Occam’s Razor – the simplest explanation is most likely to be correct.
In the Emergency Room, we are faced with a multitude of cases, and Occam’s Razor serves best when we need to narrow down on the differential diagnoses.
Sometimes, a few cases may evade this category and continue to baffle us even after a thorough history is obtained or a detailed clinical examination is performed. If we are lucky enough to get the point-of-care (POC) lab tests in time (or the mere availability of POC), they aid in the diagnosis and decision-making. At times, these POC lab tests also may not provide much help.
I have described one such case – a 21-year-old male with fever, dyspnea, desaturation, and multiple petechiae of 3 days duration.
Case Presentation
A 21-year-old male came at 9.30 pm to the ER with fever and breathlessness for three days. Being a healthcare worker himself, he had suspected pneumonia and started oral Amoxiclav, oral Clarithromycin, and Paracetamol. Despite this, there was no improvement in clinical status. He had progressively worsening breathlessness and continuous low-grade fever. On day 3, he developed a few petechial spots over his arms and minimal subconjunctival hemorrhage.
He recalls having myalgia in the lead up to these symptoms, for which he had received several injections of intramuscular Diclofenac. The injection sites now had developed small hematomas. There were no other visible bleeding manifestations. He clearly said that he had had no contact with any infectious patients and had self-isolated after developing these symptoms. His workplace had sent blood and sputum cultures – which came back negative. Their only concern was a continuous rise in the WBC count and sent to our hospital for further management.
Assessment
The patient was very ill-looking and extremely dyspneic with obvious usage of accessory respiratory muscles. He was profusely diaphoretic, had bilateral subconjunctival hemorrhage, multiple petechiae, anasarca, dyspnea, and 99.6⁰F. His Vitals were heart rate – 134/min, blood pressure – 110/70mmHg, respiratory rate – 34/min, SpO2 – 72% in room air; 98% with NIV. There were bilateral crepitations in all lung fields + no obvious abnormalities on CVS, CNS, and abdominal examination. POC ultrasound revealed multiple B-lines in all lung areas. Dilated IVC. The remaining cardiac, abdomen, and limb USGs were normal. ABG revealed Type 1 respiratory failure with elevated lactates. Bedside CXR and chest CT revealed diffuse bilateral lung infiltrates – not typical of pulmonary edema or pneumonia. Probable ARDS was mentioned. Blood samples had been sent for necessary investigations, including cultures and peripheral blood smear.
Management
Meanwhile, opinions were obtained from critical care consultants and pulmonologists regarding further management. Based on the clinical findings, it was decided to start the patient on broad-spectrum antibiotics (BSA), albumin transfusion, diuretics for the fluid overload status, and NIV for respiratory failure [all in suspicion of sepsis with MODS]. The patient was started on BSA before shifting to the ICU. Meanwhile, the blood reports arrived, suggestive of possible Myelodysplastic Syndrome (WBC – 95,000 cu.mm), Hb – 7g/dl. Peripheral Blood Smear report was Acute Myeloid Leukemia – possible M2 or M3.
The patient was immediately started on IV fluids, and oncology consultation was immediately obtained for chemotherapy initiation. Albumin and diuretics were withheld in suspicion of blast crisis and leukostasis / leukemic infiltration of the lungs. The patient was started on Cisplatin and other chemotherapeutic agents; bicarbonate infusion for urine alkalinization; allopurinol to treat hyperuricemia due to cytolysis; aggressive IV fluids for prevention of AKI due to chemotherapy and hyperuricemia [Tumour Lysis Syndrome]. Bone marrow biopsy was done during his hospital stay, which confirmed blast crisis AML-M3. His clinical condition improved considerably, and he was discharged from the hospital on Day 7.
Lessons Learnt
- Recognising leukostasis and hyperviscosity in the ED in an undiagnosed AML patient is extremely difficult. https://link.springer.com/chapter/10.1007/978-3-030-22445-5_3
- While considering different diagnoses based on clinical findings, always keep an open eye. Rare diseases present to the ED just like all others. https://www.medscape.com/viewarticle/860747_3
- Aggressive fluid management is needed in hyperviscosity syndrome. If we had started this patient on diuretics as planned, the blood would have become more viscous and lead to multisystem thrombosis. https://pubmed.ncbi.nlm.nih.gov/22915493/
- Increased metabolism in AML can present as pyrexia. With the other features of anemia, leucocytosis, petechiae, and anasarca, we are likely to diagnose this as sepsis. When in doubt, look through other causes of pyrexia (PUO). https://onlinelibrary.wiley.com/doi/full/10.1111/imj.13180
- Anasarca in leukemia does not warrant albumin transfusion as this may worsen fluid status. They may actually be in need of steroid therapy. https://www.hindawi.com/journals/crihem/2012/582950/
- Point of Care Lab testing is essential to reduce the number of diagnostic errors in the ED. https://acutecaretesting.org/en/articles/
