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Question 2: Is the packed cell volume ÷ 3 rule valid for estimating haemoglobin in children in malarious areas?
  1. Wilma Francisca Tanga1,
  2. Andrew James McArdle2
  1. 1 Department of Medicine, Connaught Hospital, Freetown, Sierra Leone
  2. 2 Paediatric Infectious Diseases, St Mary’s Hospital, London, UK
  1. Correspondence to Dr Wilma Francisca Tanga, Medicine, Connaught Hospital, Freetown, Sierra Leone; franciswil2007{at}

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You are working in a regional hospital in Sierra Leone. A 3-year-old child arrives with a history of fever, progressive weakness, reduced consciousness and convulsions. On examination, she has moderate respiratory distress, looks very pale and is unconscious. Her malaria rapid diagnostic test is positive. A spun packed cell volume (PCV) is 20%, leading to a haemoglobin (Hb) estimate of 6.7 g/dL. You ask yourself how accurate this estimate of Hb is, and whether you should transfuse the child regardless.

Structured clinical question

In children in malarious areas attending hospital with acute illness (patient) how accurate is PCV÷3 (investigation) compared with haemoglobin (comparison) in diagnosing severe anaemia (outcome)?


A literature search was …

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  • Contributors AJM conceived the idea for the study and performed the initial literature search. WFT updated the search. AJM and WFT appraised the studies, extracted the data and prepared the manuscript.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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