Reconsidering the effectiveness and safety of carotid sinus massage as a therapeutic intervention in patients with supraventricular tachycardia.

OBJECTIVE: The objectives of our investigation were to review the evidence for the efficacy and safety of carotid sinus massage in terminating supraventricular tachycardia and to determine if other potentially less harmful interventions have been established to be safer and more effective. METHODS: A search using PubMed, Ovid, and COCHRANE databases was performed using the terms supraventricular tachycardia, carotid sinus massage, SVT, and CSM. Articles not written in English were excluded. There was a paucity of randomized controlled trials comparing various supraventricular tachycardia (SVT) interventions. However, articles of highest quality were selected for review and inclusion. In addition, articles examining potential hazards of carotid sinus massage in case report format were reviewed, even when performed for other indications other than SVT, as the maneuver is identically performed. Selected articles were reviewed by both authors for relevance to the topic. RESULTS: Summarizing the findings of this review leads to these 3 fundamental conclusions. First, a therapeutic intervention should only be performed when the benefit of the procedure outweighs its risk. Carotid sinus massage exposes the patient to rare but potentially devastating iatrogenic harm. Second, a therapeutic intervention should be efficacious. The efficacy of carotid sinus massage in terminating supraventricular tachycardia appears to be modest at best. Third, other readily available, easily mastered, and potentially safer and more efficacious alternative interventions are available such as Valsalva maneuver and pharmacologic therapy. CONCLUSION: Based on the limited evidence available, we believe that carotid sinus massage should be reconsidered as a first-line therapeutic intervention in the termination of SVT.

Cardiac myxoma as a mimic: a diagnostic challenge.

OBJECTIVE: Patients with occult, undiagnosed cardiac myxomas (CM) often present with acute complications that mimic other, more common, conditions. We describe two recently encountered patients who classically demonstrate this phenomenon and report the results of an integrative review of CM cases to define the characteristics of such patients. METHODS: A comprehensive 20-year review of reported cases that described patient-specific data of CM was performed. Using a standardized tool, the following elements were collected: age; gender; presenting symptoms and signs; diagnostic and management approaches; and outcomes. RESULTS: One hundred twenty-six cases of CM were identified. The mean patient age was 47.5 years (range, 6-90). Seventy (56%) were women. The most common mimic conditions initially being considered were cardiac complications, including acutely decompensated heart failure, myocardial infarction, dysrhythmia and sudden death (46%); systemic embolization, including cutaneous infarction and pulmonary embolism (23%); central nervous system embolization, including transient ischemic attack and acute stroke syndrome (22%); and constitutional conditions, such as fever, myalgia, arthralgia, fatigue, and myxoma infections (17%). Echocardiography proved to be a readily available and accurate diagnostic test. The majority of reported patients experienced full recoveries after surgical intervention. CONCLUSIONS: CM is a rare but potentially life-threatening condition. Symptoms and signs relating to CM mimic other, more common conditions, resulting in diagnostic delay. Echocardiography can quickly and accurately diagnose CM and timely surgical intervention is curative. Clinician awareness of this condition, in a suggestive clinical context, will increase the likelihood of optimal patient outcome.

Injury and illness sustained by human competitors in the 2010 iditarod sled dog race.

OBJECTIVE: Alaska's 1049-mile Iditarod Trail Sled Dog Race is the world's longest sled dog race and the flagship event in the sport of sled dog racing. Race conditions are typically harsh. Physicians are not officially enlisted to care for human competitors. Instead, medical needs are met through an informal system of volunteers, local health care providers, and a fleet of bush planes. The goals of this study were to identify the types of human injury and illness experienced and the methods by which these conditions are treated. METHODS: Competitors in the 2010 Iditarod were surveyed at the halfway point and at the finish of the race. Survey elements included specific types and frequencies of injuries and illnesses, and the sources and types of treatments. RESULTS: Seventy-one teams entered the race, 62 participated in the halfway point survey, and 55 completed the finish line survey. Ninety-nine injuries were reported by 42 (68%) of the survey respondents. Frostbite was the most common injury, occurring in 20 (31%) of the respondents. Musculoskeletal pain was also commonly reported. Two mushers sustained closed head injuries, with 1 requiring evacuation. Twenty-three mushers (37%) reported an acute nontraumatic condition, most frequently an upper respiratory infection (9 respondents). In most instances, medical conditions were self-managed. Race veterinarians and support staff, as well as local village clinicians, administered the majority of care, typically wound care or oral antibiotic administration. CONCLUSIONS: Most injuries and illnesses sustained by mushers in the Iditarod are minor and self-treatable. Life-threatening conditions are rare, and the need for an organized medical care system seems low.

Spontaneous peripartum coronary artery dissection presentation and outcome.

OBJECTIVE: The objective of this study was to determine whether spontaneous peripartum coronary artery dissection (SPCAD) is a cause of acute myocardial infarction in women. METHODS: Patients with SPCAD reported in the recent literature were analyzed to elucidate the clinically relevant characteristics of this condition. RESULTS: Forty-seven cases of SPCAD are described. Patient characteristics include the following: mean age, 33.5 ± 5.2 years; gravity, 2.7 (95% confidence interval, 1.8-3.5); mean gestational age if prepartum, 32.5 ± 4.2 weeks (range, 23-36 weeks); and mean onset if postpartum, 22.9 ± 26.1 days (range, 3-90 days). Only 17 patients (36%) reported a cardiac risk factor, with the most frequent being smoking. All presented with characteristic ischemic pain; 25% of patients were hemodynamically unstable; and 81% of initial electrocardiograms demonstrated ST-elevation myocardial infarctions. The left coronary artery system was involved 81% of the time. Thirty percent of patients were managed conservatively or with thrombolytic therapy, whereas 34% received emergent percutaneous cardiac intervention and 36% required bypass surgery. There were no maternal deaths. Long-term follow-up revealed good cardiac function in the majority of patients, although 3 women required heart transplantation. CONCLUSIONS: SPCAD can occur weeks before or after delivery and should be considered in women presenting during the peripartum period with acute chest pain.

Red blood cell transfusion: experience in a rural aeromedical transport service.

INTRODUCTION: The administration of blood products to critically ill patients can be life-saving, but is not without risk. During helicopter transport, confined work space, communication challenges, distractions of multi-tasking, and patient clinical challenges increase the potential for error. This paper describes the in-flight red blood cell transfusion practice of a rural aeromedical transport service (AMTS) with respect to whether (1) transfusion following an established protocol can be safely and effectively performed, and (2) patients who receive transfusions demonstrate evidence of improvement in condition. METHODS: A two-year retrospective review of the in-flight transfusion experience of a single-system AMTS servicing a rural state was conducted. Data elements recorded contemporaneously for each transfusion were analyzed, and included hematocrit and hemodynamic status before and after transfusion. Compliance with an established transfusion protocol was determined through structured review by a multidisciplinary quality review committee. RESULTS: During the study, 2,566 missions were flown with 45 subjects (1.7%) receiving in-flight transfusion. Seventeen (38%) of these transports were scene-to-facility and 28 (62%) were inter-facility. Mean bedside and in-flight times were 22 minutes (range 3-109 minutes) and 24 minutes (range 8-76 minutes), respectively. The most common conditions requiring transfusion were trauma (71%), cardiovascular (13%) and gastrointestinal (11%). An average of 2.4 liters (L) of crystalloid was administered pre-transfusion. The mean transfusion was 1.4 units of packed red blood cells. The percentages of subjects with pre- and post-transfusion systolic blood pressures of <90 mmHg were 71% and 29%, respectively. The pre- and post-transfusion mean arterial pressures were 62 mmHg and 82 mmHg, respectively. The pre- and post- transfusion mean hematocrit levels were 17.8% and 30.4%, respectively. At the receiving institution, 9% of subjects died in the Emergency Department, 18% received additional transfusion within 30 minutes of arrival, 36% went directly to the operating room, and 36% were directly admitted to intensive care. Thirty-one percent of subjects died prior to hospital discharge. There were no protocol violations or reported high-risk provider blood exposure incidents or transfusion complications. All transfusions were categorized as appropriate. CONCLUSIONS: In this rural AMTS, transfusion was an infrequent, likely life-saving, and potentially high-risk emergent therapy. Strict compliance with an established transfusion protocol resulted in appropriate and effective decisions, and transfusion proved to be a safe in-flight procedure for both patients and providers.

Effect of bedside ultrasonography on the certainty of physician clinical decisionmaking for septic patients in the emergency department.

STUDY OBJECTIVE: Sepsis protocols promote aggressive patient management, including invasive procedures. After the provision of point-of-care ultrasonographic markers of volume status and cardiac function, we seek to evaluate changes in emergency physician clinical decisionmaking and physician assessments about the clinical utility of the point-of-care ultrasonographic data when caring for adult sepsis patients. METHODS: For this prospective before-and-after study, patients with suspected sepsis received point-of-care ultrasonography to determine cardiac contractility, inferior vena cava diameter, and inferior vena cava collapsibility. Physician reports of treatment plans, presumed causes of observed vital sign abnormalities, and degree of certainty were compared before and after knowledge of point-of-care ultrasonographic findings. The clinical utility of point-of-care ultrasonographic data was also evaluated. RESULTS: Seventy-four adult sepsis patients were enrolled: 27 (37%) sepsis, 30 (40%) severe sepsis, 16 (22%) septic shock, and 1 (1%) systemic inflammatory response syndrome. After receipt of point-of-care ultrasonographic data, physicians altered the presumed primary cause of vital sign abnormalities in 12 cases (17% [95% confidence interval {CI} 8% to 25%]) and procedural intervention plans in 20 cases (27% [95% CI 17% to 37%]). Overall treatment plans were changed in 39 cases (53% [95% CI 41% to 64%]). Certainty increased in 47 (71%) cases and decreased in 19 (29%). Measured on a 100-mm visual analog scale, the mean clinical utility score was 65 mm (SD 29; 95% CI 58 to 72), with usefulness reported in all cases. CONCLUSION: Emergency physicians found point-of-care ultrasonographic data about cardiac contractility, inferior vena cava diameter, and inferior vena cava collapsibility to be clinically useful in treating adult patients with sepsis. Increased certainty followed acquisition of point-of-care ultrasonographic data in most instances. Point-of-care ultrasonography appears to be a useful modality in evaluating and treating adult sepsis patients.