pituitrin and Respiratory-Tract-Infections

This review aims to provide physicians with an overview of the potential of biomarkers to complement existing clinical severity scores and in conjunction with clinical parameters to improve the diagnosis, risk-stratification and management of lower respiratory tract infections (LRTIs). The usefulness of biomarkers for diagnosing LRTIs is still unclear. However, the specificity of pneumonia diagnosis is high when high sensitivity C-reactive protein (CRP) and procalcitonin (PCT) are used. PCT, CRP and particularly pro-atrial natriuretic peptide (MR-proANP), pro-vasopressin (CT-proAVP) and proadrenomedullin (proADM) levels can reliably predict LRTIs mortality. These markers do not significantly improve the severity scores predictive values, confirming that biomarkers are meant to complement, rather than supersede, clinician's judgment and validated severity scores. Biomarkers, and particularly PCT, are useful tools as antibiotic treatment duration indicators both in pneumonia and exacerbations of chronic obstructive pulmonary disease (COPD). Even if more data are required to fully appreciate the role of biomarkers in LRTIs management, there is emerging evidence that biomarkers have the potential to improve the daily clinical management of LRTIs.

Topics: Adrenomedullin; Atrial Natriuretic Factor; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Humans; Pneumonia; Prognosis; Protein Precursors; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Infections; Vasopressins

17 patients with severe hyponatraemia (none had cardiac failure or had lately had an operation) all had excessively high plasma-antidiuretic hormone (A.D.H.). Only 13 had features typical of the syndrome of inappropriate secretion of A.D.H. (S.I.A.D.H.). Plasma-A.D.H. was not related to either plasma-sodium or diagnosis. There were as many patients with chest infection as with carcinoma of the lung. Plasma-sodium and plasma-A.D.H. returned rapidly towards normal in the patients with chest infection or volume depletion but these concentrations corrected much more slowly in patients with carcinoma of the lung. The increase in plasma-sodium in patients with chest infection was too rapid to be produced by water-deprivation treatment and was due to return of plasma-A.D.H. to normal. The term S.I.A.D.H. implies an understanding of pathophysiology that does not exist. As a diagnosis it does not help in management or prognosis. A simpler, more descriptive terminology such as "hyponatraemia with carcinoma of the lung" would be more useful and less confusing in the clinical situation.

Topics: Aged; Female; Humans; Hyponatremia; Lung Neoplasms; Male; Middle Aged; Respiratory Tract Infections; Sodium; Syndrome; Terminology as Topic; Vasopressins

A 38-year-old physician developed polyuria and hypodipsia four days after the onset of an upper respiratory tract infection. Subsequent investigation showed a concentration defect with dehydration that partially corrected with vasopressin injection (Pitressin) administration compatible with partial central diabetes insipidus (DI). Skull roentgenograms, EEG, and lumbar puncture were normal. The polyuria and hypodipsia slowly resolved without treatment. Normal urinary concentration ability was achieved by the 48th day, but a residual elevation in serum osmolarity persisted for one year. Review of the literature failed to show previous documentation of transient DI with elevated serum osmolarity from an acute, febrile illness. The mechanism is speculative, but may be related to a subclinical encephalitis. The true frequency of this syndrome and its relationship to the frequent observation of transient polydipsia and polyuria in "benign" febrile illness remains to be determined.

Topics: Acute Disease; Adult; Blood; Diabetes Insipidus; Humans; Hypothalamus; Kidney Concentrating Ability; Male; Osmolar Concentration; Polyuria; Respiratory Tract Infections; Thirst; Vasopressins

Topics: Aged; Chronic Disease; Humans; Lung Diseases, Obstructive; Male; Respiratory Insufficiency; Respiratory Tract Infections; Vasopressins