April 15, 2019

Background:Tracheal intubation is a common procedure performed on critically ill patients. In these patients, there is a high risk of life-threatening complications associated with the procedure, with severe hypoxemia being one of the more common. Development of severe hypoxemia, in turn, increases the risk of post-intubation cardiac arrest. Therefore, optimal preoxygenation is an essential part of tracheal intubation to help stave off subsequent complications.

Both NIV and HFNC can provide a higher fraction of inspired oxygen than standard oxygen therapies.  HFNC can provide continuous oxygen up to 70L/min via nasal prongs with the potential advantage of remaining in place for apneic oxygenation. NIV can also provide high flow oxygen but must be removed during the apneic phase of intubation.  To date there has not been a study comparing NIV vs HFNC to reduce the incidence of severe hypoxemia during intubation until now; the FLORALI-2 trial.

March 29, 2019

On the last day of the last SMACC conference, Dr. Ken Milne (The SGEM) and I had a cage match debating four critical care controversies. It was all done in good fun with both of us taking our opportunities to poke a little fun at each other. While we took a pro vs con approach to the presentation, our positions are much closer than the debate demonstrates. Although the literature is far from perfect, development of critical appraisal skills and application of evidence-based medicine to the literature is what we should be using to inform our care but not dictate our care. It is equally as important to incorporate clinical judgment and ask our patients what their values and preferences are before making decisions about care.

March 28, 2019

Pulse Checks Background: In an older study published in Resuscitation 1998 [1], ED physicians, ICU physicians, and nurses tried to identify a carotid pulse in a healthy male volunteer with normal blood pressure. 43.1% of the health professionals required >5 seconds to detect the carotid pulse and another 4.3% required >10 seconds.  Something I have advocated for in cardiac arrest is the death of pulse checks, as our fingers are poorly sensitive for detecting which patients have a pulse in a shock state.  A visible rhythm on the monitor, along with the absence of a pulse with digital palpation, does not always indicate the presence of true pulseless electrical activity (PEA).  Our reflexive action when we don’t feel a pulse is to begin CPR and give 1mg epinephrine which may not be beneficial in these patients.  Patients in profound shock don’t necessarily need cpr and 1mg of epinephrine, they need augmentation of cardiac output with either push dose pressors or hemodynamically driven epinephrine drips.  Now another study published in Resuscitation looked to compare the efficiency of cardiac ultrasonography (CUSG), doppler ultrasonography (DUSG) and manual pulse palpation to check the pulse in cardiac arrest patients [2].

March 21, 2019

Background: Rapid Sequence Intubation (RSI)  is a common procedure performed by both emergency clinicians and intensivists. Although the procedure is complex, the major pieces are pre-oxygenation, administration of a sedative agent in close proximity with a paralytic, laryngoscopy and placement of an endotracheal tube without the provision of any ventilations during the process. The avoidance of bag-mask ventilations (BMV), or any positive pressure breaths, rests on the belief that those breaths can distend the stomach and lead to regurgitation and aspiration. For this to happen, the force of the breath must exceed the pressure of the lower esophageal sphincter (~ 20 mm Hg). Critically ill patients presenting with airway compromise cannot be guaranteed to have a fasting state, regurgitation and aspiration is a major concern.

However, there’s another side to this. Many of our patients who are critically ill have intrapulmonary shunting; portions of the lung are atelectatic, filled with fluid, blood, or pus and not being oxygenated though they are being perfused. Blood running through these portions of the lung will be deoxygenated and will lower the overall O2 content of blood entering the systemic circulation after mixing with blood coming from ventilated regions. This shunting at least partially explains why we see patients rapidly desaturating during intubation. Positive pressure can recruit atelectatic portions of the lung that are not involved in gas exchange thus decreasing the physiologic shunt and increasing the patient’s oxygen reserve.

Despite decades of experience with RSI we continue to look for better approaches since the procedure still poses serious risks to the patient. Recent modifications that have seen wide adoption include using the bed-up-head-elevated (BUHE) position, suction assisted laryngoscopy for airway decontamination (SALAD) and bougie first intubation, though there are many more. Now, a publication in the NEJM makes us question the core principle of BMV during RSI.

November 8, 2018

Background: In the United States 424,000 out of hospital cardiac arrests occur per year with a 10.4% overall survival rate.1 Refractory Ventricular Fibrillation (RVF) is a complication of cardiac arrest and has varying definitions in the literature but is commonly defined as ventricular fibrillation that does not respond to, or resists, three or more defibrillation attempts.2,3Although the estimated incidence of refractory ventricular fibrillation is 0.5-0.6 per 100,000 of the population, some authors report that 10-25% of cardiac arrest cases could develop RVF or recurrent VF.3-5 Patients who experience RVF during their cardiac arrest have a mortality of up to 97%.6,7 Several case reports have shown success with excellent neurologic outcomes in terminating RVF using dual defibrillation after failure of traditional Advance Cardiac Life Support (ACLS) measures.8-12 It is important to note and distinguish that dual defibrillation can either be simultaneous or sequential depending on the duration of the defibrillation potential as well as the intershock interval between the two defibrillator shocks.9-13 The terms “sequential” and “simultaneous” are often used interchangably due to the lack of accurately measuring pulse intervals when performing dual defibrillation in the actual clinical environment. The authors of this review utilize the term dual sequential defibrillation (DSD). They present a case of RVF in a patient with cardiac arrest, on whom DSD was successful in reversion to sinus rhythm and provide a thorough review of similar cases in the literature.