The role of rapid testing and clinical decision in the diagnosis of human influenza A H1N1 infection.

OBJECTIVE: To evaluate the role of the rapid influenza diagnostic test (RIDT) and clinical decision in the diagnosis of H1N1. METHODS: In November 2009, 290 suspected influenza patients were examined for H1N1 during an outbreak in Riyadh, Saudi Arabia. Nasopharyngeal swabs were analyzed using Directigen EZ Flu A+B kit. Monoclonal anti-human influenza A/B and reverse transcription- polymerase chain reaction (RT-PCR) were used. Positive and negative controls were used in each run of specimens. Validity indices were calculated for RIDT and clinical diagnostic criteria. RESULTS: The sensitivity and specificity of RIDT were 40.5% (95% confidence interval [CI]: 33.0-48.5), and 94.5% (95% CI: 88.6-97.6). The sensitivity of clinical decision was 66.3% (95% CI: 58.4-73.4), and the specificity was 65.4% (95% CI: 56.3-73.4). The sensitivity of clinical decision was higher in early presenters (79.2%; 95% CI: 57.3-92.1). The RIDT sensitivity was higher in younger patients (48.4%; 95% CI: 35.7-61.3). The positive predictive value (PPV) was 90.4% (95% CI: 80.7-95.7) for RIDT, and 71.1% (95% CI: 63.1-78.0) for clinical decision. The PPV for RIDT was greater for older (94.7%; 95% CI: 80.9-99.1) and late (90.7%; 95% CI: 76.9-97.0) presenters. The adjusted odds ratio for clinical decision was significant for cough, headache, and fatigue. CONCLUSION: The RIDT can be useful in epidemics and high prevalence areas, whereas clinical decision, and RT-PCR complement the diagnosis of H1N1 in any setting.

The coagulopathy of liver disease: does vitamin K help?

Vitamin K is frequently administered in cirrhotic patients to correct their coagulopathy, but evidence for such practice is lacking. We aimed to assess whether vitamin K administration increases the levels of the vitamin K-dependent factor VII (FVII), protein C, and protein S in patients with different stages of liver dysfunction. Eighty-nine patients were recruited into four groups: group 1 [hepatitis B virus (HBV) inactive carriers, n = 23]; group 2 [chronic HBV and hepatitis C virus (HCV) hepatitis, n = 21]; group 3 (cirrhosis, n = 24); group 4 (hepatocellular carcinoma, n = 21); and a healthy control group (n = 39). A single dose of 10 mg of vitamin K1 was administered subcutaneously to all patients. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen, FVII, protein C, total and free protein S, and proteins induced by vitamin K absence (PIVKA)-II (des-gamma-carboxy prothrombin) were measured at baseline and 72 h after vitamin K administration. There was progressive increment in baseline PIVKA-II, and decrements in fibrinogen, FVII, protein C, and protein S across study groups (P < 0.0001). Compared to baseline, vitamin K administration did not affect the measured parameters, whereas TT showed no reduction in any of the groups. Protein C levels declined in group 2, whereas FVII, total and free protein S did not increase in any group, for all parameters. Vitamin K therapy does not cause significant improvements in the majority of coagulation parameters and hence does not seem to be routinely indicated in patients with liver disease.

Abrupt withdrawal of inhaled corticosteroids does not result in spirometric deterioration in chronic obstructive pulmonary disease: Effect of phenotyping?

BACKGROUND AND OBJECTIVE: Some studies show a decline of FEV(1) only one month after withdrawal of inhaled corticosteroids (ICS), while others show no decline. We speculate that the presence of an asthma phenotype in the Chronic Obstructive Pulmonary Disease (COPD) population, and that its exclusion may result in no spirometric deterioration. METHODS: We performed a prospective clinical observation study on 32 patients who fulfilled the Global Initiative for Chronic Obstructive lung disease definition of COPD (Grade II-IV). They were divided into two phenotypic groups. 1. Irreversible asthma (A and B) (n = 13): A. Asthma: Bronchial biopsy shows diffuse thickening of basement membrane (≥ 6.6 µm). B. Airflow limitation (AFL) likely to be asthma: KCO > 80% predicted if the patient refused biopsy. 2. COPD (A and B) (n = 19): A. COPD: hypercapneic respiratory failure with raised bicarbonate, panlobular emphysema with multiple bullas, or bronchial biopsy showing squamous metaplasia and epithelial/subepithelial inflammation without thickening of the basement membrane. B. AFL likely to be COPD: KCO < 80% predicted. RESULTS: The asthma phenotype was significantly younger, had a strong association with hypertrophy of nasal turbinates, and registered a significant improvement of FEV(1) (350 ml) vs a decline of - 26.5 ml in the COPD phenotype following therapy with budesonide/formoterol for one year. Withdrawal of budesonide for 4 weeks in the COPD phenotype resulted in FEV(1) + 1.33% (SD ± 5.71) and FVC + 1.24% (SD ± 5.32); a change of <12% in all patients. CONCLUSIONS: We recorded no spirometric deterioration after exclusion of the asthma phenotype from a COPD group.

A validation study comparing the sensitivity and specificity of the new Dr. KSU H1N1 RT-PCR kit with real-time RT-PCR for diagnosing influenza A (H1N1).

BACKGROUND AND OBJECTIVES: A new test (Dr. KSU H1N1 RT-PCR kit) was recently developed to provide a less expensive alternative to real-time reverse transcriptase-polymerase chain reaction (RT-PCR). We report the findings of a validation study designed to assess the diagnostic accuracy, including sensitivity and specificity, of the new kit, as compared to real-time RT-PCR. DESIGN AND SETTING: Cross-sectional validation study conducted from 18-22 November 2009 at a primary care clinic for H1N1 at a tertiary care teaching hospital in Riyadh. PATIENTS AND METHODS: Nasopharyngeal swab samples and data on socio-demographic characteristics and symptoms were collected from 186 patients. Swab samples were sent to the laboratory for testing with both real-time RT-PCR and the new Dr. KSU H1N1 RT-PCR kit. We measured the sensitivity and specificity of the new test across the entire sample size and investigated how these values were affected by patient socio-demographic characteristics and symptoms. RESULTS: The outcomes of the two tests were highly correlated (kappa=0.85; P<.0001). The sensitivity and specificity of the new test were 99.11% and 83.78%, respectively. The sensitivity of the new test was affected only minimally (96%-100%) by patient characteristics and number of symptoms. On the other hand, the specificity of the new test varied depending on how soon patients were tested after onset of symptoms (100% specificity when swabs were taken on the first day of the symptoms, decreasing to 75% when swabs were taken on or after the third day). The specificity of the new test also increased with increasing body temperature. CONCLUSION: The new test seems to provide a cost-effective alternative to real-time RT-PCR for diagnosing H1N1 influenza. However, further testing may be needed to verify the efficacy of the test in different settings and communities.

Lung functions in poorly controlled type 1 Saudi diabetic children and adolescents.

OBJECTIVE: To determine the lung function among Saudi type 1 diabetes mellitus (T1DM) children and adolescents. METHODS: This study was conducted in the Department of Pediatrics, Division of Pediatric Pulmonology and University Diabetes Centre, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia from December 2008 to July 2010. A group of 52 (26 male and 26 female) volunteer T1DM children were recruited with an age range from 8-14 years (mean 12.05 +/- 1.42 years), mean duration of disease of 5.25 +/- 0.47 years, and mean glycosylated hemoglobin of 11.27 +/- 0.31%. Spirometry was performed on an Electronic Spirometer (Compact Vitalograph, Stockwell, London, UK). RESULTS: Pulmonary function in children with diabetes showed significant lower mean values of actual lung function parameters forced vital capacity (FVC), peak expiratory flow (PEF), and maximum mid expiratory flow rate (MMEF) compared to their predicted values. However, there was no significant reduction in the actual forced expiratory volume in the first second (FEV1), and FEV1/FVC% compared to their predicted values. CONCLUSION: The actual lung function data among Saudi T1DM children and adolescents showed significantly lower values of FVC, PEF, and MMEF compared to the predicted lung function data.

Assessment of alpha-fetoprotein in the diagnosis of hepatocellular carcinoma in Middle Eastern patients.

BACKGROUND: Alpha-fetoprotein (AFP) levels for the diagnosis of hepatocellular carcinoma (HCC) may vary by geographical region and racial background. No data exists for this test in the Middle Eastern population. In addition, there is limited data on the impact of virological status on AFP levels. METHODS: In a multicenter, case-control study involving 206 cases, 199 cirrhotic and 197 chronic hepatitis controls, we assessed the utility of AFP in the diagnosis of HCC (sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and positive likelihood ratios (LR). PPV and NPV were evaluated for three additional HCC prevalence rates (5, 10, and 20%). RESULTS: The best discriminating AFP value was 11.7 ng/ml. The sensitivity ranged from 32 to 79.5% at different AFP levels with the specificity increasing sequentially from 47.7 to 98.5%. Sensitivity of AFP at the best cut-off level for hepatitis C virus (HCV), hepatitis B virus (HBV) and non-viral etiology for HCC was 73.7, 65.6, and 59.5%, respectively. Specificity at this level for HCV, HBV, and non-viral etiology was 36.6, 30.1, and 29.4%, respectively. AFP cut-off levels of 102, 200, and 400 ng/ml showed similar sensitivity (39.8, 35.9, and 32%, respectively) and specificity (96, 98.5, and 98.5% respectively). Positive LR for AFP at >11.7, >20, >102, >200, >400 ng/ml were 2.8, 3.3, 9.9, 23.8, and 21.2, respectively. CONCLUSIONS: In cirrhotic patients, AFP has a poor screening and diagnostic value for HCC. Underlying viral etiology fails to influence the diagnostic accuracy of this test. An AFP level greater than 100 ng/ml has a high degree of specificity and may be used as a confirmatory test.

Evaluation of three instructional methods of teaching for undergraduate medical students, at king saud university, saudi arabia.

BACKGROUND: There is an international move from traditional curriculum towards the learner - centered, and patient-oriented curriculum. In spite of its advantages, problem-based learning requires a larger number of teaching staff and space. This study was done to compare the problem-based learning (PBL), lectures and modified PBL methods. METHODS: Thirty-three fifth year medical students who were taking the Family Medicine rotation participated in the study at the College of Medicine, King Saud University. Three instructors participated in the teaching of three topics to the three groups of students. Students acted as control for themselves across the three instructional methods, namely; lectures, PBL and modified PBL. The main outcomes were students' recall of knowledge, problem solving skills and topic comprehension. RESULTS: In the initial assessment, there was a significant difference in favor of PBL and the modified PBL regarding comprehension of the topic as tested by the short answer questions (p = 0.0001), problem solving skills as tested by the modified essay question (p = 0.002). Non-significant results were observed at the second stage of assessment. The modified PBL method was the preferred one for 39% of the students, followed by the PBL (36%) and lastly the lectures (25%). CONCLUSION: This empirical study suggests some advantages for the PBL method and the modified PBL over the lecture method. Larger studies are needed to confirm our results of this important issue as the modified PBL is an affordable option for schools that can not meet the staff and space requirements of the PBL curriculum.