Use of Transparent Film Dressing to Facilitate Mask Ventilation in Bearded Patients.

BACKGROUND: Mask ventilation is a critical airway procedure made more difficult in the bearded patient. OBJECTIVE: We sought to objectively investigate whether application of transparent cling film (TegadermTM; 3M Healthcare, Maplewood, MN) over a beard in the operating room improves the quality of mask ventilation. METHODS: This was a randomized crossover trial of bearded adult patients undergoing surgery. Exclusions included emergency procedures, American Society of Anesthesiologists physical status classification > 3, a documented history of difficult mask ventilation, and body mass index (BMI) > 50. Transparent cling film was applied snuggly over the lower face with a 2- to 3-cm slit cut over the mouth after anesthesia induction. Mask ventilation performed by an anesthesiology resident, anesthesiology assistant, or anesthesiology assistant student and standardized to a thenar-eminence grip without use of airway adjuncts in a sniffing position. Standardized pressure-controlled ventilations were delivered via an anesthesia machine. A calibrated external pneumotachograph was used to measure delivered and returned tidal volumes from which raw and percent air leak were calculated. A clinically significant difference was determined a priori to be 15%, necessitating the enrollment of 25 patients. RESULTS: Of 25 subjects, 96% were men with a mean ± SD BMI of 29.3 ± 6. Seventeen (68%) had a full beard and 8 (32%) had a partial beard. The mean ± SD leakage was 48% ± 26% for transparent cling film vs. 46% ± 20% without its application, which was not significantly different (p = 0.67). CONCLUSIONS: The use of transparent cling film to cover the lower half of the bearded face did not have an impact on the ability or efficacy to perform mask ventilation in the operating room setting. CLINICALTRIALS: gov, Number NCT04274686.

Effect of paratracheal pressure on the effectiveness of mask ventilation in obese anesthetized patients: a randomized, cross-over study.

Paratracheal pressure has been recently suggested to compress and occlude the upper esophagus at the lower left paratracheal region to prevent gastric regurgitation alternative to cricoid pressure. It also prevents gastric insufflation. The aim of this randomized cross-over study was to investigate the effectiveness of paratracheal pressure on mask ventilation in obese anesthetized paralyzed patients. After the induction of anesthesia, two-handed mask ventilation was initiated in a volume-controlled mode with a tidal volume of 8 mL kg‒1 based on ideal body weight (IBW), a respiratory rate of 12 breaths min- 1, and positive end-expiratory pressure of 10 cmH2O. Expiratory tidal volume and peak inspiratory pressure were recorded alternately with or without the application of 30 Newtons (approximately 3.06 kg) paratracheal pressure during a total of 16 successive breaths over 80 s. Association of patient characteristics with the effectiveness of paratracheal pressure on mask ventilation, defined as the difference in expiratory tidal volume between the presence or absence of paratracheal pressure were evaluated. In 48 obese anesthetized paralyzed patients, expiratory tidal volume was significantly higher with the application of paratracheal pressure than without paratracheal pressure [496.8 (74.1) mL kg- 1 of IBW vs. 403.8 (58.4) mL kg- 1 of IBW, respectively; P < 0.001]. Peak inspiratory pressure was also significantly higher with the application of paratracheal pressure compared to that with no paratracheal pressure [21.4 (1.2) cmH2O vs. 18.9 (1.6) cmH2O, respectively; P < 0.001]. No significant association was observed between patient characteristics and the effectiveness of paratracheal pressure on mask ventilation. Hypoxemia did not occur in any of the patients during mask ventilation with or without paratracheal pressure. The application of paratracheal pressure significantly increased both the expiratory tidal volume and peak inspiratory pressure during face-mask ventilation with a volume-controlled mode in obese anesthetized paralyzed patients. Gastric insufflation was not evaluated in this study during mask ventilation with or without paratracheal pressure.

Evaluation the quality of bag-mask ventilation by E/C, T/E and hook technique (a new proposed technique).

BACKGROUND: Bag-Mask Ventilation (BMV) is a crucial skill in managing emergency airway situations and induction of general anesthesia. Ensuring proficient BMV execution is imperative for healthcare providers. Various techniques exist for performing BMV. This study aims to compare the quality of ventilation achieved using the E/C technique, Thenar Eminence (T/E) technique and a novel approach referred to as the hook technique. The goal is to identify the most effective single-person BMV method. METHOD: We conduct a pilot study on manikins involving 63 medical staff members who used the hook technique for ventilation. Subsequently, we obtained ethical approval and patient guardian consent to perform the study on 492 emergency department (ED) patients. These patients were randomly divided into three groups, with each group subjected to one three ventilation techniques. The study focused on patients requiring reliable airway management for rapid sequence intubation (RSI). Ventilation was administrated using bag-mask device connected to the capnograph. End-tidal CO2 (ETCO2) levels were recorded. Demographic data were collected and analyzed by SPSS software version 22. Success rates were reported as frequency (percentage) as well as mean ± standard deviation. RESULT: Comparing partial pressure of CO2 (PCO2) results obtained via capnography between T/E, E/C and hook techniques, we found that the successful ventilation rate was 87.2% for T/E, 89.6% for E/C, and 93.3% for the hook methods. The hook method demonstrated significantly higher success rate compared to the other two techniques (P-value = 0.038). Furthermore, we observed statistically significant trends in PCO2 changes between measurements both within and between groups (P-value < 0/001). CONCLUSION: Our study indicates that the hook method achieved notably higher success rate in ventilation compared to the T/E and E/C methods. This suggests that the hook method, which involves a chin lift maneuver while securely fitting the mask, could serve as a novel BMV technique, particularly for resuscitation with small hands for a prolonged use without fatigue and finger discomfort. Our finding contributes to the development of a new BMV method referred to as the hook technique. TRIAL REGISTRATION: IRCT registration number: IRCT20121010011067N5. URL of trial registry record: https://www.irct.ir/trial/57420 .

Quantitative end-tidal carbon dioxide at initiation of resuscitation may help guide the ventilation of infants born at less than 30 weeks gestation.

AIM: Estimation of end-tidal carbon dioxide (EtCO2 ) with capnography can guide mask ventilation in infants born at less than 30 weeks of gestation. Chemical-sensitive colorimetric devices to detect CO2 are widely used at resuscitation. We aimed to quantify EtCO2 in the first breaths following initiation of mask ventilation at birth and correlated need for endotracheal intubation. METHODS: Infants <30 weeks gestation receiving mask ventilation were randomised into two groups of mask-hold technique (one-person vs. two-person). Data on EtCO2 in the first 30 breaths, time to achieve 5 mmHg, 10 mmHg and 15 mmHg CO2 using a respiratory function monitor was determined. RESULTS: Twenty-five infants with a mean gestation of 27.3 (±3 weeks) and mean birth weight 920.4 (±188.3 g) were analysed. The median EtCO2 was 5.6 mmHg in the first 10 breaths, whereas it was 12.6 mmHg for 11-20 breaths and 18 mmHg for 21-30 breaths. There was no significant difference in maximum median EtCO2 for the first 20 breaths, although EtCO2 was significantly lower in infants who were intubated (32.0 vs. 15.0, p = 0.018). CONCLUSION: EtCO2 monitoring in infants <30 weeks gestation at birth is feasible and reflective of alveolar ventilation. EtCO2 may help guide ventilation of preterm infants at birth.

Aerosol generation during general anesthesia is comparable to coughing: An observational clinical study.

BACKGROUND: Intubation, laryngoscopy, and extubation are considered highly aerosol-generating procedures, and additional safety protocols are used during COVID-19 pandemic in these procedures. However, previous studies are mainly experimental and have neither analyzed staff exposure to aerosol generation in the real-life operating room environment nor compared the exposure to aerosol concentrations generated during normal patient care. To assess operational staff exposure to potentially infectious particle generation during general anesthesia, we measured particle concentration and size distribution with patients undergoing surgery with Optical Particle Sizer. METHODS: A single-center observative multidisciplinary clinical study in Helsinki University Hospital with 39 adult patients who underwent general anesthesia with tracheal intubation. Mean particle concentrations during different anesthesia procedures were statistically compared with cough control data collected from 37 volunteers to assess the differences in particle generation. RESULTS: This study measured 25 preoxygenations, 30 mask ventilations, 28 intubations, and 24 extubations. The highest total aerosol concentration of 1153 particles (p)/cm³ was observed during mask ventilation. Preoxygenations, mask ventilations, and extubations as well as uncomplicated intubations generated mean aerosol concentrations statistically comparable to coughing. It is noteworthy that difficult intubation generated significantly fewer aerosols than either uncomplicated intubation (p = .007) or coughing (p = 0.006). CONCLUSIONS: Anesthesia induction generates mainly small (<1 µm) aerosol particles. Based on our results, general anesthesia procedures are not highly aerosol-generating compared with coughing. Thus, their definition as high-risk aerosol-generating procedures should be re-evaluated due to comparable exposures during normal patient care. IMPLICATION STATEMENT: The list of aerosol-generating procedures guides the use of protective equipments in hospitals. Intubation is listed as a high-risk aerosol-generating procedure, however, aerosol generation has not been measured thoroughly. We measured aerosol generation during general anesthesia. None of the general anesthesia procedures generated statistically more aerosols than coughing and thus should not be considered as higher risk compared to normal respiratory activities.

Rocuronium versus saline for effective facemask ventilation during anesthesia induction: a double-blinded randomized placebo-controlled trial.

BACKGROUND: Mask ventilation progressively improves after loss of consciousness during anesthesia induction possibly due to progression of muscle paralysis. This double-blinded randomized placebo-controlled study aimed to test a hypothesis that muscle paralysis improves mask ventilation during anesthesia induction. METHODS: Forty-four adults patients including moderate to severe obstructive sleep apnea undergoing scheduled surgeries under elective general anesthesia participated in this study. Randomly-determined test drug either rocuronium or saline was blinded to the patient and anesthesia provider. One-handed mask ventilation with an anesthesia ventilator providing a constant driving pressure and respiratory rate (15 breaths per minute) was performed during anesthesia induction, and changes of capnogram waveform and tidal volume were assessed for one minute. The needed breaths for achieving plateaued-capnogram (primary variable) within 15 consecutive breaths were compared between the test drugs. RESULTS: Measurements were successful in 38 participants. Twenty-one and seventeen patients were allocated into saline and rocuronium respectively. The number of breaths achieving plateaued capnogram did not differ between the saline (95% C.I.: 6.2 to 12.8 breaths) and rocuronium groups (95% C.I.: 5.6 to 12.7 breaths) (p = 0.779). Mean tidal volume changes from breath 1 was significantly greater in rocuronium group than saline group (95% C.I.: 0.56 to 0.99 versus 3.51 to 4.53 ml kg-IBW-1, p = 0.006). Significantly more patients in rocuronium group (94%) achieved tidal volume greater than 5 mg kg-ideal body weight-1 within one minute than those in saline group (62%) (p = 0.026). Presence of obstructive sleep apnea did not affect effectiveness of rocuronium for improvement of tidal volume during one-handed mask ventilation. CONCLUSIONS: Use of rocuronium facilitates tidal volume improvement during one-handed mask ventilation even in patients with moderate to severe obstructive sleep apnea. TRIAL REGISTRATION: The clinical trial was registered at (05/12/2013, UMIN000012495): https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000014515.

Early neonatal mortality is modulated by gestational age, birthweight and fetal heart rate abnormalities in the low resource setting in Tanzania - a five year review 2015-2019.

BACKGROUND: Early Neonatal mortality (ENM) (< 7 days) remains a significant problem in low resource settings. Birth asphyxia (BA), prematurity and presumed infection contribute significantly to ENM. The study objectives were to determine: first, the overall ENM rate as well as yearly ENM rate (ENMR) from 2015 to 2019; second, the influence of decreasing GA (< 37 weeks) and BW (< 2500 g) on ENM; third, the contribution of intrapartum and delivery room factors and in particular fetal heart rate abnormalities (FHRT) to ENM; and fourth, the Fresh Still Birth Rates (FSB) rates over the same time period. METHODS: Retrospective cohort study undertaken in a zonal referral teaching hospital located in Northern Tanzania. Labor and delivery room data were obtained from 2015 to 2019 and included BW, GA, fetal heart rate (FHRT) abnormalities, bag mask ventilation (BMV) during resuscitation, initial temperature, and antenatal steroids use. Abnormal outcome was ENM < 7 days. Analysis included t tests, odds ratios (OR), and multivariate regression analysis. RESULTS: The overall early neonatal mortality rate (ENMR) was 18/1000 livebirths over the 5 years and did not change significantly comparing 2015 to 2019. Comparing year 2018 to 2019, the overall ENMR decreased significantly (OR 0.62; 95% confidence interval (CI) 0.45-0.85) as well as infants ≥37 weeks (OR 0.45) (CI 0.23-0.87) and infants < 37 weeks (OR 0.57) (CI 0.39-0.84). ENMR was significantly higher for newborns < 37 versus ≥37 weeks, OR 10.5 (p < 0.0001) and BW < 2500 versus ≥2500 g OR 9.9. For infants < 1000 g / < 28 weeks, the ENMR was ~ 588/1000 livebirths. Variables associated with ENM included BW - odds of death decreased by 0.55 for every 500 g increase in weight, by 0.89 for every week increase in GA, ENMR increased 6.8-fold with BMV, 2.6-fold with abnormal FHRT, 2.2-fold with no antenatal steroids (ANS), 2.6-fold with moderate hypothermia (all < 0.0001). The overall FSB rate was 14.7/1000 births and decreased significantly in 2019 when compared to 2015 i.e., 11.3 versus 17.3/1000 live births respectively (p = 0.02). CONCLUSION: ENM rates were predominantly modulated by decreasing BW and GA, with smaller/ less mature newborns 10-fold more likely to die. ENM in term newborns was strongly associated with FHRT abnormalities and when coupled with respiratory depression and BMV suggests BA. In smaller newborns, lack of ACS exposure and moderate hypothermia were additional associated factors. A composite perinatal approach is essential to achieve a sustained reduction in ENMR.

Utilization of apnea-hypopnea index as a novel predictive factor for difficult mask ventilation in the Chinese population under general anesthesia.

PURPOSE: Difficult mask ventilation (DMV) is a potentially life-threatening situation that can arise during anesthesia. However, most clinical predictors of DMV are based on European and US populations. On the other hand, most predictive models consist of multiple factors and complicated assessments. Since obstructive sleep apnea (OSA) is among the most important risk factors associated with DMV, the apnea-hypopnea index (AHI) may play an important role in determining patient risk.The purpose of this study was to investigate the relationship between DMV and AHI, and to determine preoperative risk factors for DMV in Chinese patients. METHODS: A prospective cohort trial enrolled patients scheduled for elective surgery. After obtaining informed consent, patient demographic information was collected, and patients were tested with pre-operative polysomnography. The anesthesiologist who managed the airway graded the mask ventilation. The difficult mask ventilation was defined as the mask ventilation provided by an unassisted anesthesiologist without oral airway or other adjuvant. A logistic regression model was used to analyze the association between AHI and DMV. RESULTS: A total of 159 patients were analyzed. For both primary and secondary outcomes, the unadjusted and adjusted odds ratio for DMV showed significant increases by 5 AHI units. AHI, age, and the Mallampati classification were found to be independent predictive factors for DMV. CONCLUSIONS: AHI is associated with DMV as a novel independent risk factor in Chinese patients. Along with age and Mallampati classification, AHI should be included in establishing a superior predictive strategy for DMV screening. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-DDD-17013076.

The Articulated Oral Airway as an aid to mask ventilation: a prospective, randomized, interventional, non-inferiority study.

BACKGROUND: Oropharyngeal airways are used both to facilitate airway patency during mask ventilation as well as conduits for flexible scope intubation, though none excel at both. A novel device, the Articulated Oral Airway (AOA), is designed to facilitate flexible scope intubation by active displacement of the tongue. Whether this active tongue displacement also facilitates mask ventilation, thus adding dual functionality, is unknown. This study compared the AOA to the Guedel Oral Airway (GOA) in regards to efficacy of mask ventilation of patients with factors predictive of difficult mask ventilation. The hypothesis was that the AOA would be non-inferior to the GOA in terms of expiratory tidal volumes by a margin of 1 ml/kg, thus demonstrating dual functionality. METHODS: In this randomized controlled clinical trial, fifty-eight patients with factors predictive of difficult mask ventilation were mask ventilated with both the GOA and the AOA. Video of the anesthetic monitors were evaluated by a blinded member of the research team, noting inspiratory and expiratory tidal volumes and expiratory CO2 waveforms. RESULTS: The AOA was found to be non-inferior to the GOA at a margin of 1 ml/kg with a mean weight-standardized expiratory tidal measurement 0.45 ml/kg lower (CI: 0.34-0.57) and inspiratory tidal measurement 0.109 lower (CI: - 0.26-0.04). There was no significant difference in expiratory waveforms (p = 0.2639). CONCLUSIONS: The AOA was non-inferior to the GOA for mask ventilation of patients with predictors of difficult mask ventilation and there was no significant difference in EtCO2 waveforms between the groups. These results were consistent in the subset of patients who were initially difficult to mask ventilate. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03144089 , May 2017.

Performance of health workers on neonatal resuscitation care following scaled-up quality improvement interventions in public hospitals of Nepal - a prospective observational study.

BACKGROUND: High-quality resuscitation among non-crying babies immediately after birth can reduce intrapartum-related deaths and morbidity. Helping Babies Breathe program aims to improve performance on neonatal resuscitation care in resource-limited settings. Quality improvement (QI) interventions can sustain simulated neonatal resuscitation knowledge and skills and clinical performance. This study aimed to evaluate the effect of a scaled-up QI intervention package on the performance of health workers on basic neonatal resuscitation care among non-crying infants in public hospitals in Nepal. METHODS: A prospective observational cohort design was applied in four public hospitals of Nepal. Performances of health workers on basic neonatal care were analysed before and after the introduction of the QI interventions. RESULTS: Out of the total 32,524 births observed during the study period, 3031 newborn infants were not crying at birth. A lower proportion of non-crying infants were given additional stimulation during the intervention compared to control (aOR 0.18; 95% CI 0.13-0.26). The proportion of clearing the airway increased among non-crying infants after the introduction of QI interventions (aOR 1.23; 95% CI 1.03-1.46). The proportion of non-crying infants who were initiated on BMV was higher during the intervention period (aOR 1.28, 95% CI 1.04-1.57) compared to control. The cumulative median time to initiate ventilation during the intervention was 39.46 s less compared to the baseline. CONCLUSION: QI intervention package improved health workers' performance on the initiation of BMV, and clearing the airway. The average time to first ventilation decreased after the implementation of the package. The QI package can be scaled-up in other public hospitals in Nepal and other similar settings.

An approach to define newborns´ sniffing position using an angle based on reproducible facial landmarks.

BACKGROUND: The neutral or sniffing position is advised for mask ventilation in neonates to avoid airway obstruction. As definitions are manifold and often unspecific, we wanted to investigate the reliability and reproducibility of angle measurements based on facial landmarks that may be used in future clinical trials to determine a hypothetical head position with minimal airway obstruction during mask ventilation. METHODS: In a prospective single-center observational study, 2D sagittal photographs of 24 near-term and term infants were taken, with five raters marking facial landmarks to assess interobserver agreement of those landmarks and angle δ, defined as the angle between the line parallel to the lying surface and the line crossing Subnasale (Sn) and Porion' (P'). Angle δ was assessed in sniffing (δsniff ) and physiologic (δphys ) head position, the former based on a published, yet poorly defined head position where the tip of the nose aligns to the ceiling with the head in a supine, relaxed mid-position. RESULTS: Infants had a mean (SD) gestational age of 37.3 (2.3) weeks. Angle δ could be determined in all 48 images taken in either the sniffing or the physiological head position. Interobserver correlation coefficient was 98.6 for all measurements independent of head position. Angle δsniff was 90.5° (5.7) in the sniffing position. CONCLUSIONS: This study provides a new measuring technique using an angle that is reproducible and reliable and may be used in future studies to correlate head position with airway obstruction.

Modified Two-Rescuer CPR With a Two-Handed Mask-Face Seal Technique Is Superior To Conventional Two-Rescuer CPR With a One-Handed Mask-Face Seal Technique.

BACKGROUND: Bag-valve-mask (BVM) ventilation using a two-handed mask-face seal has been shown to be superior to a one-handed mask-face seal during cardiopulmonary resuscitation (CPR). OBJECTIVE: We aimed to compare CPR quality metrics during simulation-based two-rescuer CPR with a modified two-handed mask-face seal technique and two-rescuer CPR with the conventional one-handed mask-face seal technique. METHODS: Participants performed two-rescuer CPR on a simulation manakin and alternated between the modified and conventional CPR methods. For the modified method, the first rescuer performed chest compressions and thereafter squeezed the BVM resuscitator bag during the ventilatory pause, while the second rescuer created a two-handed mask-face seal. For the conventional method, the first rescuer performed chest compressions and the second rescuer thereafter delivered rescue breaths by creating a mask-face seal with one hand and squeezing the BVM resuscitator bag with the other hand. RESULTS: Among the 40 participants that were enrolled, the mean ± standard deviation (SD) delivered respiratory volume was significantly higher for the modified two-rescuer method (319.4 ± 71.4 mL vs. 190.2 ± 50.5 mL; p < 0.0001). There were no statistically significant differences between the two methods with regard to mean ± SD compression rate (117.05 ± 9.67 compressions/min vs. 118.08 ± 10.99 compressions/min; p = 0.477), compression depth (52.80 ± 5.57 mm vs. 52.77 ± 6.77 mm; p = 0.980), chest compression fraction (75.92% ± 2.14% vs. 76.57% ± 2.57%; p = 0.186), and ventilatory pause time (4.62 ± 0.64 s vs. 4.56 ± 0.43 s; p = 0.288). CONCLUSIONS: With minor modifications to the conventional method of simulated two-rescuer CPR, rescuers can deliver significantly higher volumes of rescue breaths without compromising the quality of chest compressions.

[Paediatric Life Support]. / Lebensrettende Maßnahmen bei Kindern (Paediatric Life Support, PLS): Leitlinien des European Resuscitation Council 2021.

The European Resuscitation Council (ERC) Paediatric Life Support (PLS) guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations of the International Liaison Committee on Resuscitation (ILCOR). This section provides guidelines on the management of critically ill or injured infants, children and adolescents before, during and after respiratory/cardiac arrest.

Detection of gastric inflation using transesophageal echocardiography after different level of pressure-controlled mask ventilation: a prospective randomized trial.

This study aimed to assess the technique of using transesophageal echocardiography (TEE) to detect gastric inflation and to determine the optimal level of inspiratory pressure during face mask ventilation (FMV). In this prospective and randomized trial, seventy-five adults scheduled for cardiac surgery were enrolled to one of the three groups (P12, P15, P20) defined by the applied inspiratory pressure during FMV. After induction, mask ventilation was performed with the corresponding level of pressure-control ventilation for 2 min in each patient. Respiratory and hemodynamic parameters were recorded every 15 s. Arterial blood gases were tested before induction and at the time of intubation. Gastric cross-section area was detected using transesophageal echocardiography after intubation. The gastric cross-section areas were 3.1 ± 0.81, 3.8 ± 1.37 and 4.8 ± 2.29 cm2 respectively. It statistically increased in group P20 compared with group P12 and P15. PaCO2 before intubation statistically increased compared with the baseline in groups P12 and P15, while decreased in group P20. The mean values of PaCO2 equaled to 44.4 mmHg (40-51.5), 42.9 mmHg (34-50.5) and 36.9 mmHg (30.9-46) respectively in three groups. Peak airway pressure of 12-20 cmH2O could provide acceptable sufficient ventilation during mask ventilation, but 20 cmH2O result in higher incidence of gastric inflation. TEE is useful to detect the gastric inflation related to the entry of air into the stomach during pressure-controlled face mask ventilation.Trial Registration Number ChiCTR-IOR-14005325.

A comparison of controlled ventilation with a noninvasive ventilator versus traditional mask ventilation.

After induction, but before intubation, many general anesthesia patients are manually bag-mask ventilated. The objective of this study was to determine the efficacy of bag-mask ventilation (MkV) of an anesthetized patient versus mask ventilation using a noninvasive ventilator (NIV). We hypothesized that feedback-controlled, mask ventilation via NIV is more efficacious and safer. This critical short period of time in the operating room was chosen to compare MkV versus NIV. 30 ASA I-III patients, aged 18-74, presenting for elective surgery under general anesthesia were enrolled in the study. Patients were ventilated first with MkV and then with NIV. One minute of ventilation data was collected for each method. Respiratory inductance plethysmography (RIP) bands around the chest and abdomen were used to measure tidal volumes and breath rates for each method of ventilation. The NIV was set to deliver 10 breaths per minute with 12 cmH2O of pressure support. A non-inferiority test was used to compare MkV and NIV. MkV breaths had an average of 13 breaths and tidal volume of 364 mL (SD 145 mL). NIV resulted in an average of 10 breaths and tidal volume of 552 mL, i.e., 188 mL more than MkV (lower bound of the 95% confidence interval equal to 120 mL). The hypothesis of non-inferiority at the - 100 mL level and the superiority hypothesis at the + 100 mL level was accepted. NIV also resulted in much more consistent ventilation rates (zero variation since it is controlled by the ventilator) when compared to manual ventilation while maintaining safe airway pressures (8 cmH2O EPAP and 20 cmH2O IPAP). Feedback controlled mask ventilation via a NIV is a viable alternative to MkV. It can deliver more optimal tidal volumes with the operator utilizing only one hand. The airway pressures are fixed at safe limits during a period where the goal is to reach a maximal level of oxygenation prior to intubation. Over-ventilation or over-pressurization of the airway is not a concern with NIV since the pressures are maintained well within safe thresholds to avoid injury.

Awake fiberoptic intubation with an epidural catheter in a morbidly obese patient.

We report successful awake intubation in a morbidly obese patient (body mass index of 61.2) using an epidural catheter inserted through the external forceps channel of the fiberscope for delivery of local anesthetic. Direct application of local anesthetic to the pharyngolaryngeal area and proximal tracheal, through the use of a relatively firm epidural catheter. We conclude that awake intubation can be achieved by this method which spares the subsequent use of any sedative drugs.

Effect of an endoscopic bite block on one-handed mask ventilation.

PURPOSE: An endoscopic bite block is a device to ensure that the patient's mouth remains wide open during endoscopic procedures. Wide opening of the mouth may facilitate the efficiency of one-handed mask ventilation. We evaluated the effect of an endoscopic bite block on mask ventilation among three ventilation techniques: one-handed ventilation, one-handed ventilation with an endoscopic bite block, and two-handed ventilation. METHODS: Fifty-nine anesthetized and paralyzed patients were included. After induction of anesthesia, one-handed ventilation, one-handed ventilation with an endoscopic bite block and two-handed ventilation were performed in a cross-over, randomized order. The primary outcome was the expiratory tidal volume (mL/kg of predicted body weight). Secondary outcomes included minute ventilation (L/min) and the incidence of inadequate mask ventilation or dead space ventilation. RESULTS: The expiratory tidal volume of one-handed ventilation with an endoscopic bite block was significantly improved when compared with that of one-handed ventilation (8.2 [6.8-10.2] mL/kg vs. 7.1 [4.5-9.0] mL/kg, respectively, difference = 1.1 mL/kg; 95% CI 0.8-2.4; P < 0.001), and was comparable to that of two-handed ventilation (8.9 [6.3-11.5] mL/kg; difference = 0.7 mL/kg; 95% CI - 0.7 to 1.5; P = 0.432). Minute ventilation was also significantly improved in one-handed ventilation with an endoscopic bite block compared with that in one-handed ventilation (7.4 [6.3-8.6] L/min vs. 6.7 [4.2-7.9] L/min, respectively, difference = 0.7 L/min; 95% CI 0.6-2.0; P < 0.001), and was comparable to that of two-handed ventilation (7.7 [6.5-9.5] L/min; difference = 0.3 L/min; 95% CI - 0.5 to 1.4; P = 0.390). The incidence of inadequate ventilation or dead space ventilation was not different among the ventilation techniques (P = 0.080). CONCLUSION: The use of an endoscopic bite block improved one-handed mask ventilation, showing comparable efficacy with two-handed mask ventilation.

[Hypoglossal nerve palsy after follicle puncture]. / Hypoglossusparese nach Follikelpunktion.

A 42-year-old female patient suffered an infranuclear hypoglossal nerve paresis with right-sided swelling and weakness of the tongue following a short duration mask anesthesia for a follicle puncture. This resulted in dysarthria and dysphagia persisting for more than 3 months. A return to work was initially impossible. Etiopathogenetically, a mechanical compression of the peripheral hypoglossal nerve by positioning or reclination during mask ventilation is discussed. Conclusion for clinical practice: In order to protect against lesions of the hypoglossal nerve, the pre-anaesthesiological examination should ask specifically about cervical problems as an indication of individual sensitivity to reclination. In such cases, special attention should be paid to careful patient positioning. Even shorter periods of reclination or compression of the soft tissues of the neck can result in lesions, therefore tolls such as a Wendl or Guedel tube should be used accordingly.

Airway management in bariatric surgery patients, our experience in Qatar: A prospective observational cohort study.

Background: Obesity has always been considered a criterion of difficult airway management, and many authors have tackled this subject. We are presenting our experience in airway management in obese patients undergoing bariatric surgery in Qatar and comparing the results with previous studies. Objective: The primary objective of this study was to explore the relationship between difficult mask ventilation and difficult intubation. The secondary objective was to identify other factors that may play a role in either difficulty such as gender, associated comorbidities, and the skill and experience of anesthetists. Design: This study was a prospective observational cohort study. Sample: A total of 401 patients were selected for various elective bariatric surgery in Hamad General Hospital, including 130 males and 271 females with an average body mass index(BMI) of 46.03 kg m- 2. Results: We used Pearson Chi-Square and Yates corrected Chi-square statistical tests in our statistical analysis. Neck circumference had a p value of 0.001 in both genders. The male gender had a p value of 0.052 and 0.012 in mask ventilation and difficult intubation, respectively. The Mallampati score had a p value of 0.56 and 0.006 in mask ventilation and intubation, respectively. In general, neck circumference, Mallampati score, gender, obstructive sleep apnea, and diabetes mellitus had greater negative effects on airway management than BMI alone. Conclusion: It was hard to intubate 25% of patients who had difficult mask ventilation (DMV). All DMV and 20 out of 23 of difficult intubation patients were in the high BMI group ( ≥ 40). Neck circumference, Mallampati score, and male gender were major independent factors; however, other factors, such as obstructive sleep apnea, and diabetes mellitus, should be kept in mind as additional risks.

Predictors of difficult airway in the obese are closely related to safe apnea time!

BACKGROUND AND AIMS: We aimed to redefine the preoperative factors that may challenge the airway and safe apnea time (SAT) in the obese. MATERIAL AND METHODS: We analyzed 834 patients with body mass index (BMI) >35 kg/m2 for their difficult airway score (DASc). DASc is a consolidation of measures of difficult airway like mask ventilation, difficult intubation, change of device, and number of personnel required. DASc varied from "0" no difficulty to "12" serious difficulty and DASc ≥6 was considered difficult. Preoperative parameters - neck circumference (NC), BMI, STOPBANG score, Mallampati score, obstructive sleep apnea grade, and waist circumference- were assessed. RESULTS: Receiver operating characteristic curve was used to identify risk factors for obese patients at DASc ≥6. The Youden index (for the best threshold, with highest sensitivity and specificity) was BMI 45 kg/m2 and NC 44.5 cm. Their absence had an 81% negative predictive value to include a difficult airway, while their presence had a positive predictive value of 55%. This further has sensitivity of 66% and specificity of 73%. The mean SAT (256 ± 6 s) was inversely related to DASc (P < 0.001). CONCLUSION: This study demonstrates that BMI and NC have a strong association with difficult airway in obese patients and are inversely related to SAT. Amongst these NC is the single most important predictor of difficult airway in obese and should be used as a screening tool.