Facemask Ventilation Research Articles

Management of Anesthesia in Mandibular Tumors with Difficult Airway

A 39-year-old female patient with a diagnosis of mandibular tumor underwent mandibleectomy surgery and Free Fibular Flap reconstruction. Preoperative evaluation is carried out on the patient, namely by conducting an anamnesis, physical examination, and supporting examination to determine the problem and conclusion of the patient's physical status. The physical status of the patient is ASA III. During the surgical durante, a tracheostomy is performed with local anesthesia. Next, the patient is positioned head down to undergo the surgical procedure. The operation lasted for 10 hours with stable hemodynamics. Postoperatively, patients are treated in the ICU treatment room, vital signs observation, and postoperative pain management. A closed study by the American Society of Anesthesiologists (ASA) Professional Committee revealed that the risks and severe complications of anesthesia are most often closely related to airway management problems. Success in overcoming complications depends on early detection of symptoms and corrective actions to prevent the situation from worsening. In this patient, airway management based on the Difficult Airway Algorithm other options, local anesthesia with tracheostomy and watershed algorithm was successful with plan A, namely facemask ventilation and tracheal intubation.

An Innovative Technique to Prevent Air Leaks from Cervical Esophagostomy during Face Mask Ventilation.

The objective of the study was to report the indigenous use of an electrocardiography (ECG) electrode in successfully occluding the Cx-esophagostomy to prevent inadvertent loss of tidal volume. Twenty-nine observations were recorded on 27 patients (mean age: 10.9 months; male:female = 2.6:1). The oral cavity, pharynx, and Cx-esophagostomy were cleared of saliva. Peristomal area was cleaned with dry gauze and dried with alcohol. Latex-free, 50 mm, ECG electrode was pasted symmetrically over the Cx-esophagostomy. The efficacy of the electrode was assessed using a five-point algorithm: (i) collapse of reservoir bag, (ii) chest expansion, (iii) ballooning of electrode, (iv) cotton-wisp test, and (v) change in compliance with manual compression of the electrode. Subgroup analysis was conducted for laterality and health of Cx-esophagostomy. Study cohort: Cx-esophagostomy was located on the left in 58.26% (n = 17/29) patients. The health of Cx-esophagostomies was graded from I to IV (n = 9, 16, 3, and 1, respectively). The collapse of the reservoir bag and chest rise indicated successful ventilation. Ballooning of the electrode with each breath was observed in 79% (23/29) patients. Partial separation of the electrode from the skin (exaggerated with each breath) was observed in 10.3% (3/29) patients (Group I: n = 1, Group III: n = 1, and Group IV: n = 1). This was related to poor local preparation or pooling of saliva (n = 1; Group I: resolved with procedural re-application of a fresh electrode) and underlying skin condition (n = 2; Groups III and IV: resolved only temporarily with re-application). The cotton-wisp test was positive in two additional patients (1 each in Groups II and III) and was related to the pooling of saliva. No change in compliance was observed with manual compression of the electrode. No difference in success was observed between left and right Cx-esophagostomies. Overall success with this technique was 82.8% with a potential for 100% in those with peristomal health graded I-III. The ECG electrode is a technically simple, cost-effective, and widely available device, instrumental in addressing the problem of air leak through Cx-esophagostomy during face mask ventilation before intubation.

Difficult Airway Prediction in Infants with Apparently Normal Face and Neck Features.

Background/Objectives: Prediction of a difficult airway during pre-anesthetic evaluation is of great importance because it enables an adequate anesthetic approach and airway management. As there is a scarcity of prospective studies evaluating the role of anthropometric measures of the face and neck in predicting difficult airways in infants with an apparently normal airway, we aimed to identify the aforementioned predictors of difficult facemask ventilation and intubation in infants. Methods: A prospective, observational study that included 97 infants requiring general endotracheal anesthesia was conducted. Anthropometric and specific facial measurements were obtained before ventilation and intubation. Results: The incidence of difficult facemask ventilation was 15.5% and 38.1% for difficult intubation. SMD (sternomental distance), TMA (tragus-to-mouth angle distance), NL (neck length) and mouth opening were significantly lower in the difficult facemask ventilation group. HMDn (hyomental distance in neutral head position), HMDe (hyomental distance in neck extension), TMD (thyromental distance), SMD, mandibular development and mouth opening were significantly different in the intubation difficulty group compared to the non-difficult group. HMDn and HMDe showed significantly greater specificities for difficult intubation (83.8% and 76.7%, respectively), while higher sensitivities were observed in TMD, SMD and RHSMD (ratio of height to SMD) (89.2%, 75.7%, and 70.3%, respectively). Regarding difficult facemask ventilation, TMA showed greater sensitivity (86.7%) and SMD showed greater specificity (80%) compared to other anthropometric parameters. In a multivariate model, BMI (body mass index), COPUR (Colorado Pediatric Airway Score), BOV (best oropharyngeal view) and TMA were found to be independent predictors of difficult intubation, while BMI, ASA (The American Society Physical Status Classification System), CL (Cormack-Lehane Score), TMA and SMD predicted difficult facemask ventilation. Conclusions: Preoperative airway assessment is of great importance for ventilation and intubation. Patient's overall condition and facial measurements can be used as predictors of difficult intubation and ventilation.

Airway management and pulmonary aspiration during surgical interventions in pregnant women in the 2nd/3rd trimester and immediate postpartum – a retrospective study in a tertiary care university hospital

BackgroundPregnancy is associated with an increased risk of pulmonary aspiration during general anaesthesia, but the incidence of this complication is not well defined.MethodsWe performed a retrospective database review in a tertiary care university hospital to determine the incidence of pulmonary aspiration in pregnant patients undergoing endotracheal intubation, with and without Rapid Sequence Induction (RSI), as well as face-mask ventilation and supraglottic airway devices. We included Patients in the 2nd or 3rd trimester of pregnancy and immediate postpartum undergoing surgical procedures. The primary endpoint was the occurrence of pulmonary aspiration.ResultsData from 2,390 patients undergoing general anaesthesia for cerclage of cervix uteri, manual removal of retained placenta, repair of obstetric laceration, or postpartum bleeding were retrospectively evaluated. A supraglottic airway device or face-mask ventilation was used in 1,425/2,390 (60%) of patients, while 638/2,390 (27%) were intubated. RSI was used in 522/638 (82%) of patients undergoing tracheal intubation, or 522/2,390 (22%) of the entire cohort. In-depth review of the charts, including 54 patients who had been initially classified as “possible pulmonary aspiration" by anaesthetists, revealed that this adverse event did not occur in the cohort.ConclusionsIn conclusion, in this obstetric surgery patient population at risk for pulmonary aspiration, supraglottic airway devices were used in approximately 60% of cases. Yet, no aspiration event was detected with either a supraglottic airway or endotracheal intubation.

Airway management in patients with suspected or confirmed cervical spine injury: Guidelines from the Difficult Airway Society (DAS), Association of Anaesthetists (AoA), British Society of Orthopaedic Anaesthetists (BSOA), Intensive Care Society (ICS), Neuro Anaesthesia and Critical Care Society (NACCS), Faculty of Prehospital Care and Royal College of Emergency Medicine (RCEM).

There are concerns that airway management in patients with suspected or confirmed cervical spine injury may exacerbate an existing neurological deficit, cause a new spinal cord injury or be hazardous due to precautions to avoid neurological injury. However, there are no evidence-based guidelines for practicing clinicians to support safe and effective airway management in this setting. An expert multidisciplinary, multi-society working party conducted a systematic review of contemporary literature (January 2012-June 2022), followed by a three-round Delphi process to produce guidelines to improve airway management for patients with suspected or confirmed cervical spine injury. We included 67 articles in the systematic review, and successfully agreed 23 recommendations. Evidence supporting recommendations was generally modest, and only one moderate and two strong recommendations were made. Overall, recommendations highlight key principles and techniques for pre-oxygenation and facemask ventilation; supraglottic airway device use; tracheal intubation; adjuncts during tracheal intubation; cricoid force and external laryngeal manipulation; emergency front-of-neck airway access; awake tracheal intubation; and cervical spine immobilisation. We also signpost to recommendations on pre-hospital care, military settings and principles in human factors. It is hoped that the pragmatic approach to airway management made within these guidelines will improve the safety and efficacy of airway management in adult patients with suspected or confirmed cervical spine injury.

Effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange compared with standard facemask oxygenation for pre- and apneic oxygenation during anesthesia induction: A meta-analysis based on randomized controlled trials.

To further identify the effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) for pre- and apneic oxygenation during the anesthesia induction by comparison to facemask ventilation (FMV) based on current available evidence. Medline, EMBASE, Web of Science, Cochrane Library and CNKI databases were searched from inception to December 22, 2023 for available randomized controlled trials (RCTs). Primary outcomes were PaO2 and PaCO2 after intubation and safe apnoea time. Secondary outcomes included the O2 desaturation, end expiratory carbon dioxide (EtCO2) and complications. The effect measures for continuous and categorical outcomes were separately the mean difference (MD) and relative risk (RR) with 95% confidence interval. Twelve RCTs with 403 patients in the THRIVE group and 401 patients in th FMV group were included. Pooled results demonstrated that the PaO2 after intubation was significantly higher (MD = 82.90mmHg, 95% CI: 12.25~153.54mmHg, P = 0.02) and safe apnoea time (MD = 103.81s, 95% CI: 42.07~165.56s, P = 0.001) was longer in the THRIVE group. Besides, the incidence rate of O2 desaturation (RR = 0.28, 95% CI: 0.12-0.66, P = 0.004) and gastric insufflation (RR = 0.26, 95% CI: 0.13-0.49, P<0.001) was significantly lower in the THRIVE group. Based on current evidence, THRIVE manifested better effectiveness representing as improved oxygenation, prolonged safe apnoea time and decreased risk of complications compared to standard FMV in surgical patients. Therefore, THRIVE could be served as a novel and valuable oxygenation technology for patients during anesthesia induction.

How Much Training Is Enough? Low-Dose, High-Frequency Simulation Training and Maintenance of Competence in Neonatal Resuscitation.

Facemask ventilation is a crucial, but challenging, element of neonatal resuscitation.In a previously reported study, instructor-led training using a novel neonatal simulator resulted in high-level ventilation competence for health care providers (HCPs) involved in newborn resuscitation. The aim of this study was to identify the optimal frequency and dose of simulation training to maintain this competence level. Prospective observational study of HCPs training through 9 months. All training was logged. Overall ventilation competence scores were calculated for each simulation case, incorporating 7 skill elements considered important for effective ventilation.Overall scores and skill elements were analyzed by generalized linear mixed effects models using frequency (number of months of 9 where training occurred and total number of training sessions in 9 months) and dose (total number of cases performed) as predictors. Training loads (frequency + dose) predictive of high scores were projected based on estimated marginal probabilities of successful outcomes. A total of 156 HCPs performed 4348 training cases. Performing 5 or more sessions in 9 months predicted high global competence scores (>28/30). Frequency was the best predictor for 4 skill elements; success in maintaining airway patency and ventilation fraction was predicted by performing training in, respectively, 2 and 3 months of 9, whereas for avoiding dangerously high inflating pressures and providing adequate mask seal, 5 and 6 sessions, respectively, over the 9 months, predicted success. Skills reflecting global performance (successful resuscitation and valid ventilations) and ventilation rate were more dose-dependent. Training frequency is important in maintaining neonatal ventilation competence. Training dose is important for some skill elements. This offers the potential for individualized training schedules.

Comparison of nasal and face mask ventilation in anaesthetised obese adults: A randomised controlled study.

The use of a face mask while inducing general anaesthesia (GA) in obese patients is often ineffective in providing adequate ventilation. Although nasal mask ventilation has demonstrated effectiveness for continuous positive airway pressure (CPAP) in obese patients with obstructive sleep apnoea (OSA), it has not yet been applied to the induction of anaesthesia. This study evaluated the efficacy of nasal mask ventilation against standard face mask ventilation in anaesthetised obese patients with body mass index (BMI)>25 kg/m2. Ninety adult patients with BMI >25 kg/m2 were randomly assigned to receive either facemask (Group FM) or nasal-mask (Group NM) ventilation during induction of GA. Expired tidal volume (VtE), air leak, peak inspiratory pressure (PIP), plateau pressure (PPLAT), oxygen saturation (SpO2), and end-tidal carbon dioxide (EtCO2) were recorded for10 breaths, and their mean was analysed. The mean (standard deviation) VtE measured was not significantly higher in Group NM [455.98 (55.64) versus 436.90 (49.50) mL, P = 0.08, degree of freedom (df):88, mean difference (95% confidence interval [CI]) -19.08 (-41.14, 2.98) mL]. Mean air-leak [16.44 (22.16) versus 31.63 (21.56) mL, P = 0.001, df: 88, mean difference 95%CI: 15.19 (6.03,24.35)], mean PIP [14.79 (1.39) versus 19.94 (3.05) cmH2O, P = 0.001, df: 88, mean difference, 95%CI: 5.15 (4.16, 6.14)], and mean PPLAT [12.04 (1.21) versus 16.66 (2.56) cmH2O, P = 0.001, df: 88, mean difference 95% CI: 4.62 (3.78, 5.45)] were significantly lower in Group NM. EtCO2, SpO2, and haemodynamic measurements were similar between the two groups. Nasal mask ventilation is an effective ventilation method and can be used as an alternative to face mask ventilation in anaesthetised obese adults with BMI>25 kg/m2.

Rescue nasopharyngeal tube for preterm infants non-responsive to initial ventilation after birth

BackgroundPhysiological changes during the insertion of a rescue nasopharyngeal tube (NPT) after birth are unclear.MethodsObservational study of very preterm infants in the delivery room. Data were extracted at predefined timepoints starting with first facemask placement after birth until 5 min after insertion of NPT. End-expiratory lung impedance (EELI), heart rate (HR) and SpO2/FiO2-ratio were analysed over time. Changes during the same time span of NIPPV via facemask and NIPPV via NPT were compared.ResultsOverall, 1154 inflations in 15 infants were analysed. After NPT insertion, EELI increased significantly [0.33 AU/kg (0.19–0.57), p < 0.001]. Compared with the mask period, changes in EELI were not significantly larger during the NPT period [median difference (IQR) = 0.14 AU/kg (−0.14–0.53); p = 0.12]. Insertion of the NPT was associated with significant improvement in HR [52 (33–96); p = 0.001] and SpO2/FiO2-ratio [161 (69–169); p < 0.001] not observed during the mask period.ConclusionsIn very preterm infants non-responsive to initial facemask ventilation after birth, insertion of an NPT resulted in a considerable increase in EELI. This additional gain in lung volume was associated with an immediate improvement in clinical parameters. The use of a NPT may prevent intubation in selected non-responsive infants.ImpactAfter birth, a nasopharyngeal tube may be considered as a rescue airway in newborn infants non-responsive to initial positive pressure ventilation via facemask. Although it is widely used among clinicians, its effect on lung volumes and physiological parameters remains unclear.Insertion of a rescue NPT resulted in a considerable increase in lung volume but this was not significantly larger than during facemask ventilation. However, insertion of a rescue NPT was associated with a significant and clinically important improvement in heart rate and oxygenation.This study highlights the importance of individual strategies in preterm resuscitation and introduces the NPT as a valid option.

Assessment of facemask ventilation: Adequacy and understanding

Assessment of facemask ventilation: Adequacy and understanding

Comparison of Facemask Ventilation Quality Between the Three-Finger Grip and the Three-Finger Grip Plus the Newly-Devised Submental Maneuver in Infants: A Double-Blind, Randomized Controlled Trial

Background: Mask ventilation is one of the most important aspects of managing and maintaining a patient's airway. Performing good mask ventilation can avoid the need for intubation. Objectives: This study aimed to compare the ventilation quality of two different mask-holding techniques in infants: The three-finger grip and the three-finger grip plus the newly-devised submental maneuver. Methods: This double-blind, randomized controlled trial included 90 infants under 1 year of age undergoing elective surgery under general inhalation anesthesia in Tehran Children's Medical Center. Each patient was randomly allocated to one of the interventional groups, and general anesthesia was induced using one of the mask-holding techniques before intubation. Demographic data for each patient was collected. Expired tidal volume (VTE) was assessed quantitatively by the Drager machine and then classified into three groups of quality of breath flow as either good (5 - 7 mL/kg), fair (3 - 5 mL/kg), or bad (&lt; 3 mL/kg). Results: In this study, VTE was shown to be statistically significantly better in the submental maneuver compared with the three-finger grip. Good, fair, and bad qualities were recorded for 30, 15, and 0 patients in the three-finger grip group and 39, 6, and 0 patients in the submental maneuver group, respectively (P = 0.025). Classifying patients into four groups of body mass index (BMI), 10 - 14, 15 - 19, 20 - 24, and 25 - 29, we compared VTE between the two techniques within each group. The results showed that in the BMI group of 20 - 24, the quality of breath flow was statistically significantly better in the submental maneuver (P = 0.047). Conclusions: Adding the submental maneuver to the three-finger grip seems to provide better expired tidal volume in infants. Also, it seems that in children with higher BMI and larger submental soft tissue, the submental maneuver provides better ventilation quality than the three-finger grip.

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.

A comparative analysis of aerosol exposure and prevention strategies in bystander, pre-hospital, and inpatient cardiopulmonary resuscitation using simulation manikins

To evaluate aerosol exposure risk and prevention strategies during bystander, pre-hospital, and inpatient cardiopulmonary resuscitation (CPR). This study compared hands-only CPR, CPR with a surgical or N95 mask, and CPR with a non-rebreather mask at 15 L/min. 30:2 compression–ventilation ratio CPR was tested with face-mask ventilation (FMV), FMV with a high efficiency particulate air (HEPA) filter; supraglottic airway (SGA), SGA with a surgical mask, SGA with a HEPA filter, or SGA with both. Continuous CPR was tested with an endotracheal tube (ET), ET with a surgical mask, a HEPA filter, or both. Aerosol concentration at the head, trunk, and feet of the mannequin were measured to evaluate exposure to CPR personnel. Hands-only CPR with a surgical or N95 face mask coverings and ET tube ventilation CPR with filters showed the lowest aerosol exposure among all study groups, including CPR with NRM oxygenation, FMV, and SGA ventilation. NRM had a mask effect and reduced aerosol exposure at the head, trunk, and feet of the mannequin. FMV with filters during 30:2 CPR reduced aerosol exposure at the head and trunk, but increased at the feet of the mannequin. A tightly-sealed SGA when used with a HEPA filter, reduced aerosol exposure by 21.00–63.14% compared with a loose-fitting one. Hands-only CPR with a proper fit surgical or N95 face mask coverings is as safe as ET tube ventilation CPR with filters, compared with CPR with NRM, FMV, and SGA. FMV or tight-sealed SGA ventilation with filters prolonged the duration to achieve estimated infective dose of SARS-CoV-2 2.4–2.5 times longer than hands-on CPR only. However, a loose-fitting SGA is not protective at all to chest compressor or health workers standing at the foot side of the victim, so should be used with caution even when using with HEPA filters.

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.

Nasopharyngeal Ventilation Compared to Facemask Ventilation: A Prospective, Randomized, Crossover Trial in Two Different Elective Cohorts.

Facemask ventilation is routinely used to preoxygenate patients before endotracheal intubation during anesthesia induction or to secure ventilation in patients with respiratory insufficiency. Occasionally, facemask ventilation cannot be performed adequately. The placement of a regular endotracheal tube through the nose into the hypopharynx may be a valid alternative to improve ventilation and oxygenation before endotracheal intubation (nasopharyngeal ventilation). We tested the hypothesis that nasopharyngeal ventilation is superior in its efficacy compared to traditional facemask ventilation. In this prospective, randomized, crossover trial, we enrolled surgical patients requiring either nasal intubation (cohort #1, n = 20) or patients who met "difficult to mask ventilate" criteria (cohort #2, n = 20). Patients in each cohort were randomly assigned to receive pressure-controlled facemask ventilation followed by nasopharyngeal ventilation or vice versa. The ventilation settings were kept constant. The primary outcome was tidal volume. The secondary outcome was the difficulty of ventilation, measured using the Warters grading scale. Tidal volume was significantly increased by nasopharyngeal ventilation in cohort #1 (597 ± 156 ml vs.462 ± 220 ml, p = 0.019) and cohort #2 (525 ± 157 ml vs.259 ± 151 ml, p < 0.01). Warters grading scale for mask ventilation was 0.6 ± 1.4 in cohort #1, and 2.6 ± 1.5 in cohort #2. Patients at risk for difficult facemask ventilation may benefit from nasopharyngeal ventilation to maintain adequate ventilation and oxygenation before endotracheal intubation. This ventilation mode may offer another option for ventilation at induction of anesthesia and during the management of respiratory insufficiency, especially in the setting of "unexpected" ventilation difficulty.

Comparison of preoxygenation efficiency measured by the oxygen reserve index between high-flow nasal oxygenation and facemask ventilation: a randomised controlled trial

BackgroundHigh-flow nasal oxygenation and the oxygen reserve index (ORI), which is a non-invasive and innovative modality that reflects the arterial oxygen content, are used in general anaesthesia. This study compares the preoxygenation efficiency (measured by the ORI) of high-flow nasal oxygenation and facemask ventilation during the induction process.MethodsThis single-centre, two-group, randomised controlled trial included 197 patients aged ≥ 20 years who underwent orotracheal intubation for general anaesthesia for elective surgery. The patients were randomly allocated to receive preoxygenation via facemask ventilation or high-flow nasal oxygenation. The ORI was measured and compared between both groups.ResultsThe ORI increased during preoxygenation in all patients. At 1 min of preoxygenation, the ORI was significantly higher in the high-flow nasal oxygenation group (0.34 ± 0.33) than in the facemask ventilation group (0.21 ± 0.28; P = 0.003). The highest ORI was not significantly different between the two groups (0.68 ± 0.25 in the high-flow nasal oxygenation group vs. 0.70 ± 0.28 in the facemask ventilation group; P = 0.505).ConclusionsHigh-flow nasal oxygenation results in an oxygenation status similar to that provided by facemask ventilation during the induction process of general anaesthesia; therefore, high-flow nasal oxygenation is a feasible preoxygenation method.Trial RegistrationClinicaltrials.gov (NCT04291339).

Difficult or impossible facemask ventilation in children with difficult tracheal intubation: a retrospective analysis of the PeDI registry

BackgroundDifficult facemask ventilation is perilous in children whose tracheas are difficult to intubate. We hypothesised that certain physical characteristics and anaesthetic factors are associated with difficult mask ventilation in paediatric patients who also had difficult tracheal intubation. MethodsWe queried a multicentre registry for children who experienced “difficult” or “impossible” facemask ventilation. Patient and case factors known before mask ventilation attempt were included for consideration in this regularised multivariable regression analysis. Incidence of complications, and frequency and efficacy of rescue placement of a supraglottic airway device were also tabulated. Changes in quality of mask ventilation after injection of a neuromuscular blocking agent were assessed. ResultsThe incidence of difficult mask ventilation was 9% (483 of 5453 patients). Infants and patients having increased weight, being less than 5th percentile in weight for age, or having Treacher-Collins syndrome, glossoptosis, or limited mouth opening were more likely to have difficult mask ventilation. Anaesthetic induction using facemask and opioids was associated with decreased risk of difficult mask ventilation. The incidence of complications was significantly higher in patients with “difficult” mask ventilation than in patients without. Rescue placement of a supraglottic airway improved ventilation in 71% (96 of 135) of cases. Administration of neuromuscular blocking agents was more frequently associated with improvement or no change in quality of ventilation than with worsening. ConclusionsCertain abnormalities on physical examination should increase suspicion of possible difficult facemask ventilation. Rescue use of a supraglottic airway device in children with difficult or impossible mask ventilation should be strongly considered.

PREOPERATIVE SINGLE ANTHROPOMETRIC SCREENING TESTS OF DIFFICULT FACE MASK VENTILATION AND DIFFICULT DIRECT LARYNGOSCOPY INTUBATION IN PATIENTS UNDERGOING OTORHINOLARYNGOLOGICAL SURGERY: A PROSPECTIVE, OBSERVATIONAL, SINGLE CENTER STUDY.

The aim of this study was to assess preoperative airway history data and single anthropometric screening tests of difficult face mask ventilation (FMV) and difficult direct laryngoscopy intubation (DLI) in otorhinolaryngological surgery. Final analysis included 62 patients aged ≥14 years undergoing elective surgery with endotracheal intubation at a single center during a one-month period. Data on difficult intubation history, airway symptoms and pathology related to difficult airway were prospectively collected. Han scoring classification of FMV and Intubation Difficulty Score (IDS) were used. There were 14 (22.6%) patients with a history of current airway tumors or abscesses. Only two (3.2%) patients were preoperatively evaluated as anticipated difficult airway. Both were slightly difficult to ventilate and scored IDS 5 and IDS 8. FMV was graded as easy in 50 (80.5%), slightly difficult in 10 (16.1%) and difficult in 2 (3.2%) cases. There were 29 (46.78%) slightly difficult DLIs and one (1.6%) case of difficult DLI. The study confirmed clinically relevant incidence of difficulties with FMV and DLI in otorhinolaryngologic surgery patients. However, there should be stronger evidence to identify a single preoperative variable predicting difficult airway.

AIRWAY MANAGEMENT GUIDELINES IN OBSTETRICS.

Anatomic and physiologic changes during pregnancy make it more difficult to establish a safe airway in pregnant women in case of the need for surgery under general anesthesia than in the non-obstetric population. The inability to ventilate and oxygenate is one of the most common causes of morbidity and mortality associated with general anesthesia for cesarean section. The aim of this paper is to present and analyze modern guidelines and algorithms for the management of difficult airway in obstetrics as an important segment of anesthesiology practice. Modern difficult airway management guidelines for pregnant women describe the procedure of difficult facemask ventilation, difficult airway management by using supraglottic devices, difficult endotracheal intubation, and emergency cricothyrotomy or tracheotomy in a situation where oxygenation and ventilation are impossible. Algorithms describe the procedures and equipment for each variant of difficult airway and decision-making strategies in situations when neither airway nor adequate oxygenation can be provided. Croatian anesthesiologists in most obstetric departments have appropriate equipment, as well as necessary experience in difficult airway management for pregnant women, and modern algorithms from the most developed countries can be adopted and accommodated to our daily practice, as well as incorporated into the training curricula of residents.

Effect of facemask oxygenation with and without positive pressure ventilation on gastric volume during anesthesia induction in patients undergoing laparoscopic cholecystectomy or partial hepatectomy: a randomized controlled trial

BackgroundStudies focusing on the relationship between gastric volume and facemask oxygenation without ventilation during apnea in anesthesia induction are scarce. This study compared the change in gastric volume during apnea in anesthesia induction using facemask ventilation and facemask oxygenation without ventilation in adults undergoing laparoscopic surgery.MethodsIn this prospective, randomized, double-blinded trial, 70 adults undergoing laparoscopic surgery under general anesthesia were divided into two groups to receive facemask oxygenation with and without ventilation for 60 seconds after loss of consciousness. Before anesthesia induction and after endotracheal intubation, the gastric antral cross-sectional area was measured with ultrasound imaging. Arterial blood gases were tested at baseline (T1), after preoxygenation (T2), after loss of consciousness (T3), and before and after endotracheal intubation (T4 and T5, respectively).ResultsSixty patients were included (ventilation n = 30; non ventilation n = 30, 10 patients were excluded). The median [IQR] change of gastric antral cross-sectional area in ventilation group was significantly higher than in non ventilation group (0.83 [0.20 to 1.54] vs. 0.10 [− 0.11 to 0.56] cm2, P = 0.001). At T4 and T5, the PaO2 in ventilation group was significantly higher than in non ventilation group (T4: 391.83 ± 61.53 vs. 336.23 ± 74.99 mmHg, P < 0.01; T5: 364.00 ± 58.65 vs. 297.13 ± 86.95 mmHg, P < 0.01), while the PaCO2 in non ventilation group was significantly higher (T4: 46.57 ± 5.78 vs. 37.27 ± 6.10 mmHg, P < 0.01; T5: 48.77 ± 6.59 vs. 42.63 ± 6.03 mmHg, P < 0.01) and the pH value in non ventilation group was significantly lower (T4: 7.35 ± 0.029 vs 7.42 ± 0.047, P < 0.01; T5: 7.34 ± 0.033 vs 7.39 ± 0.044, P < 0.01). At T4, the HCO3− in non ventilation group was significantly higher (25.79 ± 2.36 vs. 23.98 ± 2.18 mmol l− 1, P < 0.01).ConclusionsDuring apnoea, the increase in gastric volume was milder in patients undergoing facemask oxygenation without ventilation than with positive pressure ventilation.Trial registrationChiCTR2100054193, 10/12/2021, Title: “Effect of positive pressure and non-positive pressure ventilation on gastric volume during induction of general anesthesia in laparoscopic surgery: a randomized controlled trial”. Website: https://www.chictr.ogr.cn.