Extending the preoxygenation period from 4 to 8 mins in critically ill patients undergoing emergency intubation

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part I

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

A Nomogram Model for Post-Intubation Hypotension in Patients with Severe Pneumonia in the Emergency Department

Background

Post-intubation hypotension (PIH) frequently occurs in the management of critically ill patients and is associated with prognosis. The study aimed to construct a prediction model for PIH events by analyzing risk factors in patients with severe pneumonia in the emergency department.

Methods

We retrospectively enrolled 572 patients with severe pneumonia diagnosed in the emergency department of West China Hospital of Sichuan University. Five hundred patients with severe pneumonia who underwent endotracheal intubation were included in the study. All patients were randomized according to 7:3 and divided into a training cohort (n=351) and a validation cohort (n=149). Risk factors for PIH were analyzed using Least Absolute Shrinkage and Selection Operator (LASSO) and multivariable logistic regression. Calibration curves, receiver operating characteristic (ROC) curve, and decision curve analysis were applied to assess the predictive model's fitness, discrimination, and clinical utility.

Results

A total of 500 patients with severe pneumonia who underwent endotracheal intubation were enrolled in this study, and PIH occurred in 234 (46.8%) of these patients. Age, heart rate, systolic blood pressure, chronic obstructive pulmonary disease, acute physiology and chronic health evaluation II score, and induction agent use were identified as significant risk factors for the occurrence of PIH. Additionally, the body mass index was the opposite of the above. The area under the ROC curve (AUC) for the model was 0.856 (95% CI, 0.818-0.894) in the training cohort and 0.849 (95% CI, 0.788-0.910) in the validation cohort. The nomogram model was validated and demonstrated good calibration and high net clinical benefit. Finally, to facilitate application by clinicians, an online server has been set up which can be accessed free of charge via the website https://chinahospitals.shinyapps.io/DynNomapp/.

Conclusion

The nomogram is used for individualized prediction of patients with severe pneumonia prior to intubation and is simple to perform with high clinical value.

Managing the Physiologically Difficult Airway in Critically Ill Adults

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2023 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

Preoxygenation: from hardcore physiology to the operating room

If we define the human body by the mass of the elements that compose it, we could say that we are oxygen and other elements. Oxygen, in addition to being fundamental in our composition, is an element that we constantly need to support cellular respiration and, therefore, life. Interestingly, despite its importance, humans have not developed mechanisms that allow us to store it and, therefore, we are unable to sustain life if we are deprived of ventilation, even for brief periods. Accordingly, the ability to induce the cessation of ventilation in a patient must be accompanied by different technical and non-technical skills that allow the patient's safety to be maintained in this highly vulnerable state. Through the use of basic mathematical tools and comparative physiology, we hereby propose to review the physiological foundations of preoxygenation to understand the reasons behind the clinical recommendations in this field.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

A Cross-Sectional Study on Hyomental Distance Ratio (HMDR) as a New Predictor of Difficult Laryngoscopy in ICU Patients

Background: Intubation in the ICU is sometimes unpredictable unlike in an operation theatre, where pre-anesthetic assessment for airway has been done. This study has been done to evaluate the usefulness of hyomental distance ratio (HMDR) in accurately predicting difficult laryngoscopy in ICU patients.

Methods: In this study, 104 critically ill patients in the age group 18-70 years, undergoing tracheal intubation in ICU were included. A hard plastic ruler was pressed on the skin surface just above the hyoid bone and the distance to the tip of the anterior-most part of the mentum measured was defined as hyomental distance (HMD). HMD was assessed in neutral and extended head positions, and the HMDR was calculated. All patients were sedated, pre-oxygenated, induced, and relaxed prior to glottic visualization by direct laryngoscopy, which was performed by an experienced anesthetist. Cormack-Lehane's (CL's) grade was assessed without external laryngeal manipulation. Further management was as per ICU protocol.

Results: Using the Chi-Square test for statistical analysis, a p-value of HMDR in assessing difficult laryngoscopy was found to be <0.001 suggesting strong significance. HMD in the extended head position (HDMe) showed moderate significance with a p-value of 0.047. HMDR <1.2 can be considered a clinically reliable individual predictor of difficult laryngoscopy in ICU patients.

Conclusion: HMDR <1.2 can be used as a simple, easy, and reliable bedside test to predict difficult laryngoscopy amongst ICU patients. An optimal combination of tests is suggested if feasible for better accuracy. 

Oxygen reserve index for non-invasive early hypoxemia detection during endotracheal intubation in intensive care: the prospective observational NESOI study

Background

To evaluate the ability of the oxygen reserve index (ORI) to predict the occurrence of mild hypoxemia (defined as SpO₂  <  97%) during endotracheal intubation (ETI) of patients in the intensive care unit (ICU).

Methods

This observational single-centre study included patients without hypoxemia (defined as SpO₂/FiO₂  >  214) who required ETI in the ICU. Patients were followed during preoxygenation and ETI then until hospital discharge and/or day 28. We recorded cases of mild hypoxemia, moderate (SpO₂  <  90%) and severe (SpO₂  <  80%) hypoxemia, moderate arterial hypotension (systolic arterial pressure  <  90 mmHg), oesophageal intubation, aspiration, cardiac arrest, and death.

Results

Between January 2019 and July 2020, 56 patients were included prospectively and 51 patients were analysed. Twenty patients had mild hypoxemia between the end of preoxygenation and the end of intubation; in 10 of these patients, the decrease in SpO₂ below 97% was preceded by an ORI  <  0.4, the median time difference being 81 s [interquartile range, 34–146]. By multivariable analysis, a higher ORI (by 0.1 increase) value during preoxygenation was associated with absence of hypoxemia (odds ratio, 0.76; 95% confidence interval, 0.61;0.95; P  =  0.0141).

Conclusion

In non-hypoxemic patients, the 81-s [34–146] median time between the ORI decrease below 0.4 and the SpO₂ decrease below 97% during apnoea may allow preventive action. A higher ORI value during preoxygenation was independently protective against hypoxemia. Whether these findings also apply to hypoxemic patients, and the clinical impact of a preoxygenation strategy based on ORI monitoring, remain to be evaluated prospectively.

Trial Registration ClinicalTrial.gov, #NCT03600181.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00903-8.

Airway Management in the Critically Ill Patient

Purpose of Review

This paper will evaluate the recent literature and best practices in airway management in critically ill patients.

Recent Findings

Cardiac arrest remains a common complication of intubation in these high-risk patients. Patients with desaturation or peri-intubation hypotension are at high risk of cardiac arrest, and each of these complications have been reported in up to half of all intubations in critically ill patient populations.

Summary

There have been significant advances in preoxygenation and devices available for performing laryngoscopy and rescue oxygenation. However, the risk of cardiovascular collapse remains concerningly high with few studies to guide therapeutic maneuvers to reduce this risk.

BET 2: Video laryngoscopy for patients requiring endotracheal intubation in the emergency department

A short-cut review of the literature was carried out to examine whether video laryngoscopy (VL) could improve first-pass success and reduce complication rates in ED patients requiring endotracheal intubation, when compared with direct laryngoscopy. Four papers were identified as suitable for inclusion using the reported search strategy. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of the best papers are tabulated. It is concluded that current evidence suggests VL is likely to improve first-pass success and reduce oesophageal intubation rates, but there is no evidence at present that it improves clinically relevant outcomes. In addition, no difference was found between first-pass success rates in senior/experienced operators, who should use techniques with which they are familiar.

Unanticipated Respiratory Compromise and Unplanned Intubations on General Medical and Surgical Floors

BACKGROUND

Unanticipated respiratory compromise that lead to unplanned intubations is a known phenomenon in hospitalized patients. Most events occur in patients at high risk in well-monitored units; less is known about the incidence, risk factors, and trajectory of patients thought at low risk on lightly monitored general care wards. The aims of our study were to quantify demographic and clinical characteristics associated with unplanned intubations on general care floors and to analyze the medications administered, monitoring strategies, and vital-sign trajectories before the event.

METHODS

We performed a multicenter retrospective cohort study of hospitalized subjects on the general floor who had unanticipated, unplanned intubations on general care floors from August 2014 to February 2018.

RESULTS

We identified 448 unplanned intubations. The incidence rate was 0.420 per 1,000 bed-days (95% CI 0.374-0.470) in the academic hospital and was 0.430 (95% CI 0.352-0.520) and 0.394 per 1,000 bed-days (95% CI 0.301-0.506) at our community hospitals. Extrapolating these rates to total hospital admissions in the United States, we estimate 64,000 events annually. The mortality rate was 49.1%. Within 12 h preceding the event, 35.3% of the subjects received opiates. All received vital-sign assessments. Most were monitored with pulse oximetry. In contrast, 2.5% were on cardiac telemetry, and only 4 subjects used capnography; 53.7% showed significant vital-sign changes in the 24 h before the event. However, 46.3% had no significant change in any vital signs.

CONCLUSIONS

Our study showed unanticipated respiratory compromise that required an unplanned intubation of subjects on the general care floor, although not common, carried a high mortality. Besides pulse oximetry and routine vital-sign assessments, very little monitoring was in use. A significant portion of the subjects had no vital-sign abnormalities leading up to the event. Further research is needed to determine the phenotype of the different etiologies of unexpected acute respiratory failure to identify better risk stratification and monitoring strategies.

Emergent airway management of the critically ill patient: current opinion in critical care

PURPOSE OF REVIEW

To describe techniques to facilitate safe intubation in critically ill patients.

RECENT FINDINGS

Despite advances in the treatment of critically ill patients, endotracheal intubation remains a high-risk procedure associated with complications that can lead to appreciable morbidity and mortality. In addition to the usual anatomical factors that can predict a difficult intubation, incorporating pathophysiological considerations and crisis resource management may enhance safety and mitigate risk. Enhancing preoxygenation with high-flow oxygen or noninvasive ventilation, the early use of intravenous fluids and/or vasopressors to prevent hypotension and videolaryngoscopy for first pass success are all promising additions to airway management.Facilitating intubation by either sedation with paralysis or allowing patients to continue to breathe spontaneously are reasonable options for airway management. These approaches have potential advantages and disadvantages.

SUMMARY

Recognizing the unique challenges of endotracheal intubation in critically ill patients is paramount in limiting further deterioration during this high-risk procedure. A safe approach to intubation focuses on recognizing risk factors that predict challenges in achieving an optimal view of the glottis, maintaining optimal oxygenation, and minimizing the risks and benefits of sedation/induction strategies that are meant to facilitate intubation and avoid clinical deterioration.

Normal and difficult airways in children: "What's New"-Current evidence

BACKGROUND

Pediatric difficult airway is one of the most challenging clinical situations. We will review new concepts and evidence in pediatric normal and difficult airway management in the operating room, intensive care unit, Emergency Department, and neonatal intensive care unit.

METHODS

Expert review of the recent literature.

RESULTS

Cognitive factors, teamwork, and communication play a major role in managing pediatric difficult airway. Earlier studies evaluated videolaryngoscopes in a monolithic way yielding inconclusive results regarding their effectiveness. There are, however, substantial differences among videolaryngoscopes particularly angulated vs. nonangulated blades which have different learning and use characteristics. Each airway device has strengths and weaknesses, and combining these devices to leverage both strengths will likely yield success. In the pediatric intensive care unit, emergency department and neonatal intensive care units, adverse tracheal intubation-associated events and hypoxemia are commonly reported. Specific patient, clinician, and practice factors are associated with these occurrences. In both the operating room and other clinical areas, use of passive oxygenation will provide additional laryngoscopy time. The use of neuromuscular blockade was thought to be contraindicated in difficult airway patients. Newer evidence from observational studies showed that controlled ventilation with or without neuromuscular blockade is associated with fewer adverse events in the operating room. Similarly, a multicenter neonatal intensive care unit study showed fewer adverse events in infants who received neuromuscular blockade. Neuromuscular blockade should be avoided in patients with mucopolysaccharidosis, head and neck radiation, airway masses, and external airway compression for anticipated worsening airway collapse with neuromuscular blocker administration.

CONCLUSION

Clinicians caring for children with difficult airways should consider new cognitive paradigms and concepts, leverage the strengths of multiple devices, and consider the role of alternate anesthetic approaches such as controlled ventilation and use of neuromuscular blocking drugs in select situations. Anesthesiologists can partner with intensive care and emergency department and neonatology clinicians to improve the safety of airway management in all clinical settings.

Compared Efficacy of Four Preoxygenation Methods for Intubation in the ICU: Retrospective Analysis of McGrath Mac Videolaryngoscope Versus Macintosh Laryngoscope (MACMAN) Trial Data

OBJECTIVES

Severe hypoxemia is the most common serious adverse event during endotracheal intubation. Preoxygenation is performed routinely as a preventive measure. The relative efficacy of the various available preoxygenation devices is unclear. Here, our objective was to assess associations between preoxygenation devices and pulse oximetry values during endotracheal intubation.

DESIGN

Post hoc analysis of data from a multicenter randomized controlled superiority trial (McGrath Mac Videolaryngoscope Versus Macintosh Laryngoscope [MACMAN]) comparing videolaryngoscopy to Macintosh laryngoscopy for endotracheal intubation in critical care.

SETTING

Seven French ICUs.

PATIENTS

Three-hundred nineteen of the 371 critically ill adults requiring endotracheal intubation who were included in the MACMAN trial.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Minimal pulse oximetry value during endotracheal intubation was the primary endpoint. We also sought risk factors for pulse oximetry below 90%. Of 319 patients, 157 (49%) had bag-valve-mask, 71 (22%) noninvasive ventilation, 71 (22%) non-rebreathing mask, and 20 (7%) high-flow nasal oxygen for preoxygenation. Factors independently associated with minimal pulse oximetry value were the Simplified Acute Physiology Score II severity score (p = 0.03), baseline pulse oximetry (p < 0.001), baseline PaO2/FIO2 ratio (p = 0.02), and number of laryngoscopies (p = 0.001). The only independent predictors of pulse oximetry less than 90% were baseline pulse oximetry (odds ratio, 0.71; 95% CI, 0.64-0.79; p < 0.001) and preoxygenation device: with bag-valve-mask as the reference, odds ratios were 1.10 (95% CI, 0.25-4.92) with non-rebreathing mask, 0.10 (95% CI, 0.01-0.80) with noninvasive ventilation, and 5.75 (95% CI, 1.15-28.75) with high-flow nasal oxygen.

CONCLUSIONS

Our data suggest that the main determinants of hypoxemia during endotracheal intubation may be related to critical illness severity and to preexisting hypoxemia. The differences across preoxygenation methods suggest that noninvasive ventilation may deserve preference in patients with marked hypoxemia before endotracheal intubation. Ongoing studies will provide further clarification about the optimal preoxygenation method for endotracheal intubation in critically ill patients.

Critical Care Airway Management

Critical care airway management is associated with a variety of complications, including severe oxygen desaturation, life-threatening hypotension, and death. This article reviews aspects of airway management that are relevant to intensivists and emergency medicine clinicians tasked with improving the quality of urgent endotracheal intubation in the critically ill patient.

Risk Factors for and Prediction of Hypoxemia during Tracheal Intubation of Critically Ill Adults

RATIONALE

Hypoxemia is a common complication during tracheal intubation of critically ill adults and is a frequently used endpoint in airway management research. Identifying patients likely to experience low oxygen saturations during tracheal intubation may be useful for clinical practice and clinical trials.

OBJECTIVES

To identify risk factors for lower oxygen saturations and severe hypoxemia during tracheal intubation of critically ill adults and develop prediction models for lowest oxygen saturation and hypoxemia.

METHODS

Using data on 433 intubations from two randomized trials, we developed linear and logistic regression models to identify preprocedural risk factors for lower arterial oxygen saturations and severe hypoxemia between induction and 2 minutes after intubation. Penalized regression was used to develop prediction models for lowest oxygen saturation after induction and severe hypoxemia. A simplified six-point score was derived to predict severe hypoxemia.

RESULTS

Among the 433 intubations, 426 had complete data and were included in the model. The mean (standard deviation) lowest oxygen saturation was 88% (14%); median (interquartile range) was 93% (83-98%). Independent predictors of severe hypoxemia included hypoxemic respiratory failure as the indication for intubation (odds ratio [OR], 2.70; 95% confidence interval [CI], 1.58-4.60), lower oxygen saturation at induction (OR, 0.92 per 1% increase; 95% CI, 0.89-0.96 per 1% increase), younger age (OR, 0.97 per 1-year increase; 95% CI, 0.95-0.99 per 1-year increase), higher body mass index (OR, 1.03 per 1 kg/m2; 95% CI, 1.00-1.06 per 1 kg/m2), race (OR, 4.58 for white vs. black; 95% CI, 1.97-10.67; OR, 4.47 for other vs. black; 95% CI, 1.19-16.84), and operator with fewer than 100 prior intubations (OR, 2.83; 95% CI, 1.37-5.85). A six-point score using the identified risk factors predicted severe hypoxemia with an area under the receiver operating curve of 0.714 (95% CI, 0.653 to 0.778).

CONCLUSIONS

Lowest oxygen saturation and severe hypoxemia during tracheal intubation in the intensive care unit can be accurately predicted using routinely available preprocedure clinical data, with saturation at induction and hypoxemic respiratory failure being the strongest predictors. A simple bedside score may identify patients at risk for hypoxemia during intubation to help target preventative interventions and facilitate enrichment in clinical trials.

Difficult tracheal intubation in critically ill

Background

Endotracheal intubation in critically ill is a high-risk procedure requiring significant expertise in airway handling as well as understanding of pathophysiology of the disease process.

Main body

Critically ill patients are prone for hypotension and hypoxemia in the immediate post-intubation phase due to blunting of compensatory sympathetic response. Preoxygenation without NIV is frequently suboptimal, as alveolar flooding cause loss of alveolar capillary interface in many of these patients. All these factors, along with relative fluid deficit, neuromuscular fatigue and coexistent organ dysfunction lead to physiologically difficult airway. Airway in ICU can be classified as anatomically difficult, physiologically difficult and anatomically as well as physiologically difficult. Though rapid sequence intubation is the recommended method for securing airway in these patients, other methods like delayed sequence intubation awake intubation and double setup approach can be used in specific subgroups. Further research is needed in this field to set guidelines and fine tune airway management for patients with specific organ failure or dysfunction.

Conclusion

Airway in ICU should be managed according to the physiological as well as the anatomical abnormalities.

Guidelines for the management of tracheal intubation in critically ill adults

These guidelines describe a comprehensive strategy to optimize oxygenation, airway management, and tracheal intubation in critically ill patients, in all hospital locations. They are a direct response to the 4^th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, which highlighted deficient management of these extremely vulnerable patients leading to major complications and avoidable deaths. They are founded on robust evidence where available, supplemented by expert consensus opinion where it is not. These guidelines recognize that improved outcomes of emergency airway management require closer attention to human factors, rather than simply introduction of new devices or improved technical proficiency. They stress the role of the airway team, a shared mental model, planning, and communication throughout airway management. The primacy of oxygenation including pre- and peroxygenation is emphasized. A modified rapid sequence approach is recommended. Optimal management is presented in an algorithm that combines Plans B and C, incorporating elements of the Vortex approach. To avoid delays and task fixation, the importance of limiting procedural attempts, promptly recognizing failure, and transitioning to the next algorithm step are emphasized. The guidelines recommend early use of a videolaryngoscope, with a screen visible to all, and second generation supraglottic airways for airway rescue. Recommendations for emergency front of neck airway are for a scalpel-bougie-tube technique while acknowledging the value of other techniques performed by trained experts. As most critical care airway catastrophes occur after intubation, from dislodged or blocked tubes, essential methods to avoid these complications are also emphasized.

Emergency Department use of Apneic Oxygenation Versus Usual Care During Rapid Sequence Intubation: A Randomized Controlled Trial (The ENDAO Trial)

OBJECTIVES

Desaturation leading to hypoxemia may occur during rapid sequence intubation (RSI). Apneic oxygenation (AO) was developed to prevent the occurrence of oxygen desaturation during the apnea period. The purpose of this study was to determine if the application of AO increases the average lowest oxygen saturation during RSI when compared to usual care (UC) in the emergency setting.

METHODS

A randomized controlled trial was conducted at an academic, urban, Level I trauma center. All patients requiring intubation were included. Exclusion criteria were patients in cardiac or traumatic arrest or if preoxygenation was not performed. An observer, blinded to study outcomes and who was not involved in the procedure, recorded all times, while all saturations were recorded in real time by monitors on a secured server. Two-hundred patients were allocated to receive AO (n = 100) or UC (n = 100) by predetermined randomization in a 1:1 ratio.

RESULTS

A total of 206 patients were enrolled. There was no difference in lowest mean oxygen saturation between the two groups (92, 95% confidence interval [CI] = 91 to 93 in AO vs. 93, 95% CI = 92 to 94 in UC; p = 0.11).

CONCLUSION

There was no difference in lowest mean oxygen saturation between the two groups. The application of AO during RSI did not prevent desaturation of patients in this study population.

Improved Oxygenation After Transport in Patients With Hypoxemic Respiratory Failure

OBJECTIVE

The purpose of this study is to measure the rate and magnitude of changes in oxygenation that occur in patients with hypoxemic respiratory failure after transport by a critical care transport team.

METHODS

We performed a retrospective review of 239 transports of patients with hypoxemic respiratory failure requiring a fraction of inspired oxygen (Fio2) > 50% transported from October 2009 to December 2012 from referring hospitals to 3 tertiary care hospitals. We analyzed the change the ratio of the partial pressure of oxygen in the blood to FiO2 from the sending to the receiving hospital as well as the percentage saturation of oxygen (Spo2) before, after, and en route.

RESULTS

The mean change in the Pao2/Fio2 ratio from the sending to the receiving hospital was an increase of 27.62 (95% confidence interval [CI], 15.84-39.40; P = .0003). The mean change in Pao2 was an increase of 27.85 mm Hg (CI, 17.49-38.22; P < .0001). The mean Spo2 was not significantly changed at -0.12 (CI, - 1.69 to 1.45, P = .9). Despite improvement in the Pao2/Fio2 ratio and a stable Spo2 on arrival, 28.1% of patients desaturated to Spo2 < 90% in transport.

CONCLUSION

In patients with hypoxemic respiratory failure, Pao2/Fio2 and Pao2 increased after transport by a critical care transport team despite 28.1% of patients desaturating with hypoxemia in transit.

Apneic oxygenation is associated with a reduction in the incidence of hypoxemia during the RSI of patients with intracranial hemorrhage in the emergency department

Critically ill patients undergoing emergent intubation are at risk of oxygen desaturation during the management of their airway. Patients with intracranial hemorrhage (ICH) are particularly susceptible to the detrimental effects of hypoxemia. Apneic oxygenation (AP OX) may be able to reduce the occurrence of oxygen desaturation during the emergent intubation of these patients. We sought to assess the effect AP OX on oxygen desaturation during the rapid sequence intubation (RSI) of patients with ICH in the emergency department (ED). We prospectively collected data on all patients intubated in an urban academic ED over the 2-year period from July 1, 2013 to June 30, 2015. Following each intubation, the operator completed a standardized continuous quality improvement (CQI) data form, which included information on patient, operator and intubation characteristics. Operators recorded data on the use of AP OX, the oxygen flow rate used for AP OX, and the starting and lowest saturations during intubation. Adult patients with ICH who underwent RSI by emergency medicine (EM) residents were included in the analyses. The primary outcome variable was any oxygen saturation <90 % during the intubation. We performed a backward stepwise multivariate logistic regression analysis to identify variables associated with oxygen desaturation. The primary independent variable of interest was the use of AP OX during the intubation. Inclusion criteria for the study was met by 127 patients. AP OX was used in 72 patients (AP OX group) and was not used in 55 patients (NO AP OX group). The incidence of desaturation was 5/72 (7 %) in the AP OX group and was 16/55 (29 %) in the NO AP OX group. In the multivariate logistic regression analysis the use of AP OX was associated with a reduced odds of desaturation (aOR 0.13; 95 % CI 0.03-0.53). Patients with ICH who received AP OX during RSI in the ED were seven times less likely to have an oxygen saturation of <90 % during the intubation compared to patients who did not receive AP OX. AP OX is a simple intervention that may minimize the risk of oxygen desaturation during the RSI of patients with ICH.

Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill

RATIONALE

Hypoxemia is common during endotracheal intubation of critically ill patients and may predispose to cardiac arrest and death. Administration of supplemental oxygen during laryngoscopy (apneic oxygenation) may prevent hypoxemia.

OBJECTIVES

To determine if apneic oxygenation increases the lowest arterial oxygen saturation experienced by patients undergoing endotracheal intubation in the intensive care unit.

METHODS

This was a randomized, open-label, pragmatic trial in which 150 adults undergoing endotracheal intubation in a medical intensive care unit were randomized to receive 15 L/min of 100% oxygen via high-flow nasal cannula during laryngoscopy (apneic oxygenation) or no supplemental oxygen during laryngoscopy (usual care). The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after completion of endotracheal intubation.

MEASUREMENTS AND MAIN RESULTS

Median lowest arterial oxygen saturation was 92% with apneic oxygenation versus 90% with usual care (95% confidence interval for the difference, -1.6 to 7.4%; P = 0.16). There was no difference between apneic oxygenation and usual care in incidence of oxygen saturation less than 90% (44.7 vs. 47.2%; P = 0.87), oxygen saturation less than 80% (15.8 vs. 25.0%; P = 0.22), or decrease in oxygen saturation greater than 3% (53.9 vs. 55.6%; P = 0.87). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality were similar between study groups.

CONCLUSIONS

Apneic oxygenation does not seem to increase lowest arterial oxygen saturation during endotracheal intubation of critically ill patients compared with usual care. These findings do not support routine use of apneic oxygenation during endotracheal intubation of critically ill adults. Clinical trial registered with www.clinicaltrials.gov (NCT 02051816).

Acute respiratory compromise on inpatient wards in the United States: Incidence, outcomes, and factors associated with in-hospital mortality

AIM

To estimate the United States' incidence and in-hospital mortality of acute respiratory events on inpatient wards and to identify factors associated with mortality.

METHODS

This is an analysis of prospectively collected data from the Get With the Guidelines(®) - Resuscitation registry. We included adult patients with index acute respiratory events on inpatient wards from January 2005 to December 2013. A negative binomial regression model was used to estimate the 2012 United States incidence and a multivariable logistic regression model was used to examine time trends and characteristics associated with in-hospital mortality.

RESULTS

There were 13,086 index events from 320 hospitals included in the analysis. Using 2012 data, the estimated number of events in the United States was 44,551 (95%CI: 25,170-95,371). The in-hospital mortality for the entire cohort was 39.4% (95%CI: 38.5, 40.2) and rose to 82.6% (95%CI: 79.9, 85.2) for events leading to cardiac arrest. There was a decrease in in-hospital mortality over time (48.3% in 2005 to 34.5% in 2013, p<0.001). Characteristics associated with mortality included agonal breathing, hypotension and septicemia.

CONCLUSIONS

Acute respiratory events on inpatient wards in the US is common with an associated in-hospital mortality of approximately 40% that has been decreasing over the past decade. Multiple factors were associated with in-hospital mortality.

The utility of noninvasive nasal positive pressure ventilators for optimizing oxygenation during rapid sequence intubation

OBJECTIVES

The objective of the study is to investigate the feasibility of noninvasive nasal positive pressure ventilation (NINPPV) for optimizing oxygenation during the rapid sequence intubation in critically ill patients.

METHODS

A prospective, observational study was performed in an emergency department. Noninvasive nasal positive pressure ventilation was applied in the preoxygenation step and maintained until successful intubation. A pulse oximetry (Spo2) was continuously monitored throughout the procedure and recorded 5 times. The degree of interfering was surveyed with 10-point Likert scale.

RESULTS

Thirty patients were enrolled. The most of enrolled patients were diagnosed as pneumonia, acute heart failure, and traumatic brain injury. The Spo2 was increased to 100% (98%-100%) at the time of starting endotracheal intubation with NINPPV and maintained as 97% (95%-100%) until successful intubation (P< .001). Total apnea duration was 195 seconds (190-196). The degree of interfering intubation was 1 (0-1).

CONCLUSIONS

Noninvasive nasal positive pressure ventilation would be useful for optimizing oxygenation during rapid sequence intubation.

Mortality and Resource Utilization After Critical Care Transport of Patients With Hypoxemic Respiratory Failure

INTRODUCTION

We performed this study to quantify resources required by mechanically ventilated patients with hypoxemia after critical care transport (CCT) and to assess short-term clinical outcomes.

METHODS

We performed a retrospective review of transports of patients with severe hypoxemic respiratory failure from referring hospitals to 3 tertiary care hospitals to assess the outcomes including in-hospital mortality, ventilator days, intensive care unit length of stay (LOS), hospital LOS, disposition, and reported neurologic status on hospital discharge as well as medical interventions specific to acute respiratory failure and critical care.

RESULTS

Of 230 patients transported with hypoxemic respiratory failure, 152 survived to hospital discharge, for a mortality rate of 34.5%, despite a predicted mortality of 64% by Acute Physiology and Chronic Health Evaluation II (APACHE II) score. Twenty-five percent of patients were treated with neuromuscular blockade, 10.1% received inhaled pulmonary vasodilators, and extracorporeal membrane oxygenation was initiated in 2.6%.

CONCLUSIONS

In this cohort with hypoxemic respiratory failure transported to tertiary care facilities, patients had a mortality rate comparable to patients with acute respiratory distress syndrome treated with best practices and a mortality rate lower than predicted based on APACHE-II score. The risks of CCT are outweighed by the benefits of transfer to a tertiary care facility, and pretransport hypoxemia should not be used as an absolute contraindication to transport.

Airway and ventilator management in trauma patients

PURPOSE OF REVIEW

Securing the airway to provide sufficient oxygenation and ventilation is of paramount importance in the management of all types of emergency patients. Particularly in severely injured patients, strategies should be adapted according to useful recent literature findings.

RECENT FINDINGS

The role of out-of-hospital endotracheal intubation in patients with severe traumatic brain injury as prevention of hypoxia still persists, and the ideal neuromuscular blocking agent will be a target of research. Standardized monitoring, including capnography and the use of standardized medication protocols without etomidate, can reduce further complications. Prophylactic noninvasive ventilation may be useful for patients with blunt chest trauma without respiratory insufficiency.

SUMMARY

An algorithm-based approach to airway management can prevent complications due to inadequate oxygenation or procedural difficulties in trauma patients; therefore, advanced equipment for handling a difficult airway is needed. After securing the airway, ventilation must be monitored by capnography, and normoventilation involving the early use of protective ventilation with low-tidal volume and moderate positive end-expiratory pressure must be the target. After early identification of patients with blunt chest trauma at risk for respiratory failure, noninvasive ventilation might be a treatment strategy, which should be evaluated in future research.

High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial

PURPOSE

Intubation of hypoxemic patients is associated with life-threatening adverse events. High-flow therapy by nasal cannula (HFNC) for preoxygenation before intubation has never been assessed by randomized study. Our objective was to evaluate the efficiency of HFNC for preoxygenation, compared to high fraction-inspired oxygen facial mask (HFFM).

METHODS

Multicenter, randomized, open-labelled, controlled PREOXYFLOW trial (NCT 01747109) in six French intensive care units. Acute hypoxemic adults requiring intubation were randomly allocated to HFNC or HFFM. Patients were eligible if PaO2/FiO2 ratio was below 300 mmHg, respiratory rate at least 30/min and if they required FiO2 50% or more to obtain at least 90% oxygen saturation. HFNC was maintained throughout the procedure, whereas HFFM was removed at the end of general anaesthesia induction. Primary outcome was the lowest saturation throughout intubation procedure. Secondary outcomes included adverse events related to intubation, duration of mechanical ventilation and death.

RESULTS

A total of 124 patients were randomized. In the intent-to-treat analysis, including 119 patients (HFNC n = 62; HFFM n = 57), the median (interquartile range) lowest saturation was 91.5% (80-96) for HFNC and 89.5% (81-95) for the HFFM group (p = 0.44). There was no difference for difficult intubation (p = 0.18), intubation difficulty scale, ventilation-free days (p = 0.09), intubation-related adverse events including desaturation <80% or mortality (p = 0.46).

CONCLUSIONS

Compared to HFFM, HFNC as a preoxygenation device did not reduce the lowest level of desaturation.

How to preoxygenate in operative room: healthy subjects and situations "at risk"

Intubation is one of the most common procedures performed in operative rooms. It can be associated with life-threatening complications when difficult airway access occurs, in patients who cannot tolerate even a slight hypoxemia or when performed in patients at risk of oxygen desaturation during intubation, as obese, critically-ill and pregnant patients. To improve intubation safety, preoxygenation is a major technique, extending the duration of safe apnoea, defined as the time until a patient reaches an arterial saturation level of 88% to 90%, to allow for placement of a definitive airway. Preoxygenation consists in increasing the lung stores of oxygen, located in the functional residual capacity, and helps preventing hypoxia that may occur during intubation attempts. Obese, critically-ill and pregnant patients are especially at risk of reduced effectiveness of preoxygenation because of pathophysiological modifications (reduced functional residual capacity (FRC), increased risk of atelectasis, shunt). Three minutes tidal volume breathing or 3-8 vital capacities are recommended in general population, mostly allowing achieving a 90% end-tidal oxygen level. Recent studies have indicated that in order to maximize the value of preoxygenation (i.e, oxygenation stores) obese and critically-ill patients can benefit from the combination of breathing 100% oxygen and non-invasive positive pressure ventilation (NIV) with end-expiratory positive pressure (PEEP) in the proclive position (Trendelenburg reverse). Recruitment manoeuvres may be of interest immediately after intubation to limit the risk of lung derecruitment. Further studies are needed in the field of preoxygenation in pregnant women.

Does medical emergency team intervention reduce the prevalence of emergency endotracheal intubation complications?

PURPOSE

Emergency endotracheal intubation (EEI) is a complex process that leads to various complications. Previous studies mainly demonstrated that the Medical Emergency Team (MET) intervention reduced the incidence of cardiac arrest, however, the impact of a MET on airway management has not been investigated in detail. Our purpose was to confirm the impact of a MET on airway management and compare the incidence of complications of EEI before and after MET intervention in a general ward.

MATERIALS AND METHODS

We performed an observational study and reviewed 318 patients intubated by a MET in a general ward.

RESULTS

The patients enrolled during the control (2007) and study (2009) periods were 103 and 215, respectively. Cardiopulmonary resuscitation requiring emergency intubation in a general ward was reduced after MET intervention at the Asan Medical Center (39.8% vs. 19.1%, p<0.001). Pre-intubation and post-intubation oxygen saturation levels were higher after MET intervention (pre-intubation, 80% before vs. 92% after MET, p<0.001; post-intubation, 95% before vs. 99% after MET, p<0.001). The use of vasopressors after intubation decreased as a result of MET intervention (62.1% before vs. 36.7% after MET, p<0.001). Hypotension was also reduced (34% before vs. 8.8% after MET, p<0.001).

CONCLUSION

Early interventions of a MET changed the causes of emergency intubation in a general ward from cardiopulmonary resuscitation to respiratory distress or shock and improved hypoxemia and hypotension related to emergency intubation. The MET intervention is safe and effective system for emergency intubation in a general ward.

Techniques for the difficult airway

PURPOSE OF REVIEW

Management of the difficult airway is associated with significant morbidity and mortality in critically ill patients. An increasing array of advanced airway tools are available, but appropriate selection and application in the ICU remains poorly defined.

RECENT FINDINGS

Difficult airway incidence during emergent intubation is 10%, but complications of ICU airway management remain common. Training and equipment in many ICUs remain variable despite data that demonstrate that an 'intubation management bundle' and a systematic approach to teamwork and training can reduce life-threatening airway complications. A protocol employing an extraglottic airway (EGA) early in cases of inadequate ventilation has been associated with no episodes of prolonged hypoxemia in 12 225 consecutive intubations. Direct laryngoscopy with gum elastic bougie is the most commonly employed method to manage emergent difficult airways, and videolaryngoscopes also provide greater glottic visualization and a high rate of intubation success in patients with difficult airway risk factors or a failed airway.

SUMMARY

A systematic approach to intubation that emphasizes planning and teamwork can reduce intubation complications. Early use of an EGA or cricothyroidotomy may reduce complications when oxygenation is inadequate. Use of a gum elastic bougie or indirect optical device is also associated with a high rate of intubation success when oxygenation permits.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate  < 6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)  < 90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)  < 9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)  < 90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate  > 29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices need to be available preclinical and a fiber-optic endoscope should be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful endotracheal intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate <6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)<90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)<9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)<90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate >29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation and oxygenation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices and a fiber-optic endoscope need to be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

A program to improve the quality of emergency endotracheal intubation

OBJECTIVE

To assess the results of a quality improvement (QI) project designed to improve safety of emergency endotracheal intubation (EEI).

DESIGN

Single center prospective observational.

SETTING

16-bed intensive care unit.

PARTICIPANTS

Nine pulmonary/critical care fellows.

INTERVENTIONS

For 3 years, EEI performed by the medical intensive care unit team were analyzed to identify interventions that would improve quality of the procedure. By segmental process analysis, the procedure of EEI was subjected to iterative change. Major components of process improvement were development of a combined team approach, a mandatory checklist, use of crew resource management (CRM) tactics, and postevent debriefing. Quality analysis and improvement included training of fellows using scenario-based training (SBT) with computerized patient simulator (CPS) to improve mechanical skills of intubation and team leadership. Fellows received 15 sessions of SBT with CPS using a combined checklist and team approach before assuming team leadership position during real-life EEI.

MEASUREMENTS

For a 10-month period, fellows carried digital voice recorders to EEI; which, when combined with recording of continuous oximetry and BP monitoring were used to assess the quality of EEI.

MAIN RESULTS

128 EEI were performed of which 101 had full data recorded. Complications were 14% severe hypoxemia (<80% saturation), 6% severe hypotension (SBP<70 mm Hg), 1% death, 20% difficult EEI (≥ 3 attempts), 11% esophageal intubations, 2% aspiration, and 1% dental injury; 62% EEI were successfully achieved on first attempt, 11% required >3 attempts.

CONCLUSIONS

EEI may be performed by pulmonary/critical medicine (PCCM) fellows with safety comparable to that described in other studies on EEI. Important parts of the program included the use of formal iterative QI approach, the use of intensive SBT with CPS, basic CRM, a comprehensive checklist, and a combined team approach. A key benefit of the program was to make the process of EEI fully transparent for ongoing quality and safety improvement.