Clinical and laboratory features of spontaneous bacterial peritonitis

Bacterial profile, drug resistance pattern, clinical and laboratory predictors of ascites infection in cirrhosis patients

Ascites is a pathological collection of free fluid in the peritoneal cavity, which is a common complication in patients with cirrhosis, an advanced liver disease. Bacterial infection increases the mortality rate of hospitalized patients with cirrhosis, irrespective of the severity of the liver disease. Around 60% of patients with compensated cirrhosis developed ascites within 10 years during the course of their disease. The in-hospital mortality rate due to spontaneous bacterial peritonitis (SBP) could exceed 90%, but with early diagnosis and prompt antibiotic therapy, this rate has been shown to decrease to 20%. Here, we enrolled adult (age ≥ 18) patients with liver disease with evidence of cirrhosis who developed ascites and assessed the presence of spontaneous ascites fluid infection (SAFI) in these patients. Of the total 218 patients, 22.9% (50/218) develop ascites infection. The liver organ function tests like alanine aminotransferase, aspartate aminotransferase, total bilirubin, and direct bilirubin were found to be significantly (P < 0.05) higher in patients with ascites fluid infection compared to patients with non-ascites fluid infection. Of the gram-negative bacteria, K. pneumonia and E. coli were isolated and found to be 100% resistant to amoxicillin and clavulanate. From the gram-positive bacterial isolates, S. aureus was only resistant to penicillin, whereas Str. viridans was resistant to ceftriaxone, cefotaxime, cefepime, and penicillin. On the other hand, clinical features such as a history of jaundice, low arterial blood pressure, and ultrasound results such as a shrunken liver and enlarged spleen were also independent predictors of spontaneous bacterial peritonitis. In conclusion, given the high probability of death following SAFI, early detection, and treatment, as well as knowledge of the microbial agent, resistance profile, and predictive markers in various contexts, are essential for the timely diagnosis and management of SAFI in these patients.

Retrospective Investigation of Factors Affecting Mortality in Spontaneous Bacterial Peritonitis

Background

Spontaneous bacterial peritonitis (SBP) is an important reason for mortality in cirrhosis. This study aimed to identify the factors associated with mortality in SBP.

Materials and methods

A total of 69 patients with cirrhosis and 74 with SBP attacks that occurred in this group were assessed. Demographic data, symptoms at admission, comorbidities, laboratory parameters, treatment protocols, causes of cirrhosis, scoring characteristics, cirrhosis complications, and mortality were analyzed.

Results

Model for end-stage liver disease (MELD; p = 0.001), sodium-MELD (p = 0.001), and Child-Pugh-Turcotte (CTP) (p < 0.001) scores were correlated with mortality in patients with SBP episodes. Hepatorenal syndrome (p = 0.001) and esophageal variceal bleeding (p < 0.001) related to mortality. Serum lactate dehydrogenase (LDH) (p = 0.007), serum leukocyte (p = 0.017), and serum hemoglobin (p = 0.010) values had a statistically significant effect on mortality in multivariate regression analysis.

Discussion

The mortality rate can be reduced by identifying factors influencing death in patients with SBP episodes.

How to cite this article

Ocak T, Gülten M. Retrospective Investigation of Factors Affecting Mortality in Spontaneous Bacterial Peritonitis. Euroasian J Hepato-Gastroenterol 2023;13(1):5-9.

Clinical impression and ascites appearance do not rule out bacterial peritonitis

BACKGROUND

Previous research has demonstrated that physician clinical suspicion, determined without assessing fluid appearance, is not adequate to rule out spontaneous bacterial peritonitis (SBP) without fluid testing.

STUDY OBJECTIVE

To determine the sensitivity of physician clinical suspicion, including a bedside assessment of fluid appearance, in the detection of SBP in Emergency Department (ED) patients undergoing paracentesis.

METHODS

We conducted a prospective, observational study of ED patients with ascites undergoing paracentesis at three academic facilities. The enrolling physician recorded the clinical suspicion of SBP ("none," "low," "moderate," or "high"), and ascites appearance ("clear," "hazy," "cloudy," or "bloody"). SBP was defined as an absolute neutrophil count ≥ 250 cells/mm(3), or culture pathogen growth. We defined "clear" ascites fluid as negative for SBP, and "hazy," "cloudy," or "bloody" as positive. A physician clinical suspicion of "none" or "low" was considered negative for SBP, and an assessment of "moderate" or "high" was considered positive. The primary outcome measure was sensitivity of physician clinical impression and ascites appearance for SBP.

RESULTS

There were 348 cases enrolled, with SBP diagnosed in 43 (12%). Physician clinical suspicion had a sensitivity of 42% (95% confidence interval [CI] 29-55%) for the detection of SBP. Fluid appearance had a sensitivity of 72% (95% CI 58-83%).

CONCLUSION

Physician clinical impression, which included an assessment of fluid appearance, had poor sensitivity for the detection of SBP and cannot be used to exclude the diagnosis. Routine laboratory fluid analysis is indicated after ED paracentesis, even in patients considered to have a low degree of suspicion for SBP.

Bacterial epidemiology and antimicrobial resistance in ascitic fluid: a 2-year retrospective study

The bacterial epidemiology of bacterascites and spontaneous bacterial peritonitis is evolving. Four hundred and eleven strains isolated from ascites in cirrhotic patients from 5 French hospitals were isolated in 2006 and 2007. Of these, 114 were definitely associated with spontaneous bacterial peritonitis. The proportion of Gram-positive and Gram-negative agents was quite similar, even after excluding coagulase-negative staphylococci, or when considering only definite spontaneous bacterial peritonitis or community-acquired strains. Staphylococci and Escherichia coli were the most frequent pathogens, but enterococci were also involved in nearly 15% of the cases. Among the E. coli, 28% were intermediate or resistant to amoxicillin+clavulanate, 5.3% expressed cephalosporinases or extended beta-lactamases and 17.3% were intermediate or resistant to fluoroquinolones. Resistance to methicillin was observed in 27% of Staphylococcus aureus. Cefotaxime and amoxicillin-clavulanate remained the most effective 'single' agents, however on less than 70% of isolates. Some combinations (such as cefotaxime+amoxicillin) extended coverage to a further 15% of strains. Since inadequate empiric antibiotic therapy is associated with increased mortality, these combinations may be of great interest as first-line treatment, even though they may also lead to the development of antimicrobial resistance. Repeated epidemiological surveys and new clinical trials are thus needed.

Aeromonas spontaneous bacterial peritonitis: a highly fatal infectious disease in patients with advanced liver cirrhosis

BACKGROUND/PURPOSE

Aeromonas infections, rarely reported in Western countries, are not uncommon infectious diseases in Taiwan. The clinical manifestations and prognostic factors of Aeromonas spontaneous bacterial peritonitis (SBP) in patients with liver cirrhosis were investigated.

METHODS

We reviewed the medical charts and microbiological records of liver cirrhosis patients with Aeromonas SBP between January 1990 and December 2005, in a medical center in southern Taiwan.

RESULTS

Thirty-one liver cirrhosis patients developed Aeromonas SBP within a 16-year period. The majority (26, 84%) had concurrent Aeromonas bacteremia. A. sobria (55%) and A. hydrophila (45%) were the causative species. The predominant clinical manifestations included fever (84%), abdominal pain (74%), hypotension on admission (48%), altered mental status (45%), and acute renal failure (42%). Gram-negative bacilli were found in Gram staining of ascitic fluids in 27% of 26 patients, while aeromonads were isolated from ascitic fluids in 55% of 31 patients. The yield rate of ascitic fluid cultures decreased greatly, if paracentesis was performed at > 3 hours after the administration of antimicrobial therapy. All but one patient received in-vitro-active antimicrobial agents within 48 hours, but the all-cause mortality rate was 56%. Initial high Pitt's bacteremia score was independently associated with a fatal outcome in multivariate analysis.

CONCLUSION

Aeromonas SBP is a fatal disease, and must be included in the differential diagnosis of SBP in patients with advanced liver cirrhosis in endemic areas.

Physician clinical impression does not rule out spontaneous bacterial peritonitis in patients undergoing emergency department paracentesis

STUDY OBJECTIVE

We determine whether clinical characteristics and physician assessment are useful in the exclusion of spontaneous bacterial peritonitis in emergency department (ED) patients with ascites requiring paracentesis.

METHODS

We conducted a prospective, observational study of ED patients with ascites undergoing paracentesis. Predefined clinical characteristics including historical features and ED vital signs were recorded. Each patient was assessed by 2 separate, blinded physicians for severity of abdominal tenderness and overall clinical suspicion for spontaneous bacterial peritonitis. The primary outcome measures were sensitivity, specificity, and likelihood ratios (LR) of the individual clinical characteristics and the physician assessments. Spontaneous bacterial peritonitis was defined by absolute neutrophil count greater than 250 cells/mm(3) or positive fluid culture result.

RESULTS

There were 285 separate physician assessments in 144 patients enrolled with complete data. Spontaneous bacterial peritonitis was diagnosed in 17 (11.8%) patients. Physician clinical impression had a sensitivity of 76% (95% confidence interval [CI] 62% to 91%) and specificity of 34% (95% CI 28% to 40%) for the detection of spontaneous bacterial peritonitis. The lowest negative LR was associated with the presence of any abdominal pain or tenderness (negative LR=0.4); however, the presence of pain/tenderness was also observed in 85% of patients without spontaneous bacterial peritonitis. Six patients (4.2%) with spontaneous bacterial peritonitis had at least 1 physician assessment of little to no risk for spontaneous bacterial peritonitis, and 3 of the 6 subsequently died during their hospitalization.

CONCLUSION

Clinical characteristics and physician assessment were insufficient in the diagnosis or exclusion of spontaneous bacterial peritonitis in the ED patient undergoing diagnostic or therapeutic paracentesis. This finding supports routine laboratory fluid analysis after ED paracentesis.

Can clear ascitic fluid appearance rule out spontaneous bacterial peritonitis?

OBJECTIVE

The objective of the study was to determine the sensitivity and specificity of abnormal ascitic fluid appearance in the detection of spontaneous bacterial peritonitis (SBP), as a sensitivity approaching 100% could exclude SBP if the fluid is clear.

METHODS

We performed a retrospective review of all ascitic fluid samples sent for cell count over a 4-year period. Spontaneous bacterial peritonitis was defined as an absolute neutrophil count of more than 250 cells/mm3 or a positive culture. Abnormal fluid appearance was defined as hazy, cloudy, or bloody.

RESULTS

There were 916 ascitic fluid samples analyzed during the study period. Eighteen percent of samples had a clear appearance, whereas 82% were abnormal. Abnormal ascitic fluid appearance had a sensitivity of 98.1% (95% confidence interval, 95.3%-99.5%) and a specificity of 22.7% (95% confidence interval, 19.4%-26.3%) in the detection of SBP.

CONCLUSIONS

Abnormal fluid appearance has a high sensitivity for the detection of SBP. Thus, clear fluid might safely exclude SBP.

Spontaneous bacterial peritonitis results in oxidative and nitrosative stress in ascitic fluid

BACKGROUND AND AIM

Spontaneous bacterial peritonitis (SBP) is a major complication of liver cirrhosis and accounts for significant mortality. Although oxygen free radicals and nitric oxide been implicated in the pathophysiology of liver cirrhosis, information on their role during the development of SBP is scarce. This study examined these active species in ascitic fluid from patients with SBP, and in response to treatment.

METHODS

Forty-nine consecutive patients with cirrhosis and ascitic fluid neutrophil counts less than 250/cumm were studied as controls. Another 21 patients whose ascitic neutrophil count exceeded 250/cumm were treated as cases. Ascitic fluid was collected from these patients at entry and 48 h after treatment with antibiotics. Nitrate and markers of oxidative stress such as malondialdehyde, protein carbonyl content and total and protein thiols were measured.

RESULTS

A significant increase in malondialdehyde and protein carbonyl levels was seen in ascites from patients with SBP when compared to controls. This was accompanied by a decrease in total thiols and protein thiols. In addition, there was a significant increase in ascitic fluid nitrate in patients with SBP when compared to control patients. After antibiotic treatment, malondialdehyde, protein carbonyl and nitrate levels dropped back towards control values, and total thiols also recovered.

CONCLUSIONS

This study demonstrated the presence of oxidative stress in ascitic fluid from patients with SBP, and showed that ascitic fluid nitrate may be a marker for diagnosing SBP and a useful index in determining therapeutic response to antibiotic treatment.

Abdominal tenderness in ascites patients indicates spontaneous bacterial peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP), which has been reported to be present in 10-30% of patients with cirrhotic ascites, may easily be overlooked. An important aim of our study was to determine whether there are any clinical signs which, in clinical practice, may predict or exclude SBP.

METHODS

We studied 133 patients with cirrhotic ascites from medical units at nine Swedish university hospitals where there had been at least one diagnostic ascites tap with analysis of polymorphonuclear leukocytes in the ascites fluid. The patients had initially been questioned about background factors and physically examined according to a standardized case record form. Samples of blood, urine, and ascites were then drawn for analysis according to a structured schedule.

RESULTS

SBP could be excluded in 80% of all the cases and was confirmed in 8% of the 133 patients in the final analysis. Abdominal pain and abdominal tenderness were more common in patients with SBP (p<0.01), but no other physical sign or laboratory test could separate SBP cases from the others.

CONCLUSIONS

SBP was present in about one-tenth of the hospitalized patients with cirrhotic ascites in this cohort. Performing repeated physical examinations and paying particular attention to abdominal tenderness may be the best way to become aware of the possible development of this complication.

Efficacy of leukocyte esterase dipstick test as a rapid test in diagnosis of spontaneous bacterial peritonitis

AIM: To evaluate the efficacy of dipstick test in diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients who underwent abdominal paracentesis based on the locally available dipstick test.

METHODS: There were 200 consecutive samples from cirrhotic patients who underwent abdominal paracentesis. Urine dipstick (Combur¹⁰ Test^®M, Roche, Mannheim, Germany) was used as a screening test. A manual cell count with differential study was done in all samples by experienced technicians. The polymorphonuclear (PMN) cell count more than 250 cells/mm³ was used as a diagnostic cut off level. One to three plus dipstick results were used as cut off levels for a positive result. The dipstick test results had to be agreed by three experienced readers. The sensitivity, specificity, positive and negative predictive values and accuracy of two different colorimetric cut off scales (1+ and 2+) were calculated and compared.

RESULTS: The prevalence of SBP diagnosed by manual cell count was 21.0%. There were 128 specimens that had a true negative result by dipstick. The sensitivity, specificity, positive and negative predictive values and accuracy of 1+ and 2+ cut off scale to diagnose SBP were 88%, 81%, 55%, 96% and 83% respectively, and 63%, 96%, 82%, 81% and 89% respectively.

CONCLUSION: Dipstick test can be used as a rapid test for screening of SBP. The higher cut off colorimetric scale has a better specificity and positive predictive value but a lower sensitivity.