Sevoflurane for procedural sedation in critically ill patients: A pharmacokinetic comparative study between burn and non-burn patients.

BACKGROUND: Sevoflurane has anti-inflammatory proprieties and short lasting effects making it of interest for procedural sedation in critically ill patients. We evaluated the pharmacokinetics of sevoflurane and metabolites in severely ill burn patients and controls. The secondary objective was to assess potential kidney injury. METHODS: Prospective interventional study in a burn and a surgical intensive care unit; 24 mechanically ventilated critically ill patients (12 burns, 12 controls) were included. The sevoflurane was administered with an expired fraction target of 2% during short-term procedural sedation. Plasma concentrations of sevoflurane, hexafluoroisopropanolol (HFIP) and free fluoride ions were recorded at different times. Kinetic Pro (Wgroupe, France) was used for pharmacokinetic analysis. Kidney injury was assessed with neutrophil gelatinase-associated lipocalin (NGAL). RESULTS: The mean total burn surface area was 36±11%. The average plasma concentration of sevoflurane was 70.4±37.5mg·L-1 in burns and 57.2±28.1mg·L-1 in controls at the end of the procedure (P=0.58). The volume of distribution was higher (46.8±7.2 vs 22.2±2.50L, P<0.001), and the drug half-life longer in burns (1.19±0.28h vs 0.65±0.04h, P<0.0001). Free metabolite HFIP was higher in burns. Plasma fluoride was not different between burns and controls. NGAL did not rise after procedures. CONCLUSION: We observed an increased volume of distribution, slower elimination rate, and altered metabolism of sevoflurane in burn patients compared to controls. Repeated use for procedural sedation in burn patients needs further evaluation. No renal toxicity was detected. TRIAL REGISTRY NUMBER: ClinicalTrials.gov Identifier NCT02048683.

Exposure of hospitalised pregnant women to plasticizers contained in medical devices.

BACKGROUND: Medical devices (MDs) in polyvinyl chloride (PVC) are not a well-known source of exposure to plasticizers, in particular during pregnancy. Because of its toxicity, the di-(2-ethylhexyl) phthalate (DEHP) has been replaced by other plasticizers such as di (isononyl)-cyclohexane-1,2-dicarboxilic acid (DINCH), tri-octyltrimellitate (TOTM) and di-(isononyl) phthalate (DiNP). Our study aimed to quantify the plasticizers (DEHP and alternative plasticizers) contained in PVC medical devices used for hospitalised pregnant women and to describe which these MDs had been used (type, number, duration of exposure). METHODS: The plasticizers contained in the MDs used for daily care in the Obstetrics Department of a French University Hospital were extracted from PVC (after contact with a chloroform solution), identified and quantified by gas-chromatography-mass-spectrometry analysis. A total of 168 pregnant women hospitalised in the Obstetrics Department with at least one catheter were included in the observational study. The median number of MDs containing plasticizers used and the daily duration of exposure to the MDs were compared in three groups of pregnant women: "Pathology group" (women hospitalised for an obstetric disorder who did not give birth during this hospitalisation; n = 52), "Pathology and delivery group" (hospitalised for an obstetric disorder and who gave birth during this stay; n = 23) and "Delivery group" (admitted for planned or spontaneous delivery without obstetric disorder; n = 93). RESULTS: DiNP, TOTM and DINCH were the predominant plasticizers contained in the MDs at an amount of 29 to 36 g per 100 g of PVC. Women in the "Pathology group" (preterm labour or other pathology) were exposed to a median number of two MDs containing TOTM and one MD containing DiNP, fewer than those in the "Pathology and delivery group" (p < 0.05). Women in the "Pathology group" had a median exposure of 3.4 h/day to MDs containing DiNP and 8.2 h/day to MDs containing TOTM, longer than those in the "Delivery group" (p < 0.01). CONCLUSIONS: Our study shows that the medical management of pregnant women in a hospital setting entails exposure to MDs containing alternative plasticizers (DiNP, TOTM and DINCH).

Bilateral sternal infusion of ropivacaine and length of stay in ICU after cardiac surgery with increased respiratory risk: A randomised controlled trial.

BACKGROUND: The continuous bilateral infusion of a local anaesthetic solution around the sternotomy wound (bilateral sternal) is an innovative technique for reducing pain after sternotomy. OBJECTIVE: To assess the effects of the technique on the need for intensive care in cardiac patients at increased risk of respiratory complications. DESIGN: Randomised, observer-blind controlled trial. SETTING: Single centre, French University Hospital. PATIENTS: In total, 120 adults scheduled for open-heart surgery, with one of the following conditions: age more than 75 years, BMI >30 kg m, chronic obstructive pulmonary disease, active smoking habit. INTERVENTION: Either a bilateral sternal infusion of 0.2% ropivacaine (3 ml h through each catheter; 'intervention' group), or standardised care only ('control' group). Analgesia was provided with paracetamol and self-administered intravenous morphine. MAIN OUTCOME MEASURES: The length of time to readiness for discharge from ICU, blindly assessed by a committee of experts. RESULTS: No effect was found between groups for the primary outcome (P = 0.680, intention to treat); the median values were 42.4 and 37.7 h, respectively for the control and intervention groups (P = 0.873). Similar nonsignificant trends were noted for other postoperative delays. Significant effects favouring the intervention were noted for dynamic pain, patient satisfaction, occurrence of nausea and vomiting, occurrence of delirium or mental confusion and occurrence of pulmonary complications. In 12 patients, although no symptoms actually occurred, the total ropivacaine plasma level exceeded the lowest value for which neurological symptoms have been observed in healthy volunteers. CONCLUSION: Because of a small size effect, and despite significant analgesic effects, this strategy failed to reduce the time spent in ICU. TRIAL REGISTRATION: EudraCT (N°: 2012-005225-69); ClinicalTrials.gov (NCT01828788).

Analysis of PVC plasticizers in medical devices and infused solutions by GC-MS.

In 2008, di-(2-ethylhexyl) phthalate (DEHP), was categorized as CMR 1B under the CLP regulations and its use in PVC medical devices (MD) was called into question by the European authorities. This resulted in the commercialization of PVC MDs plasticized with the DEHP alternative plasticizers tri-octyl trimellitate (TOTM), di-(2-ethylhexyl) terephthalate (DEHT), di-isononyl cyclohexane-1,2-dicarboxylate (DINCH), di-isononyl phthalate (DINP), di-(2-ethylhexy) adipate (DEHA), and Acetyl tri-n-butyl citrate (ATBC). The data available on the migration of these plasticizers from the MDs are too limited to ensure their safe use. We therefore developed a versatile GC-MS method to identify and quantify both these newly used plasticizers and DEHP in MDs and to assess their migration abilities in simulant solution. The use of cubic calibration curves and the optimization of the analytical method by an experimental plan allowed us to lower the limit of plasticizer quantification. It also allowed wide calibration curves to be established that were adapted to this quantification in MDs during migration tests, irrespective of the amount present, and while maintaining good precision and accuracy. We then tested the developed method on 32 PVC MDs used in our hospital and evaluated the plasticizer release from a PVC MD into a simulant solution during a 24h migration test. The results showed a predominance of TOTM in PVC MDs accompanied by DEHP (<0.1% w/w), DEHT, and sometimes DEHA. The migration tests showed a difference in the migration ability between the plasticizers and a non-linear kinetic release.

Analysis of plasticizers in poly(vinyl chloride) medical devices for infusion and artificial nutrition: comparison and optimization of the extraction procedures, a pre-migration test step.

Medical devices (MDs) for infusion and enteral and parenteral nutrition are essentially made of plasticized polyvinyl chloride (PVC). The first step in assessing patient exposure to these plasticizers, as well as ensuring that the MDs are free from di(2-ethylhexyl) phthalate (DEHP), consists of identifying and quantifying the plasticizers present and, consequently, determining which ones are likely to migrate into the patient's body. We compared three different extraction methods using 0.1 g of plasticized PVC: Soxhlet extraction in diethyl ether and ethyl acetate, polymer dissolution, and room temperature extraction in different solvents. It was found that simple room temperature chloroform extraction under optimized conditions (30 min, 50 mL) gave the best separation of plasticizers from the PVC matrix, with extraction yields ranging from 92 to 100% for all plasticizers. This result was confirmed by supplemented Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and gravimetric analyses. The technique was used on eight marketed medical devices and showed that they contained different amounts of plasticizers, ranging from 25 to 36% of the PVC weight. These yields, associated with the individual physicochemical properties of each plasticizer, highlight the need for further migration studies.

Influence of lipid type on bis (2-ethylhexyl)phthalate (DEHP) leaching from infusion line sets in parenteral nutrition.

BACKGROUND: Bis(2-ethylhexyl)phthalate (or DEHP) is widely used in polyvinyl chloride (PVC) tubings for its good plasticizing properties. Because it is not covalently bound to the plastic matrix, it is able to escape from PVC during the infusion of the lipid emulsions used in parenteral nutrition (PN). This creates a vector through which it can enter into contact with the patient via the nutrition admixtures infused. This study was designed to assess the potential role of the type of lipids used in PN admixtures on the quantity of DEHP leached out from PVC-based tubings. METHODS: PVC-based infusion lines, 6 commercially available lipid emulsions, and their oil base components were left in direct contact, and the amount of DEHP leached was measured by liquid chromatography. RESULTS: After a 24-hour exposure period, DEHP migration varied significantly (P = .0000152) according to lipid type. The olive oil-based emulsion Clinoleic leached the most DEHP (65.8 µg/mL intravenous fat emulsion), followed by the fish oil-based emulsion Omegaven (37.8 µg/mL). The soybean oil-based emulsions Intralipid, Medialipide, Lipidem, and Structolipid showed comparable performances, with DEHP leaching rates into the emulsion measured at 27.3, 27.8, 23.6, and 19.6 µg/mL, respectively. Results from the same experiments run on pure-form oils (soybean oil, olive oil, coconut oil, and cod liver oil) confirmed the influence of lipid type on DEHP leaching. CONCLUSION: The major DEHP leaching caused by olive oil-based emulsions raises cause for concern because DEHP presents distinctive toxic effects, including an increased risk of cholestasis.

Simple assay of plasma sevoflurane and its metabolite hexafluoroisopropanol by headspace GC-MS.

The anesthetic sevoflurane can now be delivered over periods of up to 48h using a newly developed medical system, the AnaConDa (anesthetic conserving device). Lack of pharmacokinetic data on sevoflurane and its main metabolite (hexafluoroisopropanol, HFIP) in this indication prompted us to develop a headspace GC-MS method to quantify the two substances. The only previously published method for assaying the two substances could not be adapted to our study since it uses expensive and rarely employed system components together with toxic carbon disulfide as a dilution solvent. The method developed is straightforward and uses the relatively non-toxic solvent undecane as dilution solvent and chloroform as internal standard. The method is linear for a concentration range of 1-150microg/ml, and presents high accuracy and precision. LOD and LOQ are 0.2 and 1microg/ml, with a short analysis time (7.6 min for a single analysis). The method was applied to determine the plasma levels of sevoflurane and HFIP in six patients under 48-h anesthetic sedation delivered via the AnaConDa system. Average sevoflurane and HFIP concentrations plateaued at 75 and 4microg/ml, respectively. Sevoflurane quickly tailed off after inhalation was stopped, and HFIP levels remained low.

Leaching of diethylhexyl phthalate from multilayer tubing into etoposide infusion solutions.

PURPOSE: The extent of leaching of diethylhexyl phthalate (DEHP) from various polyvinyl chloride (PVC), polyethylene (PE), coextruded (PVC and PE), and triple-layered (PVC, ethyl vinyl acetate, and PE) i.v. extension tubing into etoposide infusion solutions was studied. METHODS: Different lengths of tubing (25, 50, and 80 cm) were tested in two types of experiments: (1) static, in which the etoposide solution was left in contact inside the tubing for various times and then removed, and chromatography was used to quantify the DEHP content of the effluate, and (2) dynamic, in which infusion was simulated using syringe reservoirs, and three flow rates were tested to assess the effect of flow rate on the quantities of DEHP leached. RESULTS: The static study showed that large quantities of DEHP were leached from all tubing types except the PE tubing. The dynamic study confirmed that leaching occurred, although the values were below the threshold limit of 5 microg/mL. The values varied depending on flow rate, tubing length, and etoposide concentration. The coextruded and triple-layered i.v. tubing did not provide the inertness and safety they are intended to have, as DEHP not only leached out but did so in quantities almost equivalent to those found with tubing made of PVC only. CONCLUSION: DEHP leached rapidly from PVC, coextruded, and triple-layered i.v. tubing into etoposide infusion solution. The quantity of DEHP found in the infusion solution was influenced by the length of the tubing and concentration of etoposide.

Analysis by liquid chromatography and infrared spectrometry of di(2-ethylhexyl)phthalate released by multilayer infusion tubing.

Di(2-ethylhexyl)phthalate (DEHP), a plasticiser present in infusion equipment, is known to be harmful to human health. Various studies have shown that DEHP is released into drug solutions from polyvinyl chloride (PVC) infusion lines. New multi-layer tubing has therefore been marketed to overcome this problem. We assessed the inertness of this tubing when placed in contact with a solution of CELLTOP. Chromatographic assay of DEHP showed no significant difference in DEHP levels in the solution when placed in contact with PVC and with multi-layer tubing. Analysis by infrared spectrometry showed that DEHP was initially present in the polyethylene layer of the multi-layer tubing even before contact with the drug solution. Contact with the solution results in release of DEHP from the container into the contents. The substance responsible for this release is in fact an excipient of CELLTOP, polysorbate. This release of DEHP further proves to depend on parameters such as temperature, time of contact between solution and tubing, and the concentration of polysorbate in the infused drug solution.