Episode 9: Bacterial Peritonitis – Tap that Belly !

Episode 9: Bacterial Peritonitis – Tap that Belly !

In this episode, Dr. Thavanathan interviews Dr. Chirag Bhat, an R5 and chief resident of the Ottawa Emergency Medicine program (at the time of this podcast), on select complications of cirrhosis.

Note that he’s previously written a Grand Rounds Summary of the topic linked here.


For an even deeper dive, we recommend reviewing the 2018 EASL Clinical Practice Guidelines for the management of patients with decompensated cirrhosis.


Patient Case:

Dr. Bhatt highlights a challenging cirrhotic case that identified knowledge gaps. The patient presented with fever, tachycardia, abdominal pain, and had ascites on clinical examination. He suspected spontaneous bacterial peritonitis (SBP) and performed a paracentesis, and the patient met diagnostic criteria for SBP. He prescribed appropriate antibiotics and consulted internal medicine. But while reviewing the chart the following day he learned that despite this, the patient had decompensated. He was later diagnosed with secondary bacterial peritonitis and required emergent surgery.


Biggest Takeaway from the EASL Guidelines:

Cirrhotic patients can have extensive complications from their liver disease. In the emergency department, we often focus on variceal bleeding and less on SBP.  However, SBP has an extremely high mortality and is common. Clinicians should start considering it as the meningitis of the abdomen; in fact, meningitis has a lower mortality rate than SBP. For every four patients that you diagnose with SBP and treat with antibiotics, one will still die in hospital. Of cirrhotic patients, one in four will have at least one episode of SBP during their lifetime. It is both common and deadly.


Diagnosing SBP:

To diagnose SBP, we must do a diagnostic paracentesis and look at the absolute neutrophil count. The paracentesis findings are an ascitic absolute neutrophil count (ANC) of greater than 250 cells/mm.


Is peritonitis needed to diagnose SBP?

No, and in fact this is a common misconception within the name. While we look for fever and abdominal pain, only ½ of patients with SBP present with these symptoms. In fact, fever occurs in only 42% of patients. This is because cirrhotic patients are relatively immunocompromised.


Patients with SBP can present with any of the following:

  • Isolated hepatic encephalopathy
  • Renal failure
  • GI bleeding
  • Any abnormal vital signs
  • Vomiting
  • Metabolic acidosis
  • Leukocytosis


One study, which included paracentesis done in outpatient clinics, even found up to 13% of SBP patients were asymptomatic. The fact that something with a mortality of 25% can be that indolent should terrify you.


If you miss this diagnosis and discharge the patient home, their mortality approaches 90%. That’s why it’s a critical diagnosis. Every hour that you delay a diagnostic paracentesis in a patient with SBP increases their mortality by 3.3%. That’s why this is an ED diagnosis, and why you shouldn’t defer doing the paracentesis to the inpatient team. 


SBP Treatment:

Antibiotics remain a key component of treatment, specifically, a 3rd generation cephalosporin for community acquired SBP in low antibiotic resistance areas. Without antibiotics, SBP has a mortality of 90%. With antibiotics, the mortality is still 25%.


However, there is another extremely important intervention, that can decrease patient mortality from 25% down to 10%. That treatment is albumin.


The EASL guidelines of 2018 recommend that we give albumin at diagnosis at a dose of 1.5 g/kg. This is a grade I recommendation.


It’s based on the theory that albumin would increase intravascular volume but also binds endotoxins in patients with SBP and ultimately prevent hepatorenal syndrome and subsequent death.


This is based on a meta-analysis of four RCT studies done with a total of 288 patients with SBP.

It suggests that albumin has an NNT of 6 to prevent one death, and it has an NNT of 4 to prevent renal failure. So, this is a second critical action you can take on your next shift. Order albumin at 1.5 g/kg within 6 hours of diagnosis for your patients with SBP and help lower the mortality of this dangerous disease.


What is secondary bacterial peritonitis?
About 1 in 20 cases thought to be spontaneous peritonitis are secondary to another source. In contrast to SBP, secondary bacterial peritonitis is when ascites fluid is infected but it’s due to another intraabdominal infection. It’s secondary to another source, like appendicitis, or cholecystitis, or perforation.


When you do the paracentesis, you’ll still have an absolute neutrophil count > 250 cells/mm3, and you will be tempted to call this spontaneous, when in fact, it is secondary from another source. The reason this matters is that secondary peritonitis is a surgical pathology. Without surgery, their mortality is around 100%. Because we wouldn’t be treating the source


How do you differentiate between SBP and Secondary Bacterial Peritonitis?
Unfortunately, this remains a challenge. There’s not much on history that will differentiate between the two. However, on physical exam, secondary bacterial peritonitis patients tend to have more severe and focal abdominal pain.


Is there a clinical tool that can help distinguish between the two?

The Runyon criteria

When you do the paracentesis, you’re looking for 2 of 3 findings in the ascitic fluid:

  1. Protein > 10 g/L
  2. Glucose < 2.8 mmol/L
  3. LDH > ULN of the serum.


These criteria have a specificity of 90%, but a sensitivity of 66% for secondary bacterial peritonitis. So, as emergency physicians, we can’t use Runyon criteria to rule out secondary peritonitis. However, applying the Runyon criteria can push you to do a CT when you weren’t going for other reasons.


Advanced Imaging

Dr. Bhatt highlights a few reasons you should strongly consider performing a CT scan on a patient with cirrhosis and ascites.

  1. Severe abdominal pain
  2. Focal abdominal pain
  3. Positive Runyon criteria
  4. Not responding to typical SBP treatment, including antibiotics and albumin
  5. Also consider a very high ANC as a clue.


Take-home Points:

  • Adopt an extremely low threshold to perform a diagnostic paracentesis in cirrhotic patients. It has an extremely high mortality with a very subtle presentation.

  • The paracentesis findings are an ascitic absolute neutrophil count (ANC) of greater than 250 cells/mm.
  • Only half of SBP patients present with fever and abdominal pain. SBP can present with isolated hepatic encephalopathy, renal failure, GI bleeding, any abnormal vital sign, vomiting, metabolic acidosis or leukocytosis.
  • For SBP treatment, in addition to antibiotics, prescribe albumin at a dose of 1.5 mg/kg as per the latest 2018 EASL guidelines. This is a grade I recommendation.
  • When diagnosing SBP also consider secondary bacterial peritonitis, which occurs in 1 in 20 patients. This is a surgical emergency of the abdomen. Have a low threshold for advanced imaging, particularly in patients with severe or focal abdominal pain, those with meeting Runyon criteria, and patients not responding to treatment as expected.


Episode 5: Tick Borne Illness Part 1 – Lyme Disease

Episode 5: Tick Borne Illness Part 1 – Lyme Disease

EMOttawa Podcast Episode 5
Tick Borne Illness Part I – Lyme Disease

In part 1 of our 2-part series on Tick-borne diseases, Dr. Rajiv Thavanathan interviews Dr. Mikki McGuinty, an infectious disease clinician-scientist. This episode covers nuances of lyme disease with relevance to the front line provider. For a basic review of the disease and pathophysiology, we suggest our previous posts on lyme disease, vector borne illnesses part I and part II. 

Local Prevalence of Lyme Disease 

Common. Five years ago, it would be incredibly rare to see a case of locally acquired Lyme disease in Ottawa. They were seen in Kingston often, but now we’re seeing more and more cases in Ottawa. In the province of Ontario in 2017, we documented over 1000 cases, and numbers have been rising since. However, four years prior, we were roughly seeing 300-cases per year. This isn’t just due to under recognition, there’s more Lyme carrying ticks. Reasons for this include complex dynamics of climate change, as well as habitat change for typical reservoir animals of these diseases. Overall, the IDSA threshold for an endemic area is 20% or more of ticks infected with Borrelia Burgdorferi.

Do we need to identify the tick?

The bottom line: no. In Dr. McGuinty’s experience, a patient bringing in a suspected tick in Ottawa hasn’t helped. Most tick-borne illnesses diagnosed do not have a tick identified. Physicians are generally not any more skilled than the public in comparing the identified tick to those found in a textbook or on the internet.

However, if you live in a region that has multiple infectious ticks (i.e. lone star ticks or dog ticks) that can carry different diseases than in our local Ontario region, there’s more value to identification to target treatment. In Ontario, we assume it’s an Ixodes tick.

Exposure Duration 

In determining prophylaxis treatment, does the duration of tick attachment matter? There’s a good science answer for this, and a practical real-life answer for this:

There are lots of good studies showing that borrelia burgdorferi is NOT transmitted during the first 24-hours of attachment. However, the vast majority of those who have a tic-borne illness don’t recall having a Tic attached. And just because you’re seeing a patient with a tick attached doesn’t mean that same patient didn’t have three ticks on them earlier and this is the only one left. Therefore, our local practice is treating regardless of the presumed attachment duration.

Tick engorgement is also notoriously unreliable to the untrained eye. Albeit if you’re an ER or family physician living in New York State, you might have more experience with this.

Erythema Migrans 

A common clinical miss for Lyme disease is failing to recognize disseminated (or secondary) Lyme. Often called about a patient febrile with a weird rash. And at this point it’s disseminated with different stages of bullseye rashes. It’s not just a simple or single lesion.

Regarding the timing of erythema migrans, its variable, with some lesions showing within 2-3 days of exposure, and some as late as 30-days after. The appearance can also vary amongst patients significantly. While many patients get the classic targetoid lesion with the central bite, some get erythema throughout. Therefore, if a patient has a tick exposure, and you think it’s a possibility the rash could be migrans, it’s best to err on the side of caution.

Clinical pearl: it should never be painful. (It should also never be pruritic, but Dr. Mcguinty has seen a few cases with associated pruritus).


IDSA Guidelines: 200mg of doxycycline x 1 dose (or 4.4mg/kg in pediatrics), beginning within 72-hours of tick removal, for an Ixodes tick, in an edemic area, where the Tick was on for 36-hours or more.

However, regarding the timing, you should use your clinical judgement.

I.e., a patient presenting at the 84-hour mark post-tick removal might still benefit from prophylaxis, whereas a patient with a tick removed one week ago will not. There’s good evidence that delayed prophylaxis doesn’t mitigate the presence of Lyme disease.

Lyme Serology 

In acute Lyme disease with erythema migrans, there’s typically no utility in sending serology for Lyme. It takes at least 3-weeks, and up to 6-weeks, to develop antibodies to Borrelia. And depending on your institution’s lab, it takes an average of 1-week for serology to come back.

ID Referrals  

Should you refer every patient treated for Lyme disease to ID?

Bottom line: No. Unless you feel uncomfortable or have questions regarding the case. Almost everyone with acute Lyme disease will improve, with outpatient wait times to see an ID specialist are typically ≥ 2-months.

Facial Nerve Palsy 

Steroids in the setting of a facial nerve palsy with suspected Lyme disease:

  • If you’re confident it’s Lyme, and you’re treating a Bell’s palsy, it’s an appropriate indication for an earlier resolution of symptoms.
  • IDSA says there’s no added benefit from adjunctive steroids in the general for Lyme neuropathy, but it’s worth starting early in the <72-hour window for cranial neuropathies.
  • There’s neither good evidence for benefit or harm.

Duration of Doxycycline 

  • 10-days? 14-days? 21-days?
  • It’s not black and white. In Dr. McGuinty’s practice, generally will give 14-day courses.
  • More likely to give 21-days if there’s features that suggest dissemination, if it’s been at least 2-3 weeks since possible exposure, presenting with delayed onset of rash or recurrence of fever. As it’s hard to say whether it’s primary or early secondary disease.


  • A common symptom of Lyme disease, and Dr. McGuinty notes clinician’s often inappropriately treat these patients for meningitis with IV antibiotics.
  • If they have no physical exam findings of meningitis, it’s likely not meningitis.
  • Headache, even severe headache, is quite common in the early stages of these diseases. i.e., Covid patients get bad headaches, but it’s often not meningitis, rather it’s related to the underlying infectious process with a significant cytokine release.

Take-Home Points 

  • Lyme disease is becoming increasingly prevalent in Ontario and across Canada, and this isn’t just due to increased disease recognition.
  • Tick identification seldom changes clinical management, and most tick-borne illnesses diagnosed never have a tick identified.
  • IDSA Prophylaxis recommendations: 200mg of doxycycline x 1 dose (or 4.4mg/kg pediatrics), within 72-hours of tick removal, for an Ixodes tick, in an endemic area, where the tick was attached for >36-hours.
  • In clinical practice, the duration of tick-attachment is notoriously unreliable, and this should not be used to preclude prophylaxis.
  • Erythema migrans has a variable appearance. However, it should never be painful.
  • Lyme serology lacks utility in the ED and should not typically be sent. In addition to the results taking 1+ weeks to result, it takes an average of 3-6 weeks to develop antibodies to borrelia burgdorferi
  • A headache with Lyme disease is common and does not typically indicate meningitis.




  1. Ottawa Prevalence. https://med.uottawa.ca/en/news/tiny-predators-park-1-out-3-ticks-tested-new-ottawa-study-carry-lyme-disease
  2. IDSA Guidelines. https://www.idsociety.org/practice-guideline/lyme-disease/