High-flow nasal cannula oxygen versus non-invasive ventilation in patients with acute hypoxaemic respiratory failure undergoing flexible bronchoscopy--a prospective randomised trial

The effectiveness of transnasal high flow nasal cannula in bronchoscopy under sedation: a systematic review and meta-analysis

Background

The objective of this study was to conduct a systematic review and meta-analysis of the clinical application effects of transnasal high flow nasal cannula compared to other conventional modalities for oxygen therapy devices in patients undergoing bronchoscopy.

Methods

A comprehensive literature search was conducted in multiple English databases, including PubMed, Web of Science, and Cochrane Library, to collect relevant studies on the application of high flow nasal cannula in patients undergoing bronchoscopy, and conducted a meta-analysis utilizing RevMan 5.4 software, following the predetermined inclusion and exclusion criteria.

Results

A total of 12 studies meeting the inclusion criteria were included, involving 1,631 patients (HFNC group: n = 811, other oxygen therapy group: n = 820). The meta-analysis results demonstrated that HFNC significantly reduced the incidence of hypoxemia and improved the minimum oxygen saturation compared to conventional oxygen therapy (RR = 0.27, 95% CI: 0.18-0.41, p < 0.00001; MD = 6.09, 95% CI: 3.73-8.45, p < 0.00001). Furthermore, HFNC showed statistically significant differences when compared to non-invasive ventilation in terms of hypoxemia incidence (RR = 3.52, 95% CI: 1.13-10.97, p = 0.03) and minimum oxygen saturation (MD = -1.97, 95% CI: -2.97--0.98, p < 0.0001). In addition, HFNC resulted in significantly shorter surgical time and higher PaO2 at the end of the procedure compared to conventional oxygen therapy (MD = 1.53, 95% CI: 0.66-2.40, p = 0.0006; MD = 15.52, 95% CI: 10.12-20.92, p < 0.00001). However, there were no statistically significant differences observed in PaCO2, EtCO2, and MAP at the end of the procedure (MD = 1.23, 95% CI: -0.74-3.20, p = 0.22; MD = -0.35, 95% CI: -3.77-3.06, p = 0.84; MD = -0.54, 95% CI: -2.44-1.36, p = 0.58).

Conclusion

When HFNC or NIV is utilized during the examination and treatment of bronchoscopy patients, both oxygenation modalities enhance oxygenation function and reduce the incidence of hypoxemia compared to conventional oxygen therapy. HFNC can be regarded as a viable alternative to NIV for specific high-risk patients undergoing bronchoscopy. It decreases the duration of bronchoscopy and improves the PaO2 levels at the end of the procedure, but does not significantly impact the PaCO2, EtCO2, and mean arterial pressure.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier 1414374462@qq.com.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

Is High-Flow Nasal Oxygenation a Game Changer in Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration?: A pilot study

Objectives

This study aimed to compare the high-flow nasal oxygen (HFNO) and supraglottic airway device (SAD) techniques in oncological patients undergoing endobronchial ultrasound (EBUS) and transbronchial needle aspiration (TBNA) to evaluate the efficacy of HFNO in them.

Methods

This pilot study was conducted at Sultan Qaboos Comprehensive Cancer Care and Research Centre, Muscat, Oman, from May 2022 to March 2023. Patients undergoing EBUS TBNA under moderate sedation were quasi-randomised into the HFNO and SAD groups. The episodes and duration of hypoxia and the lowest level of oxygen saturation were the primary outcomes measured.

Results

A total of 24 patients were included in the study (10 of them were in the HFNO group and 14 were in the SAD group), with an equal number of males and females. The duration of the procedure in both groups was similar (45 ± 20 and 44 ± 17 minutes in the HFNO and SAD groups, respectively). The mean lowest oxygen saturation in the HFNO group was 93.5 ± 4.5%, which was significantly higher than that of the SAD group (90 ± 3%; P <0.001). In both groups, maximum hypoxia occurred during the early phase of the procedure. However, the HFNO and SAD groups were similar in terms of the cumulative duration of hypotension (140 versus 95 seconds, respectively) and bradycardia (25 versus 40 seconds, respectively).

Conclusion

HFNO is a good alternative to SAD and could be used safely and efficiently in patients undergoing EBUS TBNA.

High-Flow Nasal Cannula Therapy as an Adjuvant Therapy for Respiratory Support during Endoscopic Techniques: A Narrative Review

High-flow nasal cannula (HFNC) is a respiratory support technique that delivers a controlled concentration of oxygen with high flow, heat, and humidity via the nasal pathway. As it has many physiological effects, its use has increased for a variety of clinical indications; however, there is limited guidance on using HFNC as a respiratory support tool during endoscopic procedures. We conducted a narrative review to evaluate the effect of HFNC as an adjuvant tool during fiberoptic bronchoscopy (FOB), upper gastrointestinal tract endoscopy, and surgical procedures in adults. A search of the PubMed and Cochrane databases were performed. Approximately 384 publications were retrieved, and 99 were selected (93 original works and 6 case reports with a literature review). In patients who underwent FOB, HFNC appears to be superior to conventional oxygen therapy (COT) in preventing hypoxaemia. In contrast, for gastrointestinal endoscopy, the current evidence is insufficient to recommend HFNC over COT in a cost-effective manner. Finally, in surgical procedures such as laryngeal microsurgery or thoracic surgery, HFNC has been shown to be a safe and effective alternative to orotracheal intubation. As the results are heterogeneous, we advocate for the need for more quality studies to understand the effectiveness of HFNC during endoscopic procedures.

The use of non-invasive respiratory assistance to facilitate bronchofiberoscopy performance in patients with hypoxemic (type one) respiratory failure - Study protocol

PURPOSE

Bronchofiberoscopy (FOB) is a procedure routinely performed for: lung cancer, obstruction, interstitial diseases, foreign bodies' removal, airway clearance, and hemoptysis. It causes acute airway narrowing leading to respiratory and cardiovascular stress. Due to increasing number of ill patients with respiratory failure (RF), conventional oxygen therapy (COT) is frequently insufficient to assure accurate oxygenation and prevent RF in patients requiring FOB. In this clinical scenario, patients may be intubated and supported with invasive mechanical ventilation (IMV) with the specific aim of allowing a safe FOB. However, this invasive strategy is associated with an increased risk of IMV-associated complications.

MATERIALS AND METHODS

Our study is a planned prospective multicenter three-arm randomized controlled trial (RCT). The target number of 300 patients was calculated based on the intubation risk in RF patients, which is 0.2-2%. The patients will be assigned to each arm based on Horowitz index. In each arm, the patients will be randomly assigned to one out of two dedicated respiratory support methods in each group i.e. COT/high flow nasal cannula (HFNC), HFNC/non-invasive ventilation (NIV) and NIV/IMV. In the manuscript the current state of art in the area of respiratory support is discussed. We have underlined knowledge gaps in medical evidence which we are planning to reveal with our results.

RESULTS

The results of our study are clinically crucial, because they address current gaps concerning COT/HFNC/NIV/IMV.

CONCLUSION

The expected findings of this study would allow for careful selection of respiratory support method to safely perform FOB in patients with hypoxemic RF.

Application of high-flow nasal cannula in fibreoptic bronchoscopy after congenital heart surgery: a retrospective cohort study

BACKGROUND

The purpose of this study was to compare the effectiveness and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in fibreoptic bronchoscopy (FB) after congenital heart surgery (CHS) in children.

METHODS

We did a retrospective cohort study using patients from the electronic medical record system of Fujian Children's Hospital in China. The study population was children who underwent FB in the cardiac intensive care unit after CHS for 1 year (May 2021-May 2022). Children were classified into HFNC and COT groups according to their oxygen therapy during FB. The primary outcome was oxygenation indices during FB, including pulse oximeter oxygen saturation (SpO2) and transcutaneous oxygen tension (TcPO2) during FB. Secondary outcomes were the number of interruptions during FB and their causes, and complications after FB.

RESULTS

We identified 107 children from the electronic medical record system, and 102 children after CHS were finally included in the study (53 in the HFNC group and 49 in the COT group). During the FB examination, TcPO2 and SpO2 were significantly higher in the HFNC group than in the COT group (TcPO2: 90.3±9.3 vs 80.6±11.1 mm Hg; SpO2: 95.6±2.5 vs 92.1%±2.0%, p<0.001) and the transcutaneous carbon dioxide tension was significantly lower than in the COT group (39.6±3.0 vs 43.5±3.9 mm Hg, p<0.001). During the FB, a total of 20 children in the COT group had 24 interruptions, and 8 children in the HFNC group had 9 interruptions (p=0.001). In terms of postoperative complications, eight cases had complications in the COT group and four complications in the HFNC group (p=0.223).

CONCLUSIONS

Among children undergoing FB after CHS, the application of HFNC was associated with better oxygenation and fewer procedural interruptions compared with COT, without an increased risk of postoperative complications.

Flexible Fiberoptic Bronchoscopy in Non-ventilated Children in Pediatric Intensive Care Unit: Utility, Interventions and Safety

Objective

To study the utility of flexible fiberoptic bronchoscopy (FFB), and its effects on oxygenation and hemodynamics in children while on respiratory assist devices.

Materials and methods

The data of non-ventilated patients who underwent FFB during their stay in the PICU from January 2012 to December 2019 was retrieved from medical, nurses, and bronchoscopy records. The study parameters, demography, diagnosis, indication, and findings of FFB and interventions done after FFB, were noted, and also the oxygenation and hemodynamic parameters before, during and 3 hours after FFB.

Results

Data from the first FFB of 155 patients were analyzed retrospectively. About 54/155 (34.8%) children underwent FFB while on HFNC. About 75 (48.4%) patients were on conventional oxygen therapy (COT) before FFB. There were 51 (33%) patients who had received mechanical ventilation and were extubated successfully. The 98 (63.2%) children had primary respiratory diseases. Stridor and lung atelectasis were indications for FFB in 75 (48.4%) cases and the commonest bronchoscopic finding was retained secretions in the airways. Based on the FFB findings, 50 medical and 22 surgical interventions were done. The commonest medical and surgical interventions were changes in antibiotics (25/50) and tracheostomy (16/22) respectively. There was a significant fall in SpO₂ and a rise in hemodynamic parameters during FFB. All these changes were reversed after the procedure with no consequences.

Conclusion

Flexible fiberoptic bronchoscopy is a useful tool to diagnose and guide interventions in non-ventilated pediatric intensive care unit (PICU). There were significant but transient changes in oxygenation and hemodynamics with no serious consequences.

How to cite this article

Sachdev A, Gupta N, Khatri A, Jha G, Gupta D, Gupta S, et al. Flexible Fiberoptic Bronchoscopy in Non-ventilated Children in Pediatric Intensive Care Unit: Utility, Interventions and Safety. Indian J Crit Care Med 2023;27(5):358-365.

The use of High-Flow Nasal Oxygen Therapy in 4 dogs undergoing bronchoscopy

Introduction

High-Flow Nasal Oxygen Therapy is a method to deliver warmed, humidified air-oxygen blended at high flow rates to patients through a nasal cannula using a specialized, commercially available machine. This is a well-tolerated, safe and effective method for oxygen delivery to healthy and hypoxemic dogs. Patients undergoing bronchoscopic procedures frequently develop hypoxemia. Human trials have shown a reduction in incidents of hypoxemic events and higher pulse oximeter oxygen saturation during bronchoscopies in patients on High-Flow Nasal Oxygen.

Materials and methods

This is a single-centre, prospective case series. All dogs weighing between 5 and 15 kg and undergoing bronchoscopy during the study period (03/07/2022-01/10/2022) were eligible.

Results

Twelve patients were eligible for inclusion of which four were enrolled. No clinically significant complications related to the use of High-Flow Nasal Oxygen Therapy were recorded. Two of the patients were re-intubated post bronchoscopy due to clinician preference for recovery. One of the patients had a self-limiting period of severe hypoxemia with a pulse oximeter oxygen saturation of 84% for &lt; 1 min during bronchoalveolar lavage, and whilst undergoing High-Flow Nasal Oxygen administration. Another patient had a self-limiting episode of mild hypoxemia (SpO2 of 94% lasting &lt; 1 min) 5 min after completion of bronchoalveolar lavage.

Conclusion

No clinically relevant complications relating to High-Flow Nasal Oxygen Therapy were recorded in this case series, although further studies are required to confirm this conclusion. This initial data suggests that the use of High-Flow Nasal Oxygen therapy during bronchoscopy is feasible and potentially safe, although it may not prevent hypoxemia in these patients. The use of High-Flow Nasal Oxygen Therapy during bronchoscopy in small patients carries multiple potential benefits and further studies to compare its efficacy against other traditional oxygen delivery systems are warranted in this patient population.

Comparison of high-flow nasal cannula and conventional oxygen therapy for high-risk patients during bronchoscopy examination: protocol for a randomized controlled trial

INTRODUCTION

High-flow nasal cannula (HFNC) has been proven to improve oxygenation and avoid intubation in hypoxemic patients. It has also been utilized during endoscopy examination to reduce the incidence of hypoxia. However, little is known about the effects of HFNC versus conventional oxygen therapy (COT) on oxygenation during bronchoscopy examination via nasal route; particularly, no study has compared the use of HFNC with that of COT at similar F_IO₂ for patients who have high-risk factors of desaturation during bronchoscopy examination.

METHODS AND ANALYSIS

This randomized controlled trial will be implemented in four academic centers in China. Patients who have high-risk factors including hypoxemia, hypercapnia, morbid obesity, and narrow airway will be enrolled to use HFNC or COT during bronchoscopy examination. In the HFNC group, the initial gas flow will be set at 50 L/min with a fraction of inspired oxygen (F_IO₂) at 0.45, if the patient tolerates, the flow can be increased to 60L/min at most, while in the COT group, oxygen flow will be set at 6 L/min via a conventional nasal cannula. After 5 min pre-oxygenation, the bronchoscope will be inserted via the nasal route. Vital signs, oxygenation (SpO₂), and transcutaneous CO₂ (PtCO₂) will be continuously monitored. The primary outcome is the incidence of hypoxemia, defined as SpO₂ < 90% for 10 s during bronchoscopy examination, and secondary outcomes include the need for treatment escalation and adverse events.

DISCUSSION

Hypoxia is a common complication of bronchoscopy, our study attempted to demonstrate that HFNC may reduce the probability of hypoxia during bronchoscopy in high-risk patients. The results will be disseminated through peer-reviewed journals and national and international conferences.

TRIAL REGISTRATION

http://www.chictr.org.cn/ : ChiCTR2100055038. Registered on 31 December 2021.

[The role of HFNC oxygen in pre-oxygenation prior to intubation and the practice of invasive procedures]

Over recent years, High Flow Nasal Cannula (HFNC) oxygen therapy has been more and more extensively applied in numerous medical settings, and it is now carried out in invasive procedures such as pre-oxygenation before orotracheal intubation, often leading to complications. More generally, pre-oxygenation is aimed at maintaining the highest possible oxygen saturation for extended periods of time. With this in mind, HFNC seems as effective as standard oxygen delivery with regard to hematosis in patients with mild or moderate hypoxemia, and it presents the advantage of reducing the adverse events associated with intubation. That said, during pre-oxygenation of patients with severe hypoxemia, non-invasive ventilation (NIV) is probably more effective than HFNC, especially in the prevention of respiratory events. However, in patients with little or no hypoxemia undergoing risky procedures such as bronchial endoscopy, HFNC allows better oxygen saturation than standard methods. To summarize, even though NIV remains useful in unstable patients, especially in decreasing desaturation episodes, HFNC could represent a reasonable alternative in case of poor tolerance, allowing continuous oxygenation of patients requiring digestive endoscopy or trans-esophageal ultrasound.

Incidence of oxygen desaturation using a high-flow nasal cannula versus a facemask during flexible bronchoscopy in patients at risk of hypoxemia: a randomised controlled trial

BACKGROUND

Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia.

METHODS

A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89).

RESULTS

Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P < 0.001). The facemask group required more jaw thrust manoeuvres than the HFNC group (43[48.3%] vs. 5[5.7%], P < 0.001). 8 patients (9.0%) in the facemask group and none in the HFNC group required bag-mask ventilation (P = 0.012).

CONCLUSION

The use of an HFNC can reduce the incidence of oxygen desaturation and the requirement for airway intervention in patients at risk of hypoxemia during flexible bronchoscopy under deep sedation.

TRIAL REGISTRATION

www.chiCTR.org.cn Identifier: ChiCTR2100044105. Registered 11/03/2021.

The Impact of High-flow Nasal Cannula vs Other Oxygen Delivery Devices during Bronchoscopy under Sedation: A Systematic Review and Meta-analyses

Background

The widespread diagnostic and therapeutic application of bronchoscopy is often associated with complications like desaturation. This systematic review and meta-analysis intend to scrutinize whether the high-flow nasal cannula (HFNC) is advantageous for providing respiratory support during bronchoscopic procedures under sedation, in comparison with other conventional modalities for oxygen therapy.

Materials and methods

A thorough screening of electronic databases was done till 31st December 2021 after obtaining registration in PROSPERO (CRD42021245420). Randomized controlled trials (RCT), evaluating the impact of HFNC and standard/any other oxygen-delivery devices during bronchoscopy were included in this meta-analysis.

Results

We retrieved in nine RCTs, with a total of 1306 patients, the application of HFNC during bronchoscopy led to decreased number of desaturation spells [relative risk (RR) 0.34, 95% confidence interval (CI) 0.27-0.44, I ² = 23%], higher nadir value of SpO₂ [Mean difference (MD) 4.30, 95% CI 2.41-6.19, I ² = 96%], and improved PaO₂ from baseline (MD 21.77, 95% CI 2.8-40.74, I ² = 99%), along with similar PaCO₂ values (MD -0.34, 95% CI -1.82 to 1.13, I ² = 58%) just after the procedure. However, apart from desaturation spell, the findings are significantly heterogeneous. In subgroup analysis, HFNC had significantly lesser desaturation spells and better oxygenation than low-flow devices, but in comparison to noninvasive ventilation (NIV) had a lower nadir value of SpO₂ with no other significant difference.

Conclusion

High-flow nasal cannula led to greater oxygenation and prevented desaturation spells more effectively in comparison with low-flow devices like nasal cannula, venturi mask, etc., and may be considered as an alternative to NIV during bronchoscopy in certain high-risk patients.

How to cite this article

Roy A, Khanna P, Chowdhury SR, Haritha D, Sarkar S. The Impact of High-flow Nasal Cannula vs Other Oxygen Delivery Devices during Bronchoscopy under Sedation: A Systematic Review and Meta-analyses. Indian J Crit Care Med 2022;26(10):1131-1140.

Association between oxygen saturation level during bronchoscopy and post-bronchoscopy adverse events: a retrospective cohort study

Background

Flexible bronchoscopy is widely used to diagnose and treat various respiratory diseases. However, caution is warranted for post-bronchoscopy adverse events. Although desaturation frequently occurs during bronchoscopy, its clinical impact and the optimal oxygen saturation level during the procedure remain unclear. This study aimed to investigate whether the percutaneous oxygen saturation (SpO₂) level during bronchoscopy is associated with the development of post-bronchoscopy respiratory adverse events.

Methods

In this single-center retrospective cohort study conducted from March 2020 to February 2021, 569 patients were classified into high or low oxygen saturation groups based on the SpO₂ level during bronchoscopy. The primary outcome was post-bronchoscopy respiratory adverse events, and secondary outcomes were other post-bronchoscopy adverse events and clinical outcomes.

Results

Among 569 patients, 458 and 111 patients were classified into the high oxygen saturation (SpO₂ > 96%) and low oxygen saturation (SpO₂ ≤ 94%) groups, respectively. After propensity score matching, the low oxygen saturation group had more post-bronchoscopy respiratory and febrile adverse events than the high oxygen saturation group. In the multivariable regression analysis, low SpO₂ level during bronchoscopy was an independent risk factor for post-bronchoscopy respiratory adverse events (odds ratio = 3.16 [95% confidence interval 1.37–7.30]). In the low oxygen saturation group, the high-risk subgroups for post-bronchoscopy respiratory adverse events were the elderly, women, current smokers, and patients with chronic obstructive pulmonary disease or acute decompensated heart failure before bronchoscopy. There was no significant difference in the length of hospital stay, intensive care unit admission, or mortality between the high and low oxygen saturation groups.

Conclusions

Close monitoring is recommended for patients with SpO₂ ≤ 94% during bronchoscopy due to the increased risk of respiratory adverse events after the procedure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02063-0.

High-Flow-Sauerstofftherapie – Chancen und Risiken

Mit der High-Flow-Sauerstofftherapie („high flow nasal cannula“ [HFNC]), bei der ein Sauerstoff-Luft-Gasgemisch mit Flüssen zwischen 30 und 70 l/min appliziert wird, steht ein technisch einfaches und hocheffektives Verfahren zur Therapie einer respiratorischen Insuffizienz zur Verfügung. Des Weiteren kann die HFNC während einer Bronchoskopie zur Oxygenierung, vor einer Intubation zur Präoxygenierung und nach Extubation zur Vermeidung einer Re-Intubation verwendet werden. Durch die hohen Gasflüsse wird vermieden, dass der Patient Umgebungsluft inspiriert, sodass eine präzise Einstellung einer inspiratorischen Sauerstofffraktion möglich ist, des Weiteren wird durch einen entstehenden Staudruck ein positiver endexspiratorischer Druck aufgebaut, durch die Anfeuchtung und Erwärmung der Atemluft die mukoziliäre Clearance verbessert sowie die Atemarbeit durch Auswaschen der oberen Atemwege verringert. Im Vergleich zur konventionellen Sauerstofftherapie ist die Aerosolbildung durch eine HFNC nicht erhöht, sodass dieses Verfahren auch bei COVID-19 eingesetzt werden kann. Beim hyperkapnischen Lungenversagen liegen bisher keine konklusiven Daten für die Effekte der HFNC vor, hier sollte bevorzugt eine nichtinvasive Beatmung statt einer HFNC erfolgen. Bei der Anwendung darf nicht vergessen werden, dass die mit HFNC behandelten Patienten kritisch krank sind und daher kontinuierlich überwacht werden müssen. So muss sichergestellt sein, dass jederzeit eine Eskalation z. B. auf eine Intubation und invasive Beatmung erfolgen kann.

Use of high-flow nasal cannula and intravenous propofol sedation while performing flexible video bronchoscopy in the intensive care unit: Case reports

Flexible video bronchoscopy is a procedure that plays an important role in diagnosing various types of pulmonary lesions and abnormalities. Case 1 is a 68-year-old male patient with a lesion in the right lung apex of approximately 4 mm × 28 mm with atelectasis bands due to a crash injury. High-flow system with 35 L/min and fraction of inspired oxygen (FiO₂) 0.45 and temperature of 34 °C was installed prior to the video bronchoscopy. SpO₂ was maintained at 98%-100%. The total dose of sedative was 50 mg of propofol. In Case 2, a 64-year-old male patient with bronchiectasis, cystic lesions and pulmonary fibrosis of the left lung field was placed on a high-flow system with 45 L/min and 0.35 FiO₂ at a temperature of 34 °C. SpO₂ was maintained at 100%. The total duration of the procedure was 25 min; SpO₂ of 100% was sustained with oxygenation during maintenance time with the flexible bronchoscope within the airway. The total dose of propofol to reach the degree of desired sedation was 0.5-1 mg/kg. Both patients presented hypotension. For the patient of case 1, a vasopressor (norepinephrine at doses of 0.04 µg/kg/min) was given, and for the patient of case 2, only saline volume expansion was used. The video bronchoscopy with propofol sedation and high-flow nasal cannula allows adequate oxygenation during procedure in the intensive care unit.

High flow nasal cannula versus standard low flow nasal oxygen during flexible bronchoscopy in children: A randomized controlled trial

BACKGROUND

Hypoxemia is the most frequent complication of fiberoptic bronchoscopy (FB) in children. Guidelines recommend oxygen supplementation and conventional nasal prongs (NC) are used for this purpose. The aim of this study was to evaluate if the use of high-flow nasal cannula therapy (HFNC) in children undergoing FB result in a lower incidence of hypoxemia than standard oxygen administration.

METHODS

Patients aged 1 month-16 years undergoing elective FB were included in a prospective randomized controlled, nonblinded, single-center clinical trial and randomly assigned to receive oxygen via NC or HFNC. Patients' baseline characteristics were recorded pre-bronchoscopy. The primary outcome was oxygen desaturation during the procedure defined as saturation less than 94%.

RESULTS

An intention to treat analysis for 53 patients receiving NC and 51 receiving HFNC, showed HFNC patients were less likely to have hypoxemia than were NC patients (p = .011), with an absolute risk reduction of 0.27 (95% confidence interval [CI]: 0.08-0.45) and a number needed to treat of 3.75 (95% CI: 2.22-12.04). Moderate hypoxemia (SpO₂  ≥ 90% and <94%, and <60 s) was observed significantly less often with HFNC than with NC (p = .012). Severe hypoxemia (SpO₂  < 90% and >30 s) was not different between groups. Patients undergoing bronchoalveolar lavage (BAL) presented fewer desaturations with HFNC (p = .0003).

CONCLUSIONS

HFNC offers optimized oxygenation during elective FB with a significant reduction in desaturations and can be considered for oxygen administration, especially when BAL is performed.

Should high-flow through nasal cannula be used during bronchoscopy in critically ill patients with hypoxemic acute respiratory failure?

Flexible fiberoptic bronchoscopy (FOB) is an invasive procedure with diagnostic and/or therapeutic purposes commonly used in critically ill patients. FOB may be complicated by desaturation, onset or worsening of the respiratory failure, and hemodynamic instability due to cardio-respiratory alterations occurring during the procedure. Increasing evidences suggest the use of high-flow through nasal cannula (HFNC) over conventional oxygen therapy (COT) in critically ill patients with acute respiratory failure (ARF). Indeed, HFNC has a rationale and possible physiologic advantages, even during FOB. However, to date, evidences in favor of HFNC over COT or continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) during FOB are still weak. Nonetheless, in critically ill patients with hypoxemic ARF, the choice of the oxygenation strategy during a FOB is challenging. Based on a review of the literature, HFNC may be preferred over COT in patients with mild to moderate hypoxemic ARF, without cardiac failure or hemodynamic instability. On the opposite, in critically ill patients with more severe hypoxemic ARF or in the presence of cardiac failure or hemodynamic instability, CPAP or NIV, applied with specifically designed interfaces, may be preferred over HFNC.

Modified high-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients undergoing bronchoscopy: a randomized clinical trial

Background

Hypoxemia frequently occurs during bronchoscopy. High-flow nasal cannula (HFNC) oxygen therapy may be a feasible alternative to prevent the deterioration of gas exchange during bronchoscopy. With the convenience of clinical use in mind, we modified an HFNC using a single cannula. This clinical trial was designed to test the hypothesis that a modified HFNC would decrease the proportion of patients with a single moment of peripheral arterial oxygen saturation (SpO₂) < 90% during bronchoscopy.

Methods

In this single-center, prospective randomized controlled trial, hospitalized patients in the respiratory department in need of diagnostic bronchoscopy were randomly assigned to a modified HFNC oxygen therapy group or a conventional oxygen therapy (COT) group. The primary outcome was the proportion of patients with a single moment of SpO₂ < 90% during bronchoscopy.

Results

Eight hundred and twelve patients were randomized to the modified HFNC (n = 406) or COT (n = 406) group. Twenty-four patients were unable to cooperate or comply with bronchoscopy. Thus, 788 patients were included in the analysis. The proportion of patients with a single moment of SpO₂ < 90% during bronchoscopy in the modified HFNC group was significantly lower than that in the COT group (12.5% vs. 28.8%, p < 0.001). There were no significant differences in the fraction of inspired oxygen between the two groups. The lowest SpO₂ during bronchoscopy and 5 min after bronchoscopy in the modified HFNC group was significantly higher than that in the COT group. Multivariate analysis showed that a baseline forced vital capacity (FVC) < 2.7 L (OR, 0.276; 95% CI, 0.083–0.919, p = 0.036) and a volume of fluid instilled > 60 ml (OR, 1.034; 95% CI, 1.002–1.067, p = 0.036) were independent risk factors for hypoxemia during bronchoscopy in the modified HFNC group.

Conclusions

A modified HFNC could decrease the proportion of patients with a single moment of SpO₂ < 90% during bronchoscopy. A lower baseline FVC and large-volume bronchoalveolar lavage may predict desaturation during bronchoscopy when using a modified HFNC.

Trial registration ClinicalTrials. Gov: NCT02606188. Registered 17 November 2015.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01744-8.

Bronchoscopy during COVID-19 pandemic, ventilatory strategies and procedure measures

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has changed bronchoscopy practices worldwide. Bronchoscopy is a high-risk aerosol-generating procedure with a potential for direct SARS-CoV-2 exposure and hospital-acquired infection. Current guidelines about personal protective equipment and environment considerations represent key competencies to minimize droplets dispersion and reduce the risk of transmission. Different measures should be put in field based on setting, patient's clinical characteristics, urgency and indications of bronchoscopy. The use of this technique in SARS-CoV-2 patients is reported primarily for removal of airway plugs and for obtaining microbiological culture samples. In mechanically ventilated patients with SARS-CoV-2, bronchoscopy is commonly used to manage complications such as hemoptysis, atelectasis or lung collapse when prone positioning, physiotherapy or recruitment maneuvers have failed. Further indications are represented by assistance during percutaneous tracheostomy. Continuous positive airway pressure, non-invasive ventilation support and high flow nasal cannula oxygen are frequently used in patient affected by Coronavirus Disease-2019 (COVID-19): management of patients' airways and ventilation strategies differs from bronchoscopy indications, patient's clinical status and in course or required ventilatory support. Sedation is usually administered by the pulmonologist (performing the bronchoscopy) or by the anesthetist depending on the complexity of the procedure and the level of sedation required. Finally, elective bronchoscopy for diagnostic indications during COVID-19 pandemic should be carried on respecting rigid standards which allow to minimize potential viral transmission, independently from patient's COVID-19 status. This narrative review aims to evaluate the indications, procedural measures and ventilatory strategies of bronchoscopy performed in different settings during COVID-19 pandemic.

Oxygenation strategies during flexible bronchoscopy: a review of the literature

During flexible fiberoptic bronchoscopy (FOB) the arterial partial pressure of oxygen can drop, increasing the risk for respiratory failure. To avoid desaturation episodes during the procedure several oxygenation strategies have been proposed, including conventional oxygen therapy (COT), high flow nasal cannula (HFNC), continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV). By a review of the current literature, we merely describe the clinical practice of oxygen therapies during FOB. We also conducted a pooled data analysis with respect to oxygenation outcomes, comparing HFNC with COT and NIV, separately. COT showed its benefits in patients undergoing FOB for broncho-alveolar lavage (BAL) or brushing for cytology, in those with peripheral arterial oxyhemoglobin saturation < 93% prior to the procedure or affected by obstructive disorder. HFNC is preferable over COT in patients with mild to moderate acute respiratory failure (ARF) undergoing FOB, by improving oxygen saturation and decreasing the episodes of desaturation. On the opposite, CPAP and NIV guarantee improved oxygenation outcomes as compared to HFNC, and they should be preferred in patients with more severe hypoxemic ARF during FOB.

Clinical Value of Bronchoscopy in Acute Respiratory Failure

Bronchoscopy may be considered the “added value” in the diagnostic and therapeutic pathway of different clinical scenarios occurring in acute respiratory critically ill patients. Rigid bronchoscopy is mainly employed in emergent clinical situations due to central airways obstruction, haemoptysis, and inhaled foreign body. Flexible bronchoscopy (FBO) has larger fields of acute applications. In intensive care settings, FBO is useful to facilitate intubation in difficult airways, guide percutaneous dilatational tracheostomy, and mucous plugs causing lobar/lung atelectasis. FBO plays a central diagnostic role in acute respiratory failure caused by intra-thoracic tumors, interstitial lung diseases, and suspected severe pneumonia. “Bronchoscopic” sampling has to be considered when “non-invasive” techniques are not diagnostic in suspected ventilator-associated pneumonia and in non-ventilated immunosuppressed patients. The combined use of either noninvasive ventilation (NIV) or High-flow nasal cannula (HFNC) with bronchoscopy is useful in different scenarios; the largest body of proven successful evidence has been found for NIV-supported diagnostic FBO in non-ventilated high risk patients to prevent and avoid intubation. The expected diagnostic/therapeutic goals of acute bronchoscopy should be balanced against the potential severe risks (i.e., cardio-pulmonary complications, bleeding, and pneumothorax). Expertise of the team is fundamental to achieve the best rate of success with the lowest rate of complications of diagnostic and therapeutic bronchoscopic procedures in acute clinical circumstances.

Bronchoscopy in intubated and non-intubated intensive care unit patients with respiratory failure

Bronchoscopy is one of the important tool for the pulmonary and critical care physicians to diagnose and treat various pulmonary conditions. It is increasingly being used by the intensivist due to its safety and portability. The utilization of bronchoscopy in the intensive care unit (ICU) has made the diagnosis and treatment of many conditions more feasible to intensivists. Sedation, topical or intravenous, usually helps better tolerate the procedure. However, the risks and benefits of bronchoscopy should be carefully considered in critically ill patients. The hypoxic patients in ICU pose a challenge as hypoxemia is one of the known complications of bronchoscopy, and this risk is exacerbated in patients with hypoxic respiratory failure. Bronchoscopy is relatively contraindicated in patients with severe hypoxemia and coagulopathy. However, bronchoscopy in hypoxic patients can have diagnostic as well as therapeutic implications. In patients with hypoxic respiratory failure, the use of non-invasive ventilation (NIV) during bronchoscopy has been shown to reduce the risk of intubation. On the other hand, bronchoscopy in mechanically ventilated patients is not contraindicated and has been widely used. Staying focused, monitoring vital signs closely, limiting the scope time in the airway, and understanding patient’s physiology may help decrease risk of complications. In this review, we discuss indications, techniques, complications, and yield associated with bronchoscopy in critically ill hypoxic patients.

Risk factors of complications during noninvasive mechanical ventilation -assisted flexible bronchoscopy

PURPOSE

Flexible bronchoscopy (FB) causes airway narrowing and may cause respiratory failure (RF). Noninvasive mechanical ventilation (NIV) is used to treat RF. Until recently, little was known about noninvasive mechanical ventilation assisted flexible bronchoscopy (NIV-FB) risk and complications.

MATERIALS AND METHODS

A retrospective analysis of NIV-FB performed in 20 consecutive months (July 1, 2018-February 29, 2020) was performed. Indications for: FB and NIV, as well as impact of comorbidities, blood gas results, pulmonary function test results and sedation depth, were analyzed to reveal NIV-FB risk. Out of a total of 713 FBs, NIV-FB was performed in 50 patients with multiple comorbidities, acute or chronic RF, substantial tracheal narrowing, or after previously unsuccessful FB attempt.

RESULTS

In three cases, reversible complications were observed. Additionally, due to the severity of underlining disease, two patients were transferred to the ICU where they passed away after >48h. In a single variable analysis, PaO₂ 69 ​± ​18.5 and 49 ​± ​9.0 [mmHg] (p ​< ​0.05) and white blood count (WBC) 10.0 ​± ​4.81 and 14.4 ​± ​3.10 (p ​< ​0.05) were found predictive for complications. Left heart disease indicated unfavorable NIV-FB outcome (p ​= ​0.046).

CONCLUSIONS

NIV-FB is safe in severely ill patients, however procedure-related risk should be further defined and verified in prospective studies.

High-flow Nasal Oxygen Versus Standard Oxygen During Flexible Bronchoscopy in Lung Transplant Patients: A Randomized Controlled Trial

BACKGROUND

Diagnostic and interventional flexible bronchoscopy (FB) is increasingly utilized in complex and high-risk patients. Patients are often sedated for comfort and procedure facilitation and hypoxia is commonly observed in this setting. We hypothesized that high-flow nasal oxygen (HFNO) would reduce the incidence of patients experiencing oxygen desaturation.

METHODS

In this randomized controlled trial, postlung transplant patients booked for FB with transbronchial lung biopsy were assigned to either HFNO or low-flow nasal oxygen (LFNO). The patient and bronchoscopist were blinded to group allocation. The primary endpoint was the proportion of patients experiencing mild desaturation [peripheral oxygen saturation (SpO2)<94%]. Secondary endpoints included desaturation (SpO2<90%), the number of airway interventions required and procedure interruptions, the duration of oxygen desaturation and patient, bronchoscopist and anesthesiologist satisfaction scores.

RESULTS

The trial analyzed data from 76 patients (LFNO, n=39; HFNO, n=37). HFNO reduced the proportion of patients experiencing SpO2<94% (43.2% vs. 89.7%, P<0.001) and SpO2<90% (16.2% vs. 69.2%, P<0.001). The FB was interrupted 11 times in 9 patients in the LFNO group, whereas there were no interruptions in the HFNO group. There were no differences in patient and bronchoscopist satisfaction scores between groups, anesthesiologists had higher satisfaction scores when using HFNO (P<0.001).

CONCLUSION

Hypoxia occurred less commonly in postlung transplant patients receiving HFNO during FB. Further studies are warranted in other high-risk populations undergoing longer duration FB.

The effect of Oxygen application with nCPAP for the prevention of desaturation during EBUS-TBNA

PURPOSE

EBUS-TBNA is a frequently used diagnostic method for mediastinal/hilar lymphadenopathies and masses. This procedure is performed with intravenous sedation (IVS). During IVS, patients often develop hypoxemia and nasal oxygen delivery is insufficient in some patients. The aim of this study was to investigate the effect of oxygen application with nCPAP on hypoxemia during EBUS-TBNA.

METHODS

Patients with EBUS-TBNA indication who did not have any serious heart-lung disease were randomly divided into two groups. One group received only oxygen and the other group received nCPAP+oxygen. Patient characteristics, arterial oxygen saturations, anesthetic agents, CPAP pressures, oxygen concentrations and processing times were recorded during the procedure. Practitioner satisfaction was evaluated at the end.

RESULTS

29 nCPAP+oxygen, 31 oxygen patients were included in the study. There were no significant differences in terms of age, sex, smoking history and presence of additional diseases in two groups. Neck circumference, BMI and STOP BANG questionnaire values were similar. Desaturation time was significantly longer in oxygen group than nCPAP+oxygen group (316±390 sec, 12±118 sec, respectively, p=0,019). Snoring was detected during the procedure in 22 patients in the oxygen group and in 11 patients in the nCPAP group (p=0,01). There were no serious complications in both groups. Practitioner satisfaction was higher in the nCPAP group but this was not statistically significant (p=0,052).

CONCLUSION

Oxygen application by nCPAP during EBUS-TBNA under IVS, significantly reduces desaturation time. Oxygen delivery with nCPAP seems to be a better choice especially for the patients with high Mallampati index.

Flexible Bronchoscopy in a Patient With Pneumomediastinum and Hypoxemic Respiratory Failure: High-Flow Nasal Cannula to the Rescue

Flexible bronchoscopy with bronchoalveolar lavage carries a significant risk of hypoxia in patients with acute hypoxemic respiratory failure. Noninvasive positive pressure ventilation and high-flow nasal cannula are the most commonly used modalities for reducing procedure-related hypoxemia in such patients. There is no guideline on how to safely perform a bronchoscopy in patients with spontaneous pneumomediastinum and hypoxemic respiratory failure. Here we describe a case of bilateral necrotizing pneumonia, spontaneous pneumomediastinum, and moderate acute respiratory distress syndrome who required diagnostic flexible bronchoscopy.

High-flow nasal cannula for oxygenation during emergency tracheal stenting under flexible bronchoscopy guidance

Central airway obstruction is a common complication of advanced esophageal carcinoma requiring bronchoscopic evaluation and intervention by a pulmonologist. Airway assessment by flexible bronchoscopy is crucial for the selection of the most suitable modality for the management of central airway obstruction. In such situations, flexible bronchoscopy may however be complicated by the development of hypoxemia. Oxygen therapy by high-flow nasal cannula (HFNC) has been used for the correction of hypoxemia for a number of conditions, including diagnostic bronchoscopy. This case report describes a successful use of HFNC for correction of severe hypoxemia during the placement of a metallic stent in a patient with tracheal obstruction due to esophageal carcinoma.

Comparison of high-flow and conventional nasal cannula oxygen in patients undergoing endobronchial ultrasonography

BACKGROUND

Oxygen therapy is required to prevent hypoxaemia during the endobronchial ultrasonography (EBUS) procedure.

AIMS

To compare the effectiveness of oxygen therapy delivered through high-flow nasal cannula (HFNC) and conventional nasal cannula (CNC) in patients undergoing EBUS. The primary outcome was the proportion of patients who desaturated. Patient compliance and satisfaction were also evaluated.

METHODS

This single-centre prospective interventional study was conducted in a tertiary hospital among patients who presented to the EBUS unit in 2018 and 2019. Patients were randomly assigned to the HFNC group or the CNC group.

RESULTS

The study included 170 patients (111 men and 59 women) with a mean age of 58 ± 14 years. The number of patients experiencing desaturation while receiving oxygen was statistically significantly lower (P < 0.001) in the HFNC group (n = 5) compared with the CNC group (n = 26). Oxygen therapy was adjusted in two patients in the CNC group due to desaturation. Saturation was significantly higher in the HFNC group (P < 0.0001) at the end of the EBUS procedure. Heart rate at the end of EBUS was lower in the HFNC group, but this difference was not statistically significant (96 ± 16 vs 101 ± 19, P = 0.13). Five patients in the HFNC group and 18 patients in the CNC group reported discomfort during the procedure (P = 0.006).

CONCLUSION

Oxygen therapy delivered by HFNC seems to be safer and more effective than by CNC in patients undergoing EBUS. Oxygen therapy with HFNC may be considered as an alternative to CNC because it may increase patient comfort and thereby improve compliance.

Profile of Chest Injuries and Oxygen Therapy in Trauma Patients with Acute Respiratory Failure after the Jiangsu Tornado in China: A Retrospective Study

BACKGROUND

The aim of this study was to analyze the profile of chest injuries, oxygen therapy for respiratory failure, and the outcomes of victims after the Jiangsu tornado, which occurred on June 23, 2016 in Yancheng City, Jiangsu Province, China.

METHODS

The clinical records of 144 patients referred to Yancheng City No.1 People's Hospital from June 23 through June 25 were retrospectively investigated. Of those patients, 68 (47.2%) sustained major chest injuries. The demographic details, trauma history, details of injuries and Abbreviated Injury Scores (AIS), therapy for respiratory failure, surgical procedures, length of intensive care unit (ICU) and hospital stay, and mortality were analyzed.

RESULTS

Of the 68 patients, 41 (60.3%) were female and 27 (39.7%) were male. The average age of the injured patients was 57.1 years. Forty-six patients (67.6%) suffered from polytrauma. The mean thoracic AIS of the victims was calculated as 2.85 (SD = 0.76). Rib fracture was the most common chest injury, noted in 56 patients (82.4%). Pulmonary contusion was the next most frequent injury, occurring in 12 patients (17.7%). Ten patients with severe chest trauma were admitted to ICU. The median ICU stay was 11.7 (SD = 8.5) days. Five patients required intubation and ventilation, one patient was treated with noninvasive positive pressure ventilation (NPPV), and four patients were treated with high-flow nasal cannula (HFNC). Three patients died during hospitalization. The hospital mortality was 4.41%.

CONCLUSIONS

Chest trauma was a common type of injury after tornado. The most frequent thoracic injuries were rib fractures and pulmonary contusion. Severe chest trauma is usually associated with a high incidence of respiratory support requirements and a long length of stay in the ICU. Early initiation of appropriate oxygen therapy was vital to restoring normal respiratory function and saving lives. Going forward, HFNC might be an effective and well-tolerated therapeutic addition to the management of acute respiratory failure in chest trauma.

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: a joint ESA/ESICM guideline

Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure at risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula, noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that: in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately post-extubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery.

High-flow nasal cannula therapy as apneic oxygenation during endotracheal intubation in critically ill patients in the intensive care unit: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to assess the clinical efficacy of high-flow nasal cannula (HFNC) therapy as apneic oxygenation in critically ill patients who require endotracheal intubation in the intensive care unit (ICU). This systematic review and meta-analysis included six randomized controlled trials and a prospective study identified in PubMed, Embase, Cochrane Library, and the Web of Science until August 18, 2019. In this meta-analysis including 956 participants, HFNC was noninferior to standard of care during endotracheal intubation regarding incidence of severe hypoxemia, mean lowest oxygen saturation, and in-hospital mortality. HFNC significantly shortened the ICU stay by a mean of 1.8 days. In linear meta-regression interaction analysis, the risk ratio of severe hypoxemia decreased with increasing baseline partial oxygen pressure (PaO2) to fraction of inspired oxygen (FiO2) ratio. In subgroup analysis, HFNC significantly reduced the incidence of severe hypoxemia during endotracheal intubation in patients with mild hypoxemia (PaO2/FiO2> 200 mmHg; risk difference, -0.06; 95% confidence interval, -0.12 to -0.01; number needed to treat = 16.7). In conclusion, HFNC was noninferior to standard of care for oxygen delivery during endotracheal intubation and was associated with a significantly shorter ICU stay. The beneficial effect of HFNC in reducing the incidence of severe hypoxemia was observed in patients with mild hypoxemia.

Benefit-to-risk balance of bronchoalveolar lavage in the critically ill. A prospective, multicenter cohort study

Purpose

To assess the benefit-to-risk balance of bronchoalveolar lavage (BAL) in intensive care unit (ICU) patients.

Methods

In 16 ICUs, we prospectively collected adverse events during or within 24 h after BAL and assessed the BAL input for decision making in consecutive adult patients. The occurrence of a clinical adverse event at least of grade 3, i.e., sufficiently severe to need therapeutic action(s), including modification(s) in respiratory support, defined poor BAL tolerance. The BAL input for decision making was declared satisfactory if it allowed to interrupt or initiate one or several treatments.

Results

We included 483 BAL in 483 patients [age 63 years (interquartile range (IQR) 53–72); female gender: 162 (33.5%); simplified acute physiology score II: 48 (IQR 37-61); immunosuppression 244 (50.5%)]. BAL was begun in non-intubated patients in 105 (21.7%) cases. Sixty-seven (13.9%) patients reached the grade 3 of adverse event or higher. Logistic regression showed that a BAL performed by a non-experienced physician (non-pulmonologist, or intensivist with less than 10 years in the specialty or less than 50 BAL performed) was the main predictor of poor BAL tolerance in non-intubated patients [OR: 3.57 (95% confidence interval 1.04–12.35); P = 0.04]. A satisfactory BAL input for decision making was observed in 227 (47.0%) cases and was not predictable using logistic regression.

Conclusions

Adverse events related to BAL in ICU patients are not infrequent nor necessarily benign. Our findings call for an extreme caution, when envisaging a BAL in ICU patients and for a mandatory accompaniment of the less experienced physicians.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05896-4) contains supplementary material, which is available to authorized users.

High-flow nasal cannula oxygen therapy and hypoxia during gastroscopy with propofol sedation: a randomized multicenter clinical trial

BACKGROUND AND AIMS

Hypoxia is one of the most frequent adverse events with sedated GI endoscopy and can lead to serious consequences. No modalities have been found previously to prevent hypoxia. High-flow nasal cannula (HFNC) supportive oxygen therapy provides heated and humidified oxygen up to 60 L/minute. Because of its ability to improve respiratory function and good tolerance, we aimed to evaluate the validity and safety of HFNC supportive oxygen therapy in preventing the incidence of hypoxia in patients undergoing gastroscopy with propofol sedation.

METHODS

In a multicenter, prospective randomized single-blinded study, 1994 outpatients undergoing routine gastroscopy with propofol sedation provided by an anesthesiologist were randomized into 2 groups: the nasal cannula group (O₂ [2 L/minute] was supplied via an HFNC) and the HFNC group (O₂ [30-60 L/minute] was supplied via an HFNC) at 3 centers from November 2017 to February 2018. The primary outcome was the incidence of hypoxia. Other adverse events were also recorded.

RESULTS

HFNC supportive oxygen therapy decreased the incidence of hypoxia (75% ≤ Spo₂ < 90% for <60 seconds) and severe hypoxia (Spo₂ < 75% for any duration or 75% ≤ Spo₂ < 90% for ≥60 seconds) from 8.4% to 0% (P < .001) and from 0.6% to 0% (P = .03), respectively. The only HFNC-related adverse event was xeromycteria/rhinalgia (1.7%), which was observed 1 minute after the procedure and disappeared after 30 minutes.

CONCLUSIONS

HFNC supportive oxygen therapy can prevent the incidence of hypoxia and severe hypoxia in patients in America Society of Anesthesiologists class I-II undergoing elective gastroscopy under propofol sedation, with minimal related adverse events and good tolerance. (Clinical trial registration number: NCT03332433.).

High-flow nasal cannula therapy: clinical practice in intensive care units

Background

Despite the extensive use of high-flow nasal cannula (HFNC) therapy in intensive care units (ICU) for acute respiratory failure (ARF), its daily clinical practice has not been assessed. We designed a regional survey in ICUs in North-west France to evaluate ICU physicians’ clinical practice with HFNC.

Materials and methods

We sent an observational survey to ICU physicians from 34 French ICUs over a 6-month period in 2016–2017. The survey included questions regarding the indications and expected efficiency of HFNC, practical aspects of use (initiation, weaning) and satisfaction. Comparisons between junior and senior ICU physicians were performed using a Fischer exact test.

Results

Among the 235 ICU physicians contacted, 137 responded (58.3%) all of whom regularly used HFNC. Hypoxemic ARF was considered a good indication for HFNC by all 137, but only 30% expected HFNC success (i.e., avoiding intubation in at least 60% of cases). Among hypoxemic indications, 30% of juniors considered acute pulmonary edema a good indication versus 74% of seniors (p < 0.0001). Hypercapnic ARF was considered a good indication by 33% with only 2% expecting HFNC success. A need for conventional oxygen therapy ≥ 6 L/min justified HFNC therapy for 40% and ≥ 9 L/min for 39% of responders. 58% of ICU physicians started HFNC therapy with a FiO₂ ≥ 50% and 28% with a gas flow ≥ 50 L/min. Practices for HFNC weaning were heterogeneous: 48% considered a FiO₂ ≤ 30%; whereas, 30% considered a FiO₂ ≤ 30% with a high flow ≤ 20 L/min. Criteria for HFNC failure (i.e., need for intubation) were ventilatory pauses or arrest (97%), persistent hypoxemia (95%), respiratory acidosis (81%), worsening of breathing (95%, 100% of seniors and 86% of juniors, p = 0.003), bronchial congestion (75%) and circulatory failure (61%, 72% of seniors and 44% of juniors, p = 0.007).

Conclusion

HFNC is used by ICU physicians in many situations of ARF, despite their relatively low expectations of success, especially in cases of hypercapnia. Clinical practices appear somewhat heterogeneous. Despite the physiological benefit of HFNC, further prospective observational studies are still required on HFNC outcomes and daily practices.

Noninvasive Ventilation-assisted Bronchoscopy in High-risk Hypoxemic Patients

BACKGROUND AND AIMS

Hypoxemic patients undergoing fiber-optic bronchoscopy (FOB) are at risk of worsening of respiratory failure requiring mechanical ventilation due to FOB procedure itself and its complications. As patients with respiratory failure are frequently managed by non-invasive ventilation (NIV); feasibility of FOB through NIV mask has been evaluated in some studies to avoid intubation. We describe here our own case series.

MATERIALS AND METHODS

Clinical data of 28 FOB done through NIV mask in 27 intensive care unit (ICU) patients over 6 years period at our center was collected retrospectively and analysed.

RESULTS

Study comprises 27 (17 male; 52±21.6 years age) hypoxemic (PaO2 71.3±14.2, on NIV and oxygen supplementation) patients. All FOB were done at bedside, 15 of them were given sedation for the procedure. Twenty four patients had bronchoalveolar lavage (BAL); three underwent bronchial biopsies, four brush cytology and seven transbronchial biopsies. In 10 patients lung or lobar collapse was reversed. There was no significant change between pre and post bronchoscopy ABG parameters except for improved post FOB PaO2 (p = 0.0032) and SpO2 (p = 0.0046). One patient (3.57%) developed late pneumothorax and 3 patients (10.7%) had bleeding after biopsy. Prior to bronchoscopy 17 (16 BIPAP, 1 CPAP) patients were already on NIV. Two patients required mechanical ventilation 6 hours after FOB due to subsequent clinical deterioration but could be weaned off later. One patient died on third day after FOB from acute myocardial infarction.

CONCLUSION

Hypoxemic patients in ICU can safely undergo bedside diagnostic and simple therapeutic bronchoscopy with NIV support while mostly avoiding intubation and with low complication rates.

HOW TO CITE THIS ARTICLE

Sircar M, Jha OK, Chabbra GS, Bhattacharya S. Noninvasive Ventilation-assisted Bronchoscopy in High-risk Hypoxemic Patients. Indian J Crit Care Med 2019;23(8):363-367.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

Preventing deoxygenation with high flow nasal cannula oxygen during induction of general anesthesia for rigid bronchoscopy: Two case reports

RATIONALE

Rigid bronchoscopy under general anesthesia enables performing diagnostic and/or therapeutic procedures in the tracheobronchial tree. As most patients undergoing rigid bronchoscopy have moderate to severe respiratory disease or central airway obstruction, the operators often face the risk of hypoxemia when inserting the rigid bronchoscope into the patients' airway. Applying high flow nasal cannula (HFNC) oxygen therapy before the insertion of the bronchoscope allows to maintain high fractional inspired oxygen (FiO2) and thus leading to maximizing apnea time before desaturation.

PATIENT CONCERNS AND DIAGNOSIS

Case 1: A 70-year-old female patient was diagnosed with lung cancer in the left lower lobe and a tracheal mass of about 2.6 cm * 0.8 cm in size.Case 2: A male patient, 77 years old, 55.7 kg and 157.3 cm in height, had been diagnosed with chronic obstructive pulmonary disease, and was scheduled for the bronchoscopic volume reduction surgery upon exacerbation of his symptoms of dyspnea and cough with sputum.

INTERVENTIONS

Preoxygenation was performed with HFNC (Fisher&Paykel Optiflow Thrive, New Zealand) for 3 minutes before the administration of anesthetic medications. The oxygen flow was set at 50 L/min and the FiO2 at 1.0. SpO2 increased to 100%.

OUTCOMES

The HFNC oxygen has shown its effectiveness in safely maintaining the patients' SpO2 during the prolonged apneic period of inserting bronchoscope.

LESSONS

HFNC oxygen is an effective tool in oxygenating the patients during the induction of rigid bronchoscopy, and that it may be a superior alternative to the conventional method of preoxygenation.

Clinical efficacy of high-flow nasal humidified oxygen therapy in patients with hypoxemia

To evaluate the effectiveness of high-flow nasal humidified oxygen (HFNHO) therapy in patients with mild hypoxemia after extubation. This study included 316 patients with mild hypoxemia after extubation from May 2016 to May 2018 from two intensive care units in China. Compare the effects of the Venturi Mask and High-Flow Nasal Humidified Oxygen (HFNHO) therapy on Heart Rate (HR), Respiratory Rate (RR), Oxygen Saturation (SpO₂), Oxygen Partial Pressure (PO₂), Partial Pressure Of Carbon Dioxide (PCO₂), Oxygenation Index (PO₂/FiO₂) after extubation, the use of noninvasive mechanical ventilation and tracheal intubation after treatment failure were observed and recorded. Patients have both lower HR and RR than those who received mask treatment (75.4±18.5 vs. 83.0±20.4, p = 0.0004; 18±6.5 vs. 23.6±10.3, p<0.001, respectively). There was significant difference between those who had HFNHO and mask administration’s SpO₂ and PO₂ (94.1±6.4 vs. 87.5±1.5, p<0.001; 88.16±2.9 vs. 77.3±2.3, p<0.001, respectively). For the HFNHO group, patients had lower PCO₂ with the mask group. (41.3±0.99 vs 42.2±1.2, p<0.001). On the other hand, the levels of PO₂/FiO₂ was significantly higher in the HFNHO Group, (181.0±8.3 vs. 157.2±4.9, p<0.05). We concluded HFNHO therapy could significantly relieve the symptoms of dyspnea, improve oxygenation, reduce the use of noninvasive mechanical ventilation and reduce the rate of secondary tracheal intubation in patients with mild hypoxemia after extubation.

High-flow nasal cannula oxygenation utilization in respiratory failure

High flow nasal cannula (HFNC) represents a new oxygenation system to be used in the treatment of respiratory emergencies. During HFNC therapy, the active humidification and air heating system allow the patient to tolerate higher flows by favouring physiologic mucociliary clearance and improving fluidity of respiratory secretions. Following this, FiO₂ values are more stable and reliable, by reducing losses and minimizing ambient air entrainment. Several clinical trials in acute respiratory failure patients have suggested lower rate of invasive mechanical ventilation, improved comfort and enhanced survival by early HFNC utilization in comparison with conventional oxygen therapy (COT) or non-invasive ventilation (NIV). This review aims to summarize the main evidences on the use of HFNC in the acute setting and its major indications.

Nasal high flow: physiology, efficacy and safety in the acute care setting, a narrative review

Nasal high flow (NHF) is a promising novel oxygen delivery device, whose mechanisms of action offer some beneficial effects over conventional oxygen systems. It is considered to have a number of physiological effects: it improves oxygenation, dynamic lung compliance, homogeneity and end expiratory lung volume; it decreases anatomical dead space and generates a positive airway pressure that can reduce respiratory rate, the work of breathing, and enhance patient comfort. NHF has been used as a prophylactic tool or as a treatment device mostly in patients with acute hypoxemic respiratory failure such as pre-oxygenation before intubation, immunocompromised patients and acute heart failure. Moreover, there is some evidence that NHF could be used during procedural sedation. Finally, NHF was deemed to be effective in chronic obstructive pulmonary disease patients with its positive end expiratory pressure effects and dead-space washout. However, careful monitoring is crucial to maximize NHF settings aimed at maximizing patient comfort while limiting the risk of delayed intubation. The present review presents the most updated evidence for NHF use in the adult acute care setting with the goal of providing clinicians with useful insights on the physiologic effects, main clinical indications, and safety issues of NHF treatment.

A prospective randomized comparative study of high-flow nasal cannula oxygen and non-invasive ventilation in hypoxemic patients undergoing diagnostic flexible bronchoscopy

Background

Although oxygen supplementation during bronchoscopy in patients with pre-existing hypoxemia is provided, adequacy of oxygenation may not be achieved, resulting in the occurrence of respiratory failure that requires endotracheal tube intubation. The purpose of this study was to compare high-flow nasal cannula (HFNC) with non-invasive ventilation (NIV) in patients with pre-existing hypoxemia undergoing flexible bronchoscopy (FB) on the ability to maintain oxygen saturation during bronchoscopy.

Methods

A prospective randomized study was conducted in patients who had hypoxemia [defined as partial pressure of arterial oxygen (PaO₂) less than 70 mmHg at room air] and required FB for the diagnosis of abnormal pulmonary lesions. Patients were randomized to receive either HFNC or NIV during FB. The primary outcome was the lowest oxygen saturation level during FB.

Results

Fifty-one patients underwent randomization to HFNC (n=26) or NIV (n=25). Baseline characteristics in terms of age, Simplified Acute Physiologic Score II values, and cardiorespiratory parameters were similar in both groups. After receiving HFNC or NIV, oxygen saturation as measured by pulse oximeter (SpO₂) increased to greater than 90% in all cases. During FB, although the lowest SpO₂ was similar in both groups, the lowest SpO₂ <90% tended to occur more often in the HFNC group (34.6% vs. 12.0%; P=0.057). In patients with baseline PaO₂ <60 mmHg on ambient air, a decrease in PaO₂ from preprocedure to the end of FB was less in the NIV group (-13.7 vs. -57.0 mmHg; P=0.019). After FB, the occurrence of SpO₂ <90% was 15.4% and 4.0% in the HFNC group and NIV group, respectively (P=0.17).

Conclusions

In overall, NIV and HFNC provided the similar effectiveness in prevention of hypoxemia in hypoxemic patients undergoing FB. However, in subgroup analysis, NIV provided greater adequacy and stability of oxygenation than HFNC in patients with baseline PaO₂ <60 mmHg on ambient air.

High flow nasal cannula oxygen versus noninvasive ventilation in adult acute respiratory failure: a systematic review of randomized-controlled trials

We reviewed the use of noninvasive ventilation (NIV) versus high flow nasal cannula (HFNC) oxygen in adult acute respiratory failure (ARF). We searched major databases and included randomized trials comparing at least NIV with HFNC or NIV+HFNC with NIV in ARF. Primary outcomes included intubation/re-intubation rates. Secondary outcomes were ICU mortality and morbidities. Five trials were included; three compared HFNC with NIV, one compared HFNC, NIV and oxygen whereas one compared HFNC+NIV with NIV. Patients had hypoxaemic ARF (PaO2/FiO2≤300 mmHg). Heterogeneity prevented result pooling. Three and two studies had superiority and noninferiority design, respectively. Patients were postcardiothoracic surgery, mixed medical/surgical patients and those with pneumonia. Two trials were conducted after extubation, two before intubation and one during intubation. Three trials reported intubation/re-intubation rates as the primary outcomes. The other two trials reported the lowest peripheral capillary oxygen saturation readings during bronchoscopy or intubation. In the former three trials, the odds ratio for intubation/re-intubation rates between HFNC versus the NIV group ranged from 0.80 (95% confidence interval: 0.54-1.19) to 1.65 (95% confidence interval: 0.96-2.84). In the latter two trials, only one reported a difference in the lowest peripheral capillary oxygen saturation between NIV+HFNC versus the NIV group during intubation [100% (interquartile range: 95-100) vs. 96% (interquartile range: 92-99); P=0.029]. The secondary outcomes included differences in ICU mortality and patient tolerability, favouring HFNC. Results were conflicting, but highlighted future research directions. These include patients with hypercapneic ARF, more severe hypoxaemia (PaO2/FiO2≤200 mmHg), a superiority design, an oxygen arm and patient-centred outcomes.

Invasive and non-invasive diagnostic approaches for microbiological diagnosis of hospital-acquired pneumonia

Background

Data on the methods used for microbiological diagnosis of hospital-acquired pneumonia (HAP) are mainly extrapolated from ventilator-associated pneumonia. HAP poses additional challenges for respiratory sampling, and the utility of sputum or distal sampling in HAP has not been comprehensively evaluated, particularly in HAP admitted to the ICU.

Methods

We analyzed 200 patients with HAP from six ICUs in a teaching hospital in Barcelona, Spain. The respiratory sampling methods used were divided into non-invasive [sputum and endotracheal aspirate (EAT)] and invasive [fiberoptic-bronchoscopy aspirate (FBAS), and bronchoalveolar lavage (BAL)].

Results

A median of three diagnostic methods were applied [range 2–4]. At least one respiratory sampling method was applied in 93% of patients, and two or more were applied in 40%. Microbiological diagnosis was achieved in 99 (50%) patients, 69 (70%) by only one method (42% FBAS, 23% EAT, 15% sputum, 9% BAL, 7% blood culture, and 4% urinary antigen). Seventy-eight (39%) patients underwent a fiberoptic-bronchoscopy when not receiving mechanical ventilation. Higher rates of microbiological diagnosis were observed in the invasive group (56 vs. 39%, p = 0.018). Patients with microbiological diagnosis more frequently presented changes in their empirical antibiotic scheme, mainly de-escalation.

Conclusions

A comprehensive approach might be undertaken for microbiological diagnosis in critically ill nonventilated HAP. Sputum sampling determined one third of microbiological diagnosis in HAP patients who were not subsequently intubated. Invasive methods were associated with higher rates of microbiological diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2348-2) contains supplementary material, which is available to authorized users.