😱Emergencies in Hematolo...

Metadata

• Author: @NicoGagelmann on Twitter
• Full Title: 😱Emergencies in Hematolo...
• Category: #tweets
• URL: https://twitter.com/NicoGagelmann/status/1658135643686330369

Highlights

• 😱Emergencies in hematology😱
  Hyperviscosity syndrome (HVS)
  A short 🧵 #MedTwitter
  1/19
  (View Tweet)
• Intro:
  -an oncologic emergency!
  -classical triad: neurological deficits, 👁️changes, mucosal bleeding
  -blood cell shape deformity or a pathological increase in serum proteins, red blood cells (RBC), white blood cells (WBC), or platelets (PLT)
  2/19 https://t.co/d1GZhTWHMd (View Tweet)
• Cause:
  -elevation of the (a)cellular 🩸components
  Cellular: polycythemia vera, leukemia, thrombocytosis, sickle cell disease, spherocytosis
  Acellular: myeloma, Waldenstrom macroglobulinemia, cryoglobulinemia, sero+ rheumatoid arthritis, lupus, Sjogren, Castleman disease, HIV
  3/19
  (View Tweet)
• Background I:
  -mathematics of viscosity first described by Poiseuille in 1828: volume of liquid flowing in tube of small diameter ~ to bore of tube and pressure difference at both ends when temperature is fixed
  4/19
  (View Tweet)
• Background II:
  -proteins determine viscosity in serum & plasma
  -large linear proteins spin end over end and raise viscosity👉 fibrinogen in plasma and immunoglobulins in serum
  -IgM has a high axial length-to-width ratio
  👉high intrinsic viscosity+raises the plasma viscosity
  5/19
  (View Tweet)
• History:
  -1932-37 reports of increased serum viscosity in myeloma
  -Waldenström in 1944 described elevated viscosity in macroglobulinemia
  👉triad of mucosal bleeding, visual alterations, neurological dysfunction
  -1st report of plasma exchange in 1959
  -Fahey named HVS in 1965
  6/19
  (View Tweet)
• Clinic:
  -bleeding most common manifestation (epistaxis, bleeding gums or GI)
  -headache, neuropathy, generalized stupor, coma, dizziness, ataxia, hearing impairment, seizures, and stroke syndromes
  👉bc of decreased🩸flow to CNS + deposition of (para)proteins in myelin sheath
  7/19
  (View Tweet)
• Look closely👀!
  -EXAMINE THE EYES!
  -retinopathy, blurred or double vision arise bc of thrombosis or hemorrhage
  👉"sausage link" or "boxcar" engorgement of retinal veins, papilledema, flame-shaped hemorrhages, exudates
  -SERIOUS: bilateral central retinal vein occlusion
  8/19
  (View Tweet)
• Hematologists!
  -in myeloma and WM, anemia is often found and may be partially dilutional and not well reflected by standard measurement
  -controversy: to withhold transfusion in hemodynamically stable patients until serum viscosity is normalized
  9/19 https://t.co/sT2QfqDPUd (View Tweet)
• Diagnosis controversy:
  -whole blood versus serum viscosity
  -most clinical laboratories measure serum
  -measured in centipoise (cp)
  • • 🌊is 1 cp
  • • normal serum relative to water is 1.4-1.8 cp
  • -Symptoms can appear with >3 cp, but usually, arise when it exceeds 4-5 cp
    10/19 https://t.co/DYSdDg5SWt (View Tweet)
• It's in your blood!
  -complete blood count, full serum chemistries, coagulation profile, and urinalysis
  -elevated albumin-protein gap along with significant proteinuria suggest underlying gammopathy
  -Rouleaux formation on peripheral 🩸smear highly suggestive of stasis
  11/19
  (View Tweet)
• Prognosis:
  -HVS at myeloma diagnosis is a rare but urgent complication associated with high lethality in older patients
  -associated with high tumor burden and dismal survival, independent of principal prognosis scores in modern treatment era
  -detect and act early!
  12/19
  (View Tweet)
• Treatment:
  -timely treatment can prevent life-threatening complications
  👉thromboembolic events, 🫀 infarction, ischemia
  👉multiorgan failure
  -HYDRATION: dehydration can worsen HVS and patients are usually dehydrated
  👉1-2 L of normal saline when HVS is suspected
  13/19
  (View Tweet)
• Plasma exchange:
  -2 methods
  👉centrifugation
  👉double-membrane filtration
  -⬇️ viscosity 30-50% in 1 session that exchanges 1 volume of the patient’s plasma
  fFor immunoglobulin reduction, 1 exchange can ⬇️ level by 60%
  -usually 1 session👍, 3 sessions for >6cp
  14/19
  (View Tweet)
• Adverse events of plasma exchange:
  -difficulty with access, paresthesias related to citrate and hypocalcemia, hypotension, urticaria from replacement fluids
  • when significant amounts of IgM are removed
    👉 capillary leak-like syndrome with vascular collapse
    15/19
    (View Tweet)
• Phlebotomy:
  -if prompt plasmapheresis not possible
  -phlebotomize 1-2 units of 🩸 and concurrently replace it with normal saline
  -CAUTION: aggressive exchange 👉 eliminates clotting factors, albumin, and platelets
  -only done when severe neurological deficits
  16/19 https://t.co/21BpgenSvo (View Tweet)
• Hyperleukocytosis:
  -if >100k👉hyperviscosity+microvascular obstruction
  👉acute leukemia!
  👉🫁 + CNS!
  -recommendation: ∼1.5-2 total 🩸 volumes for each leukocytapheresis to remove 30-60% of WBCs
  -target ∼5% as hematocrit of WBC collection
  CAVE: TLS https://t.co/QO2hdTRUpa
  17/19 (View Tweet)
• Treat underlying disease!
  -Plasmapheresis does NOT affect the underlying disease
  -chemotherapy
  -for myeloma: bortezomib-based therapies produce very rapid responses in 85%
  -also ibrutinib can produce rapid reduction in the IgM
  18/19 https://t.co/ndDz4YEINJ (View Tweet)
• Summary of HVS:
  ❗️Emergency
  ❗️triad: neurological symptoms, mucosal bleeding, 👁️ disturbances
  ❗️most common with hypergammaglobulinemia
  ❗️serum viscosity⬆️👉Rouleaux formation on 🩸smear
  ❗️hydration, plasmapheresis, elective phlebotomy AND treatment of underlying condition https://t.co/6I7yNbq8mV (View Tweet)
• References & resources:
  https://t.co/QPyrKnWqxw
  https://t.co/0vyNImxKQo
  https://t.co/FWbmgxhBB1
  https://t.co/r6Kq2a7BsL
  https://t.co/I5TzJbaSNR https://t.co/oal26rJrGh (View Tweet)