[Effectiveness of preoxygenation using the head-up position and noninvasive ventilation to reduce hypoxaemia during intubation]

Pilot Study Examining Bed Angles and Heights During Ramped Position Intubation in the Emergency Department

INTRODUCTION

Ramped positioning during emergent endotracheal intubation has been associated with fewer peri-intubation complications, including a decrease in difficult intubations, esophageal intubations, pulmonary aspiration, and hypoxemia. However, the optimal bed angle and height for ramped position intubation have not been determined. Our objective was to examine the effect bed angle and height in the ramped position may have on laryngeal views during emergent intubation in the emergency department (ED).

MATERIALS AND METHODS

We performed a secondary analysis of prospectively collected quality improvement data on intubations from our ED. All adult medical intubations performed with ramped positioning in the ED over a 24-month study period (September 1, 2020, through August 30, 2022) were eligible. We compared laryngeal views using the percentage of glottic opening (POGO) score between ramp angles (≥30° and <30° from horizontal) and bed heights (relative to the intubator, including xiphoid or above, umbilicus or below, and between xiphoid and umbilicus).

RESULTS

Of the 251 patients intubated during the study period, 201 were intubated in the supine position and 50 in the ramped position. Data forms were completed for 25 patients intubated using ramped position in the ED during the study period. The median ramp angle was 30° (interquartile range (IQR) 25, 40) with 16 (64%) subjects intubated at ≥30° and 9 (36%) subjects at <30°. The median POGO scores for bed angles ≥30° and <30° were 95% (IQR 79, 100) and 90% (IQR 75, 100), respectively. Bed heights varied, with four (16%) intubated at the xiphoid or above height, one (4%) at the umbilicus or below, and 20 (80%) between the xiphoid and umbilicus. The median POGO scores at each position were 95% (IQR 76, 100), 0% (IQR 0, 0), and 95% (IQR 79, 100), respectively.

CONCLUSION

ED clinicians use a variety of bed angles and heights when intubating in the ramped position. More robust investigations are necessary to determine the optimal bed angle and height for ramped position intubation in the ED.

Comparing postinduction hypoxemia between ramped and supine position endotracheal intubations with apneic oxygenation in the emergency department

INTRODUCTION

Ramped position and apneic oxygenation are strategies to mitigate hypoxemia; however, the benefits of these strategies when utilized together remain unclear. Therefore, we compared first-attempt, postinduction hypoxemia between adult emergency department (ED) endotracheal intubations performed with apneic oxygenation in the ramped versus supine positions.

METHODS

We used the National Emergency Airway Registry (NEAR), a multicenter registry of data on ED intubations from 25 academic and community sites. We included first-attempt intubations with direct (DL) and video (VL) laryngoscopy in subjects ≥ 18 years old with nontrauma indications receiving apneic oxygenation. We examined patient characteristics (e.g., sex, obesity) and key intubation outcomes, including hypoxemia (primary outcome), first-pass success, and other adverse events (e.g., bradycardia). In addition, we examined unadjusted odds ratios (OR) and adjusted ORs (aOR) for key variables and stratified by laryngoscope type.

RESULTS

We included 210 ramped cases and 1,820 supine cases in the DL cohort and 202 ramped and 1,626 supine cases in the VL cohort. Rates of postinduction hypoxemia were similar between supine and ramped position in both the DL cohort (supine 6.5% and ramped 7.6%, aOR [95% CI] = 0.96 [0.55 to 1.67]) and the VL cohort (supine 10.1% and ramped 12.4%, aOR [95% CI] = 0.97 [0.60 to 1.56]). Other outcomes were also similar between groups.

CONCLUSION

Using this large national data set, we did not identify a difference in postinduction hypoxemia between ramped and supine positions in this cohort of ED intubations with apneic oxygenation.

Impact of bed angle and height on intubation success during simulated endotracheal intubation in the ramped position

OBJECTIVE

The ramped position is often used during endotracheal intubation to improve oxygenation, improve laryngeal views, and reduce airway complications. We sought to compare the impact of ramp angle and bed height on intubation outcomes during simulated endotracheal intubation.

METHODS

We enrolled emergency medicine residents and fourth-year medical students to perform simulated direct laryngoscopy and endotracheal intubation in random order with the mannequin in the following combinations of ramp angles and bed heights; ramp angles of 25° and 45° at bed heights including knee, mid-thigh, umbilicus, xiphoid, and nipple/intermammary fold. Our primary outcome was the reported percentage of glottic opening (POGO) score. Secondary outcomes included number of laryngoscopy attempts and intubation time.

RESULTS

We enrolled 25 participants. There was no difference in reported POGO scores at 25° between bed heights, but at 45°, the umbilicus bed height had an improved reported POGO score (20; 95% confidence interval [CI] 7-33, P < 0.01) relative to xyphoid. The nipple/inframammary fold height required longer intubation times in seconds (mean difference [MD] 95% CI) at 25°, (MD, 23.9 [4.6-37.6], P < 0.01) and more laryngoscopy attempts at 45° (MD, 0.48 [0.16-0.79], P < 0.01) relative to xyphoid. There was no difference in laryngoscopy attempts and video POGO between 25° and 45° at all bed heights, but reported POGO at the umbilicus position was better at 25° than 45° (12 [1-23], P = 0.03).

CONCLUSION

The umbilicus bed height resulted in the highest reported POGO at 45°. Nipple/inframammary fold height resulted in worse intubating conditions.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Implementation of a Clinical Bundle to Reduce Out-of-Hospital Peri-intubation Hypoxia

STUDY OBJECTIVE

Peri-intubation hypoxia is an important adverse event of out-of-hospital rapid sequence intubation. The aim of this project is to determine whether a clinical bundle encompassing positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation is associated with decreased peri-intubation hypoxia compared with standard out-of-hospital rapid sequence intubation.

METHODS

We conducted a retrospective, before-after study using data from a suburban emergency medical services (EMS) system in central Texas. The study population included all adults undergoing out-of-hospital intubation efforts, excluding those in cardiac arrest. The before-period intervention was standard rapid sequence intubation using apneic oxygenation at flush flow, ketamine, and a paralytic. The after-period intervention was a care bundle including patient positioning (elevated head, sniffing position), apneic oxygenation, delayed sequence intubation (administration of ketamine to facilitate patient relaxation and preoxygenation with a delayed administration of paralytics), and goal-directed preoxygenation. The primary outcome was the rate of peri-intubation hypoxia, defined as the percentage of patients with a saturation less than 90% during the intubation attempt.

RESULTS

The before group (October 2, 2013, to December 13, 2015) included 104 patients and the after group (August 8, 2015, to July 14, 2017) included 87 patients. The 2 groups were similar in regard to sex, age, weight, ethnicity, rate of trauma, initial oxygen saturation, rates of initial hypoxia, peri-intubation peak SpO₂, preintubation pulse rate and systolic blood pressure, peri-intubation cardiac arrest, and first-pass and overall success rates. Compared with the before group, the after group experienced less peri-intubation hypoxia (44.2% versus 3.5%; difference -40.7% [95% confidence interval -49.5% to -32.1%]) and higher peri-intubation nadir SpO₂ values (100% versus 93%; difference 5% [95% confidence interval 2% to 10%]).

CONCLUSION

In this single EMS system, a care bundle encompassing patient positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation was associated with lower rates of peri-intubation hypoxia than standard out-of-hospital rapid sequence intubation.

A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults

BACKGROUND

Hypoxemia is the most common complication during endotracheal intubation of critically ill adults. Intubation in the ramped position has been hypothesized to prevent hypoxemia by increasing functional residual capacity and decreasing the duration of intubation, but has never been studied outside of the operating room.

METHODS

Multicenter, randomized trial comparing the ramped position (head of the bed elevated to 25°) with the sniffing position (torso supine, neck flexed, and head extended) among 260 adults undergoing endotracheal intubation by pulmonary and critical care medicine fellows in four ICUs between July 22, 2015, and July 19, 2016. The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after intubation. Secondary outcomes included Cormack-Lehane grade of glottic view, difficulty of intubation, and number of laryngoscopy attempts.

RESULTS

The median lowest arterial oxygen saturation was 93% (interquartile range [IQR], 84%-99%) with the ramped position vs 92% (IQR, 79%-98%) with the sniffing position (P = .27). The ramped position appeared to increase the incidence of grade III or IV view (25.4% vs 11.5%, P = .01), increase the incidence of difficult intubation (12.3% vs 4.6%, P = .04), and decrease the rate of intubation on the first attempt (76.2% vs 85.4%, P = .02), respectively.

CONCLUSIONS

In this multicenter trial, the ramped position did not improve oxygenation during endotracheal intubation of critically ill adults compared with the sniffing position. The ramped position may worsen glottic view and increase the number of laryngoscopy attempts required for successful intubation.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT02497729; URL: www.clinicaltrials.gov.

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.

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.

Airway management: from pre-assessment to intubation. A student ODP's perspective

Airway management is a fundamental skill in the implementation and maintenance of a general anaesthetic. An anaesthetised patient does not have full control over their airway, and without management a partial obstruction or other more serious complication may occur (Griffiths 1999). There are many ways to reduce the risk of complications occurring in the anaesthetic process. These methods can be subdivided into two main categories: prior preparation (Chethan & Hughes 2008) and pre-assessment (Neacsu 2002).

[Inspiratory support versus spontaneous breathing during preoxygenation in healthy subjects. A randomized, double blind, cross-over trial]

OBJECTIVE

Applying an inspiratory support (AI) and a positive end expiratory pressure (PEP) could increase the effectiveness of the preoxygenation.

STUDY DESIGN

This randomized double blinded controlled study compares the impact on the expiratory oxygen fraction (FEO(2)) of two levels of AI with PEP to a traditional preoxygenation.

PATIENTS AND METHODS

Twenty healthy volunteers were studied. The criteria of exclusion were a body mass index >30, the presence of beard or moustache and the claustrophobia. Each subject went through three modes of preoxygenation during 3 minutes each in a random order: 1-spontaneous ventilation (VS), 2-preoxygenation with AI with 4 cmH(2)O/PEP 4 cmH(2)O (AI-4/PEP-4), 3-preoxygenation with AI with 6 cmH(2)O/PEP 4 cmH(2)O (AI-6/PEP-4). Subject's tolerance and leaks were also noted.

RESULTS

The FEO(2) at the end of the 3 minutes of preoxygenation was higher (p<0,001) with AI-4/PEP-4 (94+/-3%) and AI-6/PEP-4 (94+/-4%) than with technique VS (89+/-6%). One hundred percent and 90% of the participants reached one FEO(2)=90% with AI-4/PEP-4 and AI-6/PEP-4 respectively vs 65% with VS (p=0.0013). The participants tolerated better the VS and the AI-4/PEP-4 than the AI-6/PEP-4. More leaks were noted with the AI-6/PEP-4 than with the VS and the AI-4/PEP-4.

CONCLUSION

This study shows applying AI plus PEP during preoxygenation improves its effectiveness in the healthy subjects. It also suggests that, in a population of healthy volunteers, combination AI-4/PEP-4 is preferable to AI-6/PEP-4 because so effective, but better tolerated.

[Peri-operative atelectasis and alveolar recruitment manoeuvres]

Respiratory complications are a significant cause of post-operative morbidity and mortality. Peri-operative atelectasis, in particular, affects 90% of surgical patients and its effects can be prolonged, due to changes in respiratory mechanics, pulmonary circulation and hypoxaemia. Alveolar collapse is caused by certain predisposing factors, mainly by compression and absorption mechanisms. To prevent or treat these atelectasis several therapeutic strategies have been proposed, such as alveolar recruitment manoeuvres, which has become popular in the last few years. Its application in patients with alveolar collapse, but without a previous significant acute lung lesion, has some special features, therefore its use is not free of uncertainties and complications. This review describes the frequency, pathophysiology, importance and treatment of peri-operative atelectasis. Special attention is paid to treatment with recruitment manoeuvres, with the purpose of providing a basis for the their rational and appropriate use.

[Impact of sophrology on non-invasive ventilation tolerance in patients with acute respiratory failure]

OBJECTIVES

Non-invasive ventilation (NIV) in patients with acute respiratory failure (ARF) is subject to a large number of failures due to discomfort of the art, the feeling of difficulty breathing and pain. The purpose of this study was to evaluate the efficiency of sophrology to improve conditions for the realization of NIV in patients with ARF.

PATIENTS AND METHODS

In this prospective randomized and controlled study, consecutive patients with ARF were included. From the very first NIV session, they received either sophrology during the first 30 min of NIV (S group), or standard care by the same nurse during 30 min (T group). The hemodynamic and ventilatory data were recorded continuously; pain, respiratory difficulty and discomfort were measured with a numeric scale at the end of the session.

RESULTS

Thirty patients were included in the study, 27 have been analysed. Each patient received an average of four sessions NIV during the protocol. There was no significant difference between the two groups in terms of improvement in gas exchange. In contrast, there was a significant difference in terms of reduction of difficulty in breathing (-76%), discomfort (-60%) and decrease the pain (-40%) in the sophrology group (p<0.001). Respiratory rate, heart rate and systolic arterial blood pressure were decrease during NIV.

CONCLUSION

Sophrology constitutes aid for the achievement of the meetings of NIV in patients' IRA.