Effects of acute liver injury on blood coagulation

Summary.  The mechanisms leading to the hemostatic changes of acute liver injury are poorly understood. To study these further we have assessed coagulation and immune changes in patients with acute paracetamol overdose and compared the results to patients with chronic cirrhosis and normal healthy controls. The results demonstrate that in paracetamol overdose coagulation factors (F)II, V, VII and X were reduced to a similar degree and were significantly lower than FIX and FXI (mean levels 0.28, 0.16, 0.13, 0.19, 0.51 and 0.72 IU mL⁻¹, respectively). In cirrhosis, by contrast, FII, FV, FVII, FIX and FX were equally reduced whilst FXI was lower than the other factors (mean levels 0.64, 0.69, 0.62, 0.60, 0.66 and 0.40 IU mL⁻¹, respectively). FVIII was raised in paracetamol overdose patients but normal in those with cirrhosis (mean levels 1.95 and 1.01 IU mL⁻¹, respectively). Interleukin-6 and tumor necrosis factor-α levels were raised in both patient groups, but higher levels were found in paracetamol overdose, compared to cirrhosis. Thrombin-antithrombin and soluble tissue factor levels were higher in those with acute liver injury but normal in cirrhosis. Antithrombin levels were reduced in both acute liver injury and cirrhosis. From these data we put forward a novel mechanism for the coagulation changes in acute paracetamol induced liver injury. We propose that immune activation leads to tissue factor-initiated consumption of FII, FV, FVII and FX, but that levels of FIX and FXI are better preserved because antithrombin inhibits the thrombin induced positive feedback loop that activates these latter factors.     

Introducing dental students to clinical patient care: The complete denture prosthodontics transition clinic

Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience.     

Influenza vaccination: incidence of symptoms and resulting absenteeism in hospital employees.

A convenience sample of hospital workers, those receiving influenza vaccine and those not receiving vaccine, were asked to complete questionnaires delineating the occurrence of symptoms (e.g., fever, headache, extreme tiredness, dry cough, sore throat, runny nose, stuffy nose, muscle aches) and absenteeism in the 7-day period post-vaccination if vaccinated. Those unvaccinated completed the questionnaire in a self-selected 7 consecutive day period during the study conducted from November 2004 to February 2005. Those receiving either Fluzone or FluMist reported significantly fewer symptoms and related absenteeism than the unvaccinated group (p < .05). Administration of influenza vaccine did not result in higher rates of post-vaccination symptoms as compared to an unvaccinated group. Further, vaccinated employees did not experience higher absenteeism rates as a result of receiving either influenza vaccine. However, for those reporting absenteeism as a result of symptoms, mean absenteeism days were highest in the FluMist group (4.5 days) compared to the unvaccinated group (2.1 days) and the Fluzone group (1.9 days).     

Popliteal artery pseudoaneurysm following total knee arthroplasty: a case report

Direct vascular injury after primary total knee arthroplasty is rare. This case report illustrates a 65-year-old female who was diagnosed with a pseudoaneurysm of the popliteal artery when she was investigated for increased leg swelling and pain 1 week after total knee arthroplasty. She had a percutaneous endovascular repair with a stent after thrombectomy.     

Interobserver Agreement for the Diagnosis of Venous Thromboembolism on Computed Tomography Chest Angiography and Indirect Venography of the Lower Extremities in Emergency Department Patients

Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography.