Bronchitis laboratory tests

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Classification Acute bronchitis Chronic bronchitis
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]

Overview

Diagnostic tests are rarely needed to confirm the diagnosis of acute bronchitis. In very specific condition serologic tests, viral cultures or sputum analyses may be applied. Generally the inflammatory markers such as CRP raises during the course of acute bronchitis.
Chronic bronchitis is a diagnosis by definition although there are some laboratory findings as the disease advances and causes consequences.

Laboratory Findings

Acute Bronchitis

Viral cultures, serologic assays, and sputum analyses may be perform when a potentially treatable infection is thought to be circulating or because of epidemiologic purposes^[1].

Serologic assays

Nasopharyngeal swab and aspirates to test for PCR are available but not widely used^[1].

Procalcitonin

Procalcitonin level is helpful to distinguish bacterial from other causes of inflammation. During bacterial infections the level of procalcitonin will raise over 0.25 mcg/L and it encourages the physician to prescribe antibiotics^[2]^[3]^[4].

Chronic Bronchitis

Pulse Oximetry

Though pulse oximetry is not as accurate in predicting the percentage oxygen saturation as arterial blood gas analysis. However, it gives a quick estimate of patient status when combined with the clinical status.

Arterial Blood Gas (ABG)

ABG may show changes of hypoxemia and hypercapnia depending on the severity of disease.

Hematocrit

COPD patients may have hypoxemia due to the chronic underlying disease. This chronic hypoxemia may lead to polycythemia(hematocrit > 55% in men or 50% in women is diagnostic of polycythemia.
A sputum sample showing neutrophil granulocytes (inflammatory white blood cells) and culture showing that has pathogenic microorganisms such as Streptococcus spp.

Alpha 1 Antitrypsin Levels

Serum alpha1 antitrypsin levels below the protective threshold value (ie, 3-7 mmol/L) lead to severe form of emphysema
95% cases are due to the severe variant the Z allele present in these patients.
Specific phenotyping, and genetic counselling is reserved for patients in whom serum levels are 7-11 mmol/L.

References

↑ ^1.0 ^1.1 Wenzel RP, Fowler AA (2006). "Clinical practice. Acute bronchitis". N. Engl. J. Med. 355 (20): 2125–30. doi:10.1056/NEJMcp061493. PMID 17108344.
↑ Schuetz P, Christ-Crain M, Thomann R, Falconnier C, Wolbers M, Widmer I, Neidert S, Fricker T, Blum C, Schild U, Regez K, Schoenenberger R, Henzen C, Bregenzer T, Hoess C, Krause M, Bucher HC, Zimmerli W, Mueller B (2009). "Effect of procalcitonin-based guidelines vs standard guidelines on antibiotic use in lower respiratory tract infections: the ProHOSP randomized controlled trial". JAMA. 302 (10): 1059–66. doi:10.1001/jama.2009.1297. PMID 19738090.
↑ Briel M, Schuetz P, Mueller B, Young J, Schild U, Nusbaumer C, Périat P, Bucher HC, Christ-Crain M (2008). "Procalcitonin-guided antibiotic use vs a standard approach for acute respiratory tract infections in primary care". Arch. Intern. Med. 168 (18): 2000–7, discussion 2007–8. doi:10.1001/archinte.168.18.2000. PMID 18852401.
↑ Gilbert DN (2011). "Procalcitonin as a biomarker in respiratory tract infection". Clin. Infect. Dis. 52 Suppl 4: S346–50. doi:10.1093/cid/cir050. PMID 21460294.

Template:WikiDoc Sources

[pmid17108344-1] 1.0 ^1.1 Wenzel RP, Fowler AA (2006). "Clinical practice. Acute bronchitis". N. Engl. J. Med. 355 (20): 2125–30. doi:10.1056/NEJMcp061493. PMID 17108344.

[pmid19738090-2] Schuetz P, Christ-Crain M, Thomann R, Falconnier C, Wolbers M, Widmer I, Neidert S, Fricker T, Blum C, Schild U, Regez K, Schoenenberger R, Henzen C, Bregenzer T, Hoess C, Krause M, Bucher HC, Zimmerli W, Mueller B (2009). "Effect of procalcitonin-based guidelines vs standard guidelines on antibiotic use in lower respiratory tract infections: the ProHOSP randomized controlled trial". JAMA. 302 (10): 1059–66. doi:10.1001/jama.2009.1297. PMID 19738090.

[pmid18852401-3] Briel M, Schuetz P, Mueller B, Young J, Schild U, Nusbaumer C, Périat P, Bucher HC, Christ-Crain M (2008). "Procalcitonin-guided antibiotic use vs a standard approach for acute respiratory tract infections in primary care". Arch. Intern. Med. 168 (18): 2000–7, discussion 2007–8. doi:10.1001/archinte.168.18.2000. PMID 18852401.

[pmid21460294-4] Gilbert DN (2011). "Procalcitonin as a biomarker in respiratory tract infection". Clin. Infect. Dis. 52 Suppl 4: S346–50. doi:10.1093/cid/cir050. PMID 21460294.

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