Body Fluids

Deborah Goldstein

Argy Resident

September, 2005

Fluids

• CSF

• Pleural Fluid

• Peritoneal Fluid

Pt with fever, nuchal rigidity....1. Get blood cx2. Give Abx• S. pneumo (30-50%), N. Meningitidis (10-35%), H. influenza (<5%),

Listeria (5-10%), Staph

• 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

• Give with first dose of Abx!• Improves mortality, reduces incidence of hearing loss

3. R/O increased ICP w/Head CT if needed4. 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 PunctureProcedure• 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

• 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

• 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 post-meningitis (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 = 30a)Arbovirus encephalitis b)Brain toxoplasmosisc)Echovirus encephalitisd)Herpetic encephalitise)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=33Normal 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 re-sealing)

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

• 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

• Pneumothorax• Hemothorax• Pulm infarct• Parasitic disease

• Fungal infection• Drugs• Malignancy• Asbestos

Why is glucose low?(<60)

• 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 observeClass 2 = “Typical parapneumonic”• >10 mm thick on decub, pH>7.2 , Glucose>40 mg/dL• GS neg, cx neg• Diagnostic tap, then Abx aloneClass 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 AbxClass 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

• 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

• 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

• 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

• GPC in chains, GPR, GNR, fecal flora...• Increased PMN’s, Total protein >1g/dl, • Glucose <50mg/dl, LDH elevated• Pt is SICK