The possible effects of iron loss from bloodletting on mortality from pneumonia in the nineteenth century

OBJECTIVE: To estimate iron losses and disease severity following 19th century bloodletting in patients with pneumonia. STUDY DESIGN AND SETTING: Benefits of bloodletting in pneumonia patients were contested during the 19th century. Although large blood volumes during infection were removed there was no systematic data collection assessing efficacy and knowledge of iron composition of blood was rudimentary. This observational analysis of historical data quantifies iron losses in pneumonia cases in relation to disease severity. RESULTS: Based on one detailed case series average blood volume removed for survivors was 830 mL (range 114-2272 mL), and mean recovery times were shorter in patients bled within 2 days of illness (P < 0.001). Average iron removed was 446 mg with phlebotomy done ≤2 days of illness presentation and 347 mg after >2 days of illness (P = 0.012). Across several European hospitals average case fatality in pneumonia patients receiving phlebotomy was higher than in those treated without phlebotomy (19.9% vs. 12.8%, OR 1.55, 95% CI 1.38-1.74, P < 0.001). CONCLUSION: Variable efficacy for bloodletting could at least in part be explained by altered iron status.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Quantitative analysis of 19th-century pneumonia bloodletting showing average 446 mg iron removed per phlebotomy and 19.9% case fatality versus 12.8% without phlebotomy.

Erfahren Sie, wie diese Forschung mit der klinischen Praxis verknüpft ist

More peer-reviewed studies in Klinische Studien.

• Leech Therapy for Knee Osteoarthritis — The Landmark RCT — Michalsen et al. (2003)
• Leech-Assisted Flap Salvage — Systematic Review of 277 Cases — Whitaker et al. (2012)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• Efficacy and Safety of Hirudotherapy for Improving Sperm Quality Parameters in Male Infertility: A Randomized Controlled Trial — Abtahi-Forooshani M et al. (2026)
• Reverse Sural Flap Venous Congestion Successfully Managed With Enoxaparin in a Male Patient With a Traumatic Foot Crush Injury: A Case Report — Velasco-Bustamante J et al. (2026)
• Investigation of the therapeutic effects of medicinal leech treatment on lower extremity ischemia-reperfusion injury — Ünal K et al. (2026)
• Efficacy of Medicinal Leech Therapy in Diverse Clinical Applications: A Comprehensive Study from Azerbaijan — Farzali S et al. (2025)
• HIRUDOTHERAPY IN RECONSTRUCTIVE SURGERY: CASE-REPORTS AND REVIEW — Heinz P et al. (2020)
• Hirudotherapy Efficacy and Complications in the Management of Microsurgical Breast Reconstruction: A Systematic Review — Foppiani J et al. (2024)
• Hirudotherapy in Wound Healing — Nair H et al. (2022)

Browse all ASH-analysed research →