Body Fluids
Deborah Goldstein
Argy Resident
September, 2005
Fluids
• CSF
• Pleural Fluid
• Peritoneal Fluid
Pt with fever, nuchal rigidity....
1. Get blood cx
2. Give Abx
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S. pneumo (30-50%), N. Meningitidis (10-35%), H. influenza (<5%),
Listeria (5-10%), Staph
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Ceftriaxone 2mg IV q12h for GPC, GNR
Vanc 1g IV BID for PCN-resistant Strep pneumo
Ampicillin for Listeria (in elderly, young)
Decadron 0.4mg/kg IV q12 if concern for Bact infxn
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Give with first dose of Abx!
Improves mortality, reduces incidence of hearing loss
3. R/O increased ICP w/Head CT if needed
4. Do LP
Who to LP?
Indications
• Fever, vomiting, HA, photophobia, altered level of
consciousness, leukocytosis, meningeal signs...to
r/o infection, malignancy
Contraindications
• INR>1.5
• Platelets <50,000
Risks of LP
First Do No Harm...
• Post-lumbar puncture HA
– Have pt lie down 1-3hrs after to prevent CSF
leak
• Bleeding; spinal hematoma
• Infection (poor sterile technique)
• Herniation
Lumbar Puncture
Procedure
• Pt lies in L lateral decub position, knees to chest
• Posterior iliac crest as marker for L3-L4 space
• Prep/drape lower back in sterile fashion...lidocaine
• Insert LP needle pointing towards umbilicus until
“pop”
• Obtain opening pressure (only if pt lying down)
• Fill tubes #1-4 with CSF
CSF Evaluation
• Tube 1-cell count and differential
• Tube 2-glucose, protein
• Tube 3-cultures, gram stain, cytology, (HSV
PCR, West Nile, India ink, Crypto Antigen,
VDRL, Lyme Ab, AFB...)
• Tube 4-cell count and differential
Normal CSF Composition
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Clear color
<5 RBC’s
<5 WBC’s
Protein 23-38mg/dl (can use 14-45)
Glucose—60% of serum level (75-100)
Opening pressure
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Normal = 80-180 mmHg
Obese pts: up to 250mmHg can be normal
Pathologically elevated: >250mmHg
If elevated, likely due to cerebral edema
from intracranial pathology
• Infection (cryptococcal meningitis), tumor,
benign ICH (pseudotumor)
RBCs
Always send tube #1 and #4 for cell count and
compare RBCs
Traumatic tap: Elev RBC in tube 1, nl in tube 4
– 1000 RBC : 1 WBC to adjust WBC count in bloody tap
SAH or HSV: Elev RBC in tube 1 AND tube 4
• “Crenated RBCs” and xanthochromia (yellow
supernatant after centrifuge)
– Seen in hyperbilirubinemia (ESLD), old SAH, old
blood from prior traumatic LP or bleed
WBC’s
• Infection!
• PMN predominance: likely bacterial
meningitis
• Lymphocytic predominance: viral vs. fungal
vs. TB vs. malignancy
Protein
• Normal: protein is excluded from CSF by
blood-CSF barrier
• Increased: nonspecific
• Elevated in all infectious meningitis
– May remain elevated for months postmeningitis (viral or bacterial)
• Increased in malignancy and inflammatory
conditions (ie Guillain-Barre)
Glucose
Normal
• Viral infection
Low glucose
• Bacterial meningitis, TB, fungal
Really low
• <18 is strongly suggestive of bacterial
meningitis
Typical Viral Meningitis
• CSF WBC elevated, but <250 (first PMNs,
then lymphocytes)
• CSF protein elevated, but <150
• Glucose > 50% of serum concentration
Typical Bacterial Meningitis
• CSF WBC >1000, PMN predominance
• CSF protein >500mg/dl
• CSF glucose <45 mg/dl
Example
• A previously healthy 33-year-old lawyer presents
to the ER with acute onset headache and
confusion. He develops grand mal seizures in the
ER. He is treated and sent for a head CT, which
shows bilateral hemorrhage in the temporal lobes
(and no hydrocephalus).
• CSF: mild pleocytosis (mostly lymphocytes),
gluc= 60, protein = 30
a)Arbovirus encephalitis
b)Brain toxoplasmosis
c)Echovirus encephalitis
d)Herpetic encephalitis
e)Metastatic melanoma
HSV Encephalitis
• Aseptic meningitis: CSF w/mild lymphs, nl gluc, nl prot
• Most common etiologic agent of sporadic viral encephalitis
• Previously healthy pt with rapid onset of confusion and
seizures
• CT: hemorrhagic necrosis of the temporal lobes
• Arbovirus encephalitis: most important cause of epidemic viral
encephalitis; clinical course is milder and prognosis is better than
herpetic encephalitis
• CNS Toxo: in immunocompromised pts; round, ring-enhancing
intracerebral masses
• Echovirus encephalitis: common cause of asceptic meningitis; mild
symptoms (headache, malaise) with normal CSF
• Metastatic melanoma: CNS lesions may hemorrhage; but mets appear as
space-occupying masses
Example
• Pt with AIDS on Combivir (AZT/3TC) and Indinivir c/o leg
weakness, incontinence. On exam, reduced strength in
lower extremities with mild spasticity. Also diminished
sensation in b/l feet, legs. Brain MRI: nonfocal
• CSF: Opening pressure=100 mm H20,
Cell count=5 lymphs, Glucose=48, Protein=33
Normal serum B12, negative serum RPR, hct nl.
• What’s he got?
A. AIDS dementia complex
B. CMV polyradiculopathy
C. Cryptococcal meningoencephalitis
D. Vacuolar (HIV) myelopathy
E. AZT neurotoxicity
HIV Myelopathy
• Common neurologic complications of AIDS
• Degeneration of spinal tracts in posterior, lateral
columns (causing them to look vacuolated)
• Physical findings are similar to B12 deficiency
• Diagnosis of exclusion!
• AIDS dementia complex: progressive memory loss, alterations in fine
motor control, urinary incontinence, altered mental status
• CMV polyradiculopathy: CSF has neutrophilic pleocytosis
• Crypto meningoencephalitis: presents with signs/symptoms of
meningitis, and CSF shows fungus
• Zidovudine-related toxicity: can cause asthenia, myopathy
Thoracentesis
Indications
• Diagnostic - All NEW effusions (except if
clearly due to heart failure)
• Therapeutic – Respiratory distress
• Suspected parapneumonic effusions must be
tapped ASAP (“Don’t let the sun set on a
pleural effusion”)
Don’t do Thoracentesis if...
• Coagulopathy (INR>2, platelets <25,000)
• Severe lung disease on contralateral side
(risk of PTX)
• Mechanical ventilation (not due to risk of
PTX from PEEP, but due to decreased resealing)
Loculated?
• Must be >1 cm and free flowing in lateral
decubitus view
• If CT shows free-flowing fluid, you don’t
also need lateral X-ray
Thoracentesis Procedure
• Confirm fluid is free-flowing, not loculated
• Obtain consent
• Consider US mark if medium-size effusion or
loculated
• Have pt sitting up and leaning forward over table
• Percuss fluid level and go 1-2 spaces below, in
midclavicular line
• Enter just ABOVE the rib to avoid neurovascular
bundle
• ALWAYS obtain a CXR post-tap
Pt gets dyspneic after you’ve
withdrawn 150cc from L chest....
You took 2.3L clear fluid off this pt’s
Right chest. F/u CXR shows....
Other Thoracentesis
Complications
• PTX
• Re-expansion pulmonary edema
– Don’t take off more than 1L
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Hemothorax
Infection
Hypotension
Hepatic or Splenic puncture
What to order?
Serum LDH, total protein (Add on to am labs)
Pleural fluid:
• Total Protein, LDH
• Glucose, cell count and diff, pH (on ice)
• Gram stain, culture, fungal stain and culture, AFB
• Cytology
• Other: triglyceride level to r/o chylothorax;
amylase to r/o pancreatitis, esoph perf; Adenosine
deaminase to eval TB
Light’s Criteria for Exudates
Fluid is exudate if it meets 1 of 3 criteria:
1. Pleural fluid LDH/serum LDH > 0.6
2. Pleural fluid protein/serum protein > 0.5
3. Pleural fluid LDH > upper limit of normal
serum LDH
• If all 3 negative, fluid is Transudate
Transudate
• Result from imbalances in oncotic and hydrostatic
pressure
• Usually low oncotic +/- high hydrostatic pressure
• Pulm Edema/CHF
• Cirrhosis with ascites
• Hypoalbuminemia/Nephrotic syndrome, ESLD
• Fluid overload s/p aggressive IVF
• Peritoneal dialysis
Exudate
Caused by local, not systemic, factors
• Infection
• Neoplasm
• Pancreatitis
• Esoph perf
• RA
• SLE
• Sarcoid, Wegeners, PE, Meig’s, Chylothorax
Lymphocytosis
• Malignancy (50-70% lymphs)
• Also TB, sarcoid, RA, chylothorax (>90%
lymphs)
Pleural eosinophilia
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Pneumothorax
Hemothorax
Pulm infarct
Parasitic disease
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Fungal infection
Drugs
Malignancy
Asbestos
Why is glucose low?
(<60)
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RA
TB
Empyema
SLE
Malignancy
Esophageal rupture
Who needs a chest tube?
• Frank pus OR
• Positive gram stain OR
• pH < 7.0
Non-TB Parapneumonic
Effusions
Class 1 = “Nonsignificant”
• <10 mm thick on decub. Don’t tap, just observe
Class 2 = “Typical parapneumonic”
• >10 mm thick on decub, pH>7.2 , Glucose>40 mg/dL
• GS neg, cx neg
• Diagnostic tap, then Abx alone
Class 3 = “Borderline complicated”
• pH>7.0, <7.2 and/or LDH>1,000 and glucose>40 mg/dL
• GS neg, cx neg
• Abx and serial thoracenteses
Grading Effusions
Class 4 = “Simple complicated”
• pH<7.0 and/or glucose<40 mg/dL and/or Gram
stain/culture positive
• Not loculated or frank pus
• Chest tube and Abx
Class 5 = “Complex complicated”
• pH<7.0 and/or glucose<40 mg/dL and/or Gram
stain/culture positive
• Multiloculated
• Chest tube and fibrinolytics (rarely require thoracoscopy or
decortication)
Grading Effusions
Class 6 = “Simple empyema”
• Frank pus
• Single locule or free flowing
• Chest tube +/- decortication
Class 7 = “Complex empyema”
• Frank pus present
• Multiple locules
• Chest tube and fibrinolytics
• Often requires thoracoscopy or decortication
Example
• A 59-year old man with HIV and Hepatitis
C develops progressive SOB and presents to
the ER satting 90% RA. On CXR, he has a
large Right-sided pleural effusion.
• Serum LDH=200, serum protein = 5.6.
• Pleural fluid: LDH 100, protein 2700, WBC
400, pH 7.35, glucose=85
• Exudate or Transudate? Retap? Abx?
• Pleural fluid LDH/serum LDH=100/200= 0.5
– needs to be >0.6 to be exudate
• Pleural fluid protein/serum protein=2700/5600=
0.4
– needs to be >0.5 to be exudate
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Pleural fluid LDH is < ULN serum LDH
Transudate
Cause is cirrhosis/ascites
Presents w/Right sided pl effusion
No Abx or need to retap
Tx the underling problem (ascites) w/diuretics,
aldactone; optimize treatment for Hep C, HIV
Example
• A 34 y.o. woman with cystic fibrosis presents to
the ER with fever, cough and night sweats for 10
days. CXR shows LLL consolidation and
surrounding free-flowing effusion.
• The lab loses tubes for serum LDH, protein
• Pleural fluid: cloudy, LDH=1360, pH=6.9,
gluc=36, gram stain neg
• Does she need a chest tube? Fibrinolytics?
Exudate
• because LDH>upper limits of normal serum LDH
Class 4 = “Simple complicated”
• pH<7.0 and/or glucose<40 mg/dL and/or Gram
stain/culture positive
• Not loculated or frank pus
• Chest tube and Abx, no fibrinolytics
Paracentesis
Indications for paracentesis
• A febrile pt with ascites is assumed to
have SBP until proven otherwise
• New onset ascites—etiology?
• Increasing abdominal pain/discomfort
• Respiratory compromise
• Unexplained leukocytosis, acidemia, renal
failure
• AMS
Risks of Paracentesis
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Bowel perforation
Hemoperitoneum (0.01%)
Hematoma (1%)
Infection (0.01%)
Contraindications
• Coagulopathy is NOT a contraindication
– But don’t do paracentesis if pt is in DIC
• Must be careful if minimal fluid visualized on U/S
• If peritoneal carcinomatosis, do not do this
procedure yourself
– Gut gets tethered to the anterior abdominal wall and
can’t move away from your needle; you can perforate
it.
Paracentesis
• Percuss pt’s abdomen for dullness/shifting
dullness
• Avoid obviously visible abdominal wall collaterals
• Avoid inferior hypogastric artery (midway
between ASIS and lateral border of pubis)
• If therapeutic, can drain up to 4L safely for
symptomatic relief (BP check pre and post safe)
• Large-volume tap: give 1 bottle (12.5g) 25% SPA
for each 2L ascitic fluid removed
Inferior hypogastric artery
After paracetesis, SBP drops to 90
and hct drops by 4 points...
What to send fluid for
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Cell count with diff
Albumin
LDH
Total protein
• glucose
• Gram stain/cx
• cytology
Appearance of fluid
• Clear—usually indicates uncomplicated
ascites, ie liver failure/cirrhosis
• Turbid/cloudy—infected
• Pink/bloody—traumatic, punctured
collateral vessel, malignancy
– Correct for bloody tap: 1 WBC: 750 RBC
1 PMN: 250 RBC
Serum-to-ascites albumin
gradient (SAAG)
=Serum albumin – ascitic fluid albumin
If the gradient is >1.1:
• Portal HTN (drives fluids into peritoneum)
• SBP, cirrhosis, Alcoholic hepatitis, CHF
If the gradient is < 1.1:
(protein leaks into peritoneum and fluid follows)
• Peritoneal carcinomatosis, peritoneal TB,
pancreatitis, nephrotic syndrome
SBP
• SAAG > 1.1
• Suspect if >250 PMNs (>100 PMNs in pt
on peritoneal dialysis)
• 70% GNR (E.coli, Klebsiella)
30% GPC (S. pneumo, Enterococcus)
• Treat with ceftriaxone, cefotaxime
• “Culture negative SBP” if >250 PMNs but
cx neg; treat the same
Bowel Perforation
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GPC in chains, GPR, GNR, fecal flora...
Increased PMN’s, Total protein >1g/dl,
Glucose <50mg/dl, LDH elevated
Pt is SICK