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Is spinach really good for you?

Is spinach really good for you?. A case of Methaemoglobinaemia Jonathan Mervis. Case Study. M.M. is a 3 month old female infant diarrhoea and vomiting for 3 days herbal medication s given (oral and enema)

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Is spinach really good for you?

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  1. Is spinach really good for you? A case of Methaemoglobinaemia Jonathan Mervis

  2. Case Study • M.M. is a 3 month old female infant • diarrhoea and vomiting for 3 days • herbal medications given (oral and enema) • increasing irritability, dyspnoea, poor feeding, depressed level of consciousness • Family have running water, electricity, sewage

  3. M.M., SHOWING CYANOSIS OF LIPS

  4. What are possible causes of M.M.’s cyanosis?

  5. Causes of cyanosis in children • Inadequate O2 of haemoglobin (common) • Pulmonary disorders • R-L shunts • Congestive heart failure • Cardiovascular collapse

  6. Causes of cyanosis in children, continued 2. Methaemoglobinaemia (rare) • Congenital: • Cytochrome B5 reductase deficiency • cytochrome B5 deficiency • haemoglobin M • Acquired: • Toxins • Drugs

  7. Normal Physiology 100 % SaO2 Ph 50 CO2 Temp 2,3 DPG 2 6 12 ( Kpa) PaO2

  8. Methaemoglobin • Oxidation= Loosing an electron • Reduction=gaining an electron Fe(2+) Ferrous ion = good Fe(3+) Ferric ion = bad

  9. Methaemoglobin Fe(3+) Fe(2+) e- Cytochrome B5 Reductase Cytochrome B5

  10. Methaemoglobinaemia • 20% acute increase = fatigue • 30% acute increase = raised heart rate • 50% acute increase = weak/ dyspnoeic/ confused • 70%-80% acute increase= coma and death

  11. Toxin induced MetHb • Dependant on toxin, dose and duration of exposure • Neonates and infants are more susceptible

  12. Common toxins producing MetH • Water from wells • Drugs (over-the-counter meds, metoclopramide, nitrites, anti-malarials) • Vegetables (SPINACH!) • Diarrhoea

  13. Case Study, continued • M.M. was profoundly acidotic, shocked • initial blood gas • Ph= 6.75/ CO2 =1.53/ O2 =26.4 unrecordable • Poor perfusion, cyanosed, but good air entry and easy to ventilate • Blood gas in ICU • Ph=6.78/ CO2=2.41/O2=57.2/ -27/ 3.4

  14. Case Study, continued • Central venous access yielded chocolate brown blood • Lactate 17.6 • throughout this time his O2 saturation remained 80%-83% • Hb= 7.8

  15. Blood on swab – note chocolate colour

  16. What is the management of methaemoglobinaemia?

  17. Management • Ascorbic acid (vitamin C) • reduces methaemoglobin directly • Methylene blue • acute levels >40% • IV 1-2mg/kg • repeat dose • G6PD deficiency • Dramatic response

  18. Blood samples, showing improvement after methylene blue therapy

  19. Treatment - note rapid improvement Treatment

  20. Conclusion Consider methaemoglobinaemia when there is • Cyanosis with high PaO2 , • Child is easy to ventilate and well-perfused

  21. Further reading • ??

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