Pt is 58 yo M with PMH of alcoholism, HCV with liver cirrhosis (h/o variceal GI bleeds, h/o SBP, h/o hepatic encephalopathy) presents to ED with 2-3 days of altered mental status and fever, you want to rule-out Spontaneous Bacterial Peritonitis and you send your newly minted intern over to get set up for a paracentesis and before you know-it, the intern is back, smiling brightly, with a vial of presumed ascitic fluid, although looking pretty bloody.
You do a quick check to make sure the patient is not hemorrhaging in the hall and then you get a call from the lab reporting a panic value of an INR of 2.2. How do you correct for a bloody paracentesis to get an accurate PMN count in order to diagnose SBP? Was there any contraindication to doing paracentesis in a person with INR 2.2?
Correction for a bloody tap:
The accepted correction is for every 250/mm3 RBC, correct 1 PMN . Still applying the cutoff of 250/mm3 PMN cutoff for diagnosis of SBP.
This correction is based on the maximum expected ratio of PMN to RBC normally present in peripheral blood [1,2]
Safe to tap with elevated INR:
A prospective study of 1100 large-volume paracenteses documented no bleeding complications with no pre- or post-procedure transfusions required despite INRs as high as 8.7 and platelet counts as low 19,000/mL, only 12 of which used ultrasound guidance .
Another study of chart review of 4,729 paracentesis procedures revealed bleeding was not related to operator experience, elevated international normalized ratio or low platelets. 
Another paper overall reduction in bleeding complications with addition of ultrasound (however, excluded patients with increased bleeding chances pre-procedure), looking at 69,859 paracentesis patient records, 45% of these procedures were ultrasound guided. Of those getting paracentesis, 0.8% (n = 565) experienced bleeding complications. After adjustment, ultrasound guidance reduced the risk by 68% for bleeding complications after paracentesis (OR, 0.32; 95% CI, 0.25-0.41). 
1. BA Runyon. Ascites and spontaneous bacterial peritonitis M Feldman, BF Scharschmidt, MH Sleisenger (Eds.), Sleisenger & Fordtran’s Gastrointestinal and Liver Disease. Pathophysiology/Diagnosis/Management, 6th ed, vol 2, W.B. Saunders Co, Philadelphia (1998), pp. 1310–1313
2. JC Hoefs. Increase in ascites WBC and protein concentrationsduring diuresis in patients with chronic liver disease
Hepatology, 1 (1981), p. 249
3. Grabau CM, Crago SF, Hoff LK, Simon JA, Melton CA, Ott BJ, Kamath PS. Performance standards for therapeutic abdominal paracentesis. Hepatology. 2004 Aug;40(2):484-8
4. Pache I. Severe haemorrhage following abdominal paracentesis for ascites in patients with liver disease. Aliment Pharmacol Ther. 2005 Mar 1;21(5):525-9.
5. Mercaldi CJ, Lanes SF.Ultrasound Guidance Decreases Complications And Improves The Cost Of Care Among Patients Undergoing Thoracentesis And Paracentesis. Chest. 2013;143(2):532-538.