8.21 s ± 2.32 s).

CONCLUSION: Propofol combined with midazolam in painless gastroscopy can effectively reduce the risk of cardiovascular diseases in patients and is associated with shorter times to wake up and drug elimination.