Effects of Vasopressors on Cerebral Circulation and Oxygenation: A Narrative Review of Pharmacodynamics in Health and Traumatic Brain Injury
The clinical use of vasoactive drugs aims to improve hemodynamic variables and thereby maintain or restore adequate perfusion and oxygenation in accordance with metabolic demands. A main focus in the management of patients with brain pathology during surgery and neurointensive care is restoring and/or maintaining adequate cerebral perfusion pressure in order to ensure cerebral blood flow in accordance with metabolic demands. One commonly used clinical strategy is the administration of vasoactive drugs aiming to increase mean arterial blood pressure and thereby cerebral perfusion pressure. Here, we first describe the anatomic and physiological basis for the cerebrovascular effects of vasopressor agents. Next, we review the pharmacodynamics of commonly used vasopressors under normal circumstances and in the presence of head injury. We further discuss the role of blood-brain barrier disruption and microvascular dysfunction with regard to the effects of the reviewed vasopressor agents.
Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome The AIRWAYS-2 Randomized Clinical Trial.
Het artikel van de week is de Airways-2 trial! Over dit artikel heeft het team van urgentiegeneeskunde.com een gezamenlijke blog gemaakt met de collega's van FanofEM. Lees in deze blog meer over de achtergronden en relevantie van dit artikel.
The optimal approach to airway management during out-of-hospital cardiac arrest is unknown.
To determine whether a supraglottic airway device (SGA) is superior to tracheal intubation (TI) as the initial advanced airway management strategy in adults with nontraumatic out-of-hospital cardiac arrest.
DESIGN, SETTING, AND PARTICIPANTS:
Multicenter, cluster randomized clinical trial of paramedics from 4 ambulance services in England responding to emergencies for approximately 21 million people. Patients aged 18 years or older who had a nontraumatic out-of-hospital cardiac arrest and were treated by a participating paramedic were enrolled automatically under a waiver of consent between June 2015 and August 2017; follow-up ended in February 2018.
Paramedics were randomized 1:1 to use TI (764 paramedics) or SGA (759 paramedics) as their initial advanced airway management strategy.
MAIN OUTCOMES AND MEASURES:
The primary outcome was modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest, whichever occurred sooner. Modified Rankin Scale score was divided into 2 ranges: 0-3 (good outcome) or 4-6 (poor outcome; 6 = death). Secondary outcomes included ventilation success, regurgitation, and aspiration.
A total of 9296 patients (4886 in the SGA group and 4410 in the TI group) were enrolled (median age, 73 years; 3373 were women [36.3%]), and the modified Rankin Scale score was known for 9289 patients. In the SGA group, 311 of 4882 patients (6.4%) had a good outcome (modified Rankin Scale score range, 0-3) vs 300 of 4407 patients (6.8%) in the TI group (adjusted risk difference [RD], -0.6% [95% CI, -1.6% to 0.4%]). Initial ventilation was successful in 4255 of 4868 patients (87.4%) in the SGA group compared with 3473 of 4397 patients (79.0%) in the TI group (adjusted RD, 8.3% [95% CI, 6.3% to 10.2%]). However, patients randomized to receive TI were less likely to receive advanced airway management (3419 of 4404 patients [77.6%] vs 4161 of 4883 patients [85.2%] in the SGA group). Two of the secondary outcomes (regurgitation and aspiration) were not significantly different between groups (regurgitation: 1268 of 4865 patients [26.1%] in the SGA group vs 1072 of 4372 patients [24.5%] in the TI group; adjusted RD, 1.4% [95% CI, -0.6% to 3.4%]; aspiration: 729 of 4824 patients [15.1%] vs 647 of 4337 patients [14.9%], respectively; adjusted RD, 0.1% [95% CI, -1.5% to 1.8%]).
CONCLUSIONS AND RELEVANCE:
Among patients with out-of-hospital cardiac arrest, randomization to a strategy of advanced airway management with a supraglottic airway device compared with tracheal intubation did not result in a favorable functional outcome at 30 days.
Rein Ketelaars, Gabby Reijnders, Geert-Jan van Geffen, Gert Jan Scheffer and Nico Hoogerwerf
Critical Ultrasound Journal201810:17 https://doi.org/10.1186/s13089-018-0099-y
Prehospital point-of-care ultrasound used by nonradiologists in emergency medicine is gaining ground. It is feasible on-scene and during aeromedical transport and allows health-care professionals to detect or rule out potential harmful conditions. Consequently, it impacts decision-making in prioritizing care, selecting the best treatment, and the most suitable transport mode and destination. This increasing relevance of prehospital ultrasonography is due to advancements in ultrasound devices and related technology, and to a growing number of applications. This narrative review aims to present an overview of prehospital ultrasonography literature. The focus is on civilian emergency (trauma and non-trauma) setting. Current and potential future applications are discussed, structured according to the airway, breathing, circulation, disability, and environment/exposure (ABCDE) approach. Aside from diagnostic implementation and specific protocols, procedural guidance, therapeutic ultrasound, and challenges are reviewed.
New England Journal of Medicine; July 18, 2018 DOI: 10.1056/NEJMoa1806842
Background: Concern about the use of epinephrine as a treatment for out-of-hospital cardiac arrest led the International Liaison Committee on Resuscitation to call for a placebo-controlled trial to determine whether the use of epinephrine is safe and effective in such patients.
Methods: In a randomized, double-blind trial involving 8014 patients with out-of-hospital cardiac arrest in the United Kingdom, paramedics at five National Health Service ambulance services administered either parenteral epinephrine (4015 patients) or saline placebo (3999 patients), along with standard care. The primary outcome was the rate of survival at 30 days. Secondary outcomes included the rate of survival until hospital discharge with a favorable neurologic outcome, as indicated by a score of 3 or less on the modified Rankin scale (which ranges from 0 [no symptoms] to 6 [death]).
Results: At 30 days, 130 patients (3.2%) in the epinephrine group and 94 (2.4%) in the placebo group were alive (unadjusted odds ratio for survival, 1.39; 95% confidence interval [CI], 1.06 to 1.82; P=0.02). There was no evidence of a significant difference in the proportion of patients who survived until hospital discharge with a favorable neurologic outcome (87 of 4007 patients [2.2%] vs. 74 of 3994 patients [1.9%]; unadjusted odds ratio, 1.18; 95% CI, 0.86 to 1.61). At the time of hospital discharge, severe neurologic impairment (a score of 4 or 5 on the modified Rankin scale) had occurred in more of the survivors in the epinephrine group than in the placebo group (39 of 126 patients [31.0%] vs. 16 of 90 patients [17.8%]).
Conclusions: In adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a significantly higher rate of 30-day survival than the use of placebo, but there was no significant between-group difference in the rate of a favorable neurologic outcome because more survivors had severe neurologic impairment in the epinephrine group. (Funded by the U.K. National Institute for Health Research and others; Current Controlled Trials number, ISRCTN73485024.)
Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials
Critical Care 2018 22:6 https://doi.org/10.1186/s13054-017-1927-3
We performed a systematic review of randomized controlled studies evaluating any drug, technique or device aimed at improving the success rate or safety of tracheal intubation in the critically ill.
We searched PubMed, BioMed Central, Embase and the Cochrane Central Register of Clinical Trials and references of retrieved articles. Finally, pertinent reviews were also scanned to detect further studies until May 2017. The following inclusion criteria were considered: tracheal intubation in adult critically ill patients; randomized controlled trial; study performed in Intensive Care Unit, Emergency Department or ordinary ward; and work published in the last 20 years. Exclusion criteria were pre-hospital or operating theatre settings and simulation-based studies. Two investigators selected studies for the final analysis. Extracted data included first author, publication year, characteristics of patients and clinical settings, intervention details, comparators and relevant outcomes. The risk of bias was assessed with the Cochrane Collaboration’s Risk of Bias tool.
We identified 22 trials on use of a pre-procedure check-list (1 study), pre-oxygenation or apneic oxygenation (6 studies), sedatives (3 studies), neuromuscular blocking agents (1 study), patient positioning (1 study), video laryngoscopy (9 studies), and post-intubation lung recruitment (1 study). Pre-oxygenation with non-invasive ventilation (NIV) and/or high-flow nasal cannula (HFNC) showed a possible beneficial role. Post-intubation recruitment improved oxygenation, while ramped position increased the number of intubation attempts and thiopental had negative hemodynamic effects. No effect was found for use of a checklist, apneic oxygenation (on oxygenation and hemodynamics), videolaryngoscopy (on number and length of intubation attempts), sedatives and neuromuscular blockers (on hemodynamics). Finally, videolaryngoscopy was associated with severe adverse effects in multiple trials.
The limited available evidence supports a beneficial role of pre-oxygenation with NIV and HFNC before intubation of critically ill patients. Recruitment maneuvers may increase post-intubation oxygenation. Ramped position increased the number of intubation attempts; thiopental had negative hemodynamic effects and videolaryngoscopy might favor adverse events.
Keywords: Tracheal intubation, Critically ill, Emergency department, Intensive care unit, Videolaryngoscopy, High flow nasal cannula
British Journal of Anaesthesia 2018, article in press
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 4th 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.
Relationship between non-technical skills and technical performance during cardiopulmonary resuscitation: does stress have an influence?
Emerg Med J 2017;34:728-733.
Non-technical skills, such as task management, leadership, situational awareness, communication and decision-making refer to cognitive, behavioural and social skills that contribute to safe and efficient team performance. The importance of these skills during cardiopulmonary resuscitation (CPR) is increasingly emphasised. Nonetheless, the relationship between non-technical skills and technical performance is poorly understood. We hypothesise that non-technical skills become increasingly important under stressful conditions when individuals are distracted from their tasks, and investigated the relationship between non-technical and technical skills under control conditions and when external stressors are present.
In this simulator-based randomised cross-over study, 30 anaesthesiologists and anaesthesia residents from the VU University Medical Center, Amsterdam, the Netherlands, participated in two different CPR scenarios in random order. In one scenario, external stressors (radio noise and a distractive scripted family member) were added, while the other scenario without stressors served as control condition. Non-technical performance of the team leader and technical performance of the team were measured using the ‘Anaesthetists’ Non-technical Skill’ score and a recently developed technical skills score. Analysis of variance and Pearson correlation coefficients were used for statistical analyses.
Results Non-technical performance declined when external stressors were present (adjusted mean difference 3.9 points, 95% CI 2.4 to 5.5 points). A significant correlation between non-technical and technical performance scores was observed when external stressors were present (r=0.67, 95% CI 0.40 to 0.83, p<0.001), while no evidence for such a relationship was observed under control conditions (r=0.15, 95% CI −0.22 to 0.49, p=0.42). This was equally true for all individual domains of the non-technical performance score (task management, team working, situation awareness, decision-making).
Conclusions During CPR with external stressors, the team’s technical performance is related to the non-technical skills of the team leader. This may have important implications for training of CPR teams.
Resuscitative Endovascular Balloon Occlusion of the Aorta: Principles, Initial Clinical Experience, and Considerations for the Anesthesiologist
Anesthesia & Analgesia: September 2017 - Volume 125 - Issue 3 - p 884–890
Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an endovascular technique that allows for temporary occlusion of the aorta in patients with severe, life-threatening, trauma-induced noncompressible hemorrhage arising below the diaphragm. REBOA utilizes a transfemoral balloon catheter inserted in a retrograde fashion into the aorta to provide inflow control and support blood pressure until definitive hemostasis can be achieved. Initial retrospective and registry clinical data in the trauma surgical literature demonstrate improvement in systolic blood pressure with balloon inflation and improved survival compared to open aortic cross-clamping via resuscitative thoracotomy. However, there are no significant reports of anesthetic implications and perioperative management in this challenging cohort. In this narrative, we review the principles, technique, and logistics of REBOA deployment, as well as initial clinical outcome data from our level-1 American College of Surgeons–verified trauma center. For anesthesiologists who may not yet be familiar with REBOA, we make several suggestions and recommendations for intraoperative management based on extrapolation from these initial surgical-based reports, opinions from a team with increasing experience, and translated experience from emergency aortic vascular surgical procedures. Further prospective data will be necessary to conclusively guide anesthetic management, especially as potential complications and implications for global organ function, including cerebral and renal, are recognized and described.
Ventilation rate in adults with a tracheal tube during cardiopulmonary resuscitation: A systematic review
The optimal ventilation rate during cardiopulmonary resuscitation (CPR) with a tracheal tube is unknown. We evaluated whether in adults with cardiac arrest and a secure airway (tracheal tube), a ventilation rate of 10 min−1, compared to any other rate during CPR, improves outcomes.
A systematic review up to 14 July 2016. We included both adult human and animal studies. A GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach was used to evaluate the quality of evidence for each outcome.
We identified one human observational study with 67 patients and ten animal studies (234 pigs and 30 dogs). All studies carried a high risk of bias. All studies evaluated for return of spontaneous circulation (ROSC). Studies showed no improvement in ROSC with a ventilation rate of 10 min-1 compared to any other rate. The evidence for longer-term outcomes such as survival to discharge and survival with favourable neurological outcome was very limited.
A ventilation rate recommendation of 10 min-1 during adult CPR with a tracheal tube and no pauses for chest compression is a very weak recommendation based on very low quality evidence.
The Acute Care Anesthesiologist as Resuscitationist
Conti, Bianca MD; Greco, Karla M. MD, MHS; McCunn, Maureen MD, MIPP, FCCM
International Anesthesiology Clinics: Summer 2017 - Volume 55 - Issue 3 - p 109–116
Resuscitation from critical illness or traumatic injury is no longer defined by massive crystalloid infusions, blood product transfusions without defined endpoints, or initiation of vasoactive medications at the physician’s discretion. Clearly defined, data-driven guidelines now exist that target specific goal-directed therapies in trauma, sepsis, and emergency general surgery, and incorporate both therapeutic and bedside diagnostic adjuncts. Ongoing research and controversy regarding resuscitation strategies in patients after trauma, for emergency surgery, or with sepsis will undoubtedly change current management paradigms. There is a need to maintain up-to-date knowledge and clinical excellence in the science of resuscitation that may suggest the need for specialization and expertise in the field of anesthesiology.
Anesthesiology has become more subspecialized, with recognized Accreditation Council for Graduate Medical Education (ACGME) fellowships offered in pediatrics, cardiac, critical care, pain management, and, most recently, obstetrics and regional anesthesia. There is currently a proposal to highlight the need for an additional American Board of Anesthesiology (ABA)/ACGME-approved fellowship—through the critical care track—targeted at trauma, acute care, and emergency care anesthesia practice: the acute care anesthesiologist. The question of whether this training should be unique to anesthesiologists, or should be combined with training in emergency medicine, has also been raised.Regardless of the structured curriculum that eventually develops, the management of resuscitation is rapidly maturing.