Coronary perfusion pressure is associated with adverse outcomes in advanced heart failure.

BACKGROUND: Myocardial perfusion is an important determinant of cardiac function. We hypothesized that low coronary perfusion pressure (CPP) would be associated with adverse outcomes in heart failure. Myocardial perfusion impacts the contractile efficiency thus a low CPP would signal low myocardial perfusion in the face of increased cardiac demand as a result of volume overload. METHODS: We analyzed patients with complete hemodynamic data in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial using Cox Proportional Hazards regression for the primary outcome of the composite risk of death, heart transplantation, or left ventricular assist device [(LVAD). DT × LVAD] and the secondary outcome of the composite risk of DT × LVAD and heart failure hospitalization (DT × LVADHF). CPP was calculated as the difference between diastolic blood pressure and pulmonary artery wedge pressure. Heart failure categories (ischemic vs non-ischemic) were also stratified based on CPP strata. RESULTS: The 158 patients (56.7 ± 13.6 years, 28.5% female) studied had a median CPP of 40 mmHg (IQR 35-52 mmHg). During 6 months of follow-up, 35 (22.2%) had the composite primary outcome and 109 (69.0%) had the composite secondary outcome. When these outcomes were then stratified based on the median, CPP was associated with these outcomes. Increasing CPP was associated with lower risk of both the primary outcome of DT × LVAD (HR 0.96, 95% CI 0.94-0.99 p = .002) and as well as the secondary outcome of DT × LVADHF (p = .0008) There was significant interaction between CPP and ischemic etiology (p = .04). CONCLUSION: A low coronary artery perfusion pressure below (median) 40mmHg in patients with advanced heart failure undergoing invasive hemodynamic monitoring with a pulmonary artery catheter was associated with adverse outcomes. CPP could useful in guiding risk stratification of advanced heart failure patients and timely evaluation of advanced heart failure therapies.

T2 Relaxation Times at Cardiac MRI in Healthy Adults: A Systematic Review and Meta-Analysis.

Background T2 mapping is an important cardiac MRI technique with applications in various conditions. However, a comprehensive evaluation of the T2 literature for normal values is lacking. Purpose To characterize the ranges of normal values and variability of myocardial T2 relaxation times using a systematic review and meta-analysis of the T2 literature. Materials and Methods PubMed and Cochrane Central were searched from June 2019 to January 2020 for myocardial T2 measurements in healthy adults. Studies quantifying T2 relaxation times conducted at 1.5 T or 3.0 T using gradient and spin-echo (GRASE) or T2-prepared balanced steady-state free precession sequences were included. Summary means were generated using a random-effects model. Subgroup analysis and meta-regression were performed to assess factors causing heterogeneity. Results Of the 2481 articles retrieved, 42 studies were included with 954 healthy adults (mean age, 42.4 years ± 10.5 [standard deviation]; 538 men). The pooled mean of T2 across studies was 52 msec at 1.5 T (95% confidence interval [CI]: 51 msec, 53 msec) and 46 msec at 3.0 T (95% CI: 44 msec, 48 msec) (P ≤ .001). I2 was 98% at 1.5 T and 3.0 T. Meta-regression at 1.5 T and 3.0 T identified vendor (ß at 1.5 T = -4 msec [with Philips as reference], P < .001; ß at 3.0 T = -5 msec, P = .02) and pulse sequence (ß at 1.5 T = -5 msec [with GRASE as reference], P < .001; ß at 3.0 T = -6 msec, P = .002) as significant covariates, but it did not identify any association with covariates of age (ß at 1.5 T = 0 msec per year, P = .70; ß at 3.0 T = 0 msec per year, P = .83) or sex (ß at 1.5 T = -1 msec, P = .88; ß at 3.0 T = 6 msec, P = .42). Conclusion The pooled mean of T2 relaxation times in healthy adults had marked heterogeneity across studies with field strength, vendor, and pulse sequence identified as covariates associated with T2. T2-prepared measurements were similar between vendors at each field strength. © RSNA, 2020 Online supplemental material is available for this article.

Clinical Outcomes of Synchronous Laparoscopic Cholecystectomy with Coronary Artery Revascularization.

BACKGROUND: There are limited data about the results of simultaneous coronary revascularization, either with coronary artery bypass grafting (CABG) surgery or percutaneous coronary intervention (PCI), and cholecystectomy operations. Here we present clinical outcomes of the patients who underwent simultaneous laparoscopic cholecystectomy (LC) and coronary revascularization at the same session. PATIENTS AND METHODS: We included a total of 19 patients who underwent simultaneous LC and CABG or PCI. Thirteen of them had been hospitalized because of acute cholecystitis prior to coronary angiography. Simultaneous CABG and LC were performed in 10 patients (group I). LC was performed immediately after CABG surgery at the same session. PCI (group II) was performed in 9 patients. In the PCI group, LC was performed under general anesthesia 2 or 3 days after PCI. RESULTS: No mortality was seen after the procedures. In the CABG group, the mean number of bypass grafts was 3.4 ± 1.9. The mean extracorporeal circulation and the total operation times were 95 ± 13.5 minutes and 259 ± 18.9 minutes, respectively; the mean intubation duration was 17 ± 4.8 hours. In the PCI group, the mean number of stents per patient was 2.1 ± 0.7; LC was performed 2 or 3 days after the PCI without the cessation of clopidogrel and acetylsalicylic acid. The mean operation times for LC were 56.5 ± 15.6 minutes and 51.3 ± 17.6 minutes in the CABG and PCI groups, respectively (P = .86). In the CABG group, the mean durations of ICU and hospital stays were 3.1 ± 1.4 and 14.2 ± 3.7 days, respectively. In the PCI group, the mean durations of ICU stay and hospitalization were 1.7 ± 0.4 and 7.4 ± 2.2 days, respectively. Significant differences were found between the 2 groups in terms of the intubation time, duration of ICU stay, and hospitalization periods (P =.001, P =.0001, and P =.001, respectively). No intra-abdominal complications or bleeding was encountered in any group. Postoperative complications of the abdominal wall or mediastinitis were not seen in the setting of concomitant procedures in the CABG group. CONCLUSION: Simultaneous CABG or PCI with LC may be performed safely in patients with cholecystitis. The durations of postcholecystectomy ICU stay and the intubation time were significantly lower in the PCI group. According to our results, PCI may be the first choice of revascularization procedure in selected patients requiring cholecystectomy prior to discharge.

Assisting differential clinical diagnosis of cattle diseases using smartphone-based technology in low resource settings: a pilot study.

BACKGROUND: The recent rise in mobile phone use and increased signal coverage has created opportunities for growth of the mobile Health sector in many low resource settings. This pilot study explores the use of a smartphone-based application, VetAfrica-Ethiopia, in assisting diagnosis of cattle diseases. We used a modified Delphi protocol to select important diseases and Bayesian algorithms to estimate the related disease probabilities based on various clinical signs being present in Ethiopian cattle. RESULTS: A total of 928 cases were diagnosed during the study period across three regions of Ethiopia, around 70% of which were covered by diseases included in VetAfrica-Ethiopia. Parasitic Gastroenteritis (26%), Blackleg (8.5%), Fasciolosis (8.4%), Pasteurellosis (7.4%), Colibacillosis (6.4%), Lumpy skin disease (5.5%) and CBPP (5.0%) were the most commonly occurring diseases. The highest (84%) and lowest (30%) levels of matching between diagnoses made by student practitioners and VetAfrica-Ethiopia were for Babesiosis and Pasteurellosis, respectively. Multiple-variable logistic regression analysis indicated that the putative disease indicated, the practitioner involved, and the level of confidence associated with the prediction made by VetAfrica-Ethiopia were major determinants of the likelihood that a diagnostic match would be obtained. CONCLUSIONS: This pilot study demonstrated that the use of such applications can be a valuable means of assisting less experienced animal health professionals in carrying out disease diagnosis which may lead to increased animal productivity through appropriate treatment.

ULTRASOUND-GUIDED SCIATIC POLITEAL NERVE BLOCK: A COMPARISON OF SEPARATE TIBIAL AND COMMON PERONEAL NERVE INJECTIONS VERSUS INJECTING PROXIMAL TO THE BIFURCATION.

OBJECTIVE: Block of the sciatic nerve at the popliteal fossa can be performed using the ultrasound machine; it may be proximally or distally to the bifurcation of the sciatic nerve using lateral, medial, or posterior approaches. It is frequently used for surgeries below the knee specially the foot and ankle operations. PURPOSE: This study compares one and two injections of the sciatic nerve in the popliteal fossa with ultrasound-guided block in foot or ankle surgeries. METHODS: Forty patients received ultrasound-guided sciatic nerve block with the nerve stimulator, using the posterior approach. The patients were enrolled into two groups (20 patients each), group 1: received one injection at 2 cm cephalad to the bifurcation of the sciatic nerve, and group 2: received two injections caudate to the sciatic bifurcation; one for tibial nerve and the other for common peroneal nerve. All patients received 20 ml of levobupivacaine 0.5%. The block performance time, block efficacy, success rate, complications and patient's satisfaction were evaluated. RESULTS: Block the tibial and common peroneal nerves separately (two injections) distal to the point of bifurcation of the sciatic nerve has a significantly (P < 0.05) faster time to complete sensory block of tibial and common peroneal nerves compared to a pre-bifurcation sciatic nerve block (one injection). The complete motor block, block time performance, success rate and patient's satisfaction were not significantly different between groups (P > 0.05). CONCLUSION: The block of tibial and common peroneal nerves separately distal to the sciatic nerve bifurcation is superior to single injection block of sciatic nerve above the bifurcation in the popliteal fossa as regard complete sensory block time.

Severe Tricuspid Regurgitation in a Patient with a Transvenous Dual-chamber Pacemaker: Considerations for Diagnosis and Management.

Cardiac implantable electronic device leads can contribute to tricuspid regurgitation and also complicate surgical and transcatheter interventions to manage tricuspid regurgitation. Here we present a case of a patient with sinus node dysfunction and complete heart block who underwent extraction of a right ventricular pacing lead before tricuspid valve surgery. We review the data regarding the contribution of leads to tricuspid regurgitation and the benefits of lead extraction, risks of jailing leads during tricuspid interventions, and pacing considerations around tricuspid valve procedures.

Remifentanil infusion prolongs spinal anesthesia.

Spinal anesthesia was given to a patient undergoing transurethral resection ofprostate (TURP). A total of 3.2 ml of bupivacaine 0.5% mixed with fentanyl 20 mcg were used. The patient started experiencing sensation after 150 min. Remifentanil intravenous infusion prolonged the duration of anesthesia for an additional 105 minutes.

Posterior mandibular glandular cyst: A rare case report.

BACKGROUND: Odontogenic glandular cyst (GOC) is one of the uncommon cysts of the jaws with difficult diagnosis due to the presence of many clinical and histopathological overlaps with other odontogenic lesions, and the definitive diagnosis is only possible by histological examination. It is initially asymptomatic and affects the anterior mandible with no gender predilection. Surgical resection is the preferred treatment due to the high rate of recurrence. To date, there are less than 200 documented cases worldwide. CASE PRESENTATION: A 33-year-old female patient who consulted the Department of Oral and Maxillofacial Surgery due to numbness and swelling. She has no medical history with medications or genetic diseases. The lesion was diagnosed as an odontogenic glandular cyst, and then treated with surgical resection and plate-and-screw replacement. CLINICAL DISCUSSION: Odontogenic Glandular cyst is an uncommon cyst it is difficult to diagnose depending on clinical features and radiographic imaging only, the definitive diagnosis is based on histological examination. The preferred treatment is surgical resection with safety edges. CONCLUSION: More care should be given to report this rare entity to assure accurate and early diagnosis.

Genetic Factors Associated with Morphine Consumption in Women Undergoing Laparoscopic Cholecystectomy: A Prospective Cohort Study.

Introduction: Morphine has been a crucial analgesic agent used perioperatively in various surgical procedures. Genetic factors can lead to morphine dose requirement interpatient variability. Our objective was to determine the contribution of genetic polymorphisms in human µ-opioid receptor gene (OPRM1), ATP binding cassette gene (ABCB1) and rs2952768 to the variation of the perioperative morphine consumption in women undergoing laparoscopic cholecystectomy. Methods: This is a prospective cohort study that included 102 adult Arab females undergoing laparoscopic cholecystectomy. The exposures were carrying the genetic variants of OPRM1, ABCB1 and rs2952768. Our primary outcome was total morphine or morphine equivalent dose required perioperatively. The secondary outcomes were pain score during the first 24 hours and adverse drug reactions. A standardized, general anaesthesia was used for all subjects. In addition to the genetic factors, we also investigated non-genetic factors influencing post-operative pain sensitivity and morphine consumption. Results: Both (rs1799971, A>G) in OPRM1 and (rs2952768, T>C) showed statistically significant association with intra-operative total morphine dose requirements. Patients carrying the "G" allele in OPRM1 had a significantly higher total morphine mean rank dose compared to the AA genotype [62.9 vs 47.1, p=0.008]. Furthermore, patients homozygous for the rs2952768 (T>C) minor allele "CC" had a higher mean rank compared to the other genotypes [72.7 vs 50.1, p=0.046]. Conclusion: OPRM1 (rs1799971) and rs2952768 are associated with variation of intra-operative morphine consumption in laparoscopic cholecystectomy. Clinical Trial Identifier: This study was registered at ClinicalTrials.gov, NCT04621864. https://clinicaltrials.gov/ct2/show/NCT04621864.

The "July Effect" in the Cardiac Catheterization Laboratory.

In Interventional Cardiology, the academic year and a new training cycle begin in July. It is unclear if patient outcomes are impacted by the time of year in the training cycle. The National Cardiovascular Data Registry collects outcomes related to percutaneous coronary interventions (PCIs). We used the database for our institution to review the relation between the time of year and patient outcomes. We performed a retrospective review of National Cardiovascular Data Registry data from 2011 to 2017. Outcomes were compared between the end (quarter 2 [Q2]) and the start of the academic year (quarter 3 [Q3]). Chi-square and Fisher's exact test was used: 1,041 (Q2) and 980 (Q3) patients underwent PCI. Patient characteristics were similar between the 2 quarters except for a higher rate of heart failure for patients in Q3 (250 [24%] vs 275 [29%], p = 0.03). There was no difference in overall nonfatal adverse events between Q2 and Q3 (53 [5.1%] vs 58 [5.9%], p = 0.41). Patients in Q3 experienced a higher incidence of stroke (1 [0.1%] vs 7 [0.7%], p = 0.03) and PCI risk-adjusted mortality (8.29 [0.8%] vs 18.13 [1.9%], p = 0.03). In conclusion, there does not appear to be a significant "July Effect" in an academic cardiac catheterization laboratory in terms of most complications with an observed higher incidence of stroke and PCI risk-adjusted mortality early in the year that may be related to a difference in the characteristics of the patient population.

Increased left and right atrial volume indices are associated with decreased survival times post-cardiac arrest.

BACKGROUND: Left and right atrial volume indices (LAVI and RAVI) are markers of cardiac remodeling. LAVI and RAVI are associated with worse outcomes in other cardiac conditions. This study aimed to determine the associations of these atrial volume indices with survival time post-cardiac arrest. METHODS: This was a single center, retrospective study of patients with a sudden cardiac arrest event during index hospitalization from 2014-2018 based on pre-arrest parameters. The analysis was stratified based on whether a pulseless ventricular tachycardia/ventricular fibrillation (pVT/VF) event or a pulseless electrical activity (PEA)/asystole event occurred. Cox proportional hazards regression and model selection with best subsets approach evaluated the association of atrial volume parameters with survival times in the context of other covariates. RESULTS: Of 305 patients studied (64 ± 14 years, 37% female), the mean LAVI was 34.0 ± 15.8 mL/m2 (based on 162 reliable measurements), and mean RAVI was 25.0 ± 15.6 mL/m2 (based on 163 measurements). Increased atrial volume indices were most strongly associated with survival in patients who had sustained pVT/VF (LAVI HR 0.47, 95% CI 0.25-0.90, p = 0.020; RAVI HR 0.57, 95% CI 0.30-1.05, p = 0.074). In multivariable best subsets Cox regression with LAVI, RAVI, and 13 other scaled covariates, LAVI < 34 ml/m2 was by far the best single predictor of survival (p < 0.0001), and the next best predictor was the absence of pulmonary hypertension. CONCLUSION: Among patients with cardiac arrest from ventricular arrhythmias, those with no more than mild left atrial enlargement pre-arrest by LAVI measurement had the best prognosis. Additional studies are indicated to validate the importance of this finding for clinical management decisions. CONDENSED ABSTRACT: In patients with sudden cardiac arrest associated with ventricular arrhythmias, a left atrial volume index (LAVI) < 34 mL/m2 prior to the arrest had the strongest association with survival among fifteen candidate predictors. Pulmonary hypertension was more common in patients with an elevated right atrial volume index (RAVI), and the absence of pulmonary hypertension was the next best pre-arrest parameter predictive of survival. Larger studies are indicated to validate the use of LAVI for clinical management decisions in this condition.

Right atrial volume index to left atrial volume index ratio is associated with adverse clinical outcomes in cardiogenic shock.

BACKGROUND: Structural remodeling in chronic systolic heart failure (HF) is associated with neurohormonal and hemodynamic perturbations among HF patients presenting with cardiogenic shock (CS) and HF. Our objective was to test the hypothesis was that atrial remodeling marked by an increased right atrial volume index (RAVI) to left atrial volume index (LAVI) ratio is associated with adverse clinical outcomes in CS. METHODS: Patients in this cohort were admitted to the intensive care unit with evidence of congestion (pulmonary capillary wedge pressure > 15) and cardiogenic shock (cardiac index < 2.2, systolic blood pressure < 90 mmHg, and clinical evidence supporting CS) and had an echocardiogram at the time of admission. RAVI was measured using Simpson's method in the apical four-chamber view, while LAVI was measured using the biplane disc summation method in the four and two-chamber views by two independent observers. Cox proportional hazards regression analysis was used to assess the association of RAVI-LAVI with the combined outcome of death or left ventricular assist device (LVAD). RESULTS: Among 113 patients (mean age 59 ± 14.9 years, 29.2% female), median RAVI/LAVI was 0.84. During a median follow-up of 12 months, 43 patients died, and 65 patients had the combined outcomes of death or LVAD. Patients with RAVI/LAVI ratio above the median had a greater incidence of death or LVAD (Log-rank p ≤ 0.001), and increasing RAVI/LAVI was significantly associated with the outcomes of death or LVAD (HR 1.71 95% CI 1.11-2.64, chi square 5.91, p = 0.010) even after adjustment for patient characteristics, echocardiographic and hemodynamic variables. CONCLUSION: RAVI/LAVI is an easily assessed novel echocardiographic parameter strongly associated with the survival and or the need for mechanical circulatory support in patients with CS.

Bio-cleaning Efficiency of Rhamnolipids Produced from Native Pseudomonas aeruginosa Grown on Agro-industrial By-products for Liquid Detergent Formulation.

The cleaning activity of surface-active agents such as rhamnolipids (RLs) requires utmost effectiveness and is employed abundantly in various industries, particularly laundry cleaning, detergents, and cosmetics. In the current study, RLs were produced from Pseudomonas aeruginosa isolated from oil-contaminated soil using a minimal medium amended with agro-industrial by-products of refinery vegetable oil wastes (comprising of unsaturated types of fatty acids as determined by GC analysis) and dairy whey. The results showed that an amount of 5.72 g/L of RLs were obtained, while lower concentrations were obtained using chemically defined carbon sources. Ten congeners of mono- and di-RLs were detected by LC-MS, and they reduced the surface tension of water to 26 mN/m with a critical micelle concentration of 33 mg/L. Furthermore, the produced RLs showed promising cleaning and detergency properties in the removal of different stains on tested fabrics with a Stain Removal Index (SRI) of 17.45%. Moreover, an efficient cleaning was obtained when RLs were applied to a liquid detergent formulation model, and a cleaning power (∆E) of 245.95 and SRI of 36.28% were achieved. The present work showed that the produced RLs could be exploited as a powerful and alternative eco-friendly cleaning agent in many industries.

Periprocedural Anticoagulation Management of Patients receiving Warfarin in Qatar: A Prospective Cohort Study.

BACKGROUND: The use of anticoagulant bridging remains controversial. This study was conducted to evaluate our warfarin periprocedural management in Qatar and investigate the associated clinical outcomes with such management. METHODS: A prospective cohort study was designed to describe the periprocedural clinical practice in warfarin patients in Qatar and to compare clinical safety and efficacy outcomes between anticoagulant bridging and nonbridging. RESULTS: 103 patients were recruited. Bridging occurred in 82% of the participants. No thromboembolic events were observed, while 39.1% of patients experienced bleeding events during the study period. The incidence of overall bleeding and major bleeding were numerically higher for bridging group compared to nonbridging but did not reach statistical significance ([30.6% vs 22.2%, P = 0.478] and [12.9% vs 5.6%, P = 0.375], respectively). CONCLUSION: Warfarin interruption and bridging are overwhelmingly used in warfarin-treated patients in Qatar. While bridging was numerically associated with increased bleeding events, there is no statistical difference in reported clinical events between bridging and nonbridging strategies.

Atrial fibrillation is associated with central sleep apnea in clinic patients undergoing diagnostic polysomnography.

INTRODUCTION: Sleep apnea is highly prevalent in patients with atrial fibrillation (AF). Obstructive sleep apnea (OSA) is the most common type, and best studied in the context of AF. However, recent investigations have indicated that central sleep apnea (CSA) may be a risk factor for incident AF. We evaluated the burden of CSA events in patients referred for diagnostic polysomnography (PSG) and whether AF is associated with CSA. METHODS: We identified patients with and without a history of AF who underwent clinically indicated PSG in a matched manner. OSA was defined as obstructive apnea-hypopnea index (AHI) ≥15/h, and CSA was defined as central apnea index (CAI) ≥5/h. The association between AF and CSA was evaluated using multivariable logistic regression. RESULTS: Among 465 patients included, mean AHI was 25.5/h, and mean CAI was 1.7/h. OSA prevalence was 53.3%, while CSA prevalence was 8.4%. The prevalence of OSA in the AF and non-AF groups (54.7% vs 52.0%, P = .56) was similar. CSA was more common in the AF group (12.3% vs 4.4%, P = .002). In multivariable analysis, AF (OR: 2.19 [1.02, 5.03], P = .05), male gender (OR: 2.5 [1.17, 5.84], P = .02), and older age (OR: 2.44, [1.16, 5.46], P = .02) were associated with CSA. CONCLUSION: Though CSA is much less common than OSA in patients with AF, the presence of AF is independently associated with CSA.

Uneventful epidural analgesia in a patient with severe thrombocytopenia.

Epidural analgesia is the most effective method for analgesia in labor. It has, however, contraindications and carries many serious side effects. Though coagulopathy is an absolute contraindication for epidural and axial blocks, yet there are no absolute limits for platelet counts that stand in the way of providing epidural analgesia. In a patient who is writhing in pain due to severe uterine contractions, and in whom there exists a recent normal platelet screening and no history of bleeding disorders, it is internationally acceptable between anesthetists to provide epidural analgesia without waiting for a new platelet screening.

Is it time for routine use of the retromolar fiberscope?

PURPOSE: This study aimed to determine the effectiveness, safety, and oral intubation time (IT) using a retromolar Bonfils fiberoptic scope compared with a conventional Macintosh laryngoscope. MATERIALS AND METHODS: Sixty patients (16-60 years old, American Society of Anesthesiology I/II) scheduled for general anesthesia for elective ear-nose-throat and plastic surgery were randomly divided into a Bonfils group (Group B, n = 30) and a Macintosh group (Group M, n = 30). Exclusion criteria included Mallampati IV, thyromental distance ≤4 cm, mouth <4 cm, cervical spine problems, body mass index >35, sleep apnea, reflux esophagitis, coronary artery disease, intracranial vascular malformation, elevated intracranial pressure, bleeding disorders, allergies to planned drugs, and patient refusal. Mallampati scoring, mouth opening, and thyromental distance were used for airway assessment. The time needed for successful intubation (IT), number of attempts, number of failures, systolic (SBP), diastolic (DBP), mean blood pressure (MBP), heart rate (HR) and Oxygen saturation (O2) and damage to the lips, dentures, and pharyngeal or laryngeal structures were recorded. Continuous variables are presented as mean ± standard deviation and categorical variables are presented as frequency and percentage. Chi-square tests and Student's t-tests were used to compare the groups. P < 0.05 was considered statistically significant. RESULTS: The groups were comparable regarding demographic data, preoperative airway parameters, IT, the number of attempts, O2, and the incidence of complications (P > 0.05). However, Bonfils intubation was associated with more stable HR, SBP, DBP and MBP (P < 0.05). CONCLUSION: The Bonfils fiberoptic scope is comparable to a Macintosh laryngoscope but assures better hemodynamic stability. In difficult cases, the Bonfils scope is a better choice because of its ability to navigate.

Occurrence and sources of natural and anthropogenic lipid tracers in surface soils from arid urban areas of Saudi Arabia.

Soil particles contain a variety of natural and anthropogenic organic components, and in urban areas can be considered as local collectors of pollutants. Surface soil samples were taken from ten urban areas in Riyadh during early winter of 2007. They were extracted with dichloromethane-methanol mixture and the extracts were analyzed by gas chromatography-mass spectrometry. The major compounds were unresolved complex mixture (UCM), plasticizers, n-alkanes, carbohydrates, n-alkanoic acids, hopanes, n-alkanols, and sterols. Vegetation detritus was the major natural source of organic compounds (24.0 ± 15.7%) in samples from areas with less human activities and included n-alkanes, n-alkanoic acids, n-alkanols, sterols and carbohydrates. Vehicular emission products and discarded plastics were the major anthropogenic sources in the soil particles (53.3 ± 21.3% and 22.7 ± 10.7%, respectively). The anthropogenic tracers were UCM, plasticizers, n-alkanes, hopanes and traces of steranes. Vegetation and human activities control the occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area.