Susan R. Wilcox

Neuromuscular blocking agent administration for emergent tracheal intubation is associated with decreased prevalence of procedure-related complications.

Background:Emergent intubation is associated with a high rate of complications. Neuromuscular blocking agents are routinely used in the operating room and emergency department to facilitate intubation. However, use of neuromuscular blocking agents during emergent airway management outside of the operating room and emergency department is controversial. We hypothesized that the use of neuromuscular blocking agents is associated with a decreased prevalence of hypoxemia and reduced rate of procedure-related complications. Methods:Five hundred sixty-six patients undergoing emergent intubations in two tertiary care centers, Massachusetts General Hospital, Boston, MA, and the University of California Los Angeles, Ronald Reagan Medical Center, Los Angeles, CA, were enrolled in a prospective, observational study. The 112 patients intubated during cardiopulmonary resuscitation were excluded, leaving 454 patients for analysis. All intubations were supervised by attendings trained in Critical Care Medicine. We measured intubating conditions, oxygen saturation during and 5 mins following intubation. We assessed the prevalence of procedure-related complications defined as esophageal intubation, traumatic intubation, aspiration, dental injury, and endobronchial intubation. Results:The use of neuromuscular blocking agents was associated with a lower prevalence of hypoxemia (10.1% vs. 17.4%, p = .022) and a lower prevalence of procedure-related complications (3.1% vs. 8.3%, p = .012). This association persisted in a multivariate analysis, which controlled for airway grade, sedation, and institution. Use of neuromuscular blocking agents was associated with significantly improved intubating conditions (laryngeal view, p = .014; number of intubation attempts, p = .049). After controlling for the number of intubation attempts and laryngoscopic view, muscle relaxant use is an independent predictor of complications associated with emergency intubation (p = .037), and there is a trend towards improvement of oxygenation (p = .07). Conclusion:The use of neuromuscular blocking agents, when used by intensivists with a high level of training and experience, is associated with a decrease in procedure-related complications.

Massive Transfusion in Traumatic Shock

BACKGROUND Hemorrhage after trauma is a common cause of death in the United States and globally. The primary goals when managing traumatic shock are the restoration of oxygen delivery to end organs, maintenance of circulatory volume, and prevention of ongoing bleeding through source control and correction of coagulopathy. Achieving these goals may require massive transfusion of blood products. Although use of blood products may be lifesaving, dose-related adverse effects are well described. DISCUSSION Complications of massive transfusion include interdependent derangements such as coagulopathy, hypothermia, acidosis, and electrolyte abnormalities, as well as infectious and immunomodulatory phenomena. This article explores the pathogenesis, implications, prevention, and treatment of these complications through the use of massive transfusion protocols. Particular attention is given to the optimal ratio of blood products transfused in large volume resuscitation and prevention of secondary coagulopathy. CONCLUSIONS Observational data indicate that the development and use of a massive transfusion protocol may reduce the morbidity and mortality associated with large-volume resuscitation of patients with hemorrhagic shock. Such protocols should include a pre-defined ratio of packed red blood cells, fresh frozen plasma, and platelets transfused; most commonly, the ratio used is 1:1:1. Additionally, such protocols should monitor for and correct hypothermia, hypofibrinogenemia, and electrolyte disturbances such as hypocalcemia and hyperkalemia.

Acute Respiratory Distress Syndrome After Spontaneous Intracerebral Hemorrhage

Objectives:Acute respiratory distress syndrome develops commonly in critically ill patients in response to an injurious stimulus. The prevalence and risk factors for development of acute respiratory distress syndrome after spontaneous intracerebral hemorrhage have not been reported. We sought to determine the prevalence of acute respiratory distress syndrome after intracerebral hemorrhage, characterize risk factors for its development, and assess its impact on patient outcomes. Design:Retrospective cohort study at two academic centers. Patients:We included consecutive patients presenting from June 1, 2000, to November 1, 2010, with intracerebral hemorrhage requiring mechanical ventilation. We excluded patients with age less than 18 years, intracerebral hemorrhage secondary to trauma, tumor, ischemic stroke, or structural lesion; if they required intubation only during surgery; if they were admitted for comfort measures; or for a history of immunodeficiency. Interventions:None. Measurements and Main Results:Data were collected both prospectively as part of an ongoing cohort study and by retrospective chart review. Of 1,665 patients identified by database query, 697 met inclusion criteria. The prevalence of acute respiratory distress syndrome was 27%. In unadjusted analysis, high tidal volume ventilation was associated with an increased risk of acute respiratory distress syndrome (hazard ratio, 1.79 [95% CI, 1.13–2.83]), as were male sex, RBC and plasma transfusion, higher fluid balance, obesity, hypoxemia, acidosis, tobacco use, emergent hematoma evacuation, and vasopressor dependence. In multivariable modeling, high tidal volume ventilation was the strongest risk factor for acute respiratory distress syndrome development (hazard ratio, 1.74 [95% CI, 1.08–2.81]) and for inhospital mortality (hazard ratio, 2.52 [95% CI, 1.46–4.34]). Conclusions:Development of acute respiratory distress syndrome is common after intubation for intracerebral hemorrhage. Modifiable risk factors, including high tidal volume ventilation, are associated with its development and in-patient mortality.

Hemoglobin-based oxygen carriers for hemorrhagic shock

Hemorrhagic shock is a pathologic state in which intravascular volume and tissue oxygen delivery are impaired, leading to circulatory collapse and cellular ischemia. Resuscitation with hemoglobin-based oxygen carriers (HBOCs) is appealing in that their use can both restore intravascular volume and tissue oxygenation, without the limitations in supply and immunomodulatory effects of packed red blood cells. However, the development of safe and effective agents has been elusive. In this article, we briefly discuss the major limitations of traditional resuscitative fluids which have driven the continued interest in HBOCs. We then review the history of early HBOC development and the modern understanding of their mechanisms of toxicity, which has informed the rational design of second-generation agents. Finally, we provide an overview of these second-generation HBOCs that are under active investigation or have recently completed phase 3 clinical trials.

Prehospital Sepsis Project (PSP): Knowledge and Attitudes of United States Advanced Out-of-Hospital Care Providers

INTRODUCTION Severe sepsis and septic shock are common and often fatal medical problems. The Prehospital Sepsis Project is a multifaceted study that aims to improve the out-of-hospital care of patients with sepsis by means of education and enhancement of skills. The objective of this Project was to assess the knowledge and attitudes in the principles of diagnosis and management of sepsis in a cohort of United States out-of-hospital care providers. METHODS This was cross-sectional study. A 15-item survey was administered via the Web and e-mailed to multiple emergency medical services list-servers. The evaluation consisted of four clinical scenarios as well as questions on the basics of sepsis. For intra-rater reliability, the first and the fourth scenarios were identical. Chi-square and Fishers Exact testing were used to assess associations. Relative risk (RR) was used for strength of association. Statistical significance was set at .05. RESULTS A total of 226 advanced EMS providers participated with a 85.4% (n = 193) completion rate, consisting of a 30.7% rural, 32.3% urban, and 37.0% suburban mix; 82.4% were paramedics and 72.5% had worked in EMS >10 years. Only 57 (29.5%) participants scored both of the duplicate scenarios correctly, and only 19 of the 193 (9.8%) responded to all scenarios correctly. Level of training was not a predictor of correctly scoring scenarios (P = .71, RR = 1.25, 95% CI = 0.39-4.01), nor was years of service (P = .11, RR = 1.64, 95% CI = 0.16-1.21). CONCLUSIONS Poor understanding of the principles of diagnosis and management of sepsis was observed in this cohort, suggesting the need for enhancement of education. Survey items will be used to develop a focused, interactive Web-based learning program. Limitations include potential for self-selection and data accuracy.

Use of hypothermia to allow low-tidal-volume ventilation in a patient with ARDS.

Low-tidal-volume ventilation reduces mortality in patients with ARDS, but there are often challenges in implementing lung-protective ventilation, such as acidosis from hypercapnia. In a patient with severe ARDS we achieved adequate ventilation with a very low tidal volume (4 mL/kg ideal body weight) by inducing mild hypothermia (body temperature 35–36°C).

Use of Video Laryngoscopy and Camera Phones to Communicate Progression of Laryngeal Edema in Assessing for Extubation A Case Series

Video laryngoscopy has demonstrated utility in airway management. For the present case series, we report the use of video laryngoscopy to evaluate the airway of critically ill, mechanically ventilated patients, as a means to reduce the risk of immediate postextubation stridor by assessing the degree of laryngeal edema. We also describe the use of cellular phone cameras to document and communicate airway edema in using video laryngoscopy for the patients’ medical records. We found video laryngoscopy to be an effective method of assessing airway edema, and cellular phone cameras were useful for recording and documenting video laryngoscopy images for patients’ medical records.

Emergent cricothyroidotomies for trauma: training considerations

BACKGROUND Emergent cricothyroidotomy remains an uncommon, but life-saving, core procedural training requirement for emergency medicine (EM) physician training. We hypothesized that although most cricothyroidotomies for trauma occur in the emergency department (ED), they are usually performed by surgeons. METHODS We conducted a retrospective analysis of all emergent cricothyroidotomies for trauma presentations performed at 2 large level I trauma centers over 10 years. Operators and assistants for all procedures were identified, as well as mechanism of injury and patient demographics were examined. RESULTS Fifty-four cricothyroidotomies were analyzed. Patients had a mean age of 50 years, 80% were male, and 90% presented as a result of blunt trauma. The most common primary operator was a surgeon (n = 47, 87%), followed by an emergency medical services (EMS) provider (n = 6, 11%) and an EM physician (n = 1, 2%). In all cases, except those performed by EMS, the operator or assistant was an attending surgeon. All EMS procedures resulted in serious complications compared with in-hospital procedures (P < .0001). CONCLUSIONS (1) Prehospital cricothyroidotomy results in serious complications. (2) Despite the ubiquitous presence of EM physicians in the ED, all cricothyroidotomies were performed by a surgeon, which may present opportunities for training improvement.

Noninvasive carbon monoxide detection: insufficient evidence for broad clinical use.

Carbon monoxide (CO) poisoning is an important public health issue, as this colorless, odorless gas is a common cause of unintentional poisoning and leads to over 400 deaths each year in the United States.[1][1] Detection of CO poisoned patients may be difficult, as even classic symptoms, including

Bedside sonographic diagnosis of tracheal stenosis.

Tracheal stenosis is a life-threatening condition that requires prompt diagnosis and action by the emergency physician. If left untreated, it can lead to severe respiratory distress and arrest secondary to hypoxemia. We present an interesting case of a severely dyspneic patient in whom a diagnosis of tracheal stenosis was made using bedside sonography. A 62-year-old woman presented to the emergency department with subacute progressive dyspnea, orthopnea, and a 4-day history of a decreased ability to phonate. She was brought in by paramedics and before arrival had been treated with albuterol, racemic epinephrine, magnesium, and steroids. On arrival, she was sitting up and speaking softly in 3to 5-word sentences, communicating by writing responses to questions on paper. Her temperature was 98.6°F, heart rate 92 beats per minute, blood pressure 116/70 mm Hg, respiratory rate 20 breaths per minute, and oxygen saturation 99% with 4 L of oxygen via a nasal cannula. The patient reported having a similar episode of a decreased ability to phonate 1 month before presentation, which resolved after treatment with azithromycin for suspected laryngitis. She noted worsening dyspnea on exertion and orthopnea over the previous few months, which had become substantially worse over the past 4 days with the recurrence of a gradual onset of the decreased ability to phonate. Her medical history consisted of radiation therapy as a child for enlarged adenoids and a total thyroidectomy for follicular thyroid cancer 9 years previously, for which she had been intubated during the operation. She had no known history of cardiopulmonary disease or other intubations. A review of systems was notable for a rash consisting of small, scattered, well-defined, blanching, red macules located most prominently on her chest and arms with mild involvement of her lower extremities, which spared her palms and soles. She denied fevers, chills, nausea, vomiting, nasal congestion, rhinorrhea, sore throat, headache, chest pain, or lower extremity swelling. The physical examination was notable for inspiratory stridor, which was most prominent on auscultation of her neck. Transmitted upper airway sounds were heard in the lungs, but breath sounds were otherwise clear. She had no peripheral edema. Laboratory test results were notable for leukocytosis of 78,000 cells/μL. A peripheral blood smear showed 25% blasts, 17% bands, and 9% lymphocytes. Bedside sonography of the neck showed a trachea filled with heterogeneous predominantly isoechoic material with only a narrow 2mm column of air anteriorly (Figure 1A). There was almost complete loss of the reverberation artifact that is seen in a normal trachea (Figure 1B). Movement of the airway within the narrow column of air was visualized in real time (Videos 1 and 2). Radiographs of the neck showed severe subglottic stenosis that was 4 cm in length and 3 mm in diameter (Figure 1C). Bedside bronchoscopy was performed, which showed a tight-appearing slitlike aperture in the anteroposterior direction. A computed tomographic (CT) scan of the neck was unable to be obtained secondary to the patient’s orthopnea. Given the patient’s airway instability in the setting of severe subglottic Stenosis, which extended low into the trachea, the patient was given a heliumoxygen mixture and transported to the operating room by the thoracic surgery team for definitive airway management. Dilation of the airway was attempted; however, during the procedure, the patient became increasingly difficult to oxygenate and ventilate, and an emergent tracheostomy was performed. The patient was taken to the intensive care unit postoperatively and was weaned off of the ventilator the next day. A pathologic examination from subsequent endotracheal biopsies showed that the stenosis was caused by a tumor from acute myeloid leukemia. Clinical Letters