Medical problem solving and uncertainty in the emergency department

STUDY OBJECTIVE: To compare the diagnostic processes of experienced emergency physicians with those of novices. DESIGN: Prospective, convenience sample of patients. SETTING: Emergency department of a county university medical center in a large southwestern urban community. PARTICIPANTS: Experienced emergency physicians (attending and senior residents) and novice clinicians (junior residents and senior medical students). INTERVENTIONS: Participants developed initial diagnostic impressions after reviewing the chief complaint, nurse triage notes, and vital signs. Tests were then selected, and a final diagnostic impression was identified after results were known. Clinicians also marked a visual analog scale corresponding to their estimate that each diagnostic possibility was correct. RESULTS: Experienced physicians increased their certainty more than novices (P = .014). They deviated from a standard history-physical-laboratory sequence more often than novices (P = .008). CONCLUSION: Expertise in medical decision making is characterized by a moderate initial level of certainty concerning a diagnosis that significantly increases as the experienced clinician follows a flexible strategy of testing to arrive at a final diagnosis.     

Patterns of meniscal injury with acute anterior cruciate ligament tears

One hundred two patients underwent an arthrotomy for the primary repair of an acute ACL tear with or without an associated collateral ligament injury. The mean age was 23 years. Forty-seven patients (46%) had meniscal injuries. Meniscal injuries were found in 41% of Group I patients (isolated ACL injuries) and in 54% of Group II patients (injured ACL/collateral ligaments). Twenty-eight medial and 22 lateral meniscal tears were noted. Twenty-six of the 50 meniscal tears (52%) were sutured in an attempt to repair the menisci. Of these, 20 of the medial (71%), and 6 of the lateral (27%) meniscal injuries were sutured. No patients in this series required a total meniscectomy. A thorough evaluation of the menisci is mandatory in knees with an acutely injured ACL.     

Glass ingestion from fracture of a laryngoscope bulb.

A 22-month-old child had a generalized tonic-clonic seizure during attempted orotracheal intubation and broke the laryngoscope bulb with his teeth. The glass was swallowed but passed uneventfully through the gastrointestinal tract. The possibility of this unusual complication should be considered when patients at risk for seizures are intubated by the orotracheal route.     

MR characteristics of histopathologic subtypes of spinal ependymoma.

PURPOSETo examine MR characteristics and enhancement patterns of spinal ependymomas and compare these data with histopathologic subtypes.METHODSThe MR images from 26 cases of pathologically proved spinal ependymomas were evaluated with respect to seven criteria: signal characteristics, enhancement pattern, length of involvement, cysts or syrinxes, hemorrhage, bony changes, and type of cord expansion. Signal characteristics were then correlated with histologic subtype.RESULTSIn the category of enhancement pattern, our results differed markedly from published data, with only 38% of cases demonstrating classic homogeneous enhancement. The remainder of our cases (62%) demonstrated other enhancement patterns, including heterogeneous (31%), rim (19%), minimal (6%), and no enhancement (6%). Pathologic comparison revealed that one histologic subtype, the myxopapillary ependymoma, demonstrated unique imaging characteristics on T1-weighted images. A highly statistically significant percentage of this variant was hyperintense on T1, whereas most nonmyxopapillary ependymomas were hypointense.CONCLUSIONThe radiologist should be aware of alternative patterns of enhancement of spinal ependymomas and not be dissuaded from the diagnosis in appropriate clinical settings. In addition, one histologic subtype, myxopapillary, often exhibits signal characteristics different from nonmyxopapillary types, appearing hyperintense on T1 probably because of their intracellular and perivascular accumulation of mucin.     

Regulation of human basophil adhesion to endothelium under flow conditions: Different very late antigen 4 regulation on umbilical cord blood-derived and peripheral blood basophils

BACKGROUND: Although soluble mediators released by basophils in tissue sites contribute to the chronic injury that occurs in hypersensitivity diseases, only limited information is available about how circulating basophils are recruited to tissues. In particular, the interaction of basophils with endothelium under conditions that mimic physiologic flow has not been explored. OBJECTIVE: We sought to identify adhesion molecules regulating the attachment of human basophils to IL-4-activated human umbilical vein endothelial cells (HUVECs) under flow conditions. METHODS: A parallel-plate flow chamber and blocking mAbs were used to define the adhesion molecules involved in the interactions of peripheral blood basophils (PBBs) and cord blood-derived basophils (CBDBs) with IL-4-activated HUVECs and with Chinese hamster ovary (CHO) cell transfectants expressing specific adhesion molecules. A fluorescent ligand specific for very late antigen 4 (VLA-4) was used to directly examine the VLA-4 affinity state of basophils. RESULTS: Flowing PBBs and CBDBs attached to activated HUVECs and to CHO cells expressing P- or E-selectin. However, only CBDBs attached to vascular cell adhesion molecule 1 (VCAM-1)-transfected CHO cells under flow conditions. The attachment of CBDBs to CHO cells was blocked by mAbs directed against E-selectin, P-selectin, and VCAM-1, whereas attachment of PBBs was blocked by E-selectin and P-selectin mAbs. Activating VLA-4 with Mn(2+) on PBBs resulted in adhesion to the VCAM-1-transfected CHO cells, indicating that VLA-4 activity on PBBs can be regulated, at least in part, through affinity changes. The Mn(2+)-induced upregulation of basophil VLA-4 affinity was demonstrated directly by using a fluorescent ligand for VLA-4 and flow cytometry. CONCLUSIONS: The interaction of human CBDBs and PBBs with endothelium under flow conditions is mediated in part by both P- and E-selectin. VLA-4 additionally contributes to the adhesion of flowing CBDBs. However, the affinity of VLA-4 is too low to support the adhesion under flow conditions of unstimulated PBBs.