Culture Negative Endocarditis 5/7/2019

We recently had a case of a middle age man with SLE on chronic prednisone, ESRD on PD, presenting with acute on chronic shoulder pain x 10 days. Presentation was initially concerning for septic arthritis, and joint washout revealed gross purulence from the shoulder joint. Cultures were sent but no additional fluid studies were obtained.

A subsequent TTE, and later a TEE, confirmed a mitral valve vegetation concerning for concurrent infective endocarditis. However, multiple sets of blood cultures, fungal cultures, synovial fluid culture from the initial I&D/wash out, and even 16S PCR of the synovial fluid were all negative. This is a rare case of culture negative endocarditis which is later thought to be more likely Libman Sacs!


Septic Arthritis

  • Epidemiology
    • Risk factors: Advanced age, pre-existing joint dz, recent surgery or injection, SSTI, IVD, indwelling catheter, immunosuppression.
    • Most cases arise from hematogenous seeding, hence bacteremia is common.
    • Direct inoculation: usually due to trauma, surgery/injections, or wounds.
  • Microbiology
    • Usually mono-microbial, and Staph aureus is the most common cause of septic arthritis in adults.
    • GNR can be seen in older adults or in immunocompromised patients
  • Presentation
    • Monoarthritis is most common
      • Edematous, painful, warmth, limited ROM
      • Older patients may not be febrile
    • 20% of cases can present as oligoarticular or polyarticular infection. Polyarticular septic arthritis is more likely to occur in pts with RA
    • Most common affected joint is the knee
    • Could be a manifestation of infective endocarditis, esp amongst IVDU
  • Diagnosis
    • Synovial fluid analysis and culture, should be obtained prior to abx
    • Positive gram stain or culture is gold standard and diagnostic
      • PCR only required in rare cases since most non-gonococcal cultures obtained prior to antibiotics return positive. Negative cultures can result due to recent abx or atypical organism.
    • In pts with purulent synovial fluid (WBC 50k-150k) but culture negative, a presumptive dx can be made.
      • Likelihood of septic arthritis inc with inc leukocyte count
    • Blood cultures should be obtained
    • Should also evaluate for endocarditis given most common organism is staph aureus
    • Imaging:
      • Always get a radiograph to evaluate for concurrent bone/joint involvement
      • CT/MRI can be useful if looking for an effusion
  • DDx
    • Infectious
      • Gonococcal arthritis
      • Lyme disease
      • TB arthritis
      • Viral (usually polyarticular), i.e. Zika, Dengue, chikungunya, parvo, rubella, adenovirus
    • Non-infectious
      • Crystal dz
      • Reactive arthritis
  • Management
    • Joint drainage, severe infectious may require repeated aspiration or even wash out.
    • Abx
      • Most cases are staph, MRSA cases on the rise
      • Suspect pseudomonas if pt is immunocompromised or has h/o IVDU
      • Intra-articular abx: typically not used
      • Duration:
        • Staph aureus with bacteremia: At least 4 weeks
        • Staph aureus without bacteremia: at least 14 days IV, followed by 1-2 weeks PO
        • Bone involvement: 4-6 weeks
        • Any organisms, any bone involvement: 4-6 weeks
        • Other organisms: Typically at least 4 weeks

Culture Negative Endocarditis

  • Definition: Endocarditis without an identified organism in at least 3 independent blood cultures with negative growth after 5 days
  • Epidemiology
    • 2-7% of IE cases
    • 3 most common causes:
      • Previous abx
      • Inadequate samples
      • Atypical organisms (fastidious bacteria i.e. zoonotic microbes, fungal)
  • Microbiology
    • Farm animal exposure: Brucella, Coxiella (Q-fever)
    • Homeless: Bartonella Quintana
    • Cat: Bartonella hensale
    • Ingestion of unpasteurized milk: Brucella, Coxiella
    • Immunocompromised: Fungi, Coxiella
    • HACEK: Most common agents of culture negative endocarditis
      • Haemophilis aphrophulus
      • Actinobacillus
      • Cardiobacterum hominis
      • Eikenella corrdens
      • Kingella
  • Diagnosis
    • PCR, histology, special cultures are helpful.
    • PCR
      • 16S Ribosomal DNA: Bacteria
      • 18S Ribosomal DNA: Fungi
  • Non-infectious DDx
    • APLS, associated with Q fever
    • Acute rheumatic fever
    • Atrial myxoma
    • Libman Sachs endocarditis (non-bacterial thrombotic endocarditis or NBTE)
      • Seen in:
        • SLE
        • Advanced cancer
        • Hypercoagulable state
    • Vasculitis
    • Mural thrombus

NBTE (Non-bacterial thrombotic endocarditis)

  • Epidemiology
    • Rare affected all age group with no sex preference, most commonly 40s – 80s
    • Most commonly associated with pts with concurrent SLE or advanced malignancy (lung cancer, pancreatic cancer, gastric cancer)
    • Other associated conditions: APLS, rheumatic heart disease, RA.
  • Pathophysiology
    • A form of non-infectious endocarditis characterized by deposition of thrombi on halve valves, most commonly mitral or aortic
  • Presentation
    • Usually asx but high risk of thromboembolic events
    • May present with acute stroke or coronary ischemia
  • Diagnosis
    • Exclusion: Demonstration of vegetations on echo in absence of systemic infection in patients with risk factors.
  • Management
    • Systemic anticoagulation
      • Clinical experience and retrospective studies had shown this is beneficial due to high rate of emboli in pts with NBTE
    • Treat underlying condition
    • Surgery
      • Surgical excision for NBTE vegetation, can be considered in only selective cases and generally avoided.

Hepatocellular Carcinoma 5/6/2019

Katie presented an elderly man presenting with few weeks of unintentional 40lbs weight loss and abdominal pain, found to be jaundiced on exam with notable hepatomegaly. Labs notable for mild hepatitis and mix conjugated and unconjugated hyperbilirubinemia with mild coagulopathy. He was ultimately diagnosed with cirrhosis and extremely likely HCC with “numerous” masses of varying size (largest one was 10 cm) with portal vein invasion.


Please refer to this previous post on etiology of hyperbilirubinemia.

Please refer to this other post on hepatitis serologies made ridiculously simple.


Hepatomegaly and jaundice: Think infiltrative/malignant process!

For patients with cirrhosis and abdominal distension, palpating and percussing the liver can be challenging.

A strategy we went over during the last physical exam round was the scratch test, which relies on the principle of the different of sound transmission through materials of various densities.

To perform the scratch test, place your stethoscope over the RUQ just above the costal margin or just below the xiphoid, and from the RLQ, lightly scratch the patient horizontally and then slowly move superiorly toward the costal margins until the sound intensities. The location of sound intensification marks the inferior edge of the liver.

Small study re: accuracy of using the scratch test.


Hepatocellular Carcinoma

Epidemiology

  • Most of the time a complication from liver cirrhosis
  • Risk Factors
    • Cirrhosis, any etiology
    • Chronic HBV even without cirrhosis (oncogenic virus)
    • HCV with cirrhosis
    • Fungal aflatoxins
  • Higher prevalence in East and SE Asia + Sub-Saharan African nations
  • HBV inc risk by 100x

Presentation

  • Variable initial presentation
    • Asx
    • Decompensated cirrhosis
    • Jaundice, abd pain, B-sx, +/- palpable pass
    • Variceal hemorrhage
    • Tumor rupture leading to acute hemorrhagic shock
    • Obstructive jaundice due to biliary tree invasion
    • 10-15% with metastatic dz at time of dx.
      • Most common sites: Lung, lymph nodes, adrenal glands.
    • Paraneoplasic: Hypoglycemia (adv HCC), erythrocytosis, hypercalcemia, diarrhea

Diagnosis

  • Imaging: Sensitivity generally dec with small lesions, but imaging alone to establish dx of HCC without a biopsy in certain patient populations.
    • Contrast enhanced CT (triphasic)
      • Arterial phase hyperenhancement: Characteristic of HCC lesions but not specific, can be small hemangiomas, focal nodular hyperplasia, atypical focal fibrosis, non-HCC malignancy
      • Venous phase Washout: Again characteristic of HCC but not specific, cirrhosis nodules can be similar.
      • Capsular appearance: Pretty specific for HCC
      • All 3 of the above = diagnostic of HCC, very specific not but as sensitive.
      • Highest PPV for pts with cirrhosis with lesions > 2cm
    • MRI
      • Contraindicated in GFR < 30, Nephrogenic systemic fibrosis
      • More sensitive than CT, ~ specificity,
    • US: Can be use as diagnosis but cannot evaluate disease burden, transplant candidacy, operator dependent. 90% sensitive and 97% specifc
    • LIRADS
      • Should only be applied to pts with cirrhosis, chronic HBV, lesions identified on surveillance US for HCC, current or prior dx of HCC.
      • Should NOT be applied to: no risk factors for HCC, < 18, cirrhosis secondary to congenital hepatic fibrosis or vascular etiology.
    • LIRADS definitions for hepatocellular carcinoma based on ACR v2017:
      • LR-1: Definitely benign
      • LR-2: Probably benign
      • LR-3: Intermediate probability for HCC
      • LR-4: Probably HCC
      • LR-5 – Definitely HCC
      • LR-5V: Definitely HCC with tumor in vein
      • LR-M: Probably malignancy, not specific for HCC
      • LR-TR Viable: Treated, probably or definitely viable HCC
      • LT-TR Nonviable: Treated, probably or definitely not viable
      • LR-TR Equivocal: Treated, equivocally viable
      • LR-TR Nonevaluable: TReated, response not evaluable
  • Labs
    • Alpha-fetoprotein: Elevated in 40-65% of patients with HCC
      • Normally produced during gestation, not during adulthood.
      • Levels do not correlate well with degree of disease
      • Sensitivity: 60%, spec: 80%, not good as a screening tool.
      • Higher levels > 400 are very specific for HCC.
      • May be seen in chronic liver disease so not very sensitive.
      • Elevated levels are associated with advanced fibrosis, pregnancy
  • Biopsy: Reserved for indeterminate nodules that do not meet radiologic criteria for HCC.
    • Not recommended for LR1, LR2, LR3, or LR5 lesions
    • Risk: spread of tumor along needle track, sampling error (false negative), usual surgical risk (bleeding, infection, etc)
  • Staging:
    • TNM
    • Barcelona Clinic Liver Cancer staging system

Management

  • Surveillance for at risk patients:
    • Cirrhosis or HBV: Q6mo liver US
  • Resection
    • Preferred therapy for localized disease
    • Sufficient liver reserve, can’t be worse than Child Pugh A cirrhosis
    • 5 year survival rate as high as 90%
    • Stage IIIB, IVA, and IVB are incurable by resection (any invasion of a major portal or hepatic vein, other organs, visceral peritoneum, nodal mets)
  • Antiviral
    • Recommended for those with active viral infection and HBV related HCC.
  • Liver transplantation
    • Milan criteria widely accepted, to be considered a candidate for transplant, pt must meet all criteria
      • Solitary tumor < 5cm or up to 3 tumors all < 3cm
      • No evidence of regional nodal or distant mets
      • No evidence of vascular invasion
  • Ablation
    • Radiofrequency or microwave or localized ethanol/acetic acid/cryo localized ablation
    • Best outcomes for tumor size < 4 cm
    • Cirrhosis: Restricted to Child Class A or B
    • Can be used to bridge to liver transplant
  • TACE
    • Disruption of HCC supply, usually derived from the hepatic artery
    • Leads to tumor necrosis from ischemia.
    • Usually used for tx of large unresectable HCC not amenable to other tx i.e. resection or RFA.
    • Best candidates: No vascular invasion or extrahepatic spread, Child Puph A or B
    • Relative contraindication:
      • bili > 2
      • LDH > 425
      • AST > 100
      • Tumor > 50% of liver
      • Untreated EV
      • Significant medical comorbidities
  • Radiation
    • Localized external radiation vs radioembolization, HCC is radiation sensitive.
  • Systemic chemo
    • Sorafenib
      • SHARP trial, prolongs survival over supportive care in pts with adv HCC)
      • Might be more beneficial for HCC related to viral etiology
    • Other agents: Regorafenib, Lenvatinib
    • Complication during tx
      • Reactivation of viral hepatitis

Prognosis

  • 10-20% of cases are curable (resectable disease)
  • 5-yr survival rates of about 5% or less if beyond stage III (portal vein invasion)
  • Some evidence that sorafenib improves survival by around 3 months but it is a costly medication (60 tablets can cost up to $9000 after discount!)

Caffeine Overdose! 5/1/2019

The world’s #1 addictive substance of choice… Caffeine! And yes you can OD on it!

A 37yo F with history of anxiety presented with nausea and palpitations after ingesting 160 pills of Diurex in an attempt to fix her constipation for the past 2 weeks. Prior to arrival to the hospital, the paramedics administered activated charcoal. She was tachycardic, mildly hypotensive, hypokalemic, and acidotic (AG 20). Methamphetamine was found in her system as well. Fortunately she improved with fluids and supportive measures, but lethal cases of caffeine overdose, while rare, have been described in the medical literature!

Of note: An expresso doubt shot contains roughly 60-100mg of caffeine.

This patient took 16000mg (16g) of caffeine, equivalent to 160-260 shots of double expresso!


Caffeine Intoxication

  • Epidemiology
    • Caffeine = world’s #1 psychoactive compound consumed
    • Pure caffeine can be easily obtained, caffeine pills introduced in 2004.
    • Death from caffeine overdose is rare, only 92 cases have been described in literature.
    • Caffeine pills heavily advertised as weight loss supplements
  • Risk factors
    • Psychiatric conditions
    • Athletes (weight loss/work out supplements, these things are NOT regulated!)
    • Infants/young kids (accidental ingestion)
  • Pathophysiology
    • Dose-dependent MOA
    • CNS and cardiac stimulation, usually occurs at plasma concentration of 15mg/L or higher
    • Usually not food/beverages related. Most cases are related to caffeine-containing medications.
    • Lethal cases reported over 10g ingestion, highest reported ingestion is 100g (1000 double shots of Expresso)
    • Absorbed in the GI tract within 30 minutes
    • Half life 5-6 hours, metabolized in the liver
  • Presentation
    • Agitation, diaphoresis, anxiety, restlessness, insomnia, GI disturbances, tremors, psychomotor agitation
    • Complications
      • Serious cases: arrhythmias (SVT, VT), even V-fib (most common cause of death in caffeine intoxication)
      • Hypotension
      • Hypokalemia
      • Seizures
      • Lactic acidosis
      • Rhabdomyolysis
      • Renal failure
  • Diagnosis
    • Life threatening caffeine overdose more commonly associated with blood concentration > 80mg/L
    • Clinical history, serum measurement, ingestion history
  • Management
    • Activated charcoal for ingestions:
      • Effective only within a short time of ingestion, typically within 1-2 hour and patients have to be mentating
      • Interacts with caffeine and prevents it from being absorbed.
    • Hydration
    • Electrolyte repletion
    • Anti-arrhythmic agents (amiodarone, even lidocaine) in setting of arrhythmias, ACLS if unstable arrhythmias
    • Dialysis: Dialyzable

Source: GrepmedToxidrome Flow

A summary of toxidromes:

Toxidrome.jpg