Potential inhibition of cytochrome P450 3A4 by propofol in human primary hepatocytes

Single stage pediatric airway reconstruction in solid organ transplant recipients

OBJECTIVES

To describe results of single stage laryngotracheal reconstruction (ssLTR) in patients with solid organ transplants and to discuss modifications which need to be considered in this subset of patients pre-operatively, intra-operatively and post-operatively.

STUDY DESIGN

We performed a retrospective case series review of children undergoing single stage laryngotracheal reconstruction in the context of prior solid organ transplant.

SETTING

A tertiary care academic setting.

METHODS

Pediatric cases undergoing Laryngotracheal reconstruction over a 3-year period. Demographic data including age, sex, presenting symptoms, operative details.

RESULTS

Two cases of ssLTR in solid organ transplant patients were found, one each with renal and cardiac transplants respectively. Both patients successfully underwent ssLTR for Grade 2 subglottic stenosis. The care of these patients was multidisciplinary and required alterations in their preoperative prophylactic antibiotics. While they did not require changes to the LTR post-operative sedation protocol, their immunosuppressant doses and target ranges were lowered. Special care was taken to avoid nephrotoxic and cardiotoxic medications throughout their hospital stay.

CONCLUSIONS

Although traditionally considered for double stage laryngotracheal reconstruction, single stage laryngotracheal reconstruction is a viable option in patients with solid organ transplant. These patients require a multidisciplinary approach and pharmacological protocol alterations pre-, intra-, and post-operatively.

Study on the mechanism of Salvia miltiorrhiza polysaccharides in relieving liver injury of broilers induced by florfenicol

In order to explore the transcriptomics and proteomics targets and pathways of Salvia miltiorrhiza polysaccharides (SMPs) alleviating florfenicol (FFC)-induced liver injury in broilers, 60 1-day-old broilers were randomly divided into 3 groups: control group ( GP1) was fed tap water, FFC model (GP2) was given tap water containing FFC 0.15 g/L, and SMPs treatment group (GP3) was given tap water containing FFC 0.15 g/L and SMPs 5 g/L. Starting from 1 day of age, the drug was administered continuously for 5 days. On the 6th day, blood was collected from the heart and the liver was taken. Then 3 chickens were randomly taken from each group, and their liver tissues were aseptically removed and placed in an enzyme-free tube. Using high-throughput mRNA sequencing and TMT-labeled quantitative proteomics technology, the transcriptome and proteome of the three groups of broiler liver were analyzed, respectively. The results of the study showed that the liver tissue morphology of the chicks in the GP1 and GP3 groups was complete and there were no obvious necrotic cells in the liver cells. The liver tissue cells in the GP2 group showed obvious damage, the intercellular space increased, and the liver cells showed extensive vacuolation and steatosis. Compared with the GP1 group, the daily gain of chicks in the GP2 group was significantly reduced (P < 0.0 5 or P < 0.01). Compared with the GP2 group, the GP3 group significantly increased the daily gain of chicks (P <0.0 5 or P <0.01). Compared with the GP1 group, the serum levels of ALT, AST, liver LPO, ROS, and IL-6 in the GP2 group were significantly increased (P < 0.0 5 or P < 0.01), and the contents of T-AOC, GSH-PX, IL-4, and IL-10 in the liver were significantly decreased (P < 0.0 5 or P < 0.01). After SMPs treatment, the serum levels of ALT, AST, liver LPO, ROS, and IL-6 were significantly reduced (P < 0.0 5 or P < 0.01), and the contents of T-AOC, GSH-PX, IL-4, and IL-10 in the liver were significantly increased (P < 0.0 5 or P < 0.01). There were 380 mRNA and 178 protein differentially expressed between GP2 group and GP3 group. Part of DEGs was randomly selected for QPCR verification, and the expression results of randomly selected FABP1, SLC16A1, GPT2, AACS, and other genes were verified by QPCR to be consistent with the sequencing results, which demonstrated the accuracy of transcriptation-associated proteomics sequencing. The results showed that SMPs could alleviate the oxidative stress and inflammatory damage caused by FFC in the liver of chicken and restore the normal function of the liver. SMPs may alleviate the liver damage caused by FFC by regulating the drug metabolism-cytochrome P450, PPAR signaling pathway, MAPK signaling pathway, glutathione metabolism, and other pathways.

Intraoperative Vitamin C Reduces the Dosage of Propofol in Patients Undergoing Total Knee Replacement

Purpose

Propofol is commonly used as an intravenous anesthetic in surgical patients. However, its usage is associated with adverse effects. Auxiliary medication can reduce the dose of intravenous anesthetics. Hence, we investigated whether vitamin C could lower propofol dosage in elderly patients undergoing total knee replacement surgery.

Patients and Methods

The trial was carried out in PLA General Hospital in Beijing, China. We enrolled patients aged ≥50 years who were undergoing unilateral total knee arthroplasty with total intravenous anesthesia combined with lumbar sciatic nerve block. The patients were randomly assigned to either the vitamin C (Vc) group (0.067 g/kg) or the control group (an equivalent dose of normal saline). Nerve block was done for all the patients before the general anesthesia. The same depth of anesthesia was maintained during the operation. We compared the propofol dosage and adverse events (eg hypotension) during anesthesia between the two groups. This study was registered with the Chinese Clinical Trial Registry, www.chictr.org.cn, number ChiCTR-TRC-16010112.

Results

There were significant differences in the total infusion dose (Vc group: 704.3 ± 188.6 mg; control group: 888.6 ± 232.7 mg; p = 0.016) and the average maintenance dose of propofol (Vc group: 5.8 ± 1.0 mg/kg/h; control group: 6.9 ± 1.6 mg/kg/h; p = 0.013). But there were no significant differences in the induction dose of propofol (control group: 90 mg, range 80-115 mg; Vc group: 100 mg, range 90-110 mg, p = 0.379) between the Vc and control groups. Furthermore, there were no significant differences in the hemodynamics and the incidence of intraoperative hypotension.

Conclusion

Vitamin C can reduce the dosage of propofol in patients undergoing total knee replacement.

Misdiagnosis of CTX due to propofol: The interference of total intravenous propofol anaesthesia with bile acid profiling

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare genetic disorder, characterised by chronic diarrhoea, xanthomas, cataracts, and neurological deterioration. CTX is caused by CYP27A1 deficiency, which leads to abnormal cholesterol and bile acid metabolism. Urinary bile acid profiling (increased m/z 627: glucuronide-5β-cholestane-pentol) serves as diagnostic screening for CTX. However, this led to a false positive CTX diagnosis in two patients, who had received total intravenous anaesthesia (TIVA) with propofol.

METHODS

To determine the influence of propofol on bile acid profiling, 10 urinary samples and 2 blood samples were collected after TIVA with propofol Fresenius 7 to 10 mg/kg/h from 12 subjects undergoing scoliosis correction. Urinary bile acids were analysed using flow injection negative electrospray mass spectrometry. Propofol binding to recombinant CYP27A1, the effects of propofol on recombinant CYP27A1 activity, and CYP27A1 expression in liver organoids were investigated using spectral binding, enzyme activity assays, and qPCR, respectively. Accurate masses were determined with high-resolution mass spectrometry.

RESULTS

Abnormal urinary profiles were identified in all subjects after TIVA, with a trend correlating propofol dose per kilogramme and m/z 627 peak intensity. Propofol only induced a weak CYP27A1 response in the spectral binding assay, minimally affected CYP27A1 activity and did not affect CYP27A1 expression. The accurate mass of m/z 627 induced by propofol differed >10 PPM from m/z 627 observed in CTX.

CONCLUSIONS

TIVA with propofol invariably led to a urinary profile misleadingly suggestive of CTX, but not through CYP27A1 inhibition. To avoid further misdiagnoses, propofol administration should be considered when interpreting urinary bile acid profiles.

Terminal Withdrawal of Mechanical Ventilation: A Hospice Perspective for the Intensivist

The intensive care unit (ICU) and hospice inpatient unit (IPU) environments differ in many ways. Although both endeavor to provide the best care possible for their patients, the day-to-day goals of these environments are almost antithetical. Similarly, the experiences and expertise of the staff differ. When performing a similar clinical task, it may be addressed in different ways because each group is engrained in their primary day-to-day focus. Terminal withdrawal of mechanical ventilation is a procedure that is performed in both ICUs and some hospice IPUs. Previous examinations of this subject have been based largely upon the correlative background, practices, and perceptions of the ICU prescriber. The purpose of this review is to examine how the manner in which this procedure is performed in the hospice environment may differ in ways that the intensivist can incorporate into their own plan of care, or better appreciate when making the decision to remove mechanical ventilation in the critical care unit or transfer the patient to a hospice environment for the procedure to be completed.

Comparison of propofol monotherapy and propofol combination therapy for sedation during gastrointestinal endoscopy: A systematic review and meta-analysis

BACKGROUND AND AIM

Previous randomized controlled trials have reported conflicting findings comparing propofol combination therapy (PCT) with propofol monotherapy (PMT) for sedation of patients undergoing gastrointestinal endoscopy. Therefore, a systematic review was carried out to compare the efficacy and safety of PCT and PMT in such patients.

METHODS

We searched MEDLINE, EMBASE and CENTRAL databases to identify all randomized controlled trials that compared the efficacy and safety of PCT and PMT for sedation of patients undergoing gastrointestinal endoscopy. Primary endpoints were incidence of respiratory complications, hypotension and arrhythmia, dose of propofol used, and recovery time. Procedure duration and the satisfaction of patients and doctors were also evaluated.

RESULTS

A total of 2250 patients from 22 studies were included in the final analysis. The combined analysis did not show any difference between PCT and PMT in the incidence of respiratory complications (risk ratio [RR], 0.80; 95% CI, 0.52 to 1.23; I2 = 58.34%), hypotension (RR, 1.06; 95% CI, 0.63 to 1.78; I2 = 72.13%), arrhythmia (RR,1.40; 95% CI, 0.74 to 2.64; I2 = 43.71%), recovery time (standardized mean difference [SMD], 0.16; 95% CI, -0.49 to 0.81; I2 = 95.9%), procedure duration (SMD, 0.04; 95% CI, -0.05 to 0.14; I2 = 0.0%), patient satisfaction (SMD, 0.13; 95% CI, -0.26 to 0.52; I2 = 89.63%) or doctor satisfaction (SMD, 0.01; 95% CI, -0.15 to 0.17; I2 = 0.00%). However, the dose of propofol used was significantly lower in PCT than in PMT (SMD, -1.38; 95% CI, -1.99 to -0.77; I2 = 97.70%).

CONCLUSION

PCT showed comparable efficacy and safety to PMT with respect to respiratory complications, hypotension and arrhythmia, recovery time, procedure duration, patient satisfaction, and doctor satisfaction. However, the average dose of propofol used was higher in PMT.

Estimated Maximal Safe Dosages of Tumescent Lidocaine

Supplemental Digital Content is available in the text.

Published ahead of print February 18, 2016

BACKGROUND:

Tumescent lidocaine anesthesia consists of subcutaneous injection of relatively large volumes (up to 4 L or more) of dilute lidocaine (≤1 g/L) and epinephrine (≤1 mg/L). Although tumescent lidocaine anesthesia is used for an increasing variety of surgical procedures, the maximum safe dosage is unknown. Our primary aim in this study was to measure serum lidocaine concentrations after subcutaneous administration of tumescent lidocaine with and without liposuction. Our hypotheses were that even with large doses (i.e., >30 mg/kg), serum lidocaine concentrations would be below levels associated with mild toxicity and that the concentration-time profile would be lower after liposuction than without liposuction.

METHODS:

Volunteers participated in 1 to 2 infiltration studies without liposuction and then one study with tumescent liposuction totally by local anesthesia. Serum lidocaine concentrations were measured at 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, and 24 hours after each tumescent lidocaine infiltration. Area under the curve (AUC∞) of the serum lidocaine concentration-time profiles and peak serum lidocaine concentrations (Cmax) were determined with and without liposuction. For any given milligram per kilogram dosage, the probability that Cmax >6 μg/mL, the threshold for mild lidocaine toxicity was estimated using tolerance interval analysis.

RESULTS:

In 41 tumescent infiltration procedures among 14 volunteer subjects, tumescent lidocaine dosages ranged from 19.2 to 52 mg/kg. Measured serum lidocaine concentrations were all <6 μg/mL over the 24-hour study period. AUC∞s with liposuction were significantly less than those without liposuction (P = 0.001). The estimated risk of lidocaine toxicity without liposuction at a dose of 28 mg/kg and with liposuction at a dose of 45 mg/kg was ≤1 per 2000.

CONCLUSIONS:

Preliminary estimates for maximum safe dosages of tumescent lidocaine are 28 mg/kg without liposuction and 45 mg/kg with liposuction. As a result of delayed systemic absorption, these dosages yield serum lidocaine concentrations below levels associated with mild toxicity and are a nonsignificant risk of harm to patients.

Feed-drug interaction of orally applied butyrate and phenobarbital on hepatic cytochrome P450 activity in chickens

The expression of hepatic drug-metabolizing cytochrome P450 (CYP) enzymes may be affected by several nutrition-derived compounds, such as by the commonly applied feed additive butyrate, possibly leading to feed-drug interactions. The aim of this study was to provide some evidence if butyrate can alter the activity of hepatic CYPs in chickens exposed to CYP-inducing xenobiotics, monitoring for the first time the possibility of such interaction. Ross 308 chickens in the grower phase were treated with daily intracoelomal phenobarbital (PB) injection (80 mg/kg BW), applied as a non-specific CYP-inducer, simultaneously with two different doses of intra-ingluvial sodium butyrate boluses (0.25 and 1.25 g/kg BW) for 5 days. Activity of CYP2H and CYP3A subfamilies was assessed by specific enzyme assays from isolated liver microsomes. According to our results, the lower dose of orally administered butyrate significantly attenuated the PB-triggered elevation of both hepatic CYP2H and CYP3A activities, which might be in association with the partly common signalling pathways of butyrate and CYP-inducing drugs, such as that of PB. Based on these data, butyrate may take part in pharmacoepigenetic interactions with simultaneously applied drugs or other CYP-inducing xenobiotics, with possible consequences for food safety and pharmacotherapy. Butyrate was found to be capable to maintain physiological CYP activity by attenuating CYP induction, underlining the safety of butyrate application in poultry nutrition.

Effect of intravenous haloperidol on the duration of delirium and coma in critically ill patients (Hope-ICU): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Delirium is frequently diagnosed in critically ill patients and is associated with poor clinical outcomes. Haloperidol is the most commonly used drug for delirium despite little evidence of its effectiveness. The aim of this study was to establish whether early treatment with haloperidol would decrease the time that survivors of critical illness spent in delirium or coma.

METHODS

We did this double-blind, placebo-controlled randomised trial in a general adult intensive care unit (ICU). Critically ill patients (≥18 years) needing mechanical ventilation within 72 h of admission were enrolled. Patients were randomised (by an independent nurse, in 1:1 ratio, with permuted block size of four and six, using a centralised, secure web-based randomisation service) to receive haloperidol 2.5 mg or 0.9% saline placebo intravenously every 8 h, irrespective of coma or delirium status. Study drug was discontinued on ICU discharge, once delirium-free and coma-free for 2 consecutive days, or after a maximum of 14 days of treatment, whichever came first. Delirium was assessed using the confusion assessment method for the ICU (CAM-ICU). The primary outcome was delirium-free and coma-free days, defined as the number of days in the first 14 days after randomisation during which the patient was alive without delirium and not in coma from any cause. Patients who died within the 14 day study period were recorded as having 0 days free of delirium and coma. ICU clinical and research staff and patients were masked to treatment throughout the study. Analyses were by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Registry, number ISRCTN83567338.

FINDINGS

142 patients were randomised, 141 were included in the final analysis (71 haloperidol, 70 placebo). Patients in the haloperidol group spent about the same number of days alive, without delirium, and without coma as did patients in the placebo group (median 5 days [IQR 0-10] vs 6 days [0-11] days; p=0.53). The most common adverse events were oversedation (11 patients in the haloperidol group vs six in the placebo group) and QTc prolongation (seven patients in the haloperidol group vs six in the placebo group). No patient had a serious adverse event related to the study drug.

INTERPRETATION

These results do not support the hypothesis that haloperidol modifies duration of delirium in critically ill patients. Although haloperidol can be used safely in this population of patients, pending the results of trials in progress, the use of intravenous haloperidol should be reserved for short-term management of acute agitation.

FUNDING

National Institute for Health Research.

Effect of an anesthesia with propofol compared with desflurane on free radical production and liver function after partial hepatectomy

Propofol has shown antioxidant properties, but no study has focused on liver resection surgery. The aim of this study was to investigate the effect of an anesthesia with propofol compared with desflurane on oxidative stress and hepatic function during and after partial hepatectomy. This was a prospective randomized study performed on two parallel groups. The primary endpoint was malondialdehyde (MDA) plasma concentration 30 min after hepatic vascular unclamping. Hepatic damages were evaluated by plasma levels of alpha-glutathione S-transferase (α-GST) 120 min after hepatic vascular unclamping and of aminotransferases at 120 min and on days 1, 2, 5, and 10. Liver function recovery was assessed by monoethylglycinexylidide (MEGX) formation 15 min after lidocaine injection on day 2 and by prothrombin time and plasma factor V at 120 min and on days 1, 2, 5, and 10. Thirty patients were analyzed (propofol group: 17; desflurane group: 13). There was no significant difference between groups for MDA plasma concentration 30 min after hepatic vascular unclamping (mean ± standard-deviation: 1.28 ± 0.40 and 1.21 ± 0.29 in propofol and desflurane groups, respectively, P = 0.608). Plasma levels of α-GST at 120 min were lower in propofol than in desflurane group (142.2 ± 75.4 vs. 205.7 ± 66.5, P = 0.023), and MEGX on day 2 was higher (0.092 ± 0.096 vs. 0.036 ± 0.020, P = 0.007). No differences between groups were observed with regard to plasma levels of aminotransferases, prothrombin time, and plasma factor V. Our study showed that in patients undergoing partial hepatectomy, propofol did not reduce MDA formation but seemed to display a protective effect on hepatic damages and liver function when compared to desflurane.

Safety of fluvastatin in patients undergoing high-risk non-cardiac surgery

IMPORTANCE OF THE FIELD

In patients undergoing vascular surgery there is a high incidence of adverse cardiac events, due to sudden coronary plaque rupture. The non-lipid lowering or pleiotropic effects of statins can help reduce adverse cardiovascular events associated with vascular surgery.

AREAS COVERED IN THIS REVIEW

The evidence for perioperative use of fluvastatin, as well as other statins, in high-risk surgery patients is summarized in this review. Data on pharmacokinetics and metabolism is presented, together with considerations on possible drug interactions in the perioperative period.

WHAT THE READER WILL GAIN

The reader will gain a comprehensive understanding of the existing safety and efficacy data for fluvastatin and other statins in the perioperative period. The practical considerations of perioperative fluvastatin therapy will be presented, including potential side-effects and management of the early non-oral phase immediately post surgery. Finally, advice on when to initiate therapy and safety recommendations are offered.

TAKE HOME MESSAGE

In patients scheduled for high-risk vascular surgery, fluvastatin improves postoperative outcome, reducing the incidence of myocardial damage by approximately 50% in the first 30 days following vascular surgery. In comparison with placebo, fluvastatin was not associated with a rise in liver enzymes or creatine kinase levels. To bridge the non-oral phase, an extended-release formula is recommended.

Propofol reduces the distribution and clearance of midazolam

BACKGROUND

Midazolam, at sedative levels, increases blood propofol concentrations by 25%. We evaluated the reverse interaction and determined the influence of propofol on the pharmacokinetics of midazolam.

METHODS

Eight healthy male volunteers were studied on 2 occasions in a random crossover manner. During session A, volunteers received midazolam 0.035 to 0.05 mg x kg(-1) IV for 1 minute followed by an infusion of 0.035 to 0.05 mg x kg(-1) x h(-1) for 59 minutes. During session B, in addition to this midazolam infusion scheme, a target-controlled infusion of propofol (constant C(T): 0.6 or 1.0 microg x mL(-1)) was given from 15 minutes before the start until 6 hours after termination of the midazolam infusion. Arterial blood samples for propofol and midazolam concentration analysis were taken until 6 hours after termination of the midazolam infusion. Nonlinear mixed-effect models examining the influence of propofol and hemodynamic variables on midazolam pharmacokinetics were constructed using Akaike's information-theoretic criterion for model selection.

RESULTS

In the presence of a mean blood propofol concentration of 1.2 microg x mL(-1), the plasma midazolam concentration was increased by 26.9% + or - 9.4% compared with midazolam given as a single drug. Propofol (C(blood): 1.2 microg x mL(-1)) reduced midazolam central volume of distribution from 5.37 to 2.98 L, elimination clearance from 0.39 to 0.31 L x min(-1), and rapid distribution clearance from 2.77 to 2.11 L x min(-1). Inclusion of heart rate further improved the pharmacokinetic model of midazolam.

CONCLUSIONS

Propofol reduces the distribution and clearance of midazolam in a concentration-dependent manner. In addition, inclusion of heart rate as a covariate improved the pharmacokinetic model of midazolam predominantly through a reduction in the intraindividual variability.

Natural heme oxygenase-1 inducers in hepatobiliary function

Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defences and modulate the cellular redox state. Changes in the cellular redox state may have wide-ranging consequences for cellular growth and differentiation. The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. However, in recent years a possible novel aspect in the mode of action of these compounds has been suggested; that is, the ultimate stimulation of the heme oxygenase-1 (HO-1) pathway is likely to account for the established and powerful antioxidant/anti-inflammatory properties of these polyphenols. The products of the HO-catalyzed reaction, particularly carbon monoxide (CO) and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to protection against liver damage in various experimental models. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect the liver against various stressors in several pathological conditions.