Infectiological diagnostic problems in tertiary peritonitis

Tertiary peritonitis: considerations for complex team-based care

Peritonitis, as a major consequence of hollow visceral perforation, anastomotic disruption, ischemic necrosis, or other injuries of the gastrointestinal tract, often drives acute care in the emergency department, operating room, and the ICU. Chronic critical illness (CCI) represents a devastating challenge in modern surgical critical care where successful interventions have fostered a growing cohort of patients with prolonged dependence on mechanical ventilation and other organ supportive therapies who would previously have succumbed much earlier in the acute phase of critical illness. An important subset of CCI patients are those who have survived an emergency abdominal operation, but who subsequently require prolonged open abdomen management complicated by persistent peritoneal space infection or colonization, fistula formation, and gastrointestinal (GI) tract dysfunction; these patients are described as having tertiary peritonitis (TP).The organ dysfunction cascade in TP terminates in death in between 30 and 64% of patients. This narrative review describes key—but not all—elements in a framework for the coordinate multiprofessional team-based management of a patient with tertiary peritonitis to mitigate this risk of death and promote recovery. Given the prolonged critical illness course of this unique patient population, early and recurrent Palliative Care Medicine consultation helps establish goals of care, support adjustment to changes in life circumstance, and enable patient and family centered care.

Tertiary peritonitis: A disease that should not be ignored

Intra-abdominal infections can be classified into uncomplicated or complicated (peritonitis). Peritonitis is divided into primary, secondary, and tertiary. Tertiary peritonitis is the less common but the most severe among peritonitis stratifications, being defined as a recurrent intra-abdominal infection that occurs 48 h after a well-succeeded control of a secondary peritonitis. This disease has a complex pathogenesis that is closely related to the capacity of the peritoneal cavity to activate immunological processes. Patients who progress to persistent peritonitis are at an increased risk of developing several infectious complications such as sepsis and multiple organ failure syndrome. Moreover, tertiary peritonitis remains an important cause of hospital death mainly among patients with associated risk factors. The microbiological profile of organisms causing tertiary peritonitis is often different from that observed in other types of peritonitis. In addition, there is a high prevalence of multidrug-resistant pathogens causing this condition, and an appropriate and successful clinical management depends on an early diagnosis, which can be made easier with the use of clinical scores presenting a good prediction value during the intensive care unit admission. Complementarily, immediate therapy should be performed to control the infectious focus and to prevent new recurrences. In this sense, the treatment is based on initial antimicrobial therapy and well-performed peritoneal drainage.

MANAGEMENT OF POSTOPERATIVE PERITONITIS IN LOW-RESOURCES SERVICES

Background. Postoperative peritonitis (PP) reminds one of the most difficult complications in abdominal surgery with mortality rate 22.3 – 90 %. Methods. In Ivano-Frankivsk Regional (tertiary level) Clinical Hospital (Ivano-Frankivsk, Ukraine) during 2010–2017 were operated 8762 patients with acute and chronic diseases of digestive system (appendicitis, pancreatitis, cholecystitis, bowel obstruction, complicated ulcer of upper gastrointestinal truck, mesenteric vessels thrombosis, abdominal adhesion diseases, hernia, Chron’s diseases, abdominal trauma), among them in 209 (2.4 %) patients developed PP. Local PP (abscess of abdominal cavity) had 142 (67.9 %), diffuse PP – 67 (42.1 %) patients. Results. Clear local symptoms of peritonitis were absent in 178 (85.1 %) of 209 patients. General complication, such as acute respiratory failure had 95 (45.5 %), cardiovascular insufficiency – 68 (32.5 %), hepato-renal dysfunction - 46 (22 %) patients with PP. 129 (61.7 %) patients were treated by minimally invasive approach: 24 patients had laparoscopic lavage with drain of abdominal cavity abscess and 105 - ultrasound guided drain of abscess with catheter. 80 (38.3 %) patients had re-laparotomy (RL): 61 (91 %) from 67 with diffuse PP, 19 (13.4 %) from 142 patients – with local PP. 46 (57.5 %) patients underwent one RL, 26 (32.5 %) – two, 8 (10 %) patients – three RL. With increasing numbers of RL, increase mortality rate: after first RL died 7 (15.2 %) of 46 patients, after second RL – 12 (63.2 %) of 19, after third RL 6 (75 %) of 8 patients. Conclusions. Together with standard surgical methods and precise technique were used lavage of abdominal cavity with 8 – 12 litres of antiseptic solutions, solution for peritoneal dialysis intraabdominally, nasointestinal drain tube, what was favourable for faster treatment of abdominal sepsis, reducing number of RL and postoperative mortality.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

Dynamic changes of microbial flora and therapeutic consequences in persistent peritonitis

Introduction

Persistent peritonitis is a frequent complication of secondary peritonitis requiring additional reoperations and antibiotic therapy. This situation raises specific concerns due to microbiological changes in peritoneal samples, especially the emergence of multidrug-resistant (MDR) strains. Although this complication has been extensively studied, the rate and dynamics of MDR strains have rarely been analysed.

Methods

We compared the clinical, microbiological and therapeutic data of consecutive ICU patients admitted for postoperative peritonitis either without subsequent reoperation (n = 122) or who underwent repeated surgery for persistent peritonitis with positive peritoneal fluid cultures (n = 98). Data collected on index surgery for the treatment of postoperative peritonitis were compared between these two groups. In the patients with persistent peritonitis, the data obtained at the first, second and third reoperations were compared with those of index surgery. Risk factors for emergence of MDR strains were assessed.

Results

At the time of index surgery, no parameters were able to differentiate patients with or without persistent peritonitis except for increased severity and high proportions of fungal isolates in the persistent peritonitis group. The mean time to reoperation was similar from the first to the third reoperation (range: 5 to 6 days). Septic shock was the main clinical expression of persistent peritonitis. A progressive shift of peritoneal flora was observed with the number of reoperations, comprising extinction of susceptible strains and emergence of 85 MDR strains. The proportion of patients harbouring MDR strains increased from 41% at index surgery, to 49% at the first, 54% at the second (P = 0.037) and 76% at the third reoperation (P = 0.003 versus index surgery). In multivariate analysis, the only risk factor for emergence of MDR strains was time to reoperation (OR 1.19 per day, 95%CI (1.08 to 1.33), P = 0.0006).

Conclusions

Initial severity, presence of Candida in surgical samples and inadequate source control are the major risk factors for persistent peritonitis. Emergence of MDR bacteria is frequent and increases progressively with the number of reoperations. No link was demonstrated between emergence of MDR strains and antibiotic regimens, while source control and its timing appeared to be major determinants of emergence of MDR strains.

An introduction of Tertiary Peritonitis

Intraperitoneal infection known as peritonitis is a major killer in the practice of clinical surgery. Tertiary peritonitis (TP) may be defined as intra-abdominal infection that persists or recurs ³48 h following successful and adequate surgical source control. A planned or on-demand relaparotomy after an initial operation is probably most frequent way to diagnose TP, but is a late event to occur. Hence it is desirable to have timely and nonoperative diagnosis of TP after the initial operation and subsequent initiation of an appropriate therapy to reduce the complications and to improve the outcome.

Poor outcome in bacterial peritonitis is associated with dysregulated microRNAs and an increased inflammatory response

BACKGROUND

Peritonitis is a common cause of surgical sepsis. The failure of the host to mount an appropriate immune response contributes to persistence of the infection. We investigated the role microRNAs may play in this failed immune response.

METHODS

Klebsiella pneumoniae was injected intraperitoneally in mice. Weight loss was used to predict clinical outcome. Peritoneal exudate cells (PECs) and supernatant were collected. RNA from PECs was run on screening microRNA array cards to determine gene expression, and validated by single assay analysis. Cytokine levels in supernatant were assayed by enzyme-linked immunosorbent assay.

RESULTS

Despite similar bacterial levels, PEC counts were higher in the predicted death group. The predicted deaths had higher levels of proinflammatory tumor necrosis factor-α/IL-6 and significantly lower levels of interleukin-10. MiR-221 was up-regulated in both the predicted death and predicted survivor groups. Five miRNAs were up-regulated in the predicted survivor group compared with normal controls.

CONCLUSION

Higher PEC counts and proinflammatory cytokines in the predicted death group indicates an exaggerated inflammatory response, with lower IL-10 levels despite similar bacterial counts. There were two dysregulated miRNAs with transcriptional targets that may explain our results. A more balanced immune response with an appropriate counter inflammatory response may be important for improving survival.

Infective severe acute pancreatitis: A comparison of 99mTc-ciprofloxacin scintigraphy and computed tomography

AIM: To evaluate ^99mTc-ciprofloxacin scintigraphy compared with computed tomography (CT) for detecting secondary infections associated with severe acute pancreatitis (SAP) in swine.

METHODS: Six healthy swine were assigned to a normal control group (group A, n = 6). SAP was induced in group B (n = 9) and C (n = 18), followed by inoculation of the resulting pancreatic necroses with inactive Escherichia coli (E. coli) (group B) and active E. coli (group C), respectively. At 7 d after inoculation, a CT scan and a series of analyses using infecton imaging (at 0.5, 1, 2, 3, 4 and 6 h after the administration of 370 MBq of intravenous infecton) were performed. The scintigrams were visually evaluated and semi-quantitatively analyzed using region of interest assignments. The differences in infecton uptake and changes in the lesion-background radioactive count ratios (L/B) in the 3 groups were recorded and compared. After imaging detection, histopathology and bacterial examinations were performed, and infected SAP was regarded as positive. The imaging findings were compared with histopathological and bacteriological results.

RESULTS: In group A, 6 animals survived without infection in the pancreas. In group B, 7/9 swine survived and one suffered from infection. In group C, 15/18 animals survived with infection. Hence, the number of normal, non-infected and infected SAP swine was 6, 6 and 16, respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the infecton method were 93.8% (15/16), 91.7% (11/12), 92.9% (26/28), 93.8% (15/16) and 91.7% (11/12), whereas these values for CT were 12.5% (2/16), 100.0% (12/12), 50.0% (14/28), 100.0% (2/2) and 46.2% (12/26), respectively. The changes in L/B for the infected SAP were significantly different from those of the non-infected and normal swine (P < 0.001). The mean L/B of the infectious foci at 0.5, 1, 2, 3, 4 and 6 h was 1.17 ± 0.10, 1.71 ± 0.30, 2.46 ± 0.45, 3.36 ± 0.33, 2.04 ± 0.37 and 1.1988 ± 0.09, respectively. At 3 h, the radioactive counts (2350.25 ± 602.35 k) and the mean L/B of the infectious foci were significantly higher than that at 0.5 h (P = 0.000), 1 h (P = 0.000), 2 h (P = 0.04), 4 h (P = 0.000) and 6 h (P = 0.000).

CONCLUSION: ^99mTc-ciprofloxacin scintigraphy may be an effective procedure for detecting SAP secondary infections with higher sensitivity and accuracy than CT.

Intraabdominal Infections in the Intensive Care Unit

Intraabdominal infections are frequent and dangerous entity in intensive care units. Mortality and morbidity are high, causes are numerous, and treatment options are variable. The intensivist is challenged to recognize and treat intraabdominal infections in a timely fashion to prevent complications and death. Diagnosis of intraabdominal infection is often complicated by confounding underlying disease or masked by overall comorbidity. Current research describes a wide heterogeneity of patient populations, making it difficult to suggest a general treatment regimen and stressing the need of an individualized approach to decision making. Early focus-oriented intervention and antibiotic coverage tailored to the individual patient and hospital is warranted.

[Candida peritonitis in a haemodynamically stable patient. First choice of antifungal treatment … fluconazole?]

BACKGROUND

Candida peritonitis in postoperative patients is an independent predictor of mortality. Empirical early antifungal therapy should be started in these patients, since according to the results of studies in patients with candidemia, this has an impact on the prognosis. The treatment recommended by clinical practice guidelines in patients with haemodynamic instability are candins, but they do not make explicit recommendations for patients with dysfunction of other organs, or high lactate levels.

CASE REPORT

A case of rescue treatment with anidulafungin in a patient with candidemia and Candida glabrata peritonitis postoperative haemodynamically stable, but with an acute renal failure and elevated plasma lactate, is reported. We discuss the antifungal treatment recommendations established by clinical practice guidelines.

CONCLUSIONS

One conclusion based on this case is that the haemodynamic instability as a marker of severe sepsis must be equated with dysfunction of any organ and/or a plasma lactate level ≥ 2.5 mmol/l in order to advocate candins as an antifungal treatment. In addition, it should be emphasised that anidulafungin was effective in a clinically difficult patient with candidemia and Candida peritonitis, even when used as late rescue antifungal treatment.

Identification of patients at risk for development of tertiary peritonitis on a surgical intensive care unit

BACKGROUND

Tertiary peritonitis (TP) is defined as a severe recurrent or persistent intra-abdominal infection after adequate surgical source control of secondary peritonitis (SP). The aim of this study was to analyze the characteristics of patients with SP who will further develop TP in order to define early diagnostic markers for TP.

STUDY DESIGN

Over a 1-year period, all patients on the surgical intensive care unit (ICU) with SP were prospectively assessed for the development of TP applying the definition of the ICU consensus conference. The Mannheim Peritonitis Index (MPI), C-reactive protein (CRP) and Simplified Acute Physiology Score II (SAPS II) were assessed at the initial operation (IO) that was diagnostic for SP and in the postoperative period.

RESULTS

Among 69 patients with SP, 15 patients further developed TP, whereas 54 patients did not develop TP. Compared to SP, patients with transition to TP had significantly higher MPI at IO (28.6 vs. 19.8; p < 0.001), relaparotomy rate (2.00 vs. 0.11; p < 0.001), mortality (60% vs. 9%; p < 0.001), duration of ICU stay (14 vs. 4 days; p < 0.005), as well as SAPS II (45.1 vs. 28.4; p < 0.005) and CRP (265 mg/dL vs. 217 mg/dL; p < 0.05) on the second postoperative day after IO.

CONCLUSIONS

The MPI at IO as well as CRP and SAPS II at the second postoperative day helps to identify patients at risk for tertiary peritonitis.

Candida peritonitis

PURPOSE OF REVIEW

The review highlights current insights in the epidemiology, diagnosis and therapy of Candida peritonitis, focusing on complicated secondary and tertiary peritonitis.

RECENT FINDINGS

Candida peritonitis is still associated with poor prognosis. Antifungal prophylaxis is therefore recommended in patients with an overt risk profile for invasive candidiasis (immunodeficiency and prior antibiotic exposure). The clinical and microbiological diagnosis of Candida peritonitis remains problematic. It is still unclear which peritonitis patients may benefit from antifungal treatment. Antifungal therapy can be suggested in critically ill patients with nosocomial peritonitis where Candida is diagnosed based on perioperatively sampled peritoneal fluid. Patients with prior exposure to fluconazole are at risk for Candida nonalbicans spp. involvement with possible reduced susceptibility.

SUMMARY

The main challenge in Candida peritonitis remains the interpretation of Candida cultured from the peritoneal cavity. Future research should focus on more conclusive diagnosis and on factors potentially confounding outcome, such as site of the perforation and failure of surgical source control. While awaiting progress to discriminate Candida colonization from invasive infection, antifungal therapy is recommended in high-risk critically ill surgical patients. Rapid detection of Candida might be beneficial in this regard. Besides antifungal therapy, adequate source control is of key importance.