Bronchoaspiration: incidence, consequences and management:

Supraglottic airway device to improve ventilation success and reduce pulmonary aspiration during cardio-pulmonary resuscitation by basic life support rescuers: a randomised cross-over human cadaver study

Objectives: Early airway management during cardiopulmonary resuscitation (CPR) prevents aspiration of gastric contents. Endotracheal intubation is the gold standard to protect airways, but supraglottic airway devices (SGA) may provide some protection with less training. Bag-mask ventilation (BMV) is the most common method used by rescuers. We hypothesized that SGA use by first rescuers during CPR could increase ventilation success rate and also decrease intragastric pressure and pulmonary aspiration.Methods: We performed a randomized cross-over experimental trial on human cadavers. Protocol A: we assessed the rate of successful ventilation (chest rise), intragastric pressure, and CPR key time metrics. Protocol B: cadaver stomachs were randomized to be filled with 300 mL of either blue or green serum saline solution through a Foley catheter. Each rescuer was randomly assigned to use SGA or BMV during a 5-minute standard CPR period. Then, in a crossover design, the stomach was filled with the second colour solution and another 5-minute CPR period was performed using the other airway method. Pulmonary aspiration, defined as the presence of coloured solution below the vocal cords, was assessed by a blinded operator using bronchoscopy. A generalized linear mixed model was used for statistical analysis.Results: Protocol A: Forty-eight rescuers performed CPR on 11 cadavers. Median ventilation success was higher with SGA than BMV: 75.0% (IQR: 59.8-87.3) vs. 34.7% (IQR: 25.0-50.0), (p = 0.003). Gastric pressure and differential (maximum minus minimum) gastric pressure were lower in the SGA group: 2.21 mmHg (IQR: 1.66; 2.68) vs. 3.02 mmHg (IQR: 2.02; 4.22) (p = 0.02) and 5.70 mmHg (IQR: 4.10; 7.60) vs. 8.05 mmHg (IQR: 5.40; 11.60) (p = 0.05). CPR key times were not different between groups. Protocol B: Ten cadavers were included with 20 CPR periods. Aspiration occurred in 2 (20%) SGA procedures and 5 (50%) BMV procedures (p = 0.44).Conclusion: Use of SGA by rescuers improved the ventilation success rate, decreased intragastric pressure, and did not affect key CPR metrics. SGA use by basic life support rescuers appears feasible and efficient.

A New Scope of Practice: Adult Pulmonary Aspiration Managed With a Pediatric Gastroscope: A Case Report

Pulmonary aspiration continues to be a major cause of anesthesia-related mortality. Anesthesiologists are encouraged to perform bronchoscopy to manage aspiration of particulate matter; however, they have limited training and experience in clearing luminal obstructions endoscopically. In our report, an adult with achalasia aspirated during induction for a per-oral endoscopic myotomy (POEM), resulting in desaturation and high airway pressures. Bronchoscopy by the anesthesiologist was ineffective. However, bronchoscopy by the gastroenterologist using a pediatric gastroscope cleared the bronchi of debris and led to immediate clinical improvement. Anesthesiologists, faced with particulate matter aspiration, could consider assistance from a gastrointestinal endoscopist.

Factors associated with bronchopulmonary aspiration: a national-based study

OBJECTIVES

to determine the prevalence of bronchopulmonary aspiration in the Brazilian scenario, the factors associated with the incident and the variables associated with death.

METHODS

a cross-sectional and analytical study, carried out from analysis of notifications of incidents related to bronchopulmonary aspiration of the Health Surveillance Notification System, from January 2014 to December 2018.

RESULTS

of the 264,590 notifications, 553 referred to aspiration, whose prevalence rate was 0.21%. There was an association between the event and age, ethnicity, main medical diagnosis, country region, service type, health unit and consequences for patients. Furthermore, four independent predictor variables for death were found: living in the North or South regions, being elderly and receiving healthcare at night.

CONCLUSIONS

the prevalence rate of bronchopulmonary aspiration was small, but with a negative impact on patients.

Effect of Paratracheal Pressure on the Glottic View During Direct Laryngoscopy: A Randomized Double-Blind, Noninferiority Trial

BACKGROUND

Cricoid pressure has been used as a component of the rapid sequence induction and intubation technique. However, concerns have been raised regarding the effectiveness and safety of cricoid pressure. Paratracheal pressure, a potential alternative to cricoid pressure to prevent regurgitation of gastric contents or aspiration, has been studied to be more effective to cricoid pressure in preventing gastric insufflation during positive pressure ventilation. However, to adopt paratracheal compression into our practice, adverse effects including its effect on the glottic view during direct laryngoscopy should be studied. We conducted a randomized, double-blind, noninferiority trial comparing paratracheal and cricoid pressures for any adverse effects on the view during direct laryngoscopy, together with other secondary outcome measures.

METHODS

In total, 140 adult patients undergoing general anesthesia randomly received paratracheal pressure (paratracheal group) or cricoid pressure (cricoid group) during anesthesia induction. The primary end point was the incidence of deteriorated laryngoscopic view, evaluated by modified Cormack-Lehane grade with a predefined noninferiority margin of 15%. Secondary end points included percentage of glottic opening score, ease of mask ventilation, change in ventilation volume and peak inspiratory pressure during mechanical mask ventilation, ease of tracheal intubation, and resistance encountered while advancing the tube into the glottis. The position of the esophagus was assessed by ultrasound in both groups to determine whether pressure applied to the respective area would be likely to result in esophageal compression. All secondary outcomes were tested for superiority, except percentage of glottic opening score, which was tested for noninferiority.

RESULTS

Paratracheal pressure was noninferior to cricoid pressure regarding the incidence of deterioration of modified Cormack-Lehane grade (0% vs 2.9%; absolute risk difference, -2.9%; 95% confidence interval, -9.9 to 2.6, P <.0001). Mask ventilation, measured on an ordinal scale, was found to be easier (ie, more likely to have a lower score) with paratracheal pressure than with cricoid pressure (OR, 0.41; 95% confidence interval, 0.21-0.79; P = .008). The increase in peak inspiratory pressure was significantly less in the paratracheal group than in the cricoid group during mechanical mask ventilation (median [min, max], 0 [-1, 1] vs 0 [-1, 23]; P = .001). The differences in other secondary outcomes were nonsignificant between the groups. The anatomical position of the esophagus was more suitable for compression in the paratracheal region, compared to the cricoid cartilage region.

CONCLUSIONS

Paratracheal pressure was noninferior to cricoid pressure with respect to the effect on glottic view during direct laryngoscopy.

Race and major pulmonary complications following inpatient pediatric otolaryngology surgery

BACKGROUND

Compared to their white peers, black children are more likely to experience serious respiratory complications in the perioperative period. Whether a racial difference exists in the occurrence of late postoperative respiratory complications is largely unknown. Here, we evaluated a multi-institutional cohort of children who underwent various elective otolaryngology procedures to examine the racial differences in major postoperative pulmonary complications.

METHODS

We performed a retrospective analysis of elective inpatient otolaryngology cases from the National Surgical Quality Improvement Program (2012-2018). We used propensity score matching of black to white patients to compare the risk of postoperative pulmonary complications, defined as the occurrence of either pneumonia, unplanned reintubation, or prolonged postoperative mechanical ventilation.

RESULTS

The matched cohort was comprised of 4786 black and white patients (2 393 of each race). Black children were more likely to develop postoperative pulmonary complications compared to white peers (29.3% vs. 24.2%; odds ratio: 1.38; 95% confidence interval: 1.20, 1.59; P-value < .001). Furthermore, black children were almost two times more likely to require unplanned postoperative reintubation, relative to their white peers (2.6% vs. 1.3%; odds ratio: 2.07; 95% confidence interval: 1.33, 3.22; P-value < .001). Similarly, black children were estimated to have 37% relative greater odds of requiring prolonged mechanical ventilation (28.6% vs. 23.7%; 95% confidence interval: 1.19, 1.58; P-value < .001). Finally, being of black race conferred greater odds of requiring prolonged hospital length of stay, relative to being of white race (38.6% vs. 34.5%; odds ratio:1.24; 95% confidence interval: 1.09, 1.42; P-value = .004).

CONCLUSION

Black children undergoing elective otolaryngological surgery are more likely to develop major postoperative pulmonary complications.

[New aspects of rapid sequence induction including treatment of pulmonary aspiration]

Pulmonary aspiration of solid components leads to displacement of the tracheobronchial tree, the aspiration of acidic gastric juices to chemical pneumonitis (Mendelson's syndrome) and the aspiration of oropharyngeal secretions or gastrointestinal pathogens to aspiration pneumonia. Principally, pulmonary aspiration can occur at any stage of anesthesia. In the clinical routine the aim must therefore be to identify those patients who have an increased risk of aspiration. When this is successful, measures can be taken to reduce the risk; these can be regional anaesthesia or the performance of general anaesthesia as rapid sequence induction (RSI). If severe pulmonary aspiration occurs despite all preventive measures, mostly during induction of anaesthesia, extensive experience and rapid action are necessary. This can only be achieved if the induction to RSI is performed by three persons with supervision of the trainee anaesthetist by a consultant anaesthetist.

Pulmonary aspiration during procedural sedation for colonoscopy resulting from positional change managed without oral endotracheal intubation

Background

Pulmonary aspiration under anaesthesia is a feared complication. It is likely that the incidence of aspiration occurring during procedural sedation is underreported; although rare, fatalities do occur. The supine position increases the risk of pulmonary aspiration in gastrointestinal endoscopy during procedural sedation. Immediate oral endotracheal intubation has traditionally been the cornerstone of management for aspiration during anaesthesia; however, this may not be always beneficial when aspiration occurs during procedural sedation. To my knowledge, this is the first case report of aspiration pneumonitis resulting from surgical repositioning during colonoscopy under procedural sedation.

Case presentation

A 72-year-old female underwent elective outpatient diagnostic colonoscopy. Intravenous propofol infusion was commenced for the procedural sedation. A large amount of non-particulate vomitus was expelled from the oropharynx as the patient was repositioned from the left lateral to supine position. Oxygen saturation on pulse oximetry immediately dropped to below 90% during the event. The patient was managed successfully without oral endotracheal intubation.

Conclusions

Anaesthesiologists need to be mindful of factors that raise the risk of aspiration during procedural sedation. Gastrointestinal endoscopy poses a higher risk of aspiration than other procedures, and positional change may be a precipitant. Aspiration that occurs during procedural sedation may be more safely managed by avoiding immediate oral endotracheal intubation.

Anesthetic Management for Cesarean Delivery in a Patient with a Gigantic Intracranial Tumor

A 31-year-old G5P1 patient with unremarkable past medical history at 29 weeks of gestation was diagnosed with a gigantic left frontotemporal brain mass. Initial clinical management as an inpatient achieved an improvement in the symptoms. The patient and surgical team agreed to schedule a cesarean delivery at 32 weeks of gestation if no neurological deterioration was observed. Intraoperative course with general endotracheal anesthesia and bilateral transversus abdominis plane block was uneventful and promoted efficient postoperative pain control. Seven days after delivery, the patient underwent craniotomy for brain tumor resection. This report describes the anesthetic management of a patient with an intracranial tumor during pregnancy.

[Physiological changes during pregnancy]

The physiological state of a woman experiences multiple changes in the body during pregnancy. These alterations could be of particular importance in the medical care of pregnant women. This review article highlights the physiological developments of various organ systems throughout gestation with a focus on endocrinology, the cardiovascular system, hematology, the respiratory system and water balance.

Regeneration of severely damaged lungs using an interventional cross-circulation platform

The number of available donor organs limits lung transplantation, the only lifesaving therapy for the increasing population of patients with end-stage lung disease. A prevalent etiology of injury that renders lungs unacceptable for transplantation is gastric aspiration, a deleterious insult to the pulmonary epithelium. Currently, severely damaged donor lungs cannot be salvaged with existing devices or methods. Here we report the regeneration of severely damaged lungs repaired to meet transplantation criteria by utilizing an interventional cross-circulation platform in a clinically relevant swine model of gastric aspiration injury. Enabled by cross-circulation with a living swine, prolonged extracorporeal support of damaged lungs results in significant improvements in lung function, cellular regeneration, and the development of diagnostic tools for non-invasive organ evaluation and repair. We therefore propose that the use of an interventional cross-circulation platform could enable recovery of otherwise unsalvageable lungs and thus expand the donor organ pool.

Regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) with a laryngeal tube: A pilot crossover human cadaver study

Background

High-quality chest compressions are imperative for Cardio-Pulmonary-Resuscitation (CPR). International CPR guidelines advocate, that chest compressions should not be interrupted for ventilation once a patient’s trachea is intubated or a supraglottic-airway-device positioned. Supraglottic-airway-devices offer limited protection against pulmonary aspiration. Simultaneous chest compressions and positive pressure ventilation both increase intrathoracic pressure and potentially enhances the risk of pulmonary aspiration. The hypothesis was, that regurgitation and pulmonary aspiration is more common during continuous versus interrupted chest compressions in human cadavers ventilated with a laryngeal tube airway.

Methods

Twenty suitable cadavers were included, and were positioned supine, the stomach was emptied, 500 ml of methylene-blue-solution instilled and laryngeal tube inserted. Cadavers were randomly assigned to: 1) continuous chest compressions; or, 2) interrupted chest compressions for ventilation breaths. After 14 minutes of the initial designated CPR strategy, pulmonary aspiration was assessed with a flexible bronchoscope. The methylene-blue-solution was replaced by 500 ml barium-sulfate radiopaque suspension. 14 minutes of CPR with the second designated ventilation strategy was performed. Pulmonary aspiration was then assessed with a conventional chest X-ray.

Results

Two cadavers were excluded for technical reasons, leaving 18 cadavers for statistical analysis. Pulmonary aspiration was observed in 9 (50%) cadavers with continuous chest compressions, and 7 (39%) with interrupted chest compressions (P = 0.75).

Conclusion

Our pilot study indicate, that incidence of pulmonary aspiration is generally high in patients undergoing CPR when a laryngeal tube is used for ventilation. Our study was not powered to identify potentially important differences in regurgitation or aspiration between ongoing vs. interrupted chest compression. Our results nonetheless suggest that interrupted chest compressions might better protect against pulmonary aspiration when a laryngeal tube is used for ventilation.

Peak airway pressure is lower during pressure-controlled than during manual facemask ventilation for induction of anesthesia in pediatric patients-a randomized, clinical crossover trial

PURPOSE

Facemask ventilation during the induction of general anesthesia in paediatric patients remains a challenge as it may result in hypoxic conditions and gastric insufflation with subsequent regurgitation and aspiration. So far, it is unclear if pressure-controlled or manual facemask ventilation is preferable in children. We hypothesized that pressure-controlled ventilation in apnoeic children results in lower peak airway pressure and flow rates compared to manual ventilation at comparable respiratory rates and tidal volumes.

METHODS

Sixty-two lung-healthy children undergoing scheduled ear-nose-throat surgery were included in the study. After the induction of anesthesia, the patient's lungs were consecutively ventilated via a facemask in either manual or pressure-controlled mode, in randomized order. The primary outcome measure was peak airway pressure. Secondary outcome measures included positive end-expiratory pressure, airway compliance, tidal volume and airway flow.

RESULTS

Data of 52 patients could be analyzed. Pressure-controlled ventilation resulted in a lower mean and peak inspiratory pressure (both p < 0.001), airway pressure amplitude (p = 0.01) and inspiratory peak flow rate (p = 0.005) compared to manual ventilation. The ratio of inspiration to expiration time was lower in pressure-controlled ventilation compared to manual ventilation (p < 0.001).

CONCLUSION

Pressure-controlled facemask ventilation during induction of anesthesia in pediatric patients results in lower airway pressure, and lower flow rates compared to manual ventilation, at comparable tidal and minute volumes.

Comparison of blind intubation via supraglottic airway devices versus standard intubation during different airway emergency scenarios in inexperienced hand: Randomized, crossover manikin trial

BACKGROUND

Securing the airway and enabling adequate oxygenation and ventilation is essential during cardiopulmonary resuscitation (CPR). The aim of the study was to evaluate the success rate of blind intubation via the I-Gel and the Air-Q compared with direct laryngoscopy guided endotracheal intubation by inexperienced physician and to measure time to successful intubation.

METHODS

The study was designed as a randomized, cross-over simulation study. A total of 134 physicians, from specialties other than Anesthesia or Emergency Medicine, who considered themselves skilled in endotracheal intubation but who have never used any kind of supraglottic airway device performed blind intubation via the I-Gel and Air-Q and direct laryngoscopy guided endotracheal intubation in 3 randomized scenarios: normal airway without chest compression during intubation attempt; normal airway with continuous chest compression during intubation attempt; difficult airway with continuous chest compression.

RESULTS

Scenario A: Success rate with initial intubation attempt was 72% for endotracheal intubation, 75% in Air-Q, and 81% in I-Gel. Time to endotracheal intubation and ease of intubation was comparable with all 3 airway devices used. Scenario B: Success rate with the initial intubation attempt was 42% for endotracheal intubation, compared with 75% in Air-Q and 80% in I-Gel. Time for endotracheal intubation was significantly prolonged in endotracheal intubation (42 seconds, 35-49), compared with Air-Q (21 seconds, 18-32) and I-Gel (19 seconds, 17-27). Scenario C: The success rate with the initial intubation attempt was 23% in endotracheal intubation, compared with 65% in Air-Q and 74% in I-Gel. Time to intubation was comparable with both supraglottic airway devices (20 vs 22 seconds) but was significantly shorter compared with endotracheal intubation (50 seconds, P < .001).

CONCLUSIONS

Less to moderately experienced providers are able to perform endotracheal intubation in easy airways but fail during ongoing chest compressions and simulated difficult airway. Consequently, less to moderately experienced providers should refrain from endotracheal intubation during ongoing chest compressions during CPR and in expected difficult airways. Supraglottic airway devices are reliable alternatives and blind intubation through these devices is a valuable airway management strategy.

Management of the risk of bronchoaspiration in patients with oropharyngeal dysphagia

ABSTRACT Objective: to manage the risk of bronchoaspiration in patients with oropharyngeal dysphagia through signalizing plates in the hospital bed. Methods: a descriptive, quantitative study, developed in the medical clinic I (diagnostic investigation), medical clinic II (infectology / pneumology), surgical clinics and intensive care unit of the University Hospital of the Federal University of Sergipe, from February to August 2017. It was composed of patients in the age group ≥ 18 years of age, of both sexes, diagnosed with oropharyngeal dysphagia, based on the application of the adapted protocol of clinical evaluation in the hospital bed and instrumental examination of swallowing, when pertinent. Following the clinical evaluation and identification of the risk of bronchoaspiration due to oropharyngeal dysphagia, the signs were inserted at the hospital bed by the speech therapist. Results: the study included 43 patients at risk of bronchoaspiration due to oropharyngeal dysphagia, average age of 53.7 ± 3.53 years old, with 51.1% (n = 22) females and 48.9% (n = 21) males. A predominance of neuropathies (53.4%) and severe neurogenic oropharyngeal dysphagia (37.2%) was observed. The intensive care unit stood out with 44.18% (n = 19) of the application of signs of risk of bronchoaspiration. Conclusion: the management of bronchoaspiration risk has been shown to be a promising measure to reduce adverse events, which affect the patient's safety and consequently the quality of care in the hospital environment, as well as a possible strategy for measuring respiratory complications triggered by aspiration of oropharyngeal contents.

Characterization of the seven-day course of pulmonary response following unilateral lung acid injury in rats

BACKGROUND

Aspiration of gastric acid is an important cause of acute lung injury. The time course of the pulmonary response to such an insult beyond the initial 48 hours is incompletely characterized. The purpose of this study was to comprehensively describe the pulmonary effects of focal lung acid injury over a seven day period in both directly injured and not directly injured lung tissue.

METHODS

Male Wistar rats underwent left-endobronchial instillation with hydrochloric acid and were sacrificed at 4, 24, 48, 96 or 168 h after the insult. Healthy non-injured animals served as controls. We assessed inflammatory cell counts and cytokine levels in right and left lung lavage fluid and blood, arterial oxygen tension, alterations in lung histology, lung wet-to-dry weight ratio and differential lung perfusion.

RESULTS

Lung acid instillation induced an early strong inflammatory response in the directly affected lung, peaking at 4-24 hours, with only partial resolution after 7 days. A less severe response with complete resolution after 4 days was seen in the opposite lung. Alveolar cytokine levels, with exception of IL-6, only partially reflected the localization of lung injury and the time course of the functional and histologic alterations. Alveolar leucocyte subpopulations exhibited different time courses in the acid injured lung with persistent elevation of alveolar lymphocytes and macrophages. After acid instillation there was an early transient decrease in arterial oxygen tension and lung perfusion was preferentially distributed to the non-injured lung.

CONCLUSION

These findings provide a basis for further research in the field of lung acid injury and for studies exploring effects of mechanical ventilation on injured lungs. Incomplete recovery in the directly injured lung 7 days after acid instillation suggests that increased vulnerability and susceptibility to further noxious stimuli are still present at that time.

Dexmedetomidine and Magnesium Sulfate: A Good Combination Treatment for Acute Lung Injury?

Objectives: In this study, we aimed to investigate the therapeutic effects of magnesium sulfate (MgSO₄) and dexmedetomidine (dex) in a model of acute lung injury (ALI). We determined whether concomitant administration decreased the inflammatory effects of hydrochloric acid (HCl)-induced ALI in a synergistic manner. Materials and Methods: In this study, 42 Sprague-Dawley rats were randomized into six groups: Group S (saline), Group SV (saline + mechanical ventilation), Group HCl (HCl), Group Dex (Dex), Group Mag (MgSO₄), and Group DM (Dex + MgSO₄). All groups except Group S were mechanically ventilated prior to HCl-induced ALI. Saline or HCl was administered via tracheostomy. Prior to treatment, HCl was administered to Group HCl, Group Dex, Group Mag, and Group DM to induce ALI. Dex and MgSO₄ were administered intraperitoneally. The rats were monitored for 4 h after treatment to measure oxidative stress parameters in blood, and prolidase enzyme activity. Lung tissue damage were determined via histopathology. Results: A significant increase in heart rate and rapid desaturation was observed in HCl-administered groups. Treatment administration decreased the pulse values. Increased saturation values and decreased oxidative stress indices were observed in groups that were subsequently administered​ Dex and MgSO₄. Serum prolidase activity increased significantly in Group HCl. Severe pathological findings were detected following HCl-induced ALI. Group Mag showed greater improvement in the pathology of HCl-induced ALI than did Group Dex. Administration of both Dex and MgSO₄ did not improve the pathological scores. Conclusions: The antioxidant and anti-inflammatory effects of Dex and MgSO₄ ameliorated the detrimental effects of HCI-induced ALI. However, adverse effects on hemodynamics and lung damage were observed when the two drugs were administered together.

Gastrointestinal endoscopy under sedation is associated with pneumonia in older inpatients-results of a retrospective case-control study

Background and aims

Apparent aspiration is a notable adverse event during gastrointestinal endoscopy under sedation (GIES), but data about inapparent aspiration are scarce. Generally, particularly older patients are at higher risk of suffering from adverse events.

Objective

The objective of this article is to determine the risk of pneumonia, lower respiratory tract infection (LRI) and systemic inflammatory activation after GIES, especially in patients of at least 65 years.

Methods

The retrospective case-control study included 250 patients undergoing GIES and assigned age-, gender- and time of performance-matched controls without invasive procedure or sedation (ratio 1:1).

Results

On day 3 patients of advanced age presented with both pneumonia and LRI more often (2.6 vs. 0.0%, p = 0.041 and 7.8 vs. 2.5%, p = 0.034, respectively). In general, several inflammatory parameters increased significantly after GIES (i.e. white blood cell count (increase of ≥ 25%) 18.6 vs. 6.9%, p < 0.001), leading to more frequent antibiotic treatment (6.8 vs. 1.6%, p = 0.004). The effects were less pronounced on day 7.

Conclusions

Patients of advanced age carry an increased risk of pneumonia and LRI after GIES. Patients are generally more likely to feature inflammation and to receive antibiotic treatment.

Evaluation of six different airway devices regarding regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) - A human cadaver pilot study

BACKGROUND

Chest compressions and ventilation are lifesaving tasks during cardio-pulmonary resuscitation (CPR). Besides oxygenation, endotracheal intubation (ETI) during CPR is performed to avoid aspiration of gastric contents. If intubation is difficult or impossible, supraglottic airway devices are utilized. We tested six different airway devices regarding their potential to protect against regurgitation and aspiration during CPR in a randomized experimental human cadaver study.

METHODS

Five-hundred ml of 0.01% methylene-blue-solution were instilled into the stomach of 30 adult human cadavers via an oro-gastric tube. The cadavers were then randomly assigned to one of six groups, resulting in 5 cadavers in each group. Airway management was performed with either bag-valve ventilation, Laryngeal Tube, EasyTube, Laryngeal Mask (Classic), I-Gel, or ETI. Thereafter 5min of CPR were performed according to the 2010 Guidelines of the European Resuscitation Council. Pulmonary aspiration was defined as the presence of methylene-blue-solution below the vocal cords or the ETI cuff as assessed by fiber-optic bronchoscopy.

RESULTS

Thirty cadavers were included (14 females, 16 males). Aspiration was detected in three out of five cadavers receiving bag-valve ventilation and in two out of five intubated with LMA or I-Gel. In cadavers intubated with the LT, aspiration occurred in one out of five cases. No aspiration could be detected in cadavers intubated with ETI and EasyTube.

CONCLUSION

This study provides experimental evidence that, during CPR, ETI offers superior protection against regurgitation and pulmonary aspiration of gastric contents than supraglottic airway devices or bag-valve ventilation.

High-Risk Residual Gastric Content in Fasted Patients Undergoing Gastrointestinal Endoscopy: A Prospective Cohort Study of Prevalence and Predictors

In this prospective cohort study, we examined the residual gastric contents of 255 fasted patients undergoing gastrointestinal endoscopy. The volume and pH of residual gastric contents collected by suction under direct visualisation during gastroscopy were accurately quantified. All patients completed the minimum two-hour fast for clear fluids and 97.2% of patients completed the minimum six-hour fast for solids. High-risk residual gastric content, defined as volume >25 ml and pH <2.5, was present in 12.2% (95% CI 8.7% to 16.7%) of patients. We used multiple logistic regression analysis to identify demographic and clinical factors associated with high-risk residual gastric content. The odds of having high-risk residual gastric content were reduced with increase in age (adjusted odds ratio 0.77, 95% CI 0.61 to 0.96, P=0.0230), and use of a proton pump inhibitor or histamine type 2 receptor antagonist (adjusted odds ratio 0.24, 95% CI 0.10 to 0.55, P=0.0013), and were increased in male patients (adjusted odds ratio 2.36, 95% CI 1.06 to 5.28, P=0.0348). Notably, residual gastric content was classified as high-risk in 20.4% of patients who did not take a proton pump inhibitor or histamine type 2 receptor antagonist versus only 5.6% of those who did. Our findings suggest that, despite currently recommended fasting, males presenting for endoscopy are more likely to have high-risk gastric content than females, and that the incidence appears to be reduced with increasing age, and by the use of proton pump inhibitors or histamine type 2 receptor antagonists, we were unable to confirm or exclude an effect of body mass index, peptic pathology, diabetes or other clinical or demographic factors in our study population.

Aspiration-related pulmonary syndromes

Aspiration of foreign matter into the airways and lungs can cause a wide spectrum of pulmonary disorders with various presentations. The type of syndrome resulting from aspiration depends on the quantity and nature of the aspirated material, the chronicity, and the host responses. Aspiration is most likely to occur in subjects with a decreased level of consciousness, compromised airway defense mechanisms, dysphagia, gastroesophageal reflux, and recurrent vomiting. These aspiration-related syndromes can be categorized into airway disorders, including vocal cord dysfunction, large airway obstruction with a foreign body, bronchiectasis, bronchoconstriction, and diffuse aspiration bronchiolitis, or parenchymal disorders, including aspiration pneumonitis, aspiration pneumonia, and exogenous lipoid pneumonia. In idiopathic pulmonary fibrosis, aspiration has been implicated in disease progression and acute exacerbation. Aspiration may increase the risk of bronchiolitis obliterans syndrome in patients who have undergone a lung transplant. Accumulating evidence suggests that a causative role for aspiration is often unsuspected in patients presenting with aspiration-related pulmonary diseases; thus, many cases go undiagnosed. Herein, we discuss the broadening spectrum of these pulmonary syndromes with a focus on presenting features and diagnostic aspects.

Aspiration-related deaths in 57 consecutive patients: autopsy study

Background

Aspiration can cause a diverse spectrum of pulmonary disorders some of which can lead to death but can be difficult to diagnose.

Patients and Methods

The medical records and autopsy findings of 57 consecutive patients in whom aspiration was the immediate cause of death at Mayo Clinic (Rochester, MN, USA) over a 9-yr period, from January 1 2004 to December 31 2012 were analyzed.

Results

The median age at death was 72 years (range, 13–95 years) and included 39 (68%) males. The most common symptom before death was dyspnea (63%) and chest radiography revealed bilateral infiltrates in the majority (81%). Most common precipitating factors for aspiration were depressed consciousness (46%) and dysphagia (44%). Aspiration-related syndromes leading to death were aspiration pneumonia in 26 (46%), aspiration pneumonitis in 25 (44%), and large airway obstruction in 6 patients (11%). Aspiration was clinically unsuspected in 19 (33%) patients. Antimicrobial therapy had been empirically administered to most patients (90%) with aspiration pneumonia and aspiration pneumonitis.

Conclusion

We conclude aspiration-related deaths occur most commonly in the elderly with identifiable risks and presenting bilateral pulmonary infiltrates. One-third of these aspiration-related pulmonary syndromes were clinically unsuspected at the time of death.

Incidence, outcomes, and mortality of reintubation after anterior cervical fusion

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

To compare perioperative patient characteristics, hospital resource utilization, and early postoperative outcomes in patients requiring reintubation after anterior cervical fusion (ACF).

SUMMARY OF BACKGROUND DATA

Airway compromise is a potential complication after anterior cervical surgery. Postsurgical soft-tissue edema or hematoma formation may be so severe that an unplanned reintubation may be required. The rate of reintubation after ACF and the effect on hospital outcomes remains unknown.

METHODS

The Nationwide Inpatient Sample database was queried from 2002-2011. Patients undergoing elective ACF procedures for degenerative diagnoses were selected. Those who required an unplanned reintubation after ACF were identified. Patient demographics, comorbidities, length of stay, costs, number of levels fused, and mortality were analyzed. SPSS version 20 was used for statistical analysis and a P < 0.001 denoted statistical significance.

RESULTS

A total of 262,425 patients underwent an elective ACF between 2002 and 2011 of which 1464 patients (5.6 per 1000 cases) required reintubation during their admission. The rate of reintubation was statistically greater for 3+-level fusions than the 1- to 2-level fusion cases. On average, patients requiring reintubation were older and had a greater number of comorbidities. These patients also incurred a significantly greater hospital stay and total hospital costs than unaffected patients. In addition, significant predictors for reintubation included 3+-level fusions, congestive heart failure, anemia, postoperative aspiration pneumonia, hematoma, thromboembolic events, and dysphagia.

CONCLUSION

The reintubation rate after an elective ACF is 0.5%, and it increases to 1.6% after 3+-level fusions. Older patients with greater comorbidities are at an increased risk for reintubation. Given the greater LOS, costs and mortality associated with reintubation, it is imperative to identify patients at increased risk to help improve patient outcomes and decrease hospital resource utilization.

LEVEL OF EVIDENCE

4.

The therapeutic effects of anti-oxidant and anti-inflammatory drug quercetin on aspiration-induced lung injury in rats

Aspiration pneumonitis refers to acute chemical lung injury caused by aspiration of sterile gastric contents. The aim of this study was to evaluate the role of quercetin (QC) in acid aspiration-induced lung injury in rats. Twenty-eight female Sprague-Dawley rats were used and divided into the following groups (n = 7): sham (aspirated normal saline, S), hydrochloric acid (aspirated HCl), S plus treatment with QC (S + QC), and HCl plus treatment with QC (HCl + QC). After aspiration, the treatment groups received QC 60 mg/kg/day intraperitoneally once a day for 7 days. As a result of acid aspiration, an increase was observed in the levels of serum clara cell protein-16 (CC-16) and advanced oxidation protein products, whereas there was a decrease in serum thiobarbituric acid-reactive substances, superoxide dismutase (SOD), and catalase levels. There was a significant decrease in peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, and alveolar exudate scores, except in the alveolar histiocytes in the HCl + QC group. The expression of nitric oxide synthase, which increased after aspiration in the HCl group, showed a statistically significant decrease after the QC treatment. After the treatment with QC, an increase in the serum SOD level was observed, whereas a significant decrease was determined in the serum CC-16 level relative to that of the aspiration group (HCl). The antioxidant QC is effective in the treatment of lung injury following acid aspiration and can be used as a serum CC-16 biomarker in predicting the severity of oxidative lung injury.

The duration of fibre-optic intubation is increased by cricoid pressure. A randomised double-blind study

BACKGROUND

In some categories of patients, a rapid sequence induction using a fibre-optic method may be indicated. The aim of the present study was to examine the effect of cricoid pressure (CP) on the duration of fibre-optic intubation. The hypothesis was that CP would prolong the intubation time.

METHODS

The study was a randomised, double-blind, cross-over study. The patients were intubated twice, in a randomised way, using a flexible fibrescope once with and once without CP. The intubation time and the visualisation of the glottis were registered. If the intubation was not completed within 180 s, it was registered as failed. CP was standardised to a pressure of 30 N. The data are given as the mean (standard deviation) or median [interquartile] (range).

RESULTS

Fifty patients were included, with a mean age of 53 years (14.6) and mean body mass index of 26.4 (4.3). Three intubations without and 13 intubations with CP failed. The durations of intubation without and with CP were 59 s [53-79 s] (34-144 s) and 75 s [67-104 s] (43-179 s), respectively (P < 0.001).

CONCLUSION

The study showed that CP prolongs the duration of fibre-optic intubation in patients with Mallampati grades 1-2.

[Modified rapid sequence induction for Caesarian sections : case series on the use of rocuronium and sugammadex]

BACKGROUND

Aspiration is a feared complication of anesthesia and is accompanied by increased morbidity and mortality. Rapid sequence induction (RSI) describes the preferred procedure to perform endotracheal placement of the tubus in emergency cases of patients with an increased risk of aspiration of gastric contents. For more than 50 years RSI has consisted of the application of suxamethonium for neuromuscular blockade because of its fast onset and ultra short duration. Due to the serious side effects of suxamethonium attempts were made to find better alternative neuromuscular blocking drugs, e.g. rocuronium, to perform RSI.

MATERIALS AND METHODS

In this small clinical series RSI was performed for general anesthesia of ten pregnant women for Caesarean sections using 1.0 mg/kgBW rocuronium for induction and maintaining deep relaxation until the end of surgery. For rapid reversal of the neuromuscular blockade to a train-of-four (TOF) ratio of 0.9, the µ-cyclodextrin sugammadex was administered at the end of surgery. Major and minor side effects, such as cardiac dysrhythmia, anaphylactic reactions, hoarseness and postoperative nausea and vomiting were documented.

CONCLUSIONS

The combination of rocuronium and sugammadex for RSI combines rapid onset and rapid reversal of neuromuscular blockades with avoidance of serious side effects and very comfortable conditions for intubation in all cases. Minor side effects such as hoarseness, throat discomfort (in up to 30%) and myalgia (10%) for up to 48 h were documented.

Risk factors for gastric distension in patients with acute appendicitis: a retrospective cohort study

PURPOSE

There has been no report on risk factors for gastric distension (GD) when inducing general anesthesia in an emergency situation. The aim of this study was to clarify the risk factors for GD in patients with acute appendicitis at their hospital visit.

METHODS

We reviewed medical records of patients from April 2007 to March 2010 who underwent open appendectomy for acute appendicitis and were diagnosed pathologically. GD was defined as a larger anteroposterior diameter and larger lateral diameter of the stomach than those of the left kidney in computed tomography (CT) imaging. The primary outcome was the presence of GD. Candidate variables such as patient characteristics, physical findings, and CT imaging findings associated with GD were assessed. Time after beginning of abdominal pain was categorized and compared. Determinants with significant univariate association (P < 0.20) with the primary outcome were used to construct multivariable logistic regression models.

RESULTS

We enrolled 121 patients and divided this cohort into a GD group (44 cases, 36%) and a non-GD group (77 cases, 64%). Results of univariate analysis showed longer duration of time after beginning of abdominal pain (P = 0.016), younger age (P < 0.001), and more frequent distended small bowel (P < 0.001) in the GD group than in the non-GD group. In multivariate analysis, age [odds ratio (OR) = 0.939, P = 0.002] and time after beginning of abdominal pain (OR = 1.807, P = 0.031) were shown to be independent risk factors.

CONCLUSION

Younger appendicitis patients with acute abdominal pain for 1 or more days should be treated as patients with high risk for GD.