A 42-year-old male is admitted to your intensive care day 4 post induction chemotherapy for acute promyelocytic leukemia (AML-M3). The patient was initially treated with idarubicin and all-trans retinoic acid (ATRA). He has progressively become more dyspnoeic in the ward. A chest X-Ray demonstrates a bilateral, diffuse pulmonary infiltrate.Initial examination reveals:
- RR 40 breaths/min
- SpO2 88% on 10 L/min O2 by face mask
- Glasgow Coma Scale 14 (E4 M6 V4)
- Temperature 38.9 oC
- Heart rate 144 beats/min
- Blood pressure 95/50 mmHg
Full blood count is as follows on admission:
- Give your differential diagnosis for his respiratory failure. (40% marks)
- What are the major issues in this patient and how would you manage them? (60% marks)
Answer and interpretation
a) Give your differential diagnosis for his respiratory failure. (40% marks)
Sepsis in a patient with immune compromise secondary to leukaemia.
- Bacterial –Gm negative –E.coli, Pseudomonas, Klebsiella
- Gm positive: Strep, Staph epi
- Fungal: Aspergillus, Candida, Cryptococcus
- Atypical: Legionella, mycoplasma
- Viral: CMV, HSV, RSV, Influenza, H1N1, VZV
- TB (depending on background)
- Idiopathic pneumonia syndrome
- Cardiac failure (cardiotoxicity due to induction chemo)
- Diffuse alveolar haemorrhage
- Non cardiogenic capillary leak syndrome
- Chemo induced ALI / pneumonitis
- Retinoic Acid Syndrome
b) What are the major issues in this patient and how would you manage them? (60% marks)
Major issues are:
1. Hypoxic respiratory failure
- Probable nosocomial pneumonia now requiring respiratory support and is likely to be progressive
- Problem with invasive respiratory support carrying very high mortality and complications including barotrauma, further nosocomial infections
- Management – Non-invasive respiratory support commencing with CPAP progressing to BiPAP using the lowest FiO2 to maintain PaO2 above 60 mmHg. Attempt to avoid invasive respiratory support if possible.
2. Possible Sepsis
- May rapidly progress to septic shock in this patient
- Possible unusual infective agent
- Early commencement of Broad cover (Cefepime / Ceftazadime / Tazocin and Vancomycin + Voriconazole / caspofungin / liposomal amphotericin + acyclovir + Bactrim.) Discussion with ID and haematology specialists for prior antimicrobial therapy, CMV status, previous aspergillus infection etc
- Removal of indwelling intravenous catheters that are in anyway suspicious for infection
- Central access (with platelet cover), consideration of inotropes after transfusion of blood products and IV fluids preferentially using Albumin containing solutions.
3. Prognosis from acute promyelocytic leukemia (AML-M3).
- Management is to liaise early with treating haematologist to ascertain likely outcome from primary disease and also discuss with family and patient the significant risk of deterioration and mortality.
- Treatment of coagulopathy- Vit K, Platelets, FFP Difficulties in making definitive diagnosis
- Possible atypical infection with low yield probable from cultures
- Significant other non-infective differential diagnosis.
- Management includes having a high degree of suspicion for resistant or unusual organism and managing with broad cover.
- Pass rate: 37%
- Highest mark: 8.3
Additional Examiners’ Comments:
- Candidates were expected to give some indication of treatment strategies e.g. antibiotics, reversal of coagulopathy rather than just writing D/W ID, haematology etc.