April 28, 2010 by badgett
Diagnostic accuracy of confrontation visual field tests
among 332 eyes with a prevalence of defects of 57%
| Selected findings |
Sensitivity (%) |
Specificity (%) |
Kappa |
| Red comparison |
77
|
27
|
0.74
|
| Kinetic 5 mm red target |
74
|
93
|
0.67
|
| Finger comparison |
71
|
57
|
0.69
|
| Static finger wiggle |
44
|
97
|
0.63
|
| Finger counting |
25
|
100
|
0.79
|
How to do the tests
- Red comparison: “Two identical red atropine bottle tops, approximately 20 mm in diameter, were presented in a fashion analogous to the finger comparison test described above and the patient was asked if the bottle tops appeared equally red. Any quadrant in which the bottle top appeared less red was considered abnormal.”
- Kinetic red target: “A 5-mm red-topped pin was moved inward from beyond the boundary of each quadrant along a line bisecting the horizontal and vertical meridians. The patient was asked to report when the pin was first perceived to be red.”
- Finger comparison: “The examiner’s index fingers were presented simultaneously on either side of the vertical meridian in the superior and then inferior quadrants approximately 20° eccentric to fixation and the patient was asked to report if the fingers appeared equally clear. Any quadrant in which the finger appeared less clear was recorded as abnormal.”
- Static finger wiggle: “Two index fingers were presented simultaneously on either side of the vertical meridian approximately 20° eccentric to fixation and equidistant from the quadrant borders in the superior and then inferior quadrants. The patient was asked to report which finger wiggled (<5° oscillation).”
- Finger counting: “The patient was asked to count 1 or 2 static fingers presented sequentially in each of the 4 quadrants approximately 20° eccentric to fixation and equidistant from the quadrant borders.”
Reference
Kerr NM, Chew SS, Eady EK, Gamble GD, & Danesh-Meyer HV (2010). Diagnostic accuracy of confrontation visual field tests. Neurology, 74 (15), 1184-90 PMID: 20385890
Tags: visual fields
Posted in Neurology | Leave a Comment »
March 18, 2010 by badgett
This post, and the last post to ClinDx about heart failure, use the physical examination not as a traditional diagnostic test, but rather to help predict response to treatment.
The current study shows that an increase of pulse pressure of ≥ 9% (as measured by a radial artery catheter) can predict an increase in stroke volume after 500 cc of 6% hydroxyethyl starch among patients with severe sepsis or pancreatitis. The differences in the areas under the ROC curves were no significantly different among the three findings in the table.
Predicting increase in cardiac stroke volume after intravenous infusion of 500 cm of fluids
| Finding after passive leg raising |
Sensitivity |
Specificity |
| Increase ≥ 9% in pulse pressure as measured by radial arterial catheter |
79% |
85% |
| Increase ≥ 8% in femoral artery blood flow as measured by Doppler ultrasonography |
86% |
80% |
| Increase ≥ 10% in stroke volume as measured by bedside echocardiography |
86% |
90% |
A limitation is that the pulse pressure was measured by radial artery catheter. Presumably, an auscultated blood pressure would perform similarly, but this is not certain.
This has been added to http://en.citizendium.org/wiki/Head-down_tilt.
Tags: shock
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March 3, 2010 by badgett
Targeting a clinical score to a score of 2 or less based on the Framingham diagnosis of heart failure with the following findings may reduce mortality similarly to targeting a NT-proBNP level and better than usual care:
- Major findings (1 point each)
- Minor findings (0.5 point each)
- Orthopnea
- Reduction in exercise tolerance
- Resting heart rate > 100 bpm
- Hepatomegaly
- Peripheral edema
This has been added to http://en.citizendium.org/wiki/Heart_failure#Goals.
Citation:
Lainchbury JG, Troughton RW, Strangman KM, Frampton CM, Pilbrow A, Yandle TG, Hamid AK, Nicholls MG, & Richards AM (2009). N-terminal pro-B-type natriuretic peptide-guided treatment for chronic heart failure: results from the BATTLESCARRED (NT-proBNP-Assisted Treatment To Lessen Serial Cardiac Readmissions and Death) trial. Journal of the American College of Cardiology, 55 (1), 53-60 PMID: 20117364
Posted in Cardiology | 1 Comment »
January 29, 2010 by badgett
The current study validates a prior symptom index developed by Goff (PMID: 17154394) and consensus critiera for prompting testing for ovarian cancer promoted by the Gynecologic Cancer Foundation (GCF), the Society of Gynecologic Oncologists (SGO), and the American Cancer Society (ACS). The current study reports test accuracy similar to the prior reports, but the current study adds the analyses that the societies failed to do: projecting the positive predictive values based on a the prevalence of ovarian cancer found in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial (PMID: 16260202). Not surprisingly, with such a low prevalence of cancer in the general population, the predictive values of these tests are all less than 1%. This study demonstrates a case of specialty societies prematurely promoting testing for their diseases.
Diagnostic accuracy for symptoms starting within the past year and an estimated prevalence of ovarian cancer of 60 per 100,000 women (0.06 %).
| Symptom (starting in the last year) |
Sensitivity (%)
(early stage – late stage dz) |
Specificity (%) |
Positive predictive value |
| Pelvic or abdominal pain |
49 to 52
|
97
|
< 1%
|
| Bloating or feeling full |
44 to 58
|
97
|
< 1%
|
| Urinary frequency or urgency |
30 to 30
|
96
|
< 1%
|
| Symptom index (any of the above at least daily for at least 1 week in the last year) PMID: 17154394 |
62 to 71
|
95
|
< 1%
|
| Consensus criteria (any of the above at least daily for at least 1 month in the last year) PMID: 17848663 |
59 to 69
|
94
|
< 1%
|
Citation
Rossing, M., Wicklund, K., Cushing-Haugen, K., & Weiss, N. (2010). Predictive Value of Symptoms for Early Detection of Ovarian Cancer JNCI Journal of the National Cancer Institute DOI: 10.1093/jnci/djp500
Posted in Gynecology | Leave a Comment »
January 28, 2010 by badgett
In this study of 55 patients, the authors studied five findings and concluded, “The cut point of 3 or more positive of 5 tests can confirm the diagnosis…, while less than 3 positive of 5 rules out.” If you look at the accuracies and the predictive values below, I think you will agree these results are overstated and not very helpful clinically. The shoulder is still very hard to examine.
Diagnostic Accuracy for Impingement Shoulder Tests
among 55 patients with a prevalence of impingement of 29%
| Finding |
Sensitivity (%) |
Specificity (%) |
Kappa |
Positive
predictive value |
Negative
predictive value |
| Hawkins-Kennedy |
63
|
62
|
.39
|
40
|
61
|
| Neer |
81
|
54
|
.40
|
42
|
13
|
| Painful arc |
75
|
67
|
.45
|
48
|
13
|
| Empty can (Jobe) |
50
|
87
|
.47
|
61
|
19
|
| External rotation resistance |
56
|
87
|
.67
|
64
|
17
|
| 3 or more of 5 findings positive |
75
|
74
|
|
54
|
12
|
How to do the tests
YouTube videos demonstrating the tests
Citation
Michener LA, Walsworth MK, Doukas WC, & Murphy KP (2009). Reliability and diagnostic accuracy of 5 physical examination tests and combination of tests for subacromial impingement. Archives of physical medicine and rehabilitation, 90 (11), 1898-903 PMID: 19887215
Posted in Orthopedics | Leave a Comment »
November 22, 2009 by badgett
Does This Patient With Palpitations Have a Cardiac Arrhythmia?
This systematic review by the Rational Clinical Examination found that an arrhythmia was more likely (LR > 2) if that patient has:
- A history of cardiac disease (likelihood ratio [LR], 2.03; 95% CI, 1.33-3.11)
- Palpitations affected by sleeping (LR, 2.29; 95% CI, 1.33-3.94)
- Palpitations while at work (LR, 2.17; 95% CI, 1.19-3.96)
A arrhythmia was less likely (LR < 0.5) if that patient has:
- A known history of panic disorder (LR, 0.26; 95% CI, 0.07-1.01)
- Palpitations lasting less than 5 minutes (LR, 0.38; 95% CI, 0.22-0.63)
Additional findings that need further discussion are:
- Description by the patient of an irregular heart rate was an independent predictor of a cardiac arrhythmia(PMID: 8629647). The authors of the systematic review did not conclude this finding was helpful because the likelihood ratio, while significant, was within 0.5 to 2.0.
- An increased number of symptoms suggested psychiatric causes in the univarate, but not multivariate analysis of Weber (PMID: 8629647). This finding is part of a theme in general that the more symptoms are present the more likely there is an underlying psychiatric diagnosis in the evaluation of syncope (PMID: 17397948) and symptoms in general in primary care (PMID: 7987511).
This has been added to http://en.citizendium.org/wiki/Palpitation.
Citation:
Thavendiranathan, P., Bagai, A., Khoo, C., Dorian, P., & Choudhry, N. (2009). Does This Patient With Palpitations Have a Cardiac Arrhythmia? JAMA: The Journal of the American Medical Association, 302 (19), 2135-2143 DOI: 10.1001/jama.2009.1673 – PMID 19920238
Posted in Cardiology | Leave a Comment »
November 22, 2009 by badgett
Association of physical examination with pulmonary artery catheter parameters in acute lung injury
The authors found that physical findings had good specificity in predicting low cardiac index (CI) and low central oxygenation; however, at the low prevalence of low CI in this study, even when all three physical findings were present, the positive predictive value was 40%.
This cross sectional study looked at three physical findings (delayed capillary refill time, knee mottling, and cool skin temperature) in predicting cardiac index, central venous oxygen saturation (ScvO2 –
a quality measure of IHI), and mixed venous oxygen saturation (SvO
2) among 392 patients with acute lung injury studied by
ARDSNet.
Results:
For cardiac index < 2.5 (similar results for the measures of oxygenation):
|
Sensitivity |
Specificity |
Predictive values at prevalence of 8% |
| Positive |
Negative |
| Any one of three findings* present |
52% |
78% |
17% |
95% |
| All three findings* present |
12% |
98% |
40% |
93% |
| * Findings are: delayed capillary refill time, knee mottling, and cool skin temperature. |
Did not look at proportional pulse pressure < 25% which has previously been found to be predictive (PMID:
2913385; PMID:
11420761)
Citation:
Grissom CK, Morris AH, Lanken PN, Ancukiewicz M, Orme JF Jr, Schoenfeld DA, Thompson BT, & National Institutes of Health/National Heart, Lung and Blood Institute Acute Respiratory Distress (2009). Association of physical examination with pulmonary artery catheter parameters in acute lung injury. Critical care medicine, 37 (10), 2720-6 PMID: 19885995
Posted in Cardiology, Intensive care | Leave a Comment »
November 11, 2009 by badgett
The medical history taking and physical examination each contributed to 10% of self-reported errors by internal medicine and emergency medicine physicians. This combined rate of 20% is a little higher than a prior report of 10% (PMID: 16009864).
This has been added to Citizendium: Physical_examination - Importance_of_the_physical_examination.
Citation:
Schiff, G., Hasan, O., Kim, S., Abrams, R., Cosby, K., Lambert, B., Elstein, A., Hasler, S., Kabongo, M., Krosnjar, N., Odwazny, R., Wisniewski, M., & McNutt, R. (2009). Diagnostic Error in Medicine: Analysis of 583 Physician-Reported Errors Archives of Internal Medicine, 169 (20), 1881-1887 DOI: 10.1001/archinternmed.2009.333
Posted in Diagnostic error | Leave a Comment »
October 20, 2009 by badgett
Dysphagia among stroke patients is suggested by the following test:
- First check the patient for “swallowing complaints, abnormalities of voice quality, facial asymmetry, or either expressive or receptive aphasia.” If none is detected then go to step 2.
- Have the patient drink 10 mL of water from a cup without a straw while seated upright while oxygenation saturation is monitored during and for 2 minutes after the test. Check whether the patient
- “Coughed or choked during the water drinking or had a change in voice quality after the swallow”.
- Oxygenation drops by 2% or more.
In this small study of 84 patients, this two-step test detected 96% of patients with dysphagia as compared to testing by a speech pathologist.
This had been added to http://en.citizendium.org/wiki/Dysphagia.
Citation:
Turner-Lawrence DE, Peebles M, Price MF, Singh SJ, & Asimos AW (2009). A feasibility study of the sensitivity of emergency physician Dysphagia screening in acute stroke patients. Annals of emergency medicine, 54 (3) PMID: 19362752
Posted in Neurology | Leave a Comment »
October 20, 2009 by badgett
The preferred locations for testing according to this systematic review are filled green in the image. As the independent addition of the monofilament to visually inspecting for deformities, pressure marks, cracked skin, infected nails, evidence of prior ulcers, and other findings is not clear in the major trial of screening (http://pubmed.gov/8498761), it seems we should limit our time to testing three points rather than 10.
This has been added to http://en.citizendium.org/wiki/Diabetic_neuropathy#Screening
Citation:
Feng Y, Schlösser FJ, & Sumpio BE (2009). The Semmes Weinstein monofilament examination as a screening tool for diabetic peripheral neuropathy. Journal of vascular surgery : official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter, 50 (3) PMID: 19595541
Posted in Diabetes, Neurology | Leave a Comment »
