IntroductionAcute appendicitis is the most common abdominal emergency requiring emergency surgery. However, the diagnosis is often challenging and the decision to operate, observe or further work-up a patient is often unclear. The utility of clinical scoring systems (namely the Alvarado score), laboratory markers, and the development of novel markers in the diagnosis of appendicitis remains controversial. This article presents an update on the diagnostic approach to appendicitis through an evidence-based review.MethodsWe performed a broad Medline search of radiological imaging, the Alvarado score, common laboratory markers, and novel markers in patients with suspected appendicitis.ResultsComputed tomography (CT) is the most accurate mode of imaging for suspected cases of appendicitis, but the associated increase in radiation exposure is problematic. The Alvarado score is a clinical scoring system that is used to predict the likelihood of appendicitis based on signs, symptoms and laboratory data. It can help risk stratify patients with suspected appendicitis and potentially decrease the use of CT imaging in patients with certain Alvarado scores. White blood cell (WBC), C-reactive protein (CRP), granulocyte count and proportion of polymorphonuclear (PMN) cells are frequently elevated in patients with appendicitis, but are insufficient on their own as a diagnostic modality. When multiple markers are used in combination their diagnostic utility is greatly increased. Several novel markers have been proposed to aid in the diagnosis of appendicitis; however, while promising, most are only in the preliminary stages of being studied.ConclusionWhile CT is the most accurate mode of imaging in suspected appendicitis, the accompanying radiation is a concern. Ultrasound may help in the diagnosis while decreasing the need for CT in certain circumstances. The Alvarado Score has good diagnostic utility at specific cutoff points. Laboratory markers have very limited diagnostic utility on their own but show promise when used in combination. Further studies are warranted for laboratory markers in combination and to validate potential novel markers.

Prognostic study, level III.

No abstract

Prognostic and epidemiologic study, level V.

Trauma outcomes are improved by protocols for substantial bleeding, typically activated after physician evaluation at a hospital. Previous analysis suggested that prehospital vital signs contained patterns indicating the presence or absence of substantial bleeding. In an observational study of adults (aged ≥18 years) transported to level I trauma centers by helicopter, we investigated the diagnostic performance of the Automated Processing of the Physiological Registry for Assessment of Injury Severity (APPRAISE) system, a computational platform for real-time analysis of vital signs, for identification of substantial bleeding in trauma patients with explicitly hemorrhagic injuries. We studied 209 subjects prospectively and 646 retrospectively. In our multivariate analysis, prospective performance was not significantly different from retrospective. The APPRAISE system was 76% sensitive for 24-h packed red blood cells of 9 or more units (95% confidence interval, 59% - 89%) and significantly more sensitive (P < 0.05) than any prehospital Shock Index of 1.4 or higher; sensitivity, 59%; initial systolic blood pressure (SBP) less than 110 mmHg, 50%; and any prehospital SBP less than 90 mmHg, 50%. The APPRAISE specificity for 24-h packed red blood cells of 0 units was 87% (88% for any Shock Index ≥1.4, 88% for initial SBP <110 mmHg, and 90% for any prehospital SBP <90 mmHg). Median APPRAISE hemorrhage notification time was 20 min before arrival at the trauma center. In conclusion, APPRAISE identified bleeding before trauma center arrival. En route, this capability could allow medics to focus on direct patient care rather than the monitor and, via advance radio notification, could expedite hospital interventions for patients with substantial blood loss.

No abstract

Objectives Historically fever, pneumonia and sepsis after trauma are ascribed to pain and poor pulmonary toilet. No evidence supports that assertion however, and no known biologic mechanisms link injury to infection. Our studies show injured tissues release mitochondria (MT). Mitochondrial danger-associated molecular patterns (mtDAMPs) however, can mimic bacterial pathogen-associated danger molecules (PAMPs) and attract neutrophils (PMN). We hypothesized mtDAMPs from traumatized tissue divert neutrophils from the lung, causing susceptibility to infection. Methods Anesthetized rats (6–10/group) underwent pulmonary contusion (PC) by chest percussion. Modeling traumatic MT release, some rats had MT isolated from liver (equal to 5% liver necrosis) injected intra-peritoneal (IPMT). Negative controls had PC plus buffer IP. Positive controls underwent PC plus cecal ligation and puncture (CLP). At 16h bronchoalveolar and peritoneal lavages were performed. Bronchial and peritoneal lavage fluids (BALF, PLF) were assayed for PMN count, albumin, IL-β and CINC-1. Assays were normalized to BUN to calculate absolute concentrations. Results PC caused alveolar IL-1β and CINC production and a 34-fold increase in BALF neutrophils. As expected, IPMT increased peritoneal IL-1β and CINC and attracted PMN to the abdomen. But remarkably, IPMT after PC attenuated BALF cytokine accumulation and decreased BALF PMN. CLP had no direct effect on BALF PMNs, but like IPMT blunted BALF leukocytosis after PC. Conclusions Rather than acting as a 'second hit' to enhance PMN-mediated lung injury, mtDAMPs from trauma and PAMPs from peritoneal infection diminish PMN accumulation in contused lung. This may make the lung susceptible to pneumonia. This paradigm provides a novel mechanistic model of the relationship between blunt tissue trauma, systemic inflammation and pneumonia that can be studied to improve trauma outcomes.

No abstract