Airway challenges in critical care

[Prehospital postcardiac-arrest-sedation and -care in the Federal Republic of Germany-a web-based survey of emergency physicians]

BACKGROUND

This study evaluates the implementation of postcardiac-arrest-sedation (PCAS) and -care (PRC) by prehospital emergency physicians in Germany.

MATERIALS AND METHODS

Analysis of a web-based survey from October to November 2022. Questions were asked about implementation, medications used, complications, motivation for implementing or not implementing PCAS, and measures and target parameters of PRC.

RESULTS

A total of 500 emergency physicians participated in the survey. In all, 73.4% stated that they regularly performed PCAS (hypnotics: 84.7%; analgesics: 71.1%; relaxants: 29.7%). Indications were pressing against the respirator (88.3%), analgesia (74.1%), synchronization to respirator (59.5%), and change of airway device (52.6%). Reasons for not performing PCAS (26.6%) included unconscious patients (73.7%); concern about hypotension (31.6%), re-arrest (26.3%), and worsening neurological assessment (22.5%). Complications of PCAS were observed by 19.3% of participants (acute hypotension [74.6%]); (re-arrest [32.4%]). In addition to baseline monitoring, PRC included 12-lead-electrocardiogram (96.6%); capnography (91.6%); catecholamine therapy (77.6%); focused echocardiography (20.6%), lung ultrasound (12.0%) and abdominal ultrasound (5.6%); induction of hypothermia (13.6%) and blood gas analysis (7.4%). An etCO2 of 35-45 mm Hg was targeted by 40.6%, while 9.0% of participants targeted an SpO2 of 94-98% and 19.2% of participants targeted a systolic blood pressure of ≥ 100 mm Hg.

CONCLUSIONS

Prehospital PRC in Germany is heterogeneous and deviations from its target parameters are frequent. PCAS is frequent and associated with relevant complications. The development of preclinical care algorithms for PCAS and PRC within preclinical care seems urgently needed.

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.

A nomogram for predicting the necessity of tracheostomy after severe acute brain injury in patients within the neurosurgery intensive care unit: A retrospective cohort study

Objective

This retrospective study was aimed to develop a predictive model for assessing the necessity of tracheostomy (TT) in patients admitted to the neurosurgery intensive care unit (NSICU).

Method

We analyzed data from 1626 NSICU patients with severe acute brain injury (SABI) who were admitted to the Department of NSICU at the Affiliated People's Hospital of Jiangsu University between January 2021 and December 2022. Data of the patients were retrospectively obtained from the clinical research data platform. The patients were randomly divided into training (70%) and testing (30%) cohorts. The least absolute shrinkage and selection operator (LASSO) regression identified the optimal predictive features. A multivariate logistic regression model was then constructed and represented by a nomogram. The efficacy of the model was evaluated based on discrimination, calibration, and clinical utility.

Results

The model highlighted six predictive variables, including the duration of NSICU stay, neurosurgery, orotracheal intubation time, Glasgow Coma Scale (GCS) score, systolic pressure, and respiration rate. Receiver operating characteristic (ROC) analysis of the nomogram yielded area under the curve (AUC) values of 0.854 (95% confidence interval [CI]: 0.822-0.886) for the training cohort and 0.865 (95% CI: 0.817-0.913) for the testing cohort, suggesting commendable differential performance. The predictions closely aligned with actual observations in both cohorts. Decision curve analysis demonstrated that the numerical model offered a favorable net clinical benefit.

Conclusion

We developed a novel predictive model to identify risk factors for TT in SABI patients within the NSICU. This model holds the potential to assist clinicians in making timely surgical decisions concerning TT.

Modified cadaver technique to simulate contaminated airway scenarios to train medical providers in suction-assisted laryngoscopy and airway decontamination

Simulation training plays a vital role in modern medical education, fostering safe skill development. Task-trainer manikin and cadaveric airway management training (CAMT) offer realistic airway management practice. Simulation allows learners the opportunity to manage high-risk, low-frequency scenarios, including difficult airways and massive airway contamination, common in emergent airway management. The suction-assisted laryngoscopy and airway decontamination (SALAD) technique was developed to address massive airway contamination. This paper describes two methods to simulate massive airway contamination utilizing cadavers. We detail our techniques for both esophageal and nasopharyngeal delivery of simulated airway contaminant. Nasopharyngeal delivery was less invasive and required less time to set up. Utilizing cadavers to simulate massive airway contamination in CAMT provides learners with tools to manage airway complications effectively, enhancing readiness for complex airway challenges while promoting patient safety in clinical practice.

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

Background

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

Methods

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

Results

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

Conclusion

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

Airway Management: The Current Role of Videolaryngoscopy

Airway management is usually an uncomplicated and safe intervention; however, when problems arise with the primary airway technique, the clinical situation can rapidly deteriorate, resulting in significant patient harm. Videolaryngoscopy has been shown to improve patient outcomes when compared with direct laryngoscopy, including improved first-pass success at tracheal intubation, reduced difficult laryngeal views, reduced oxygen desaturation, reduced airway trauma, and improved recognition of oesophageal intubation. The shared view that videolaryngoscopy affords may also facilitate superior teaching, training, and multidisciplinary team performance. As such, its recommended role in airway management has evolved from occasional use as a rescue device (when direct laryngoscopy fails) to a first-intention technique that should be incorporated into routine clinical practice, and this is reflected in recently updated guidelines from a number of international airway societies. However, currently, overall videolaryngoscopy usage is not commensurate with its now widespread availability. A number of factors exist that may be preventing its full adoption, including perceived financial costs, inadequacy of education and training, challenges in achieving deliverable decontamination processes, concerns over sustainability, fears over "de-skilling" at direct laryngoscopy, and perceived limitations of videolaryngoscopes. This article reviews the most up-to-date evidence supporting videolaryngoscopy, explores its current scope of utilisation (including specialist techniques), the potential barriers preventing its full adoption, and areas for future advancement and research.

Managing the Physiologically Difficult Airway in Critically Ill Adults

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

Airways management in SARS-COV-2 acute respiratory failure: A prospective observational multi-center study

OBJECTIVE

Few studies have reported the implications and adverse events of performing endotracheal intubation for critically ill COVID-19 patients admitted to intensive care units. The aim of the present study was to determine the adverse events related to tracheal intubation in COVID-19 patients, defined as the onset of hemodynamic instability, severe hypoxemia, and cardiac arrest.

SETTING

Tertiary care medical hospitals, dual-centre study performed in Northern Italy from November 2020 to May 2021.

PATIENTS

Adult patients with positive SARS-CoV-2 PCR test, admitted for respiratory failure and need of advanced invasive airways management.

INTERVENTIONS

Endotracheal Intubation Adverse Events.

MAIN VARIABLES OF INTERESTS

The primary endpoint was to determine the occurrence of at least 1 of the following events within 30 minutes from the start of the intubation procedure and to describe the types of major adverse peri-intubation events: severe hypoxemia defined as an oxygen saturation as measured by pulse-oximetry <80%; hemodynamic instability defined as a SBP 65 mmHg recoded at least once or SBP < 90 mmHg for 30 minutes, a new requirement or increase of vasopressors, fluid bolus >15 mL/kg to maintain the target blood pressure; cardiac arrest.

RESULTS

Among 142 patients, 73.94% experienced at least one major adverse peri-intubation event. The predominant event was cardiovascular instability, observed in 65.49% of all patients undergoing emergency intubation, followed by severe hypoxemia (43.54%). 2.82% of the patients had a cardiac arrest.

CONCLUSION

In this study of intubation practices in critically ill patients with COVID-19, major adverse peri-intubation events were frequent.

CLINICAL TRIAL REGISTRATION

www.

CLINICALTRIALS

gov identifier: NCT04909476.

Airways management in SARS-COV-2 acute respiratory failure: A prospective observational multi-center study

Objective

Few studies have reported the implications and adverse events of performing endotracheal intubation for critically ill COVID-19 patients admitted to intensive care units. The aim of the present study was to determine the adverse events related to tracheal intubation in COVID-19 patients, defined as the onset of hemodynamic instability, severe hypoxemia, and cardiac arrest.

Setting

Tertiary care medical hospitals, dual-centre study performed in Northern Italy from November 2020 to May 2021.

Patients

Adult patients with positive SARS-CoV-2 PCR test, admitted for respiratory failure and need of advanced invasive airways management.

Interventions

Endotracheal Intubation Adverse Events.

Main variables of interests

The primary endpoint was to determine the occurrence of at least 1 of the following events within 30 minutes from the start of the intubation procedure and to describe the types of major adverse peri-intubation events: severe hypoxemia defined as an oxygen saturation as measured by pulse-oximetry <80%; hemodynamic instability defined as a SBP 65 mmHg recoded at least once or SBP < 90 mmHg for 30 minutes, a new requirement or increase of vasopressors, fluid bolus >15 mL/kg to maintain the target blood pressure; cardiac arrest.

Results

Among 142 patients, 73.94% experienced at least one major adverse peri-intubation event. The predominant event was cardiovascular instability, observed in 65.49% of all patients undergoing emergency intubation, followed by severe hypoxemia (43.54%). 2.82% of the patients had a cardiac arrest.

Conclusion

In this study of intubation practices in critically ill patients with COVID-19, major adverse peri-intubation events were frequent.

Clinical Trial registration

www.clinicaltrials.gov identifier: NCT04909476.

Liberation from Mechanical Ventilation and Tracheostomy Practice in Traumatic Brain Injury

Liberating patients with severe traumatic brain injury (TBI) from mechanical ventilation is often a challenging task. These patients frequently require prolonged ventilation and have persistent alterations in the level and content of consciousness. Questions about their ability to protect their airway are common. Pulmonary complications and copious respiratory secretions are also very prevalent. Thus, it is hardly surprising that rates of extubation failure are high. This is a major problem because extubation failure is associated with a host of poor outcome measures. When the safety of an extubation attempt is uncertain, direct tracheostomy is favored by some, but there is no evidence that this practice leads to better outcomes. Current knowledge is insufficient to reliably predict extubation outcomes in TBI, and practices vary substantially across trauma centers. Yet observational studies provide relevant information that must be weighted when considering the decision to attempt extubation in patients with head injury. This review discusses available evidence on liberation from mechanical ventilation in TBI, proposes priorities for future research, and offers practical advice to guide decisions at the bedside.

Development and validation of a novel poisoning agitation-sedation score for predicting the need for endotracheal intubation and mechanical ventilation in acutely poisoned patients with disturbed consciousness

BACKGROUND

Accurate assessment of disturbed consciousness level (DCL) is crucial for predicting acutely poisoned patients' outcomes.

AIM

Development of a novel Poisoning Agitation-Sedation Score (PASS) to predict the need for endotracheal intubation (ETI) and mechanical ventilation (MV) in acutely poisoned patients with DCL. Validation of the proposed score on a new set of acutely poisoned patients with DCL.

METHODS

This study was conducted on 187 acutely poisoned patients with DCL admitted to hospital from June 2020 to November 2021 (Derivation cohort). Patients' demographics, toxicological data, neurological examination, calculation of the Glasgow Coma Scale (GCS), Full Outline of Unresponsiveness (FOUR) score, Richmond Agitation-Sedation Scale (RASS), and outcomes were gathered for developing a new score. The proposed score was externally validated on 100 acutely poisoned patients with DCL (Validation cohort).

RESULTS

The PASS assessing sedation consists of FOUR (reflexes and respiration) and GCS (motor) and provides a significantly excellent predictive power (AUC = 0.975) at a cutoff ≤9 with 100% sensitivity and 92.11% specificity for predicting the need for ETI and MV in sedated patients. Additionally, adding RASS (agitation) to the previous model exhibits significantly good predictive power (AUC = 0.893), 90.32% sensitivity, and 73.68% specificity at a cutoff ≤14 for predicting the need for ETI and MV in disturbed consciousness patients with agitation.

CONCLUSION

The proposed PASS could be an excellent, valid and feasible tool to predict the need for ETI and MV in acutely poisoned disturbed consciousness patients with or without agitation.

Confidence in airway management proficiency: a mixed methods study of intensive care specialists in Australia and New Zealand

Objective: To explore self-confidence, and the respective facilitators and barriers, among intensive care specialists in Australia and New Zealand in relation to airway management. Design: A mixed methods study. Setting: 11 intensive care units across Australia and New Zealand. Participants: 48 intensive care specialists. Intervention: A structured online interview and the presentation of three discrete airway management clinical scenarios - routine endotracheal intubation, awake fibreoptic intubation (AFOI), and emergency front of neck access (FONA). Main outcome measures: Graded Likert scale responses regarding confidence in airway management were analysed, and perceptions of facilitators and barriers to confidence in each select scenario were obtained as free text. A deductive thematic analysis was done iteratively on free text entry and allowed for the development of a coding framework. NVivo software used the coding framework to run coding queries and cross-tabulations for comparison of relationships between themes and participant demographic characteristics. Results: Participants reported differing levels of confidence. Clinical experience, an anaesthetic qualification and training (including simulation) were the major facilitators to influencing confidence. Participants were more confident performing routine intubation than AFOI or FONA. Equipment, checklists or protocols, and availability of video-laryngoscopy were also identified as facilitators to confidence by most participants. Work relationships, teams and other staff availability were identified as further facilitators to confidence; lack of these factors were less commonly identified as barriers. Conclusions: Confidence in airway management among intensive care specialists in Australia and New Zealand varies, both between specialists and depending on clinical context. Multiple facilitators to improving this exist, including additional mandatory training.

Evidence-based airway management protocol for a critical ill patient in medical intensive care unit: Systematic review

Background

Airway management outside the theatre is performed either to resuscitate a physiologically unstable critically ill patients or to secure an emergency airway in the absence of essential equipments. It is a life saving procedure for critically ill and injured patients. Delaying in securing airway or awaking the patient is not an option in case of difficult airway in intensive care unit. Therefore, developing and implementation of an evidence-based airway management protocol is important.

Objective

This review was conducted to develop a clear airway management protocol for a critical ill patient in medical intensive care unit.

Methods

After formulating the key questions, scope, and eligibility criteria for the evidences to be included, a comprehensive search strategy of electronic sources was conducted. The literatures were searched using advanced searching methods from data bases and websites to get evidences on airway management of a critical ill patient. Duplication of literatures was avoided by endnote. Screening of literatures was conducted based on the level of significance with proper appraisal. This review was carried out in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 statement.

Results

A total of 626 articles were identified from data bases and websites using an electronic search. Of these articles, 95 were removed for duplication and 305 studies were excluded after reviewing their titles and abstracts. At the screening stage, 79 articles were retrieved and evaluated for the eligibility. Finally, 40 studies related to airway management of a critical ill patient in medical ICU were included in this systematic review.

Conclusion

A critical ill patient needs oxygenation and ventilation support. A focused and rapid assessment, with special attention of the airway and hemodynamic status of the critical ill patient is paramount. An appropriate airway management option should be employed to resuscitate or to control an emergency airway of a critical ill patent. This could be non invasive ventilation or invasive airway intervention.

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

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

Hemodynamics in Helicopter Emergency Medical Services (HEMS) Patients Undergoing Rapid Sequence Intubation With Etomidate or Ketamine

BACKGROUND

Rapid sequence intubation (RSI) is performed by helicopter emergency medical services (HEMS) providers to establish airway control. Common induction agents are etomidate and ketamine, both touted to have relatively stable hemodynamic profiles. Limited data comparing these medications in the air medical setting exist.

OBJECTIVE

Compare administration of ketamine and etomidate on peri-intubation hemodynamics.

METHODS

A retrospective chart review of intubations performed by a HEMS program over 69 months was completed. Heart rate (HR) change, systolic blood pressure (SBP) change, and hypotension with etomidate or ketamine use were measured.

RESULTS

There were 258 patients induced with etomidate and 48 with ketamine. Etomidate patients showed a +1.161% change in HR (SD ± 22.7) and -0.49% change in SBP (SD ± 25.0). Ketamine patients showed a -4.7% change in HR (SD ± 16.7) and 17.2% change in SBP (SD ± 43.4). The p-values for percentage change in HR and SBP between etomidate and ketamine were 0.0830 and 0.0018, respectively. Twenty-five episodes of postadministration hypotension occurred with etomidate, and two with ketamine (p = 0.028).

CONCLUSION

Both ketamine and etomidate are appropriate for intubation of HEMS patients. Ketamine was preferentially selected for hypotensive patients with statistically significant improvement in SBP. Although statistically significant, both ketamine and etomidate had relative low incidences of hypotension.

Tracheal Tube-Mounted Camera Assisted Intubation vs. Videolaryngoscopy in Expected Difficult Airway: A Prospective, Randomized Trial (VivaOP Trial)

Background: Tracheal intubation in patients with an expected difficult airway may be facilitated by videolaryngoscopy (VL). The VL viewing axis angle is specified by the blade shape and visualization of the larynx may fail if the angle does not meet anatomy of the patient. A tube with an integrated camera at its tip (VST, VivaSight-SL) may be advantageous due to its adjustable viewing axis by means of angulating an included stylet.

Methods: With ethics approval, we studied the VST vs. VL in a prospective non-inferiority trial using end-tidal oxygen fractions (etO₂) after intubation, first-attempt success rates (FAS), visualization assessed by the percentage of glottis opening (POGO) scale, and time to intubation (TTI) as outcome parameters.

Results: In this study, 48 patients with a predicted difficult airway were randomized 1:1 to intubation with VST or VL. Concerning oxygenation, the VST was non-inferior to VL with etO₂ of 0.79 ± 0.08 (95% CIs: 0.75–0.82) vs. 0.81 ± 0.06 (0.79–0.84) for the VL group, mean difference 0.02 (−0.07 to 0.02), p = 0.234. FAS was 79% for VST and 88% for VL (p = 0.449). POGO was 89 ± 21% in the VST-group and 60 ± 36% in the VL group, p = 0.002. TTI was 100 ± 57 s in the VST group and 68 ± 65 s in the VL group (p = 0.079). TTI with one attempt was 84 ± 31 s vs. 49 ± 14 s, p < 0.001.

Conclusion: In patients with difficult airways, tracheal intubation with the VST is feasible without negative impact on oxygenation, improves visualization but prolongs intubation. The VST deserves further study to identify patients that might benefit from intubation with VST.

[Pharmacotherapy and intensive care aspects of status epilepticus: update 2020/2021]

Die gezielte Therapie epileptischer Ereignisse und im Speziellen des Status epilepticus (SE) setzt das sichere Erkennen der Krankheitsbilder voraus, wofür gerade bei Formen mit vorwiegend nichtmotorischen Symptomen klinische und elektroenzephalographische Expertise notwendig ist. Die im Jahr 2020 erfolgte Fortschreibung der deutschen Leitlinie zur Behandlung des SE hält an der streng stufengerechten Therapie fest, die eskalierend die Anwendung von Benzodiazepinen, spezifischen Antiepileptika und Anästhetika vorsieht. Bisher ist die Eingrenzung eines in den allermeisten Fällen wirksamen sowie zugleich sicheren und interaktionsfreien Antiepileptikums nicht gelungen. Individuelle Vorerkrankungen und aktuelle Begleitumstände gehen daher genauso wie Erfahrungen des Behandlerteams in die differenzierte Behandlung des SE ein. Insbesondere bei therapierefraktären Formen des SE erweist sich die Therapie als durchaus kompliziert und hat regelhaft intensivmedizinische Implikationen. Mithin ergeben sich im Zuge der modernen SE-Behandlung zahlreiche interdisziplinäre Schnittstellen. Zukünftige wissenschaftliche Fragstellungen werden sich u. a. mit der optimalen Therapie des nonkonvulsiven SE und hier v. a. dem Ausmaß und dem Zeitpunkt von adäquaten Therapieschritten sowie mit assoziierten ethischen Fragen einer Therapieeskalation beschäftigen.

European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation and organ donation.

European Resuscitation Council and European Society of Intensive Care Medicine Guidelines 2021: Post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation, and organ donation.

Impact of personal protective equipment on prehospital endotracheal intubation performance in simulated manikin

Background

Tracheal intubation in COVID-19 patients is a potentially high-risk procedure for healthcare professionals. Personal protective equipment (PPE) is recommended to minimize contact with critical patients with COVID-19 infection. This study aimed to primarily examine the effect of PPE use on intubation time and success rate among prehospital healthcare professionals; additionally, we compared intubation times among prehospital health care professionals using PPE with direct laryngoscopy and video laryngoscopy assistance.

Methods

In this prospective simulation study, we compared the intubation times and success rates among prehospital healthcare professionals who were or were not using PPE. Furthermore, demographic data, previous intubation experience, and previous intubation experience with PPE were recorded.

Results

Overall time to intubation with PPE use was 51.28 ± 3.89 s, which was significantly higher than that without PPE use (33.03 ± 2.65 s; p < 0.001). In addition, the overall success rate with PPE use was 74.4%, which was significantly lower than that without PPE use (93%;p < 0.001). PPE use increased the average intubation time by 19.73 ± 2.59 s with direct laryngoscopy and by 16.81 ± 2.86 s with video laryngoscopy (p < 0.001).

Conclusions

PPE use is associated with increased intubation time and decreased success rate. Video laryngoscopy assistance in cases where PPE use is required facilitates faster endotracheal intubation than does direct laryngoscopy assistance.

Retrospective Analysis of Peri-Intubation Hypoxemia During the Coronavirus Disease 2019 Epidemic Using a Protocol for Modified Airway Management

Supplemental Digital Content is available in the text.

This single-center retrospective study evaluated a protocol for the intubation of patients with confirmed or suspected coronavirus disease 2019 (COVID-19). Twenty-one patients were intubated, 9 of whom were found to have COVID-19. Adherence to the airway management protocol was high. COVID-19 patients had lower peripheral capillary oxygen saturation by pulse oximetry (Spo₂) nadirs during intubation (Spo₂, 73% [72%–77%] vs 89% [86%–94%], P = .024), and a greater percentage experienced severe hypoxemia defined as Spo₂ ≤80% (89% vs 25%, P = .008). The incidence of severe hypoxemia in COVID-19 patients should be considered in the development of guidelines that incorporate high-flow nasal cannula and noninvasive positive pressure ventilation.

The Impact of Nighttime on First Pass Success During the Emergent Endotracheal Intubation of Critically Ill Patients

BACKGROUND

While numerous investigations have described worse outcomes for patients undergoing emergent procedures at night, few studies have investigated the impact of nighttime on the outcomes of emergent endotracheal intubation (EEI). We hypothesized that for patients requiring EEI at night, the outcome of first pass success would be lower as compared to during the day.

METHODS

We performed a retrospective cohort study of all patients admitted to our institution between January 1st, 2016 and July 17st, 2019 who underwent EEI outside of an emergency department or operating room. Nighttime was defined as between 7:00 pm and 6:59 am. The primary outcome was the rate of first pass success. Logistic regression was utilized with adjustment for demographic, morbidity and procedure related covariables.

RESULTS

The final examined cohort included 1,674 EEI during the day and 1,229 EEI at night. The unadjusted rate of first pass success was not different between the day and night (77.5% vs. 74.6%, unadjusted odds ratio (OR): 0.85; 95% confidence interval (CI): 0.72, 1.0; P = 0.073 though following adjustment for prespecified covariables the odds of first pass success was lower at night (adjusted OR: 0.83, 95% CI: 0.69, 0.99; P = 0.042. Obesity was found to be an effect modifier on first pass success rate for day vs. night intubations. In obese patients, nighttime intubations had significantly lower odds of first pass success (adjusted OR: 0.71, 95% CI: 0.52, 0.98; P = 0.037).

DISCUSSION

After adjustment for patient and procedure related factors, we have found that the odds of first pass success is lower at night as compared to the day. This finding was, to some degree, driven by obesity which was found to be a significant effect modifier in this relationship.

COVID-19 respiratory support in the emergency department setting

Introduction

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19), may result in severe complications, multiorgan dysfunction, acute respiratory failure, and death. SARS-CoV-2 is highly contagious and places healthcare workers at significant risk, especially during aerosol-generating procedures, including airway management.

Objective

This narrative review outlines the underlying respiratory pathophysiology of patients with COVID-19 and discusses approaches to airway management in the emergency department (ED) based on current literature.

Discussion

Patients presenting with SARS-CoV-2 infection are at high risk for acute respiratory failure requiring airway management. Among hospitalized patients, 10–20% require intensive care unit admission, and 3–10% require intubation and mechanical ventilation. While providing respiratory support for these patients, proper infection control measures, including adherence to personal protective equipment policies, are necessary to prevent nosocomial transmission to healthcare workers. A structured approach to respiratory failure in these patients includes the use of exogenous oxygen via nasal cannula or non-rebreather, as well as titrated high-flow nasal cannula and non-invasive ventilation. This review offers several guiding principles and resources designed to be adapted in conjunction with local workplace policies for patients requiring respiratory support.

Conclusions

While the fundamental principles of acute respiratory failure management are similar between COVID-19 and non-COVID-19 patients, there are some notable differences, including a focus on provider safety. This review provides an approach to airway management and respiratory support in the patient with COVID-19.

Emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China: lessons learnt and international expert recommendations

Tracheal intubation in coronavirus disease 2019 (COVID-19) patients creates a risk to physiologically compromised patients and to attending healthcare providers. Clinical information on airway management and expert recommendations in these patients are urgently needed. By analysing a two-centre retrospective observational case series from Wuhan, China, a panel of international airway management experts discussed the results and formulated consensus recommendations for the management of tracheal intubation in COVID-19 patients. Of 202 COVID-19 patients undergoing emergency tracheal intubation, most were males (n=136; 67.3%) and aged 65 yr or more (n=128; 63.4%). Most patients (n=152; 75.2%) were hypoxaemic (Sao2 <90%) before intubation. Personal protective equipment was worn by all intubating healthcare workers. Rapid sequence induction (RSI) or modified RSI was used with an intubation success rate of 89.1% on the first attempt and 100% overall. Hypoxaemia (Sao2 <90%) was common during intubation (n=148; 73.3%). Hypotension (arterial pressure <90/60 mm Hg) occurred in 36 (17.8%) patients during and 45 (22.3%) after intubation with cardiac arrest in four (2.0%). Pneumothorax occurred in 12 (5.9%) patients and death within 24 h in 21 (10.4%). Up to 14 days post-procedure, there was no evidence of cross infection in the anaesthesiologists who intubated the COVID-19 patients. Based on clinical information and expert recommendation, we propose detailed planning, strategy, and methods for tracheal intubation in COVID-19 patients.

Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists

Severe acute respiratory syndrome-corona virus-2, which causes coronavirus disease 2019 (COVID-19), is highly contagious. Airway management of patients with COVID-19 is high risk to staff and patients. We aimed to develop principles for airway management of patients with COVID-19 to encourage safe, accurate and swift performance. This consensus statement has been brought together at short notice to advise on airway management for patients with COVID-19, drawing on published literature and immediately available information from clinicians and experts. Recommendations on the prevention of contamination of healthcare workers, the choice of staff involved in airway management, the training required and the selection of equipment are discussed. The fundamental principles of airway management in these settings are described for: emergency tracheal intubation; predicted or unexpected difficult tracheal intubation; cardiac arrest; anaesthetic care; and tracheal extubation. We provide figures to support clinicians in safe airway management of patients with COVID-19. The advice in this document is designed to be adapted in line with local workplace policies.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

A pilot study on using Suction-Assisted Laryngoscopy Airway Decontamination techniques to assist endotracheal intubation by GlideScope® in a manikin simulating massive hematemesis

Background:

The Suction-Assisted Laryngoscopy and Airway Decontamination techniques are newly designed emergency airway management skills to assist endotracheal intubation with the complementary use of suction catheters and video laryngoscopes in patients with severe vomiting or massive hematemesis.

Objectives:

To evaluate the performance of emergency department doctors in using the two Suction-Assisted Laryngoscopy and Airway Decontamination techniques (level 1 and level 2) to assist endotracheal intubation by GlideScope® in an airway manikin simulating massive hematemesis, the Nasco airway decontamination simulator.

Methods:

A total of 30 emergency department doctors were recruited in a pilot study. Their performance of using two levels of Suction-Assisted Laryngoscopy and Airway Decontamination techniques (Suction-Assisted Laryngoscopy and Airway Decontamination 1 and Suction-Assisted Laryngoscopy and Airway Decontamination 2) with two different suction catheters, the DuCanto suction catheter and Yankauer suction catheter, were compared with the conventional suction technique. The failed endotracheal intubation rates, time for intubation and number of attempts, amount of aspirated fluid, and the subjective ease of different methods by the participants were compared.

Results:

Irrespective the choice of suction catheter, endotracheal intubation in the manikin by using Suction-Assisted Laryngoscopy and Airway Decontamination 1 had the lowest failure rate which is much better than conventional suction technique (p = 0.012), smaller amount of aspiration compared with the conventional suction technique (p = 0.027), and comparable intubation time with the conventional suction technique (p = 0.850). Most participants were able to intubate the manikin successfully in the first attempt by Suction-Assisted Laryngoscopy and Airway Decontamination 1 with the DuCanto suction catheter, and they were of the opinion that such combination was the most preferred in performing endotracheal intubation.

Conclusion:

Suction-Assisted Laryngoscopy and Airway Decontamination 1 has the best performance in this manikin study, and Suction-Assisted Laryngoscopy and Airway Decontamination 1 with the DuCanto suction catheter was the most favorable method for endotracheal intubation in this manikin study by the participants.

Emergency Airway Response Team (EART) Documentation: Criteria, Feasibility, and Usability

Patients in an acute care hospital who experience a difficult airway event outside the operating room need a specialized emergency airway response team (EART) immediately. This designated team manages catastrophic airway events using advanced airway techniques as well as surgical intervention. Nurses respond as part of this team. There are no identified difficult airway team documentation instruments in the literature, and the lack of metrics limits the quality review of the team response. This study identified EART documentation criteria and incorporated them into a nursing documentation instrument to be completed by a nurse scribe during the event. The EART instrument was tested by nurses for usability, feasibility, and completeness. Twenty-one critical care nurses participated in this study. The results confirmed good usability, positive feasibility, and 79% documentation completeness using this tool. These criteria and this instrument can be important in documenting the EART and in evaluating the quality of the team performance.

[Airway management in intensive care and emergency medicine : What is new?]

In acute respiratory insufficiency, oxygenation and/or ventilation support by mechanical ventilation is an integral part of intensive care and emergency medicine. Effective airway management is essential to prevent hypoxic complications during the securing of the airway. This includes for example the recognition of difficult airways and adequate pre-oxygenation. While the laryngeal tube can be used in the context of cardiopulmonary resuscitation in emergency medicine, endotracheal intubation is standard in intensive care medicine. In addition to direct laryngoscopy (DL), indirect laryngoscopy using video laryngoscopy (VL) is also available. Compared to DL, advantages in intubation success, anticipated difficult airways, and a reduction of mucosa damage have been shown for VL, whereas the advantage for intubation success could only be demonstrated for experienced physicians who should always be present due to the potential complications of intubation. With regard to mortality and incidence of hypoxia, no difference between DL and VL could be shown. According to current data, the VL should not be used preclinically. A tracheostomy is often performed for long-term ventilation. It is still unclear which patients benefit from an early tracheostomy. Usually the bed-side percutaneous dilatation tracheostomy technique is used, which is often performed under bronchoscopic guidance.

Endotracheal tube-mounted camera-assisted intubation versus conventional intubation in intensive care: a prospective, randomised trial (VivaITN)

BACKGROUND

For critically ill patients, effective airway management with a high first-attempt success rate for endotracheal intubation is essential to prevent hypoxic complications during securing of the airway. Video guidance may improve first-attempt success rate over direct laryngoscopy (DL).

METHODS

With ethics approval, this randomised controlled trial involved 54 critically ill patients who received endotracheal intubation using a tube with an integrated video camera (VivaSight™-SL tube, VST, ETView Ltd., Misgav, Israel) or using conventional intubation under DL.

RESULTS

The two groups did not differ in terms of intubation conditions. The first-attempt success rate was VST 96% vs. DL 93% (not statistically significant (n. s.)). When intubation at first attempt failed, it was successful in the second attempt in all patients. There was no difference in the median average time to intubation (VST 34 s (interquartile range 28-39) vs. DL 35 s (28-40), n. s.). Neither vomiting nor aspiration or accidental oesophageal intubation were observed in either group. The lowest pulsoxymetric oxygen saturation for VST was 96 (82-99) % vs. 99 (95-100) % for DL (n. s.). Hypotension defined as systolic blood pressure < 70 mmHg occurred in the VST group at 20% vs. the DL group at 15% (n. s.).

CONCLUSION

In this pilot study, no advantage was shown for the VST. The VST should be examined further to identify patient groups that could benefit from intubation with the VST, that is, patients with difficult airway conditions.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02837055 . Registered on 13 June 2016.

Paediatric intensive care and neonatal intensive care airway management in the United Kingdom: the PIC-NIC survey

In 2011, the Fourth National Audit Project (NAP4) reported high rates of airway complications in adult intensive care units (ICUs), including death or brain injury, and recommended preparation for airway difficulty, immediately available difficult airway equipment and routine use of waveform capnography monitoring. More than 80% of UK adult intensive care units have subsequently changed practice. Undetected oesophageal intubation has recently been listed as a 'Never Event' in UK practice, with capnography mandated. We investigated whether the NAP4 recommendations have been embedded into paediatric and neonatal intensive care practice by conducting a telephone survey of senior medical or nursing staff in UK paediatric intensive care units (PICUs) and neonatal intensive care units (NICUs). Response rates were 100% for paediatric intensive care units and 90% for neonatal intensive care units. A difficult airway policy existed in 67% of paediatric intensive care units and in 40% of neonatal intensive care units; a pre-intubation checklist was used in 70% of paediatric intensive care units and in 42% of neonatal intensive care units; a difficult intubation trolley was present in 96% of paediatric intensive care units and in 50% of neonatal intensive care units; a videolaryngoscope was available in 55% of paediatric intensive care units and in 29% of neonatal intensive care units; capnography was 'available' in 100% of paediatric intensive care units and in 46% of neonatal intensive care units, and 'always available' in 100% of paediatric intensive care units and in 18% of neonatal intensive care units. Death or serious harm occurring secondary to complications of airway management in the last 5 years was reported in 19% of paediatric intensive care units and in 26% of neonatal intensive care units. We conclude that major gaps in optimal airway management provision exist in UK paediatric intensive care units and especially in UK neonatal intensive care units. Wider implementation of waveform capnography is necessary to ensure compliance with the new 'Never Event' and has the potential to improve airway management.

Use of ultrasound to predict difficult intubation in Chinese population by assessing the ratio of the pre-epiglottis space distance and the distance between epiglottis and vocal folds

Objective:

To investigate the accuracy of using the ratio of pre-epiglottis space distance (Pre-E) and the distance between the epiglottis and the vocal folds (Pre-E/E-VF) measured by the ultrasound to predict potential difficult airway in the Chinese population.

Design:

A prospective clinical study.

Setting:

The pre-operative assessment service clinic of Tuen Mun Hospital.

Patients:

Patients with age of 18 years or above, who were scheduled for elective surgery requiring general anesthesia with direct laryngoscopy and tracheal intubation.

Results:

A total of 113 patients with direct laryngoscopic assessment during elective operations were included. Thirty-nine (34.5%) patients had potential difficult airway which was defined as documented Cormack–Lehane classification grade 2b, 3, or 4 by the anesthetists. Measurement of the distance from the epiglottis to the anterior vocal folds (Pre-E/aVF) ratio had better inter-rater reliability and accuracy comparing to the measurements of the distances from the epiglottis to the midpoint between the vocal folds and to the posterior vocal folds. The performance of using the Pre-E/aVF ratio to predict potential difficult airway was compared with other clinical tests (the Mallampati classification, the thyromental distance and the neck circumference to thyromental distance ratio). By using the Pre-E/aVF ratio of 1, the sensitivity and specificity to predict a potential difficult airway were 79.5% and 39.2%, respectively (p = 0.044). The ultrasound assessment method had a comparable predictive value as the Mallampati classification (the area under the receiver operator characteristic curves 0.648 vs 0.687). The negative likelihood ratio of the ultrasound assessment method was the lowest among all the other airway assessment methods.

Conclusion:

The ultrasound airway assessment method could serve as a non-invasive test and supplement the currently used clinical assessment methods. A lower cut-off point of the Pre-E/E-VF ratio should be used in the Chinese population.

Comparison of Upper Lip Bite Test and Ratio of Height to Thyromental Distance with Other Airway Assessment Tests for Predicting Difficult Endotracheal Intubation

BACKGROUND AND AIMS

Unanticipated difficult intubation or the failed intubation in operating room and in emergency department is an imperative source of anesthesia-related patient's mortality. The aim of this study is to compare the predictive value of upper lip bite test (ULBT) and ratio of height to thyromental distance (RHTMD) with other commonly used preoperative airway assessment tests for predicting difficult intubation in Indian population.

MATERIALS AND METHODS

In this prospective, single-blinded observational study, 260 adult patients of either sex, belonging to American Society of Anesthesiologists physical Status I and II undergoing elective surgical procedure under general anesthesia were included in the study. ULBT, RHTMD, inter-incisor gap, modified Mallampati grade, horizontal length of the mandible, head and neck movements, sternomental distance, and TMD were assessed preoperatively and correlated with Cormack and Lehane's grading during laryngoscopy under anesthesia. Statistical analysis was done by Chi-square and Fisher's exact test.

RESULTS

ULBT and RHTMD had highest sensitivity (66.7% and 63.3%), specificity (99.1% and 89.6%), positive predictive value (90.9% and 44.2%), and negative predictive value (96.9% and 95.0%), respectively, when compared to other parameters in predicting difficult airway.

CONCLUSION

ULBT and RHTMD may be used as a simple bedside airway assessment tools for prediction of difficult intubation.

Guidelines for the management of tracheal intubation in critically ill adults

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

Mechanical Ventilation: State of the Art

Mechanical ventilation is the most used short-term life support technique worldwide and is applied daily for a diverse spectrum of indications, from scheduled surgical procedures to acute organ failure. This state-of-the-art review provides an update on the basic physiology of respiratory mechanics, the working principles, and the main ventilatory settings, as well as the potential complications of mechanical ventilation. Specific ventilatory approaches in particular situations such as acute respiratory distress syndrome and chronic obstructive pulmonary disease are detailed along with protective ventilation in patients with normal lungs. We also highlight recent data on patient-ventilator dyssynchrony, humidified high-flow oxygen through nasal cannula, extracorporeal life support, and the weaning phase. Finally, we discuss the future of mechanical ventilation, addressing avenues for improvement.

Laryngeal tube suction for airway management during in-hospital emergencies

OBJECTIVE:

The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation.

METHODS:

During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded.

RESULTS:

In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference.

CONCLUSIONS:

LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.

CXC Chemokine Receptor Type 4 Antagonism Ameliorated Allograft Fibrosis in Rat Kidney Transplant Model

OBJECTIVES

In this study, we evaluated the effects of CXC chemokine receptor type 4 and stromal cell-derived factor 1 signaling in the progression of chronic allograft nephropathy in a rat model.

MATERIALS AND METHODS

Experimental rats were divided into 3 groups: Lewis-to-Lewis isograft transplant (group A), Fisher 344 rat-to-Lewis allograft transplant with immunosuppressant cyclosporine (group B), and Fisher 344 rat-to-Lewis allograft transplant treated with cyclosporine and the CXC chemokine receptor type 4 antagonist AMD3100 (1 mg/kg/d) (group C). On day 90 after the operation, renal graft function, proteinuria, and histologic Banff score were measured. The expression levels of transforming growth factor β1 and collagen IV were determined by quantitative real-time polymerase chain reaction.

RESULTS

Renal function and urinary protein were increased in allografts of groups B and C compared with isografts of group A. The Banff score was significantly decreased in the AMD3100-treated animals (group C), with renal fibrosis being reduced. In addition, overexpressed levels of transforming growth factor β1 and collagen IV in group B allografts were significantly reduced versus that shown with treatment with the CXC chemokine receptor type 4 antagonist in group C.

CONCLUSIONS

Together, these data strongly implicate that CXC chemokine receptor type 4 antagonism alleviated renal interstitial fibrosis in long-term surviving allografts by down-regulating expression of transforming growth factor β1.