Apnea Time Research Articles

The effects of obstructive sleep apnea on blood pressure variability and load in patients with hypertension.

Hypertension frequently coexists with obstructive sleep apnea (OSA), and their interplay substantially impacts the prognosis of affected individuals. Investigating the influence of OSA on blood pressure variability (BPV) and blood pressure load (BPL) in hypertensive patients has become a focal point of clinical research. This cross-sectional study recruited hypertensive patients (n = 265) without discrimination and classified them into four groups based on their apnea-hypopnea index (AHI): control group (n = 40), AHI < 5; mild group (n = 74), 5 ≤ AHI ≤ 15; moderate group (n = 68), 15 < AHI ≤ 30; severe group (n = 83), AHI > 30. All participants underwent comprehensive assessments, including polysomnography (PSG) monitoring, 24-h ambulatory blood pressure (ABP) monitoring, cardiac Doppler ultrasound, and additional examinations when indicated. BPV and BPL exhibited significant elevations in the moderate and severe OSA groups compared to the control and mild OSA groups (P < 0.05). Moreover, interventricular septum thickness and left ventricular end-diastolic volume (LVEDV) demonstrated higher values in the moderate and severe OSA groups (P < 0.05). Multiple stepwise regression analysis identified noteworthy risk factors for elevated BPV in hypertensive patients with OSA, including AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea. Hypertensive patients with moderate to severe OSA exhibited substantially increased BPV and BPL. Moreover, BPV was correlated with AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea in hypertensive patients with OSA.

Feasibility of ProVu™ Video Stylet for awake intubation of patients with severe obesity: A pilot observational study

BackgroundAirway management in the obese patient is known to be challenging as oxygenation may rapidly decrease after general anesthesia induction. Mask ventilation and tracheal intubation can be complicated due to obesity-related anatomical features. The reduced safe apnea time can put the patient at risk of severe and rapid desaturation. Recent guidelines recommend avoiding the suppression of spontaneous breathing in cases of predicted anatomically or physiologically difficult airway. Many different devices, such as video stylets and video laryngoscopes, have been proposed as alternatives to traditional gold standard flexible bronchoscope use for awake intubation. AimOur study reports the use of a new flexible ProVu™ Video Stylet (Flexicare Medical Ltd., Mountain Ash, UK) for awake intubations in 11 patients with severe obesity, who presented with at least one criterion for potentially difficult oxygenation (during ventilation and/or intubation attempts) after suppression of spontaneous breathing. MethodsIn total 11 consecutive patients with severe obesity and clinical indication for an awake tracheal intubation were enrolled over a 10-months period and intubated with the ProVu™ Video Stylet. ResultsAll 11 tracheal intubations were successfully performed. The procedures also highlighted potential limitations to consider while using the device in an awake intubation setting. ConclusionDespite the limitations of this small observational pilot study, our study showed that the ProVu™ Video Stylet may be a promising tool and a valid alternative for performing awake tracheal intubation in patients with severe obesity and predictors of difficult oxygenation. Future studies are needed to compare the performance of the ProVu™ Video Stylet with video laryngoscopy and flexible bronchoscopy, and to provide stronger evidence in favor or against the use of this new device. The possible availability of an alternative device, combined with the skill and confidence to use it, may provide the anesthesiologist an additional tool for managing awake intubation of at-risk airways, in accordance with recommendations from the most recent guidelines.

Distribution characteristics of intestinal flora in patients with OSAHS and the relationship between different intestinal flora and sleep disorders, hypoxemia and obesity

ObjectiveTo investigate the distribution characteristics of intestinal flora in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS) of different severities and the relationship between different intestinal flora and sleep structure disorder, hypoxemia and obesity.MethodsA total of 25 healthy volunteers and 80 patients with OSAHS were enrolled in this study. The control group was healthy, and the experimental group comprised patients with OSAHS. The apnoea–hypopnea index (AHI), minimum saturation of peripheral oxygen (SpO2min), mean saturation of peripheral oxygen, body mass index, maximum apnoea time and other indicators were collected in clinical practice. The patients with OSAHS were divided into 20 mild and 42 moderate OSAHS cases, as well as 18 patients with severe OSAHS according to the AHI classification. Bioinformatics-related statistics were analysed using the QIIME2 software, and clinical data were analysed with the SPSS 22.0 software.ResultsThe changes in microbial alpha diversity in the intestinal flora of patients with OSAHS showed that richness, diversity and evenness decreased, but the beta diversity did not change significantly. The Thermus Anoxybacillus, Anaerofustis, Blautia, Sediminibacterium, Ralstonia, Pelomonas, Ochrobactrum, Thermus Sediminibacterium, Ralstonia, Coccidia, Cyanobacteria, Anoxic bacilli and Anaerobes were negatively correlated with AHI (r = −0.38, −0.36, −0.35, −0.33, −0.31, −0.29, −0.22, −0.18) and positively correlated with SpO2min (r =0.38, 0.2, 0.25, 0.22, 0.24, 0.11, 0.23, 0.15).ConclusionSome bacteria showed a significant correlation with clinical sleep monitoring data, which provides a possibility for the assessment of disease risk, but the mechanisms of their actions in the intestinal tract are not clear at present. Further research and observations are needed.

First Real-Life Data on the Diving Response in Healthy Children.

Swimming and diving are popular recreational activities, representing an effective option in maintaining and improving cardiovascular fitness in healthy people. To date, only little is known about the cardiovascular adaption to submersion in children. This study was conducted to improve an understanding thereof. We used a stepwise apnea protocol with apnea at rest, apnea with facial immersion, and at last apnea during whole body submersion. Continuous measurement of heart rate, oxygen saturation, and peripheral resistance index was done. Physiologic data and analysis of influencing factors on heart rate, oxygen saturation, and peripheral vascular tone response are reported. The current study presents the first data of physiologic diving response in children. Data showed that facial or whole body submersion leads to a major drop in heart rate, and increase of peripheral resistance, while the oxygen saturation seems to be unaffected by static apnea in most children, with apnea times of up to 75s without change in oxygen saturation.

HIGH-FLOW NASAL OXYGEN THERAPY: AN ALTERNATIVE TO PRE-OXYGENATION IN THE OPERATING ROOM

High-flow nasal oxygen therapy (HFO) is a device that supplies warmed and humidified inspiratory gas through a nasal cannula at higher flow rates than conventional oxygen therapy, with an inspired oxygen fraction that can fluctuate from 21% to 100%. The primary aim of our study is to compare the efficacy of ONHD versus face mask. This trial was an experimental cohort study carried out at the Central Block of the Ibn Rochd University Hospital in Casablanca, over a period of three months, and involved 40 patients distributed into two groups: the face mask PO group (n=20) and the ONHD PO group (n=20). We evaluated apnea time without desaturation (SPO2˃95%), mean SPO2 during pre-oxygenation and apnea time, ETCO2 value after intubation and the frequency of complications during pre-oxygenation, The results show that ONHD compared with the face mask prolongs the duration of apnea without desaturation (SPO2˃95%), especially in high-risk patients, especially obese individuals.

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange to the Rescue of the Anaesthesiologist in a Difficult Airway Case

Airway surgeries pose challenges to the anaesthesiologist due to a potentially difficult airway and shared workspace with the surgeons. Apnoeic oxygenation is a technique to increase apnoea time safely during airway surgeries, which can be achieved with multiple devices, one of which is high-flow nasal oxygen (HFNO). Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is one of the modes of delivering HFNO. We present an interesting case report wherein THRIVE was incorporated into successful anaesthetic management of an intratracheal tumour located close to the carina almost obliterating the tracheal lumen.

Intubação de sequência rápida em emergências pediátricas: uma revisão integrativa

Objectives: To identify up-to-date information that contributes to increasing the progress of rapid sequence intubation (RSI) in pediatric emergencies. Methods: This is an integrative literature review that used the keywords “Rapid Sequence Induction and Intubation”, “Intubation, Intratracheal” and “Pediatric Emergency Medicine” in the Scielo, PubMed and Virtual Health Library databases, using, after applying the inclusion and exclusion criteria, the content analysis for discussion. Results: We found 9 articles that were later discussed. Conclusions: Many health professionals do not correctly indicate medications during and after RSI in pediatric emergencies, and educational interventions aimed at correcting this failure are beneficial. An accurate epidemiological profile of RSI in pediatric emergencies cannot yet be established. The best way to collect data in studies involving RSI is through video recording. Interventions aimed at reducing the time spent during orotracheal tube insertion may more effectively reduce the total apnea time during RSI. The use of apneic oxygenation and fractional expired oxygen (FeO2) analysis may have some benefits in RSI.

The efficacy of intranasal leptin for opioid-induced respiratory depression depends on sex and obesity state.

Introduction: Opioid-induced respiratory depression (OIRD) is the primary cause of death associated with opioids and individuals with obesity are particularly susceptible due to comorbid obstructive sleep apnea (OSA). Repeated exposure to opioids, as in the case of pain management, results in diminished therapeutic effect and/or the need for higher doses to maintain the same effect. With limited means to address the negative impact of repeated exposure it is critical to develop drugs that prevent deaths induced by opioids without reducing beneficial analgesia. Methods: We hypothesized that OIRD as a result of chronic opioid use can be attenuated by administration of IN leptin while also maintaining analgesia in both lean mice and mice with diet-induced obesity (DIO) of both sexes. To test this hypothesis, an opioid tolerance protocol was developed and a model of OIRD in mice chronically receiving morphine and tolerant to morphine analgesia was established. Subsequently, breathing was recorded by barometric plethysmography in four experimental groups: obese male, obese female, lean male, and lean female following acute administration of IN leptin. Respiratory data were complemented with measures of arterial blood gas. Operant behavioral assays were used to determine the impact of IN leptin on the analgesic efficacy of morphine. Results: Acute administration of IN leptin significantly attenuated OIRD in DIO male mice decreasing the apnea index by 58.9% and apnea time by 60.1%. In lean mice leptin was ineffective. Blood gas measures confirmed the effectiveness of IN leptin for preventing respiratory acidosis in DIO male mice. However, IN leptin was not effective in lean mice of both sexes and appeared to exacerbate acid-base disturbances in DIO female mice. Additionally, morphine caused a complete loss of temperature aversion which was not reduced by intranasal leptin indicating IN leptin does not decrease morphine analgesia. Discussion: IN leptin effectively treated OIRD in morphine-tolerant DIO male mice without impacting analgesia. In contrast, IN leptin had no effect in lean mice of either sex or DIO female mice. The arterial blood gas data were consistent with ventilatory findings showing that IN leptin reversed morphine-induced respiratory acidosis only in DIO male mice but not in other mouse groups. Finally, a hypercapnic sensitivity study revealed that IN leptin rescued minute ventilation under hypercapnic conditions only in DIO male mice, which suggests that differential responses to IN leptin are attributable to different leptin sensitivities depending on sex and the obesity status.

Efficacy of caffeine citrate combined with mechanical ventilation in the treatment of apnea of prematurity and its influence on neurodevelopmental outcomes

Purpose: To investigate the efficacy of caffeine citrate when combined with mechanical ventilation in the treatment of apnea of prematurity and its influence on neurodevelopmental outcomes.Methods: One hundred and sixty (160) premature infants with apnea admitted in Guangdong Second Provincial General Hospital, Guangzhou, China were enrolled in this study, and divided into control and study groups. Children in the control group underwent mechanical ventilation combined with aminophylline therapy, while children in the study group were administered mechanical ventilation combined with caffeine citrate. Blood gas and pulmonary function indices, as well as clinical symptom and neurodevelopmental improvements were assessed. Also, the incidence of adverse reactions were recorded during treatment.Results: Blood gas indices including oxygen partial pressure (PaO2) and pulse oxygen saturation (SPO2) levels in the study group were significantly higher, but partial pressure of carbon dioxide (PaCO2) level was lower (p &lt; 0.05); furthermore, tidal volume, respiratory rate and peak expiratory flow (PEF) in the study group were higher than in the control group (p &lt; 0.05). On the other hand, the disappearance time of apnea, invasive mechanical ventilation time and oxygen inhalation time in the study group were shorter than in the control group (p &lt; 0.05). Mental development index (MDI) and psychomotor development index (PDI) values in the study group were significantly higher than in the control group (p &lt; 0.05), while the incidence of bronchopulmonary dysplasia, feeding intolerance, tachycardia and hyperglycemia in the study group was significantly lower than in the control group (p &lt; 0.05).Conclusion: The combination of caffeine citrate and mechanical ventilation aids improvement in the neurodevelopmental outcome of children, as well as reduction in the incidence of adverse reactions. However, further clinical trials are required prior to application of this strategy in clinical practice.

A quasi-experimental study of fresh oxygen flow on patients' oxygen reserve during mask-assisted ventilation under general anesthesia induction.

To compare the effect of different amounts of fresh oxygen flow on oxygen reserve in patients undergoing general anesthesia. Seventy-two patients were enrolled in this quasi-experimental study. Patients were randomly divided into experimental groups with a fresh oxygen flow of 1 L/min, 2 L/min, 4 L/min, and 8 L/min (denoted as G1, G2, G3, and G4, respectively) for 2 min of mask-assisted ventilation. Safe apnea time (SAT) was the primary endpoint; SAT was defined as the time from the cessation of ventilation to the time the patient's pulse oxygen saturation (SpO2) decreased to 90%. Ventilation indicators such as end-tidal oxygen concentration (EtO2), end-tidal carbon dioxide partial pressure (EtCO2), SpO2, and carbon dioxide (CO2) elimination amount, during mask-assisted ventilation, were the secondary endpoints. The SAT of G1, G2, G3, and G4 were 305.1 ± 97.0 s, 315 ± 112.5 s, 381.3 ± 118.6 s, and 359 ± 104.4 s, respectively (p > 0.05). The EtO2 after 2 min of mask-assisted ventilation in groups G1, G2, G3, and G4 were 69.7 ± 8.8%, 75.2 ± 5.0%, 82.5 ± 3.3%, and 86.8 ± 1.5%, respectively (p < 0.05). Also, there was a moderate positive correlation between the fresh oxygen flow and EtO2 (correlation coefficient r = 0.52, 95% CI 0.31-0.67, p < 0.0001). The CO2 elimination in the G1 and G2 groups was greater than that in the G4 group (p < 0.05). There was no significant difference in other indicators among the groups (all p > 0.05). The amount of fresh oxygen flow during mask-assisted ventilation was positively correlated with EtO2. Also, even though there was no significant difference, the patients' oxygen reserves increased with the increase in fresh oxygen flow.

Effect of trans-nasal humidified rapid insufflation ventilatory exchange on reflux and microaspiration in patients undergoing laparoscopic cholecystectomy during induction of general anesthesia: a randomized controlled trial.

Reflux aspiration is a rare but serious complication during induction of anesthesia. The primary aim of this study is to compare the incidence of reflux and microaspiration in patients undergoing laparoscopic cholecystectomy during induction of general anesthesia using either a facemask or trans-nasal humidified rapid insufflation ventilatory exchange. We conducted a single-center, randomized, controlled trial. Thirty patients were allocated to either a facemask or a trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) group. Pre-oxygenation for 5 min with a facemask or THRIVE, positive pressure ventilation for 2 min or THRIVE for 2 min after anesthesia induction was followed. Before endotracheal intubation, the secretion above and below the glottis was collected to measure pepsin content and analyze blood gas. The ELISA assay for supra- and subglottic human pepsin content was used to detect the presence of reflux and microaspiration. The primary outcome was the incidence of reflux and microaspiration. Secondary outcomes were apnea time, PaO2 before tracheal intubation, and the end-expiratory carbon dioxide partial pressure. Patients in the THRIVE group had a significantly longer apnea time (379.55 ± 94.12 s) compared to patients in the facemask group (172.96 ± 58.87 s; p < 0.001). There were no differences observed in PaO2 between the groups. A significant difference in gastric insufflation, reflux, and microaspiration was observed between the groups. Gastric insufflation was 6.9% in the THRIVE group vs. 28.57% kPa in the facemask group (p = 0.041); reflux was 10.34% in the THRIVE group vs. 32.14% kPa in the facemask group (p = 0.044); and microaspiration was 0% in the THRIVE group vs. 17.86% kPa in the facemask group (p = 0.023). The application of THRIVE during induction of general anesthesia reduced the incidence of reflux and microaspiration while ensuring oxygenation and prolonged apnea time in laparoscopic cholecystectomy patients. THRIVE may be an optimal way to administer oxygen during the induction of general anesthesia in laparoscopic cholecystectomy patients. Chinese Clinical Trial Registry, No: ChiCTR2100054086, https://www.chictr.org.cn/indexEN.html.

Effectiveness of high-flow nasal cannula oxygen in apneic oxygenation during intubation in high-risk surgical patients: a systematic review protocol.

This review will investigate the effectiveness of high-flow nasal oxygen in apneic oxygenation through safe apnea time and other ventilation parameters in patients at high risk of oxygen desaturation during induction and tracheal intubation for anesthesia management. High-risk surgical patient groups include obese patients, those with suspected or known obstructive sleep apnea, and critically ill patients, who are at risk of rapid oxygen desaturation during intubation. Conventional oxygen administration in induction and intubation of patients undergoing general anesthesia include nasal cannulas, simple face masks, Venturi, buccal oxygenation, bag-valve mask ventilation, and non-invasive ventilation. High-flow nasal oxygen has emerged as a novel technique, and is advantageous because it increases positive end-expiratory pressure and oxygen delivered. Eligible studies will include high-risk surgical patients aged 18 or above requiring endotracheal intubation in both emergency and elective anesthetic settings. High-risk patients are defined as those with suspected or known obstructive sleep apnea, obesity (BMI > 35), or critically ill patients (scored the American Society of Anesthesiologists classification as 3 or above). The review will follow the JBI methodology for systematic reviews of effectiveness. Databases to be searched include MEDLINE, Embase, and Scopus. Reference lists of selected studies will then be hand-searched for additional eligible studies. The primary outcome will be safe apnea time, with secondary outcomes including oxygen and carbon dioxide parameters, and adverse events (eg, gastric distension). Studies will, where possible, be pooled in statistical meta-analyses with data heterogeneity assessed using the standard χ2 and I2 tests. PROSPERO CRD42022312145.

Automatic Apnea Time Adjustments During Ventilation With Automode.

Automode is a feature on Servo ventilators that automatically switches between mandatory and spontaneous breaths. Spontaneous breaths suppress mandatory breaths until apnea. The period from the last spontaneous breath to the first mandatory breath is automatically adjusted by a calculated apnea time limit based on a maximum apnea time setting, the mandatory breathing frequency setting, and the spontaneous breath count. The purpose of this study was to validate the apnea time algorithm by using simulated mechanical ventilation. A Servo-u ventilator was connected to an ASL 5000 breathing simulator. Ventilator settings were the following: Automode (pressure control to pressure support), pressure control = 10 cm H2O; pressure support = 5 cm H2O; PEEP = 10 cm H2O; breathing frequency = 10, 12, 15, 20 breaths/min; maximum apnea time = 7 and 12 s. Simulator settings were the following: resistance = 10 cm H2O/L/s; compliance = 35 mL/cm H2O; flow trigger model: frequency = 20 breaths/min, trigger flow = 10 L/min, trigger duration = 800 ms. Flow waveforms were recorded, and the observed apnea time limit was compared with the calculated value. The outcome variable was error, defined as the difference between observed and calculated apnea times expressed as a percentage. The observed apnea time limit ranged from 3 to 12 s, depending on the mandatory frequency and the spontaneous breath count. The average error ranged from -2 to 0%. The measured apnea time for simulated ventilation settings was within 2% of calculated times. Automode allowed a spontaneous frequency lower than expected based on the mandatory frequency.

Comparison of hands-free Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) with conventional facemask ventilation technique for oxygenation in patients undergoing electroconvulsive therapy – A cross over study

ObjectivesModified ECT is routinely conducted using face mask (FM) and bag ventilation technique. Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) is a novel hands-free insufflation technique that provides oxygenation and prolongs apnoea time. There is limited literature comparing the two techniques. Primary objective of this study was to compare oxygen desaturation between THRIVE and FM techniques during ECT while secondary objective was to compare hemodynamics and complications. MethodsPatients aged 18–50 years undergoing 3rd-5th ECT treatments were enrolled. First ECT was with FM technique followed by THRIVE (with LUBO collar) in the next ECT. Except for the oxygenation technique, the protocol for ECT administration was similar with both techniques. SpO2 values were recorded every minute for 10 min while hemodynamic parameters were measured at 2 min and 5 min following administration of electrical stimulus. Any drop in SpO2 below 92 % was considered as a desaturation event. ResultsA total of 201 patients underwent ECTs, one each with FM and THRIVE technique.Median age of patients was 28 years. There was no difference in SpO2 between the techniques (main effect P = 0.324, interaction P = 0.14). Only one patient had desaturation with THRIVE requiring intervention with FM. None of the patients had any airway complications in terms of nasal injury, hoarseness, or pneumothorax with THRIVE. ConclusionTHRIVE is a safe alternative option for hands-free oxygenation while administering ECT. However, considering patient safety, an anaesthesiologist competent in airway management must be readily available.

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange Versus Conventional Facemask Breathing for Preoxygenation During Rapid Sequence Induction.

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), if used for pre-oxygenation and apnoeic oxygenation, has the propensity to extend the safe apnoea time and thereby decrease the incidence of desaturation during rapid sequence induction (RSI) for emergency surgeries. Hence, we proposed to evaluate the comparative efficacy of pre-oxygenation with the use of conventional facemask breathing versus THRIVE during RSI in patients undergoing general anaesthesia (GA) for emergency surgeries. Eighty patients undergoing RSI under GA for emergency abdominopelvic surgery were divided randomly into two groups. Patients were preoxygenated for three minutes with 100% oxygen via either a high-flow nasal cannula at a flow of 60 L/minute using THRIVE or a tightly-held, snuggly-fitting facemask at a flow of 12L/minute using a circle system. RSI was administered followed by laryngoscopy and endotracheal intubation. Arterial partial pressure of oxygen (PaO2) measured immediately after successful endotracheal intubation was our primary outcome. The lowest peripheral oxygen saturation (SpO2), apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and any adverse event were also recorded. Data thus collected were statistically analysed. No statistically significant difference in PaO2 value was observed after successful intubation, lowest SpO2, apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and adverse event between both the groups (p>0.05). We conclude that though not superior to conventional facemasks, THRIVE is a safe, practicable, and efficient pre-oxygenation tool during RSI of GA for patients undergoing emergency surgeries.

DMSO potentiates the suppressive effect of dronabinol on sleep apnea and REM sleep in rats

IntroductionDimethyl sulfoxide (DMSO) is an amphipathic molecule with innate biological activity that also is used to dissolve both polar and nonpolar compounds in preclinical and clinical studies. Recent investigations of dronabinol, a cannabinoid, dissolved in DMSO demonstrated decreased sleep apnea frequency and time spent in REM sleep in rats. Here, we tested the effects of dronabinol dissolved in 25% DMSO diluted in phosphate-buffered saline (PBS) to rule out potentiating effects of DMSO.MethodsSprague–Dawley rats were anesthetized and implanted with bilateral stainless steel screws into the skull for electroencephalogram recording and bilateral wire electrodes into the nuchal muscles for electromyogram recording. Each animal was recorded by polysomnography. The study was a fully nested, repeated measures crossover design, such that each rat was recorded following each of 8 intraperitoneal injections separated by three days: vehicle (25% DMSO/PBS); vehicle and CB1 antagonist (AM 251); vehicle and CB2 antagonist (AM 630); vehicle and CB1/CB2 antagonist; dronabinol (CB1/CB2 agonist); dronabinol and CB1 antagonist; dronabinol and CB2 antagonist; and dronabinol and CB1/CB2 antagonists. Sleep was manually scored into NREM and REM stages, and sleep apneas were quantified.ResultsDronabinol dissolved in 25% DMSO did not suppress sleep apneas or modify sleep efficiency compared to vehicle controls, in contrast to previously published results. However, dronabinol did suppress REM sleep, which is in line with previously published results.ConclusionsDronabinol in 25% DMSO partially potentiated dronabinol’s effects, suggesting a concomitant biological effect of DMSO on breathing during sleep.

Pressure-controlled versus manual facemask ventilation for anaesthetic induction in adults: A randomised controlled non-inferiority trial.

Pressure-controlled face mask ventilation (PC-FMV) with positive end-expiratory pressure (PEEP) after apnoea following induction of general anaesthesia prolongs safe apnoea time and reduces atelectasis formation. However, depending on the set inspiratory pressure, a delayed confirmation of a patent airway might occur. We hypothesised that by lowering the peak inspiratory pressure (PIP) when using PC-FMV with PEEP, confirmation of a patent airway would not be delayed as studied by the first return of CO2 , compared with manual face mask ventilation (Manual FMV). This was a single-centre, randomised controlled non-inferiority trial. Seventy adult patients scheduled for elective day-case surgery under general anaesthesia with body mass index between 18.5 and 29.9 kg m-2 , American Society of Anesthesiologists (ASA) classes I-III, and without anticipated difficult FMV, were included. Before the start of pre-oxygenation and induction of general anaesthesia, participants were randomly allocated to receive ventilation with either PC-FMV with PEEP, at a PIP of 11 and a PEEP of 6 cmH2 O or Manual FMV, with the adjustable pressure-limiting valve set at 11 cmH2 O. The primary outcome variable was the number of ventilatory attempts needed until confirmation of a patent airway, defined as the return of at least 1.3 kPa CO2 . The return of ≥1.3 kPa CO2 on the capnography curve was observed after mean ± SD, 3.6 ± 4.2 and 2.5 ± 1.9 ventilatory attempts/breaths with PC-FMV with PEEP and Manual FMV, respectively. The difference in means (1.1 ventilatory attempts/breaths) had a 99% CI of -1.0 to 3.1, within the accepted upper margin of four breaths for non-inferiority. Following induction of general anaesthesia, PC-FMV with PEEP was used without delaying a patent airway as confirmed with capnography, if moderate pressures were used.

Inspiratory muscle fatigue at the swimming tumble turns: its occurrence and effects on kinematic parameters of the turns.

Introduction: The present study had two objectives: 1) to investigate the effects of tumble turns on the development of inspiratory muscle fatigue (IMF) and compare this to whole swimming, and 2) to evaluate the effects of pre-induced IMF on the kinematic parameters of tumble turns. Fourteen young club-level swimmers (13 ± 2years of ages) completed three swim trials. Methods: The first trial was used to determine the 400-m front crawl swim time at maximal effort (400FC). The other two trials consisted of a series of 15 tumble turns at the 400FC pace. In one of the turn-only trials, IMF was pre-induced (TURNS-IMF), whereas in the other turn-only trial it was not (TURNS-C). Results: Compared with baseline values, the values for maximal inspiratory mouth pressure (PImax) at the end of the swim were significantly lower at all trials. However, the magnitude of inspiratory muscle fatigue was less after TURNS-C (PImax decreased by 12%) than after 400FC (PImax decreased by 28%). The tumble turns were slower during 400FC than during TURNS-C and TURNS-IMF. In addition, compared to TURNS-C, turns in the TURNS-IMF were performed with higher rotation times and shorter apnea and swim-out times. Discussion: The results of the present study suggest that tumble turns put a strain on the inspiratory muscles and directly contribute to the IMF observed during 400FC swimming. Furthermore, pre-induced IMF resulted in significantly shorter apneas and slower rotations during tumble turns. IMF therefore has the potential to negatively affect overall swimming performance, and strategies should be sought to reduce its effects.

Disorders of Respiration, Different types of APNEA, APNEA Time, Occurrence of APNEA in Different Conditions and Clinical Aspects of APNEA

Disorders of Respiration, Different types of APNEA, APNEA Time, Occurrence of APNEA in Different Conditions and Clinical Aspects of APNEA

Transnasal Humidified Rapid Insufflation Ventilatory Exchange Augments Oxygenation in Children With Juvenile Onset Recurrent Respiratory Papillomatosis During Surgery: A Prospective Randomized Crossover Controlled Trial.

Evidence is lacking regarding the efficacy of transnasal humidified rapid insufflation ventilatory exchange (THRIVE) in tubeless anesthesia, especially in pediatric patients. This study aimed to evaluate the use of THRIVE for juvenile onset recurrent respiratory papillomatosis (JORRP) patients. Twenty-eight children aged 2 to 12 years with JORRP, abnormal airways, and ASA physical status II-III that presented for surgical treatment under general anesthesia were included in this study. Each patient received 2 interventions in random order, with a 5-minute washout period between treatments: apnea without oxygen supplementation and apnea with THRIVE intervention. The primary outcome apnea time was defined as the duration from withdrawal of intubation to reintubation and resumption of controlled ventilation. The secondary outcomes were the mean transcutaneous carbon dioxide (tcco2) increase rate, the minimum pulse oxygen saturation (Spo2) during apnea, and the occurrence of unexpected adverse effects. The median apnea time in the THRIVE period was significantly longer than that in the control period (8.9 [8.6-9.4] vs 3.8 [3.4-4.3] minutes; mean difference [95% confidence interval (CI)], 5.0 [4.4-5.6]; P < .001) for all patients. The rate of CO2 change in the control period was higher than that in the THRIVE period both for patients aged 2 to 5 years old (6.29 [5.19-7.4] vs 3.22 [2.92-3.76] mm Hg min-1; mean difference [95% CI], 3.09 [2.27-3.67]; P < .001) and for patients aged 6 to 12 years old (4.76 [3.7-6.2] vs 3.38 [2.64-4.0] mm Hg min-1; mean difference [95% CI], 1.63 [0.75-2.56]; P < .001). The minimum Spo2 was significantly higher in the THRIVE period than in the control period (mean difference [95% CI], 19.7 [14.8-22.6]; P < .001). Our findings demonstrate that THRIVE safely increased the apnea time among children with JORRP undergoing surgery and decreased the rate of carbon dioxide increase. THRIVE is clinically recommended as an airway management technique for tubeless anesthesia in apneic children.