Authentication of Fennel, Star Anise, and Anise Essential Oils by Gas Chromatography (GC/MS) and Stable Isotope Ratio (GC/IRMS) Analyses.

The aromatic compound (E)-anethol is widely used in the flavor, fragrance, and medicinal industries. This compound is commonly produced through steam distillation of fennel, star anise, and anise seed. Given the cost of production, these natural and authentic essential oils are commonly adulterated with lower-cost natural materials or synthetic alternatives. The current study investigates essential oil profiles (gas chromatography/mass spectrometry) and stable isotope ratios (gas chromatography/isotope ratio mass spectrometry) of the abundant compound (E)-anethol in both authentic reference standards (n = 15) and commercially available samples (n = 30). This multifaceted analytical approach establishes techniques for ensuring the authenticity of essential oil sources of (E)-anethol and was then used to evaluate the current essential oil market sources of (E)-anethol. These findings report that adulteration of (E)-anethol-containing natural products takes various forms, and a multifaceted analytical approach is recommended for authentication. Of the commercial samples analyzed for this report, 27% were adulterated.

Nasal continuous positive pressure versus simple face mask oxygenation for adult obese and obstructive sleep apnea patients undergoing colonoscopy under propofol-based general anesthesia without tracheal intubation: A randomized controlled trial.

STUDY OBJECTIVE: To determine if a nasal positive airway pressure (nasal CPAP) mask would decrease the number of hypoxemic events in obese and obstructive sleep apnea patients undergoing colonoscopy. DESIGN: Single-center prospective randomized controlled trial. SETTING: Tertiary academic center. PATIENTS: We enrolled 109 patients with diagnosis of obesity and/or obstructive sleep apnea scheduled to undergo colonoscopy under propofol general anesthesia without planned tracheal intubation. INTERVENTION: Patients were randomly allocated (1:1 ratio) to receive supplementary oxygen at a flow of 10 L/min, either through a nasal CPAP or a simple facemask. MEASUREMENTS: The primary endpoint was the difference in the mean percentage of time spent with oxygen saturation below 90% between the two groups. Secondary outcomes included the need for airway maneuvers/interventions, average SpO2 during the case, duration and severity of oxygen desaturation, incidence and duration of procedural interruptions, and satisfaction and tolerance scores. MAIN RESULTS: 54 were allocated to the simple face mask and 55 to the nasal CPAP mask arms, respectively. A total of 6 patients experienced a hypoxemic event. Among these patients, the difference in the percentage of time spent with oxygen saturation below 90% was not clinically relevant (p = 1.0). However, patients in the nasal CPAP group required less chin lift (20% vs. 42.6%; p = 0.01) and oral cannula insertion (12.7% vs.29.6%; p = 0.03). The percentage of patients with at least one airway maneuver was higher in the simple face mask arm (68.5% vs. 41.8%; p = 0.005). Patient tolerance to device score was lower in the nasal CPAP group (8.85 vs. 9.56; p = 0.003). CONCLUSIONS: A nasal CPAP did not prevent hypoxemia and should not be used routinely for colonoscopy in obese or OSA patients if a simple face mask is an alternative therapy. However, potential advantages of its use include fewer airway maneuvers or interventions, which may be desirable in certain clinical settings. TRIAL REGISTRATION: Clinicaltrials.gov, identifier: NCT05175573.

Essential Oil Composition and Enantioselective Profile of Agastache urticifolia (Lamiaceae) and Monardella odoratissima (Lamiaceae) from Utah.

Two species within the Lamiaceae (mint) family, Agastache urticifolia and Monardella odoratissima, are aromatic plants that are native to the Intermountain Region (USA). Essential oil produced through steam distillation was examined to establish the essential oil yield and both the achiral and chiral aromatic profiles of both plant species. The resulting essential oils were analyzed by GC/MS, GC/FID, and MRR (molecular rotational resonance). For A. urticifolia and M. odoratissima, achiral essential oil profiles were largely composed of limonene (71.0%, 27.7%), trans-ß-ocimene (3.6%, 6.9%), and pulegone (15.9%, 4.3%), respectively. Between the two species, eight chiral pairs were analyzed and, interestingly, the dominant enantiomer (calculated as ee%) of limonene and pulegone switched between the two species. Where enantiopure standards were not commercially available, MRR was used as a reliable analytical technique for chiral analysis. This study verifies the achiral profile for A. urticifolia and, for the first time to the authors' knowledge, establishes the achiral profile for M. odoratissima and chiral profile for both species. Additionally, this study confirms the utility and practicality of using MRR for determining chiral profiles in essential oils.

Essential Oil Composition and Stable Isotope Profile of Osmorhiza occidentalis Torr. (Apiaceae) from Utah.

Osmorhiza occidentalis Torr. is an essential-oil-bearing plant in the Apiaceae family. Volatile oil was produced through steam distillation (n = 3) of the above ground plant parts and was analyzed by gas chromatography (GC/FID, GC/MS), and gas chromatography/isotope ratio mass spectrometry (GC/IRMS) to establish the essential oil composition and stable isotope profile. The resulting essential oils were found to be comprised of 33 volatile compounds. Prominent volatile compounds include methyl chavicol (avg. 61.6%), (Z)-ß-ocimene (avg. 14.7%), sabinene (avg. 10.5%), and γ-terpinene (avg. 2.8%). Stable isotope values were determined for prominent volatile compounds, including methyl chavicol, (Z)-ß-ocimene, sabinene, and γ-terpinene. Values for δ2H range from -393.479 (avg. sabinene) to -171.516 (avg. methyl chavicol). Those for δ13C range from -35.957 (avg. methyl chavicol) to -30.820 (avg. (Z)-ß-ocimene). The essential oil yield was 0.12% (w/w). The current study establishes for the first time, to the best knowledge of the authors, the essential oil yield, essential oil composition, and stable isotope profile of prominent volatile compounds extracted from the above-ground portions of O. occidentalis. These results provide insight into the volatile chemical composition produced by the plant and provide fundamental data for substantiation of ethnobotanical applications.

Essential Oil Composition and Stable Isotope Profile of Cultivated Ocimum campechianum Mill. (Lamiaceae) from Peru.

Ocimum campechianum Mill. (Peruvian basil) is an essential oil-bearing plant of the Lamiaceae family. Volatile oil produced through steam distillation of Peruvian basil was examined to establish the aromatic and stable isotope profiles of samples (n = 9) from three different cultivated plots in Peru. The resulting essential oils were analyzed by GC/FID, GC/MS, and GC/IRMS. In accordance with findings from other researchers, multiple chemotypes, defined by the most abundant aromatic compounds, exist within these populations. Overall, 55% of samples are the eugenol chemotype (values ranging 15.4-30.2%), 33% are the methyl eugenol chemotype (values ranging 68.1-68.7%), and a single sample is a mixture of both chemotypes, containing high levels of both eugenol (38.1%) and methyl eugenol (8.6%). Stable isotope ratios, δ2H and δ13C, performed on prominent compounds provide supporting data for distinguishing chemotypes. Complete aromatic profiles, stable isotope ratios, and essential oil yield are established for each sample. This study confirms the existence of multiple chemotypes and, for the first time, to the author's best knowledge, establishes stable isotope ratios for O. campechianum essential oil, which proves a useful tool in further investigating plant metabolism and determining essential oil authenticity.

Essential Oil Profile and Yield of Corolla, Calyx, Leaf, and Whole Flowering Top of Cultivated Lavandula angustifolia Mill. (Lamiaceae) from Utah.

Lavandula angustifolia Mill. (lavender) is an essential-oil-bearing plant in the Lamiaceae family. Volatile oil produced through the steam distillation of lavender was examined to establish the essential oil yield and aromatic profile from each portion of the plant-namely, the corolla, calyx, leaf, and whole flowering top. The resulting essential oils were analyzed by GC-FID and GC-MS. The different plant parts generally shared similar compounds but in varying relative percentages. Aromatic profiles of the whole flowering top and calyx were similar, with prominent compounds being linalool acetate (34.3%, 32.0%), linalool (26.5%, 32.9%), lavandulyl acetate (5.6%, 4.9%), terpinen-4-ol (5.3%, 7.0%), and (Z)-ß-ocimene (4.5%, 5.4%), respectively. Aromatic profiles for the corolla and leaf were unique. Prominent aromatic compounds of the corolla included linalool acetate (18.4%), linalool (10.8%), epi-α-cadinol (10.0%), borneol (7.3%), and lavandulyl acetate (6.3%). Prominent aromatic compounds of the leaf included epi-α-cadinol (19.8%), γ-cadinene (11.0%), borneol (6.0%), caryophyllene oxide (4.9%), and bornyl acetate (4.8%). Complete profiles and essential oil yields of corolla, calyx, leaf, and whole flowering top were established. This study establishes the influence the corolla, calyx, and leaf exert on the aromatic profile of the whole flowering top and provides insight into authentication of lavender essential oil.

Safety of the LMA®Gastro™ for Endoscopic Retrograde Cholangiopancreatography.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) patients typically receive either tubeless anesthesia or general endotracheal anesthesia (GETA). Patients receiving propofol-based total intravenous anesthesia (TIVA) are at higher risk of sedation-related adverse events (SRAEs) than patients receiving GETA, primarily due to the need for additional airway maneuvers. The increasing use of non-operating room (OR) anesthesia and the perception of a higher incidence of adverse outcomes in non-OR areas has led to the development of devices to improve safety while maintaining efficiency. The purpose of this study was to evaluate if the LMA Gastro™ could be used as a safe alternative to tubeless anesthesia for successfully completing ERCPs. METHODS: Eligible subjects were identified within the patient population at MD Anderson Cancer Center. Inclusion criteria consisted of adult patients (≥18 years old) scheduled for elective ERCP with TIVA. This was a prospective observational study in which the following data were collected: number of attempts and time to successful supraglottic airway (SGA) placement, vital signs, peripheral oxygen saturation (SpO2), median end-tidal CO2, practitioner satisfaction, and any complications. RESULTS: A total of 30 patients were included in this study. The overall rate of successful SGA placement within 3 attempts was 96.7% (95% confidence interval [CI], 82.8-99.9) or 29/30. The rate of successful ERCP with SGA placement within 3 attempts was 93.3% (95% CI, 77.9-99.2) or 28/30. Both the gastroenterologist and anesthesiologist reported satisfaction with the device in 90% of the cases (in 66.7% of the cases both anesthesiologist and gastroenterologist scored the device a 7/7 for satisfaction). Patients maintained an SpO2 of 95%-100% from induction to discharge, with the exception of 1 patient who had an SpO2 of 93%. The median end-tidal CO2 during the procedure for all patients was 35 mm Hg. Observed aspiration did not occur in any patient. Symptoms of hoarseness (13.3%), mouth soreness (6.7%), sore throat (6.6%), and minor bleeding/cuts/redness/change in taste to the tongue (3.3%) were determined through patient questioning before postanesthesia care unit (PACU) discharge. CONCLUSIONS: Our study suggests that the LMA Gastro might be a safe alternative for ERCP procedures. There was a high level of practitioner satisfaction. Only minor complications, such as hoarseness, mouth or throat soreness, or minor trauma to the tongue were experienced by patients. Similar incidences of complications may occur with GETA and tubeless anesthesia. The procedure was well tolerated by all patients; all patients maintained adequate oxygenation and required only minimal blood pressure support.

Cap-fitted endoscopic mucosal resection of ≥ 20 mm colon flat lesions followed by argon plasma coagulation results in a low adenoma recurrence rate.

Background and study aims Endoscopic mucosal resection (EMR) is increasingly used for the treatment of large colonic polyps (≥ 20 mm). A drawback of EMR is local adenoma recurrence. Therefore, we studied the impact of argon plasma coagulation (APC) of the EMR edge on local adenoma recurrence. Patients and methods This was a retrospective study of patients with laterally spreading tumors (LST) ≥ 20 mm, who underwent EMR from January 2009 to August 2018 and follow-up endoscopic assessment. A cap-fitted endoscope was used to assess completeness of resection by systematically inspecting the EMR defect for any macroscopic disease. This was followed by forced APC of the resection edge followed by clip closure of the defect. Surveillance colonoscopy was performed at 6 months after resection to detect recurrence. Results Two hundred forty-six patients met the inclusion criteria. Most were female (53 %) and white (80 %), with a Median age of 64 years. Median polyp size was 35 mm (interquartile range, 30-45 mm). Most polyps were located in the right colon (77 %) and were removed by piecemeal EMR (70 %). Eleven patients (5 %) had residual tumor at the resection site. Conclusions We observed low adenoma recurrence after argon plasma coagulation of the EMR edge with a cap fitted colonoscope in patients with LST ≥ 20 mm of the colon, which requires further validation in a randomized controlled study.

Developing an intraoperative 3T MRI-guided brachytherapy program within a diagnostic imaging suite: Methods, process workflow, and value-based analysis.

PURPOSE: We integrated a brachytherapy procedural workflow within an existing diagnostic 3.0-T (3T) MRI suite. This setup facilitates intraoperative MRI guidance for optimal applicator positioning, particularly for interstitial needle placements in gynecologic cases with extensive parametrial involvement. METHODS AND MATERIALS: Here we summarize the multidisciplinary collaboration, equipment, and supplies necessary to implement an intraoperative MRI-guided brachytherapy program; outline the operational workflow via process maps; and address safety precautions. We evaluate internal resource utilization associated with this progressive approach via time-driven activity-based costing methodology, comparing institutional costs to that of a traditional workflow (within a CT suite, followed by separate postprocedure MRI) over a single brachytherapy procedural episode. RESULTS: Resource utilization was only 15% higher for the intraoperative MRI-based workflow, attributable to use of the MRI suite and increased radiologist effort. Personnel expenses were the greatest cost drivers for either workflow, accounting for 76-77% of total resource utilization. However, use of the MRI suite allows for potential cost-shifting opportunities from other resources, such as CT, during the procedural episode. Improvements in process speed can also decrease costs: for each 10% decrease in case duration from baseline procedure time, total costs could decrease by roughly 8%. CONCLUSIONS: This analysis supports the feasibility of an intraoperative MRI-guided brachytherapy program within a diagnostic MRI suite and defines many of the resources required for this procedural workflow. Longer followup will define the full utility of this approach in optimizing the therapeutic ratio for gynecologic cancers, which may translate into lower costs and higher value with time, over a full cycle of care.

Scalp blocks for brain tumor craniotomies: A retrospective survival analysis of a propensity match cohort of patients.

To test the association between the use of scalp blocks for malignant brain tumor craniotomy and survival. This is a retrospective study conducted in a tertiary academic center. Demographic, intraoperative and survival data from 808 adult patients with malignant brain tumors was included in the analysis. Patients were divided in those who received an Intraoperative use of scalp block or not. The progression free survival (PFS) and overall survival (OS) rates were compared in patients who had and had not scalp blocks. Kaplan-Meier method was used for time-to-event analysis including recurrence free survival and overall survival. Multivariate analyses before and after propensity score matching were conducted to test the association between different covariates including scalp blocks with PFS and OS. Five hundred and ninety (73%) of the patients had a scalp block. Before PSM, patients with a scalp block were more likely to have an ASA physical status of 3-4, recurrent tumors and receive adjuvant radiation. Patients with scalp block showed no significant reduction in intraoperative opioids. After adjusting for significant covariates, the administration of a scalp block was not associated with an increase in PFS (HR, 95%CI = 0.98, 0.8-1.2, p = 0.892) or OS (HR, 95%CI = 1.02, 0.82-1.26, p = 0.847) survival. This retrospective study suggests that the use of scalp blocks during brain tumor surgery is not associated with patients' longer survival.

Delirium and Catatonia in Critically Ill Patients: The Delirium and Catatonia Prospective Cohort Investigation.

OBJECTIVES: Catatonia, a condition characterized by motor, behavioral, and emotional changes, can occur during critical illness and appear as clinically similar to delirium, yet its management differs from delirium. Traditional criteria for medical catatonia preclude its diagnosis in delirium. Our objective in this investigation was to understand the overlap and relationship between delirium and catatonia in ICU patients and determine diagnostic thresholds for catatonia. DESIGN: Convenience cohort, nested within two ongoing randomized trials. SETTING: Single academic medical center in Nashville, TN. PATIENTS: We enrolled 136 critically ill patients on mechanical ventilation and/or vasopressors, randomized to two usual care sedation regimens. MEASUREMENTS AND MAIN RESULTS: Patients were assessed for delirium and catatonia by independent and masked personnel using Confusion Assessment Method for the ICU and the Bush Francis Catatonia Rating Scale mapped to Diagnostic Statistical Manual 5 criterion A for catatonia. Of 136 patients, 58 patients (43%) had only delirium, four (3%) had only catatonia, 42 (31%) had both, and 32 (24%) had neither. In a logistic regression model, more catatonia signs were associated with greater odds of having delirium. For example, patient assessments with greater than or equal to three Diagnostic Statistical Manual 5 symptoms (75th percentile) had, on average, 27.8 times the odds (interquartile range, 12.7-60.6) of having delirium compared with patient assessments with zero Diagnostic Statistical Manual 5 criteria (25th percentile) present (p < 0.001). A cut-off of greater than or equal to 4 Bush Francis Catatonia Screening Instrument items was both sensitive (91%; 95% CI, 82.9-95.3) and specific (91%; 95% CI, 87.6-92.9) for Diagnostic Statistical Manual 5 catatonia. CONCLUSIONS: Given that about one in three patients had both catatonia and delirium, these data prompt reconsideration of Diagnostic Statistical Manual 5 criteria for "Catatonic Disorder Due to Another Medical Condition" that preclude diagnosing catatonia in the presence of delirium.

Does deep sedation with propofol affect adenoma detection rates in average risk screening colonoscopy exams?

AIM: To determine the effect of sedation with propofol on adenoma detection rate (ADR) and cecal intubation rates (CIR) in average risk screening colonoscopies compared to moderate sedation. METHODS: We conducted a retrospective chart review of 2604 first-time average risk screening colonoscopies performed at MD Anderson Cancer Center from 2010-2013. ADR and CIR were calculated in each sedation group. Multivariable regression analysis was performed to adjust for potential confounders of age and body mass index (BMI). RESULTS: One-third of the exams were done with propofol (n = 874). Overall ADR in the propofol group was significantly higher than moderate sedation (46.3% vs 41.2%, P = 0.01). After adjustment for age and BMI differences, ADR was similar between the groups. CIR was 99% for all exams. The mean cecal insertion time was shorter among propofol patients (6.9 min vs 8.2 min; P < 0.0001). CONCLUSION: Deep sedation with propofol for screening colonoscopy did not significantly improve ADR or CIR in our population of average risk patients. While propofol may allow for safer sedation in certain patients (e.g., with sleep apnea), the overall effect on colonoscopy quality metrics is not significant. Given its increased cost, propofol should be used judiciously and without the implicit expectation of a higher quality screening exam.

Malignant Catatonia Warrants Early Psychiatric-Critical Care Collaborative Management: Two Cases and Literature Review.

Malignant catatonia (MC) is a life-threatening manifestation which can occur in the setting of an underlying neuropsychiatric syndrome or general medical illness and shares clinical and pathophysiological features and medical comorbidities with the Neuroleptic Malignant Syndrome (NMS). The subsequent diagnosis and definitive therapy of MC are typically delayed, which increases morbidity and mortality. We present two cases of MC and review recent literature of MC and NMS, illustrating factors which delay diagnosis and management. When clinical features suggest MC or NMS, we propose early critical care consultation and stabilization with collaborative psychiatric management.

Association Between Perioperative Hyperglycemia and Survival in Patients With Glioblastoma.

BACKGROUND: Several studies have examined the association between hyperglycemia in the first 10 to 12 weeks following surgery and postoperative survival in glioblastoma multiforme (GBM) patients. We hypothesize that episodes of hyperglycemia before, during and/or following surgery for primary GBM are independent predictors of disease progression and mortality. MATERIALS AND METHODS: A total of 162 adult patients were included in the analysis. All patients received adjuvant temozolamide. The progression free survival (PFS) and overall survival (OS) rates at 1 and 5 years were analyzed using different glycemic cutoff values. Multivariate analyses were conducted to test the association between preoperative, intraoperative and postoperative hyperglycemia with PFS and OS. RESULTS: Kaplan-Meier curves revealed a trend toward increased PFS and OS with lower glucose concentrations with the exception of glucose concentrations >180 mg/dL in the intraoperative/postoperative day 0 time period. Univariate analysis of blood glucose levels did not demonstrate a statistically significant effect on PFS in any time period, however hyperglycemia was statistically significant for OS in the preoperative time period. Although, multivariate analysis showed no statistically significant association with hyperglycemia on PFS, a statistically significant decrease in OS was seen for plasma glucose concentrations >112 mg/dL (P=0.01) and >180 mg/dL (P=0.01) in the preoperative period. There was a decreasing effect on OS with blood glucose concentrations greater than the median in multiple time periods (P=0.02). CONCLUSIONS: Preoperative hyperglycemia is associated with poor OS after GBM surgery.

Maternal Sepsis and Septic Shock.

The year 2015 marked the 200th anniversary of the birth of Ignaz Semmelweis, the Hungarian physician who identified unhygienic practices of physicians as a major cause of childbed fever or puerperal sepsis. Although such practices have largely disappeared as a factor in the development of chorioamnionitis and postpartum or puerperal endometritis, it is appropriate that this article on sepsis in pregnancy acknowledges his contributions to maternal health. This review describes the incidence and mortality of sepsis in pregnancy, methods to identify and define sepsis in this population, including scoring systems, causes, and sites of infection during pregnancy and parturition and management guidelines.

Clinically Amyopathic Dermatomyositis Complicated by Pleural Effusion Case Report, Literature Review, and Proposed Mechanism.

Polymyositis-dermatomyositis (PM-DM) is a chronic inflammatory disorder that mainly involves muscles and skin. Clinically amyopathic dermatomyositis (CADM) is a unique subset of PM-DM with typical skin manifestations but little or no evidence of musculoskeletal involvement. Many cases of dermatomyositis and CADM are associated with internal malignancy, but pulmonary manifestations can also been seen; the most common of which is interstitial lung disease. Pleural effusion is a rare complication and may be difficult to differentiate from other causes, such as infections, heart failure, or malignancy. We report a patient with CADM complicated by rapidly progressive pleural effusions. Based on findings of this patient, as well as literature review, we suggest that the etiology of massive pleural effusion in this setting is most likely related to local immune pleuritis associated with underlying interstitial lung disease due to dermatomyositis. Optimal management should be individualized and may include immunosuppressive agents, as well as antimicrobials, and potentially other agents.

Diffuse large B-cell lymphoma presenting as multiple lymphomatous polyposis of the gastrointestinal tract.

Primary gastrointestinal (GI) lymphomas constitute 5%-10% of all gastrointestinal tumors. Involvement of the entire GI tract as multiple polypoid lesions is very rare. Multiple lymphomatous polyposis is a distinctive and rare type of malignant GI lymphoma. Multiple lymphomatous polyposis is thought to represent mantle cell lymphoma of the GI tract. Approximately 60 cases of MLP have been reported so far. We report the first case of diffuse large B-cell lymphoma presenting as multiple lymphomatous polyposis of the GI tract in a 49-year-old patient with HIV and describe the clinicopathologic features. The patient was treated with a combination therapy of highly active antiretroviral therapy and CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) and exhibited complete remission.

Can patient safety be measured by surveys of patient experiences?

BACKGROUND: A study was conducted to test whether patient reports of medical errors via surveys could produce sufficiently accurate information to be used as a measure of patient safety. METHODS: A survey mailed regularly by a large multispecialty medical group to recent patients to assess their satisfaction and error experiences was expanded to collect more details about the patient-perceived errors. Following an initial mailing to 3,109 patients and parents of child patients soon after they had office visits in June 2005, usable mailed or phone follow-up responses were obtained from 1,998 respondents (65.1% adjusted). Responses were reviewed through a two-stage process that included chart audits and implicit physician reviewer judgments. The analysis categorized the review results and compared patient-reported errors with satisfaction. RESULTS: Of the 1,998 respondents, 219 (11.0%) reported 247 separate incidents, for a rate of 12.4 errors per 100 patients. After complete review, only 5 (2.0%) of these incidents were judged to be real clinician errors. Most appeared to represent misunderstandings or behavior/communication problems, but 15.4% lacked sufficient information to categorize. Women, Hispanics, and those aged 41-60 years were most likely to report errors. Those respondents making error reports were much more likely to report visit dissatisfaction than those not reporting them (odds ratio [OR] = 13.8, p < .001). DISCUSSION: Although patient reports of perceived errors might be useful to improve the patient experience of care, they cannot be used to measure technical medical errors and patient safety reliably without added evaluation. This study's findings need to be replicated elsewhere before generalizing from one metropolitan region and a patient population that is about two-thirds members of one health plan.

Differential increase of mitochondrial matrix volume by sevoflurane in isolated cardiac mitochondria.

BACKGROUND: Mitochondrial (m) adenosine triphosphate sensitive potassium (K(ATP)) channel opening has been reported to trigger and/or mediate cardioprotection by volatile anesthetics. However, the effects of volatile anesthetics on mitochondrial function are not well understood. Prevention of mitochondrial matrix volume (MMV) contraction during ischemia may contribute to cardioprotection against ischemia/reperfusion injury. We investigated whether sevoflurane increases MMV and if this increase is mediated by mK(ATP) channel opening. METHODS: Mitochondria from fresh guinea pig hearts were isolated and diluted in buffer that included oligomycin and ATP to inhibit ATP synthesis. Changes in MMV by diazoxide, a known mK(ATP) channel opener, and by different sevoflurane concentrations, were measured by light absorption at 520 nm in the absence or presence of the mK(ATP) channel blocker, 5-hydroxydecanoate. RESULTS: Compared with control, 30-300 microM sevoflurane (approximately 0.2-2.1 vol %) increased MMV by 30%-55%, which was similar to the effect of diazoxide. These increases were blocked by 5-hydroxydecanoate. Higher sevoflurane concentration (1000 microM; 7.1 vol %), however, had no effect on MMV. CONCLUSIONS: In clinically relevant concentrations, sevoflurane increases MMV via mK(ATP) channel opening. Preservation of mitochondrial integrity may contribute to the cardioprotective effects of sevoflurane against ischemia/reperfusion injury. Impaired mitochondrial function at supraclinical anesthetic concentrations may explain the observed biphasic response. These findings add to our understanding of the intracellular mechanisms of volatile anesthetics as cardioprotective drugs.