Lecture Notes from April 8th

Notes from our conference on April 8th. If you have any corrections or comments please feel free to add!

Oncologic Emergencies

Neutropenic Fever

Definition: Fever (>101 F or >100.4 F for an hour) with ANC<500, typically avoid rectal temperatures (although no actual evidence of induced bacteremia)

Cause: Often caused by chemotherapy, WBC declines to nadir and then comes back up

  • Also myelodysplastic syndromes, post viral, medication side effect

Clinical Presentation: Often no typical signs of infection (due to lack of response)

Management: Cultures (including from any central access, sometimes fungal), +/-CSF studies, viral testing, typical infectious work-up

  • Reverse isolation, broad spectrum abx, otherwise typical therapy
  • Low threshold for hydrocortisone
  • Neutropenic enterocolitis: Typically presents with RLQ pain with neutropenia
  • Some clinical decision tools, varied validation, look up if interested

Hypercalcemia of Malignancy

General: up to 30%, most common with lung and breast cancers

Pathophysiology: Decreased GI motility, decreased muscular contractions

Mechanisms: PTH-related protein production, Vitamin D analog production, increased osteoclast activity

Treatment: Fluids, bisphosphonates, calcitonin, glucocorticoids, dialysis (for severe cases)

Tumor Lysis Syndrome

General: Typically after initiation of chemotherapy or during times of high cell turnover, found with hematologic malignancies

Clinical Presentation: Electrolyte abnormalities (hypocalcemia, hyperphosphatemia, hyperkalemia), elevated uric acid, acute renal injury, cardiac dysrhythmias, seizures

Treatment: Fluids, rasburicase, correct electrolyte abnormalities and treat as appropriate, dialysis for severe cases

-Correct calcium only if symptomatic to avoid crystallization with high phosphate load

Urinary Diversions

Types:

  • Ileal conduit: incontinent, portion of the bowel with ureters attached to one side and the other attached to skin, drains into urostomy bag
  • Indiana pouch: Similar to above with ileocecal valve making up the collecting pouch, ureters attached to onse side and the distal cecum attached to the skin, ileocecal valve functions as sphincter, urine drained by self-cath
  • Neobladder: Segment of bowel resected and made into a bladder-like sac, one side attached to ureters and the other attached to urethra, varying degrees of incontinence depending on preservation of nerves and sphincter tone, possible to urinate volitionally 

General: Since all of these diversions are made from bowel they are colonized with bacteria and will always have +UA, best practice is cleaning of skin site and catheter specimen sent for culture, diagnosis can also be made by stranding on CT

Clinical Presentation: More often nausea, vomiting, flank pain (different innervation than typical urinary system so will more closely approximate visceral/enteric nociceptor patterns)

Hypersensitivity Reactions

Types:

  • Type 1: Immediate, mediated by IgE (causes histamine release from mast cells)
    • Examples: classic allergic response, anaphylaxis
  • Type 2: Antibody mediated (autoimmune disease mediated by autoantibody against a self target)
    • Examples: Graves disease, Myasthenia, Autoimmune hemolytic anemia, Goodpasture’s 
  • Type 3: Immune complex mediated (autoimmune disease due to deposition of antibody/antigen complexes)
    • Examples: glomerulonephritis, SLE, RA, HSP
  • Type 4: T cell mediated
    • Examples: Tuberculin skin test, contact dermatitis, DM1, RA, IBD, MS

General: Should always be on the differential, often mimic infectious or traumatic pathologies. If you don’t think of them you won’t diagnose them

Lecture Notes from April 1st

Here are some notes from our conference on April 1st for some spaced repetition. Topics included are Orthopedic emergencies, fracture pattern review, disorders of coagulation, and targeted temperature management after cardiac arrest. Please comment with any thoughts or corrections!

Orthopedics Review

Arthrotomy: Takes up to 155 cc for sensitive test, can sometimes substitute CT (institution dependent)

Injury Patterns by Anatomic Location:

Clavicle fracture: Medial can be complicated by vascular injury, up to 15% are complicated by nonunion, most common location is mid shaft

Shoulder dislocation: Anterior most common, posterior associated with seizure or electrical injury

Humerus: Posterior fat pad or anterior sail sign indicative of lipohemarthrosis, concern for occult injury (supracondylar in pediatrics, radial head in adults)

Forearm: Monteggia and Galleazzi (MUGR, Monteggia Ulnar fracture with radial head dislocation, Galleazzi Radius fracture with distal radioulnar dislocation)

Wrist: Colle’s (dinner fork) and Smith fracture (opposite), Lunate vs. perilunate dislocation (based on alignment of radius, lunate, and capitate) (https://radiopaedia.org/articles/lunate-dislocation?lang=us)

Hand: Boxer’s fracture (5th metacarpal)

Pelvis: mechanism of injury classification includes anterior compression, lateral compression, vertical shear injuries, binder to reduce pelvic volume for “open book” injuries typically associated with AC mechanism, posterior hip dislocation (early management reduces risk of avascular necrosis of femoral head)

Knee: posterior knee dislocation (high incidence of vascular injury, can often spontaneously reduce), tibial plateau fracture (often occult, can only see in lipohemarthrosis in some cases, low threshold for CT), tendon rupture (based on position of patella)

Ankle: Maisonneuve (due to syndesmosis conducting force to proximal fibula, sometimes associated with mortise widening), malleolar fractures, pilon fracture (through distal articular surface of tibia, increased likelihood of poor functional outcome)

Foot: LisFranc injury (dislocation at the Tarsometatarsal joint), Jones fracture (at the base of the 5th metatarsal, high rate of nonunion) (https://radiopaedia.org/articles/avulsion-fracture-of-the-5th-metatarsal-styloid?lang=us)

Infectious complications:

Septic arthritis- typically presents with pain with passive and active ROM at the joint, diagnosis is my arthrocentesis (WBC >50,000 for bacterial), polyarticular concerning for disseminated gonococcus

Felon/Paronychia- distal finger infections, involve the pulp space (felon) and the cuticle (paronychia)

Flexor tenosynovitis- Kanavel’s signs (pain with passive extension, flexor tenderness, circumferential swelling, held in flexion)

Compartment syndrome- Often clinical diagnosis diagnosis, more sensitive with compartment pressures (delta pressure <30, diastolic – compartment pressure or pressure >30), often associated with opioid use

Microangiopathic Hemolytic Anemias, vWF disease, and DIC

Thrombotic thrombocytopenic Purpura: 

General- Primary disorder, hereditary deficiency of or autoimmune response to ADAMSTS13 resulting in decreased cleavage of vWF polymers

-leads to consumptive coagulopathy with platelet destruction

Clinical Presentation- fever, AMS, thrombocytopenia, renal injury

Treatment- Plasmapheresis and steroids

Disseminated Intravascular Coagulation:

General- Secondary disorder, due to systemic inflammation leading to consumptive coagulopathy

Clinical presentation- bleeding, elevated D dimer, abnormal coagulation studies, low fibrinogen/platelets

Treatment- Aimed at underlying cause, can also transfuse as needed

Immune Thrombocytopenic Purpura:

General- Primary disorder, autoantibodies against platelets leading to platelet destruction and thrombocytopenia

-can be caused by infections (viral or bacterial,) autoimmune disease, or various medications

Clinical Presentation- asymptomatic thrombocytopenia

Treatment- glucocorticoids, IVIG if active bleeding

VonWillebrand Factor Disease

General- deficiency in vWF (either quantitative or qualitative) resulting in decreased activity/coagulation

Type 1- Decreased quantity

Type 2- Decreased activity

Type 3- Almost no vWF, most severe

Clinical Presentation- epistasis, mucosal bleeding, heavy menstrual cycles, increased bleeding during surgery

Treatment- When uncontrolled bleeding, desmopressin (for type I, causes vWF release), cryoprecipitate (for life threatening bleeding), recombinant vWF

Targeted Temperature Management

Indications: non traumatic cardiac arrest, earlier the better

Contraindications: DNR, already hypothermic, intoxicated/other cause for coma

General: Reduction in body temperature to 33-36 C for 24 hrs after arrest

-Main goal is to prevent hyperthermia which is associated with increased mortality and poor outcomes

Patients can take weeks to recover neurologic function after cardiac arrest; be careful about prognosticating too early.