Intern Report 7.6

Case Presentation by Dr. Megan Wolf, MD

HPI:
An 86-year-old female presents with 3 weeks of gradually worsening diffuse dull constant abdominal pain.  Her abdominal pain is exacerbated by movement and is not relieved by any particular factors.  It does not radiate anywhere. She has also had decreased appetite and multiple episodes of nonbloody emesis. She has not had a bowel movement in 3 days.

REVIEW OF SYSTEMS:
Constitutional: Denies fevers or chills. Reports weight loss.
Cardiovascular: Denies chest pain.
Respiratory: Reports shortness of breath.
Gastrointestinal: Denies diarrhea or blood in the stool.

PAST MEDICAL HISTORY: hypertension, diabetes, cholelithiasis

PAST SURGICAL HISTORY: cholecystectomy

MEDICATIONS: None

ALLERGIES: No known drug allergies

SOCIAL HISTORY: Denies alcohol, tobacco, and drug use.

PHYSICAL EXAM:
Vitals: BP 94/53, HR 87, RR 24, T 36.2, SpO2 100% on room air
General: Overweight elderly female who appears uncomfortable.
Head:  Atraumatic, normocephalic.
Eyes:  No conjunctival pallor. No scleral icterus.  Pupils equal, round and reactive to light.  Extraocular movements intact.
Nose, Mouth, Throat: Moist mucous membranes.  Uvula midline.
Neck:  Trachea midline.  No jugular venous distension.
Respiratory: Tachypneic. Clear breath sounds bilaterally.  No rales, wheezing, or rhonchi.
Cardiovascular:  Regular rate and rhythm with no murmurs, rubs, or gallops.
Gastrointestinal:  Abdomen is markedly distended and tense. Significant dullness to percussion.  A fluid wave is noted. Tenderness to palpation diffusely throughout the entire abdomen.  Bowel sounds are present.  No organomegaly.
Extremities: 2+ pulses in all extremities.  No lower extremity edema.
Skin: Warm and well perfused. No rashes. No jaundice. No spider angiomata or palmar erythema.
Neurologic: Alert and appropriate.  Answers questions and follows commands.  No asterixis.

LABS:
Na 129, K 3.9, Cl 93, CO2 27, BUN 14, Cr 0.96, Glu 106, Ca 8.6

ALT 15, AST 23, Alk Phos 131, Total bilirubin 0.5, Direct bilirubin 0.1

Amylase 41, Lipase 145, Albumin 2.3

WBC 6.8, Hb 9.2, Hct 28.9, Plt 583, MCV 72.6

APTT 30.4, PT 11.4, INR 1.06

Bedside ultrasound of the abdomen reveals significant free fluid in Morrison’s pouch.  A diagnostic and therapeutic paracentesis is performed, resulting in immediate return of cloudy yellow fluid. Four liters of peritoneal fluid are removed.  The patient’s discomfort is significantly relieved and her respiratory rate returns to normal. The peritoneal fluid is sent for analysis.

Questions:

#1 Which of the following is a contraindication to performing paracentesis?
a) pregnancy
b) disseminated intravascular coagulation
c) prolonged prothrombin time
d) thrombocytopenia

#2 Which of the following tests of the peritoneal fluid would be most helpful in determining the cause of the ascites?
a) pH
b) lactate
c) cholesterol
d) albumin

#3 The peritoneal fluid is analyzed and is positive for malignant cells. You suspect ovarian carcinoma. Which of the following serum tumor markers is associated with ovarian carcinoma?
a) CA-125
b) S-100
c) alpha fetoprotein
d) CEA

Answers & Discussion:

#1 Answer: b. disseminated intravascular coagulation
Many patients undergoing paracentesis have a prolonged prothrombin time or thrombocytopenia as a result of hepatic disease. These are not considered contraindications to performing paracentesis as the incidence of clinically significant bleeding complications in these patients is low.  In a retrospective study of over 4500 paracenteses, severe hemorrhage occurred in <0.2% of cases.  Although paracentesis should be performed with caution in pregnant patients, pregnancy is not a contraindication to paracentesis.

The indications for abdominal paracentesis include the evaluation of new onset ascites, the evaluation of a patient with existing ascites who is being admitted to the hospital for any reason, and the evaluation of a patient with ascites who has signs of clinical deterioration (fever, abdominal pain, hepatic encephalopathy, peripheral leukocytosis, decline in renal function, or metabolic acidosis).

The following are relative contraindications to paracentesis: disseminated intravascular coagulation, primary fibrinolysis, and massive ileus with bowel distension (unless the paracentesis is performed under ultrasound guidance).  If there are surgical scars present on the abdomen, then the needle should be inserted several centimeters away from the scars because the bowel may be adherent to the peritoneal wall at the site of the scar.

#2 Answer: d. albumin
The serum-ascites albumin gradient (SAAG) is equal to the serum albumin level minus the ascitic fluid albumin level.  In this case, the ascitic fluid albumin level is 2.6, so the SAAG is 2.3 – 2.6 = -0.3.  Etiologies of ascites that are related to portal hypertension will have a SAAG >1.1 and these include presinusoidal causes (splenic or portal vein thrombosis, schistosomiasis), sinusoidal causes (cirrhosis), and postsinusoidal causes (right heart failure, constrictive pericarditis, Budd-Chiari syndrome).   Etiologies of ascites that are not related to portal hypertension will have a SAAG <1.1 and these include nephrotic syndrome, tuberculosis, and malignancy with peritoneal carcinomatosis such as ovarian carcinoma. In this patient, the SAAG is <1.1, indicating that the ascites is not related to portal hypertension.

#3 Answer: a. CA-125
The presence of malignant cells in the peritoneal fluid suggests peritoneal carcinomatosis, which is typically caused by secondary peritoneal surface malignancies (ovarian, colorectal, pancreatic, uterine) or extra-abdominal tumors (lymphoma, lung, breast). Malignant ascites is a poor prognostic sign.  Tumor markers are not used as a primary means of diagnosing malignancy, but in a patient with evidence of malignancy, such as malignant cells present in ascites, tumor markers can help in identifying the site of the primary. Currently CA-125 is approved by the FDA only for monitoring response to therapy in women with known epithelial ovarian carcinoma. With regard to diagnosing ovarian carcinoma in postmenopausal women, elevated serum CA-125 has a sensitivity for ovarian cancer of 69-87% and has a specificity for ovarian cancer of 81-93%.  In this patient, the CT thorax/abdomen/pelvis revealed nodular changes of the pleura and peritoneum that possibly related to a metastatic process, but did not reveal a primary tumor.  We did obtain a CA-125 level for this patient which was markedly elevated, and although it is not specific for ovarian carcinoma, it did provide guidance for what type of further imaging to pursue.  In this case we obtained a pelvic ultrasound to attempt to better visualize the ovaries.

Discussion:
When a patient presents to the ED with new onset ascites, two of the main questions you need to answer are whether the fluid is infected and whether the ascites is related to portal hypertension.  Routine tests that should be ordered on all ascitic fluid include cell count and differential, albumin, and total protein.

The results of the cell count and differential will indicate whether the fluid is infected. While a fluid culture may take hours to days to return, a cell count should be available much earlier, allowing for early detection of infection and initiation of antibiotic therapy. You should consider starting antibiotics in any patient whose ascitic fluid corrected neutrophil count is greater than or equal to 250/mm3. One WBC should be subtracted from the WBC count for every 750 RBCs to reveal to corrected WBC count.  One neutrophil should be subtracted from the absolute neutrophil count for every 250 RBCs to reveal the corrected neutrophil count.

It is crucial not to miss spontaneous bacterial peritonitis in a patient with ascites who presents to the ED since shock and multi-system organ failure may occur rapidly if antibiotics are not promptly initiated. Patients with spontaneous bacterial peritonitis often present with fever, altered mental status, and diffuse abdominal pain. They may have lab findings including leukocytosis, metabolic acidosis, and azotemia.

As discussed above, the albumin level in the ascitic fluid, along with the serum albumin level, will allow you to calculate the serum-ascites albumin gradient and determine whether the fluid is related to portal hypertension or not.

If the total protein level in the ascitic fluid is greater than or equal to 2.5 g/dL, it is classified as an exudate. If it is less than 2.5, then it is a transudate.

Other tests that you should consider ordering for ascitic fluid include culture, glucose, lactate dehydrogenase, gram stain, and amylase.

Key Points:

  • Consider paracentesis in any patient with new onset ascites or in any patient with existing ascites who is being admitted or exhibits signs of clinical deterioration.
  • When you send ascitic fluid for analysis, always order cell count and differential, albumin, and total protein.
  • Start antibiotics early if the corrected neutrophil count suggests spontaneous bacterial peritonitis.
  • Calculate the serum-ascites albumin gradient to determine whether the ascites is related to portal hypertension or not

References:
Runyon BA et al. Ascitic fluid pH and lactate: insensitive and nonspecific tests in detecting ascitic fluid infection. 1991. Hepatology 13(5):929.

Runyon BA. Malignancy-related ascites and ascitic fluid ‘humoral tests of malignancy.’ 1994 J Clin Gastroenterol. 18(2):94.

Runyon BA. Evaluation of adults with ascites. UptoDate. 2013.

Sangisetty SL et al. Malignant ascites: a review of prognostic factors, pathophysiology, and therapeutic measures.  2012. World Journal of Gastrointestinal Surgery. 4(4): 87-95.

Thomsen TW et al. Paracentesis. 2006. New England Journal of Medicine 355:e21.

5 Responses

  1. 1:
    Platelets and/or plasma may need to be preadministered in DIC. Thromocytopenia (e.g. platelet count of 2) is a relative contraindication. So is prolonged PT (or elevated INR). But the procedure can be safely carried out with a very high INR and quite low platelet count (Robert’s & Hedges p. 784). Pregnancy is considered a relative contraindication that warrants special care.

    2.
    3.

  2. For paracentesis, the approach can be altered to allow a safe attempt in pregnancy. I know there is alarm study that showed that prolonged PT and thrombocytopenia are rarely associated with adverse bleeding events for this procedure. That leaves:

    1.

    measurement of lactate dehydrogenase can be helpful, but lactate, pH, and cholesterol are not particularly meaningful. What I’m really interested in is the albumin gradient, which I can only get be measuring both the serum albumin and:

    2.

    Frankly, I’m a little unsure as to what this question has to do with my daily practice of EM, but nonetheless… I think I remember something about:

    3.

    • Eric
      I think the idea is that this is a test we can send from the ED to expedite the work-up. If we do a tap we should send all the indicated tests.

  3. 1. These are all relative contraindications….the only absolute contraindication I know of is an acute abdomen requiring immediate surgery.
    2.
    3.

  4. 1. Multiple right answers here: DIC and pregnancy are both RELATIVE contraindications, and the only real ABSOLUTE contraindication is surgical abdomen. I’ll put , but come on!!

    2.

    3.

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