Prospective Randomized Crossover Study Research Articles

Evaluation of three intravenous injectable anaesthesia protocols in healthy adult male alpacas

Few studies have investigated the effects of intravenous injectable anaesthesia in alpacas. The objective of this study was to evaluate three intravenous injectable anaesthesia protocols in healthy adult alpacas exposed...

Prospective Randomized Crossover Study of Telesimulation Versus Standard Simulation for Teaching Medical Students the Management of Critically Ill Patients

The objective was to evaluate the comparative effectiveness of telesimulation versus standard simulation in teaching medical students the management of critically ill patients. Prospective, randomized crossover study of 32 fourth-year medical students at a university medical simulation center. Students were randomized to the standard simulation (SIM) or telesimulation (TeleSIM) group between September 2014 and February 2015. The SIM group experience included participating in a live, fully immersive simulation case followed by debriefing with their SIM cohort and a live TV Internet connection to the TeleSIM group. The TeleSIM group experience included remotely observing the live simulation case at an off-site location, followed by a shared group debriefing via live TV Internet connection. Subject assessment was performed with a written evaluation tool. During a second instructional session, the students crossed over and participated in a different simulation scenario and assessment. Mean evaluation scores were calculated along with 95% confidence intervals (CIs) and were analyzed via linear regression. Our secondary outcome was a survey evaluating the perceptions and attitudes held between the two simulation modalities. Of 33 eligible students, 32 participated in the study (97.0%). We found no significant difference in the mean evaluation scores of the two groups: SIM group mean= 96.6% (95% CI= 94.5%-98.6%) and TeleSIM group mean= 96.8% (95% CI= 94.8%-98.9%). We also found no significant difference in the favorability of teaching modality (TeleSIM vs. SIM) on the survey. In our prospective randomized crossover study evaluating telesimulation versus standard simulation, we found no significant difference in evaluation scores among the two groups. There was also no significant difference found in the favorability of one teaching modality on a posteducational session survey. Our data support and highlight the capability of telesimulation to provide educational benefit to learners who do not have direct access to simulation resources.

Optimum support by high-flow nasal cannula in acute hypoxemic respiratory failure: effects of increasing flow rates

Limited data exist on the correlation between higher flow rates of high-flow nasal cannula (HFNC) and its physiologic effects in patients with acute hypoxemic respiratory failure (AHRF). We assessed the effects of HFNC delivered at increasing flow rate on inspiratory effort, work of breathing, minute ventilation, lung volumes, dynamic compliance and oxygenation in AHRF patients. A prospective randomized cross-over study was performed in non-intubated patients with patients AHRF and a PaO2/FiO2 (arterial partial pressure of oxygen/fraction of inspired oxygen) ratio of ≤300mmHg. A standard non-occlusive facial mask and HFNC at different flow rates (30, 45 and 60l/min) were randomly applied, while maintaining constant FiO2 (20min/step). At the end of each phase, we measured arterial blood gases, inspiratory effort, based on swings in esophageal pressure (ΔPes) and on the esophageal pressure-time product (PTPPes), and lung volume, by electrical impedance tomography. Seventeen patients with AHRF were enrolled in the study. At increasing flow rate, HFNC reduced ΔPes (p<0.001) and PTPPes (p<0.001), while end-expiratory lung volume (ΔEELV), tidal volume to ΔPes ratio (V T/ΔPes, which corresponds to dynamic lung compliance) and oxygenation improved (p<0.01 for all factors). Higher HFNC flow rate also progressively reduced minute ventilation (p<0.05) without any change in arterial CO2 tension (p=0.909). The decrease in ΔPes, PTPPes and minute ventilation at increasing flow rates was better described by exponential fitting, while ΔEELV, V T/ΔPes and oxygenation improved linearly. In this cohort of patients with AHRF, an increasing HFNC flow rate progressively decreased inspiratory effort and improved lung aeration, dynamic compliance and oxygenation. Most of the effect on inspiratory workload and CO2 clearance was already obtained at the lowest flow rate.

Coronary perfusion pressure and compression quality in maternal cardiopulmonary resuscitation in supine and left-lateral tilt positions: A prospective, crossover study using mannequins and swine models

ObjectiveThe risk of maternal and fetal mortality is high if cardiopulmonary arrest occurs during pregnancy. To assess the best position for maternal cardiopulmonary resuscitation (CPR), a prospective randomized crossover study was undertaken, involving basic life support mannequin-based simulation (BLS-MS) and a swine model of pulseless electrical activity (an unstable cardiac state) incorporating a fetal mannequin (PEA-FM). Study designThe BLS-MS (performed by certified rescuers) served to evaluate the quality of chest compressions in 30° left lateral tilt (LLT) and supine positions. Based on a 5-point scale, each rescuer subjectively graded their experience. The PEA-FM model was used to compare coronary perfusion pressure readings during CPR in supine, supine with left uterine displacement, 30° LLT, and 30° right lateral tilt positions. Compression rate and correctness of hand position, compression depth, and recoil were measures of compression quality (BLS-MS). ResultsCompared with LLT position, supine position enabled correct hand position (rate: 0.99 vs 0.88; p<0.05) and compression depth (rate: 0.76 vs 0.36; p<0.001) significantly more often. Moreover, BLS-MS rescuers found chest compressions significantly easier to perform with the mannequin in supine (vs LLT) position (difficulty score: 1.75 vs 3.95; p<0.001). In the PEA-FM study arm, supine position with left uterine displacement and right lateral tilt positions had the highest and lowest recorded coronary perfusion pressure readings, respectively. ConclusionSupine position with left uterine displacement is optimal for maternal CPR.

Comparison of quality of chest compressions during training of laypersons using Push Heart and Little Anne manikins using blinded CPRcards

BackgroundMass Cardio-Pulmonary Resuscitation (CPR) training using less expensive and easily portable manikins is one way to increase the number of trained laypeople in a short time. The easy-to-carry, low-cost CPR training model called Push Heart (PH) is widely used in Japan. The aim of this study was to examine if PH can achieve chest compression quality that is similar to that using more conventional Little Anne (LA) manikins for training laypersons.MethodsThis prospective randomized crossover study was done during routine community CPR training of laypersons in Singapore. The participants were randomly allocated into two groups, using the PH and LA models respectively. They crossed over during the training so that both groups had measurements using both models. Chest compression data were collected using blinded CPRcards, which are credit card-sized devices with accelerometers and data capture. Participants did not receive any CPR feedback during measurement.ResultsForty-two people had data captured for the study with 15 males. The median compression depth was 41.5 mm on LA and 38.0 mm on PH (p = 0.0664), and median compression rate was 105 cpm on LA and 103 cpm on PH (p = 0.2429). Overall, only 1.5% of compressions performed on the PH achieved adequate depth of between 50–70 mm compared to 5.5% achieved on LA (p = 0.049). In contrast, 84% of all compressions performed on the PH were within the adequate rate of 100–120 cpm compared to 79.5% on LA (p = 0.457). Only the under 20-year-old group was able to achieve adequate median compression depth (50.5 mm) on LA, while the older age groups did not (p = 0.0024). The other age groups performed similar quality of chest compression regardless of the model used. 73.8% of participants preferred the LA for training. After the training, participants felt similarly well-prepared with either model with a median score of 8/10 on LA compared to 7/10 on PH (p = 0.0011).ConclusionsThe PH can be an alternative mass CPR training model. Both models achieved satisfactory chest compression rates, but the majority of participants, especially the elderly, had difficulty achieving adequate depth.

Solving the surgeon ergonomic crisis with surgical exosuit.

The widespread adoption of laparoscopic surgery has put new physical demands on the surgeon leading to increased musculoskeletal disorders and injuries. Shoulder, back, and neck pains are among the most common complaints experienced by laparoscopic surgeons. Here, we evaluate the feasibility and efficacy of a non-intrusive progressive arm support exosuit worn by surgeons under the sterile gown to reduce pain and fatigue during surgery. This is a prospective randomized crossover study approved by the Internal Review Board (IRB). The study involves three phases of testing. In each phase, general surgery residents or attendings were randomized to wearing the surgical exosuit at the beginning or at the crossover point. The first phase tests for surgeon manual dexterity wearing the device using the Minnesota Dexterity test, the Purdue Pegboard test, and the Fundamentals of Laparoscopic Surgery (FLS) modules. The second phase tests the effect of the device on shoulder pain and fatigue while operating the laparoscopic camera. The third phase rates surgeon experience in the operating room between case-matched operating days. Twenty subjects were recruited for this study. Surgeons had the similar dexterity scores and FLS times whether or not they wore the exosuit (p value ranges 0.15-0.84). All exosuit surgeons completed 15min of holding laparoscopic camera compared to three non-exosuit surgeons (p<0.02). Exosuit surgeons experienced significantly less fatigue at all time periods and arm pain (3.11 vs 5.88, p=0.019) at 10min. Surgeons wearing the exosuit during an operation experienced significant decrease in shoulder pain and 85% of surgeons reported some form of pain reduction at the end of the operative day. The progressive arm support exosuit can be a minimally intrusive device that laparoscopic surgeons wear to reduce pain and fatigue of surgery without significantly interfering with operative skills or manual dexterity.

Physiologic Effects of High-Flow Nasal Cannula in Acute Hypoxemic Respiratory Failure.

High-flow nasal cannula (HFNC) improves the clinical outcomes of nonintubated patients with acute hypoxemic respiratory failure (AHRF). To assess the effects of HFNC on gas exchange, inspiratory effort, minute ventilation, end-expiratory lung volume, dynamic compliance, and ventilation homogeneity in patients with AHRF. This was a prospective randomized crossover study in nonintubated patients with AHRF with PaO2/setFiO2 less than or equal to 300 mm Hg admitted to the intensive care unit. We randomly applied HFNC set at 40 L/min compared with a standard nonocclusive facial mask at the same clinically set FiO2 (20 min/step). Toward the end of each phase, we measured arterial blood gases, inspiratory effort, and work of breathing by esophageal pressure swings (ΔPes) and pressure time product, and we estimated changes in lung volumes and ventilation homogeneity by electrical impedance tomography. We enrolled 15 patients aged 60 ± 14 years old with PaO2/setFiO2 130 ± 35 mm Hg. Seven (47%) had bilateral lung infiltrates. Compared with the facial mask, HFNC significantly improved oxygenation (P < 0.001) and lowered respiratory rate (P < 0.01), ΔPes (P < 0.01), and pressure time product (P < 0.001). During HFNC, minute ventilation was reduced (P < 0.001) at constant arterial CO2 tension and pH (P = 0.27 and P = 0.23, respectively); end-expiratory lung volume increased (P < 0.001), and tidal volume did not change (P = 0.44); the ratio of tidal volume to ΔPes (an estimate of dynamic lung compliance) increased (P < 0.05); finally, ventilation distribution was more homogeneous (P < 0.01). In patients with AHRF, HFNC exerts multiple physiologic effects including less inspiratory effort and improved lung volume and compliance. These benefits might underlie the clinical efficacy of HFNC.

A Comparison of the Effects of 20% Mannitol and 3% NaCl on Coagulation Parameters In Vitro using ROTEM: A Prospective Randomized Crossover Study.

The aim of the present study is to compare the effect of 20% mannitol and 3% NaCl on blood coagulation in vitro using rotational thromboelastometry (ROTEM). Twenty-millilitre blood samples were obtained from 15 volunteers. In each group, 2 mL blood samples were collected into both polypropylene tubes and EDTA tubes for ROTEM and hemogram analysis. After sampling, blood samples were diluted with test solutions. Group C (control): Only blood, Group M (mannitol): 7% vol 20% mannitol concentration in the blood, Group hypertonic saline (HS): 7% vol 3% hypertonic saline (NaCl) in the blood, Group M/H (mannitol and hydroxyethyl starch solutions [HES]): 6% vol 20% mannitol concentration and 8% vol HES in the blood and Group HS/H (hypertonic saline and HES): 6% vol 3% hypertonic saline concentration and 8% vol HES in the blood. The following thromboelastometric parameters were measured automatically: clotting time (CT) and clot formation time (CFT) with intrinsic activation by tissue factor (InTEM), CT, CFT and maximum clot firmness (MCF) with extrinsic activation by tissue factor (ExTEM) and MCF with FibTEM. The ExTEM CT value was found to be significantly longer in the M/H group than in the controls. The ExTEM CFT median and percentile values were: group C: 85 s (70-95 s), group M: 115 s (94-128 s), group HS: 102 s (84-114 s), group M/H: 128 s (110-144 s) and group HS/H: 118 s (107-132 s). In all the groups, FibTEM MCF values were significantly lower than the control and also there was a significant difference between groups M and HS according to FibTEM MCF values. Whole-blood coagulation disorder induced by these solutions is mainly dependent on fibrinogen and fibrin interaction. However, 3% HS has much less negative effect on coagulation.

Influence of head and neck position on ventilation using the air-Q® SP airway in anaesthetized paralysed patients: a prospective randomized crossover study

BackgroundThe influence of different head and neck positions on the effectiveness of ventilation with the air-Q® self-pressurizing airway remains unevaluated. This study aimed to evaluate the influence of different head and neck positions on ventilation with the air-Q® SP airway. MethodsIn this prospective, randomized crossover study, we enrolled 51 female patients who were to undergo elective gynaecological or breast surgery under general anaesthesia. An air-Q® SP airway was placed in all patients, and mechanical ventilation was performed using a volume-controlled mode with a tidal volume of 10 ml kg−1 and a respiratory rate of 12 bpm. The expiratory tidal volume, peak inspiratory pressure, oropharyngeal leak pressure, and ventilation score were assessed first for the neutral head position and then for the extended, flexed, and rotated head positions in a random order. ResultsAll parameters were similar for the rotated head and neck position and the neutral position. Compared with the neutral position, the oropharyngeal leak pressure and peak inspiratory pressure decreased in the extended position but increased significantly in the flexed position (P<0.001). However, the expiratory tidal volume and ventilation score decreased significantly in only the extended position (P<0.001) but were similar in the flexed and neutral positions. ConclusionsVentilation was not adversely affected in the rotated or flexed head and neck positions, whereas head and neck extension negatively influenced ventilation. Clinically, it is better to avoid head and neck extension during ventilation with an air-Q® SP airway. Clinical trial registrationNCT02402387.

INTRAMUSCULAR EPINEPHRINE RESULTS IN REDUCED ANESTHETIC RECOVERY TIME IN AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) UNDERGOING ISOFLURANE ANESTHESIA.

Inhalants are commonly used to anesthetize reptiles, but volatile anesthetics have been associated with prolonged recovery times. The objective of this study was to determine the effects of intramuscular (IM) epinephrine on anesthetic recovery times following isoflurane anesthesia in a population of subadult American alligators ( Alligator mississippiensis ). In this prospective randomized crossover study, five clinically healthy alligators were anesthetized for 90 min with the use of isoflurane. Alligators were randomly assigned into one of two treatment groups: Group E received IM epinephrine (0.1 mg/kg), and Group S received an equal volume of 0.9% saline administered after isoflurane was discontinued. Time from the end of inhalant administration to return of spontaneous ventilation, return of the palpebral reflex, movement in response to a standardized toe pinch, and spontaneous movement was recorded. The time of extubation was noted and occurred following the return of spontaneous ventilation and movement. Pulse rate, surface body temperature, and airway gases including expiratory and inspiratory isoflurane concentrations and end-tidal carbon dioxide were measured every 5 min throughout the study. The time from the end of anesthesia to extubation was significantly faster in Group E (51.2 ± 16.7 min) compared to Group S (107.4 ± 43.7 min). Pulse rate was significantly higher within the first 15 min following epinephrine injection compared to the saline group at these time points. Therefore, IM epinephrine administered at the end of general anesthesia can significantly hasten anesthetic recovery from isoflurane in alligators.

Internet-administered Health-related Quality of Life Questionnaires Compared With Pen and Paper in an Adolescent Scoliosis Population: A Randomized Crossover Study.

Modern technology puts into question the effectiveness of using pen and paper as a means of collecting information from web-enabled patients. This study aimed to validate and test the reliability of using the Internet as a method of administering health-related quality of life questionnaires in a pediatric spine population. A prospective randomized crossover study was conducted. Patients aged 11 to 18 with idiopathic scoliosis were invited to participate, and informed consent was obtained from a scoliosis outpatient clinic setting. Participants were randomized to one of 4 groups determining the method of questionnaire administration [Scoliosis Research Society 30 (SRS-30) and Pediatric Outcomes Data Collection Instrument (PODCI)]. Both questionnaires were completed at 2 separate timepoints and 2 weeks apart to prevent recall bias. Groups included: Paper/Paper, Paper/Internet, Internet/Paper, and Internet/Internet. Paired-samples t tests were used to determine the test-retest reliability of each group. Analysis was stratified for surveys returned within or outside of the allotted 4-week timeframe following enrollment. Of the 96 participants who completed and returned both sets of questionnaires, 26 were allocated to the Paper/Paper group (27%), 20 to the Paper/Internet group (21%), 26 to the Internet/Paper group (27%), and 24 to the Internet/Internet group (25%). The second iteration of questionnaires was returned on time by 69 of the participants (71.2%). Of the late questionnaires, 18 (67%) were paper forms. Overall, no differences were observed between Internet-administered compared with pen and paper-administered questionnaires (P=0.206). No differences were observed within any group individually for either the SRS-30 or PODCI questionnaire. In addition, no significant differences were observed within groups for surveys returned within or outside of the 4-week timeframe. Eighty-four percent of the participants who completed both paper and Internet versions of the questionnaires reported a preference of the Internet. Internet administration of both the SRS-30 and PODCI questionnaires is a valid and reliable method of acquiring health-related quality of life information in this population LEVEL OF EVIDENCE:: Level II-therapeutic study.

Prospective randomized crossover study of effects of traditional Japanese herbal medicine rikkunshito on food intake and plasma acylated ghrelin levels in patients with esophageal cancer administered with cisplatin-based chemotherapy.

133 Background: Cisplatin (CDDP) is an important chemotherapeutic drug for treating esophageal cancer that often induces chemotherapy-induced nausea and vomiting (CINV). Acylated ghrelin (AG) is an orexigenic gut hormone that can alleviate CINV. We evaluated whether rikkunshito (RKT), a traditional Japanese herbal medicine with an orexigenic effect, can improve CINV-induced anorexia and increase levels of plasma AG in patients with esophageal cancer administered with CDDP-based chemotherapy. Methods: This prospective randomized crossover study included 20 patients with esophageal cancer who were administered with CDDP-based chemotherapy between July 2013 and March 2016. Tenof them were assigned to group A (1st course with 7.5 g/day RKT on days 1 - 14; 2nd course without RKT [control]) and 10 were assigned to group B (1st course without RKT [control]; 2nd course with RKT). Food intake and levels of plasma AG (fmol/mL) were compared between the control and RKT courses. Results: Data from 18 of the patients were included in this analysis, as chemotherapy was immediately stopped due to deteriorating renal function in one patients and intracerebral bleeding in another. The median rate at which food intake decreased between days 4 and 6, which is associated with delayed-onset CINV, was considerably lower in the groups given RKT than in the control (2% vs. 30%; p = 0.07). Median levels of AG significantly decreased between days 1 to 3 in the group given RKT (15.1 to 9.6 fmol/mL, p = 0.001) and the control (14.1 to 10.2, p = 0.003), and then obviously increased from days 3 to 8 in patients with both courses (RKT: 9.6 to 15.7 fmol/mL, p &lt; 0.0001; control: 10.2 to 17.8, p = 0.0002). However, the rate at which median plasm AG levels increased from days 3 to 8 tend to be higher in the RKT, than in the control group (68% vs. 48%, p = 0.08). Conclusions: RKT might improve delayed-onset CINV as well as CINV-induced anorexia and increases in plasma AG levels among patients with esophageal cancer who undergo highly emetogenic CDDP-based chemotherapy. Clinical trial information: UMIN000010747.

THE NOVEL BIOSIMILAR OF FOLLITROPIN ALPHA TO BE MANUFACTURED IN RUSSIA STARTING FROM 2017

Within the framework of the 27th international conference «Reproductive technologies today and tomorrow», the first Russia-made follitropin alfa biosimilar for controlled ovarian stimulation in assisted reproductive technologies (ART) was presented. The follicle-stimulating hormone (FSH) biosimilar has undergone all stages of development in Russia, from the producer cells culture to the release of active FSH. Also the data are presented on a prospective randomized crossover study of phase I confirming the similarity of pharmacokinetics between the biosimilar and the original FSH. Another randomized multicenter phase III clinical study is now under way aiming to demonstrate the clinical equivalence between the biosimilar and the original FSH; preliminary results of this study are presented and discussed. As planned, the recombinant FSH biosimilar will be produced in disposable injectors (pen-injector) that provide easy-to-use handling, convenient dose setting and wide range dosing.

Comparison of radial endobronchial ultrasound with a guide sheath and with distance by thin bronchoscopy for the diagnosis of peripheral pulmonary lesions: a prospective randomized crossover trial.

Transbronchial biopsy (TBB) using radial endobronchial ultrasound with a guide sheath (REBUS-GS) has improved the diagnosis of peripheral pulmonary lesions (PPLs). Because of the high cost of the GS, REBUS with distance (REBUS-D) has certain advantages. The aim of this study was to compare the diagnostic yield of the REBUS-GS and REBUS-D by thin bronchoscopy for PPLs. Patients with PPLs were enrolled in a prospective randomized crossover study from August 2014 and July 2015. Once the lesion was localized, TBB using REBUS-GS and TBB using REBUS-D were performed sequentially in a randomized order in each patient. Each patient received four to five transbronchial biopsies with REBUS-GS as well as four to five transbronchial biopsies with REBUS-D. All brushing was performed through GS. A total of 54 patients were enrolled in this study. After excluding seven participants with PPLs that were not detected by REBUS, a total of 47 subjects underwent REBUS-TBB. The diagnostic yield of REBUS-GS-TBB and REBUS-D-TBB was 72.2% (39/54) and 75.9% (41/54) respectively (P=0.625). Moreover, there was no statistically significant difference in diagnostic yield between REBUS-GS and REBUS-D in different lobe lesions and lesion sizes. Two cases of adenocarcinoma were only diagnosed with REBUS-GS-TBB. Two cases of tuberculosis, one case of mucosa-associated lymphoid tissue lymphoma (MALT) and one case of adenocarcinoma were only diagnosed by REBUS-D-TBB. The mean biopsy time after visualization of PPLs for REBUS-GS-TBB and REBUS-D-TBB were 5.17±2.34 and 7.36±3.18 min (P=0.00053). Using thin bronchoscopy, the diagnostic yield for PPLs with REBUS-D-TBB is not inferior to the yield with REBUS-GS-TBB. The diagnosis rate of small subpleural lesions with REBUS-D is lower than the rate with REBUS-GS. Although it is associated with shorter operation time and less bleeding, REBUS-GS has a higher cost and sometimes leads to check failure due to small specimens and the impact of the bronchoscope curvature.

Effect of high-frequency oscillatory ventilation on esophageal and transpulmonary pressures in moderate-to-severe acute respiratory distress syndrome.

Background High-frequency oscillatory ventilation (HFOV) has not been shown to be beneficial in the management of moderate-to-severe acute respiratory distress syndrome (ARDS). There is uncertainty about the actual pressure applied into the lung during HFOV. We therefore performed a study to compare the transpulmonary pressure (PL) during conventional mechanical ventilation (CMV) and different levels of mean airway pressure (mPaw) during HFOV.MethodsThis is a prospective randomized crossover study in a university teaching hospital. An esophageal balloon catheter was used to measure esophageal pressures (Pes) at end inspiration and end expiration and to calculate PL. Measurements were taken during ventilation with CMV (CMVpre) after which patients were switched to HFOV with three 1-h different levels of mPaw set at +5, +10 and +15 cm H2O above the mean airway pressure measured during CMV. Patients were thereafter switched back to CMV (CMVpost).ResultsTen patients with moderate-to-severe ARDS were included. We demonstrated a linear increase in Pes and PL with the increase in mPaw during HFOV. Contrary to CMV, PL was always positive during HFOV whatever the level of mPaw applied but not associated with improvement in oxygenation. We found significant correlations between mPaw and Pes.ConclusionHFOV with high level of mPaw increases transpulmonary pressures without improvement in oxygenation.

Bedside assessment of the effects of positive end-expiratory pressure on lung inflation and recruitment by the helium dilution technique and electrical impedance tomography.

Higher positive end-expiratory pressure might induce lung inflation and recruitment, yielding enhanced regional lung protection. We measured positive end-expiratory pressure-related lung volume changes by electrical impedance tomography and by the helium dilution technique. We also used electrical impedance tomography to assess the effects of positive end-expiratory pressure on regional determinants of ventilator-induced lung injury. A prospective randomized crossover study was performed on 20 intubated adult patients: 12 with acute hypoxemic respiratory failure and 8 with acute respiratory distress syndrome. Each patient underwent protective controlled ventilation at lower (7 [7, 8] cmH2O) and higher (12 [12, 13] cmH2O) positive end-expiratory pressures. At the end of each phase, we collected ventilation, helium dilution, and electrical impedance tomography data. Positive end-expiratory pressure-induced changes in lung inflation and recruitment measured by electrical impedance tomography and helium dilution showed close correlations (R (2)=0.78, p<0.001 and R (2)=0.68, p<0.001, respectively) but with relatively variable limits of agreement. At higher positive end-expiratory pressure, recruitment was evident in all lung regions (p<0.01) and heterogeneity of tidal ventilation distribution was reduced by increased tidal volume distending the dependent lung (p<0.001); in the non-dependent lung, on the other hand, compliance decreased (p<0.001) and tidal hyperinflation significantly increased (p<0.001). In the subgroup of ARDS patients (but not in the whole study population) tidal hyperinflation in the dependent lung regions decreased at higher positive end-expiratory pressure (p=0.05), probably indicating higher potential for recruitment. Close correlations exist between bedside assessment of positive end-expiratory pressure-induced changes in lung inflation and recruitment by the helium dilution and electrical impedance tomography techniques. Higher positive end-expiratory pressure exerts mixed effects on the regional determinants of ventilator-induced lung injury; these merit close monitoring.

Comparison of different stylets used for intubation with the C-MAC D-Blade® Videolaryngoscope: a randomized controlled study

ObjectiveThe angle of the C-MAC D-Blade® videolaryngoscope, which is used for difficult airway interventions, is not compatible with routinely used endotracheal tubes. MethodsA prospective randomized crossover study was performed comparing five intubation methods for use with standardized airways, including using different stylets or no stylet: Group HS, hockey-stick stylet; Group DS, D-blade type stylet; Group CS, CoPilot® videolaryngoscope rigid stylet®; Group GEB, gum elastic bougie; and Group NS, no stylet. A manikin was used to simulate difficult intubation with a Storz C-MAC D-Blade® videolaryngoscope. The duration of each intubation stage was evaluated. ResultsParticipants in this study (33 anesthesiology residents and 20 anesthesiology experts) completed a total of 265 intubations. The number of attempts made using no stylet was significantly greater than those made for the other groups (p<0.05 for group NS- group GEB, group NS- group DS, group NS- group CS and group NS- group HS). The duration to pass the vocal cords significantly differed among all groups (p<0.001). The total intubation duration was shortest when using D-blade stylet, CoPilot stylet and hockey stick stylet. Although no difference was observed between stylet groups, a significant difference was found between each of these three and no stylet and gum elastic bougie (p<0.05 and p<0.001, respectively). ConclusionUse of the correct stylet leads to a more efficient use of the Storz C-MAC D-Blade®. In our study, the use of the D-blade stylet, the CoPilot stylet and the hockey stick stylet provided quicker intubation, allowed easier passage of the vocal cords, and decreased the total intubation duration. To confirm the findings of our study, randomized controlled human studies are needed.

Effect of mid-luteal phase GnRH agonist on frozen-thawed embryo transfers during natural menstrual cycles: a randomised clinical pilot study

This prospective randomised crossover study evaluated the effect of mid-luteal single-dose gonadotropin-releasing hormone agonist (triptoreline) on pregnancy outcomes in natural-cycle frozen embryo transfers (FETs). Ninety-eight women were randomised to receive either standard luteal support with vaginal micronised progesterone or an additional single dose of 0.1 mg triptoreline at the time of implantation. The intervention group was composed of 65 FET cycles and the control group of 62 cycles. In the intervention group, there were more positive pregnancy tests, clinical pregnancies and live births, but the differences did not reach statistical significance. The mean beta human chorionic gonadotropin (β-hCG) concentration of singleton pregnancies was significantly lower in the intervention group compared to the control group (p = 0.048). No difference was detected in the median birth weight of the newborns.

EPINEPHRINE OR GV-26 ELECTRICAL STIMULATION REDUCES INHALANT ANESTHESTIC RECOVERY TIME IN COMMON SNAPPING TURTLES (CHELYDRA SERPENTINA).

Prolonged anesthetic recovery times are a common clinical problem in reptiles following inhalant anesthesia. Diving reptiles have numerous adaptations that allow them to submerge and remain apneic for extended periods. An ability to shunt blood away from pulmonary circulation, possibly due to changes in adrenergic tone, may contribute to their unpredictable inhalant anesthetic recovery times. Therefore, the use of epinephrine could antagonize this response and reduce recovery time. GV-26, an acupuncture point with reported β-adrenergic and respiratory effects, has reduced anesthetic recovery times in other species. In this prospective randomized crossover study, six common snapping turtles (Chelydra serpentina) were anesthetized with inhalant isoflurane for 90 min. Turtles were assigned one of three treatments, given immediately following discontinuation of isoflurane: a control treatment (0.9% saline, at 0.1 ml/kg i.m.), epinephrine (0.1 mg/kg i.m.), or acupuncture with electrical stimulation at GV-26. Each turtle received all treatments, and treatments were separated by 48 hr. Return of spontaneous ventilation was 55% faster in turtles given epinephrine and 58% faster in the GV-26 group versus saline (P < 0.001). The times to movement and to complete recovery were also significantly faster for both treatments than for saline (P < 0.02). Treated turtles displayed increases in temperature not documented in the control (P < 0.001). Turtles administered epinephrine showed significantly increased heart rates and end-tidal CO(2) (P < 0.001). No adverse effects were noted in the study animals. The mechanisms of action were not elucidated in the present investigation. Nevertheless, the use of parenteral epinephrine or GV-26 stimulation in the immediate postanesthetic period produces clinically relevant reductions in anesthetic recovery time in common snapping turtle. Further research is necessary to evaluate the effects of concurrent GV-26 and epinephrine administration and to assess responses in other reptilian species.

Effect of Heated Humidification on CPAP Therapy Adherence in Subjects With Obstructive Sleep Apnea With Nasopharyngeal Symptoms.

The addition of heated humidification to CPAP has been shown to improve nasal adverse effects in subjects with obstructive sleep apnea (OSA). However, current data regarding improvement in CPAP adherence is conflicting. Furthermore, there are no data from a tropical climate area with a high humidity level. In this prospective randomized crossover study conducted in Thailand, subjects with moderate to severe OSA with nasopharyngeal symptoms post-split-night study were enrolled in the study. Subjects were randomly assigned to receive CPAP with or without heated humidification for 4 weeks and then crossed over. Information on CPAP adherence, quality of life assessed by the Functional Outcomes of Sleep Questionnaire, nasopharyngeal symptoms assessed by a modified XERO questionnaire, and bedroom ambient humidity and temperature data were obtained. Data were collected on 20 subjects with OSA during the period of January to December 2014. Although the addition of heated humidification appeared to improve average hours of use for all days when compared with conventional CPAP, the difference was not statistically significant (CPAP with heated humidification = 4.6 ± 1.7 h/night; conventional CPAP = 4.0 ± 1.7 h/night, P = .1). However, the addition of heated humidification improved CPAP adherence on the days of use (5.5 ± 1.5 h/night) compared with conventional CPAP (5.2 ± 1.4 h/night), P = .033. Quality of life was also improved according to the Functional Outcomes of Sleep Questionnaire score (median 17.6 [interquartile range 3.5]) in the heated humidification group compared with conventional CPAP group (median 17.6 [interquartile range 4.5]), P = .046. Significant reduction in the dry throat/sore throat symptom was noted only when CPAP with heated humidification was used. Even in a tropical climate area, CPAP adherence and quality of life appeared to improve when heated humidification was employed in subjects with moderate to severe OSA with nasopharyngeal symptoms post-split-night polysomnography. The improvement may be related to a reduction in the dry throat/sore throat symptom.