Garrett S. Pacheco

The Physiologically Difficult Airway.

Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation.

Inhibition of platelet GPIIb–IIIa and P-selectin expression by aspirin is impaired by stress hyperglycemia

Increased aspirin resistance may contribute to the increase in thrombotic events observed in patients with type 2 diabetes. In this study, we examined if acute exposure to increased plasma glucose impaired the inhibitory effects of aspirin on platelet activation. Whole-blood samples were incubated with 100 (euglycemia), 200, 300, and 600 mg/dl glucose followed by incubation with aspirin [acetylsalicylic acid (ASA)]. Using flow cytometry, GPIIb-IIIa and P-selectin were analyzed in unstimulated and arachidonic acid (AA)-stimulated platelets. In euglycemic blood, AA caused a significant increase in platelet GPIIb-IIIa expression [unstimulated: 59.5+/-8.2 total fluorescence intensity (TFI), AA stimulated: 319.6+/-42.7 TFI, P=.002] and P-selectin (4.4+/-0.7 and 179.5+/-38.5 TFI, P<.001). In vitro, ASA significantly inhibited both GPIIb-IIIa expression (36.5%) and P-selectin expression (81%; P<.005). However, increased blood glucose (200 mg/dl) significantly impaired the inhibitory effect of ASA (84% for GPIIb-IIIa, P<.005; 48% for P-selectin, P=NS). Increasing glucose to 600 mg/dl completely overwhelmed the inhibitory effect of ASA. A statistically significant interaction between glucose concentration and ASA dose was found (P<.001 for GPIIb-IIIa and P=.004 for P-selectin). In vitro, concentration-dependent stress hyperglycemia significantly impaired the inhibitory effects of aspirin on human platelet GPIIb-IIIa and P-selectin expression. Under acute hyperglycemic conditions, the effectiveness of ASA to inhibit platelets via the AA-activation pathway may be significantly reduced.

THE EFFECTS OF RESIDENT LEVEL OF TRAINING ON THE RATE OF PEDIATRIC PRESCRIPTION ERRORS IN AN ACADEMIC EMERGENCY DEPARTMENT

BACKGROUND Medication errors are a leading cause of increased cost and iatrogenic injury in the pediatric population. In the academic setting, studies have suggested that these increased error rates are related primarily to resident inexperience, thus advocating a higher level of supervision. STUDY OBJECTIVE We sought to identify the number of prescription errors in our institutions academic Emergency Department, how this varied between the beginning and end of the academic year and between practitioners at varying levels of training. METHODS A retrospective review of computer-based outpatient prescriptions for children aged 0-12 years old was performed. Outpatient prescriptions were reviewed during a 2-week time block at the end of the academic year and beginning of the academic year (109 [June] and 111 [July] data sets, respectively). Prescriptions were retrieved electronically and reviewed for appropriate dosing. Errors were defined as those that varied>10% above or below recommended weight-based dosing. RESULTS Twenty-nine (16.1%) of 180 written prescription orders were determined to be incorrectly written. Error rates were not significantly different between the beginning and end of the academic year. In both sampling periods, a higher percentage were found to be derived from senior level practitioners in both data sets (9/14 and 10/15; respectively), but few of these were considered high-grade prescription errors. CONCLUSIONS Overall prescription error rates at our institution are comparable to nationally reported error rates in children. Error rates were not associated with newly matriculated residents. These findings dispute previously held opinion that physician level of training is a factor of prescription errors.

Staphylococcal Scalded Skin Syndrome

Staphylococcal scalded skin syndrome is a serious and potentially life-threatening infection that requires prompt recognition and intervention. This chapter will discuss the physiology behind this exotoxin-mediated disease that results in diffuse erythroderma and subsequent desquamation. Key clinical characteristics, such as the absence of mucosal membrane involvement, are reviewed to aid in early recognition of SSSS and differentiation from conditions with a similar appearance. Treatment with anti-staphylococcal antibiotics and dermatologic care measures is essential in the acute management of SSSS, in addition to prevention of secondary infection, which is a common cause of mortality.

Pediatric Ventilator Management in the Emergency Department.

Pediatric mechanical ventilation is first initiated by emergency physicians when performing active airway management in a critically ill or injured child. When initiating and adjusting mechanical ventilation, the child has unique anatomy and physiology to consider. The EP is the first to respond to ventilator alarm triggers, and the initial medical provider to resuscitate the ventilated pediatric patient who is deteriorating while in the emergency department. This article uses cases to provide a framework to initiate and troubleshoot mechanical ventilation of pediatric patients in the emergency department.

Pediatric Emergency Noninvasive Ventilation

Noninvasive ventilation (NIV) has emerged as a powerful tool for the pediatric emergency management of acute respiratory failure (ARF). This therapy is safe and well tolerated and seems to frequently prevent both the need for invasive mechanical ventilation and the associated risks/complications. Although NIV can be the primary treatment of ARF resulting from multiple respiratory disease states, it must be meticulously monitored and, when unsuccessful, may aid in preoxygenation for prompt endotracheal intubation and invasive mechanical ventilation. The following article reviews the physiologic effects of NIV and its role in common respiratory diseases encountered in pediatric emergency medicine.

Obstructed Infradiaphragmatic Total Anomalous Pulmonary Venous Return in a 13-Day-Old Infant Presenting Acutely to the Emergency Department: A Case Report

BACKGROUND Total anomalous pulmonary venous return (TAPVR) is an uncommon congenital heart defect. Obstructed forms are more severe, and typically present earlier in life, usually in the immediate newborn period, with symptoms of severe cyanosis and respiratory failure. CASE REPORT A 13-day-old boy presented to the emergency department (ED) with respiratory extremis. He appeared cyanotic and limp, and was found to have significant hypoxia with oxygen saturation of 40%. He had no improvement of oxygenation with bag-valve-mask ventilation despite a fraction of inspired oxygen near 100%. This gave clear indication that the hypoxia was caused by a shunt and not by hypoventilation, a ventilation/perfusion mismatch, or a barrier to diffusion. Next, the patient was intubated emergently. Broad spectrum antibiotics and fluid resuscitation with normal saline were initiated. A chest radiograph showed evidence of pulmonary edema vs. diffuse interstitial disease. Cardiology was consulted and evaluated the child with an echocardiogram, which revealed TAPVR with infradiaphragmatic obstructed veins. Once stabilized, he was transferred for definitive surgical repair. This is, to our knowledge, the first reported case of TAPVR with infradiaphragmatic obstruction presenting to the ED with hemodynamic and respiratory compromise beyond the first week of life. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Despite improvements in antenatal and newborn screening, congenital heart disease often remains an elusive diagnosis. Some patients with these critical lesions are discharged home before the manifestation of their disease becomes apparent. Once symptomatic, these patients often present to the ED in extremis. We conclude that it is important to recognize this presentation to ensure proper evaluation and early diagnosis. If misdiagnosed, many of the usual therapies for other diseases could be detrimental.