Source control in the management of severe sepsis and septic shock: An evidence-based review

1. Source control in the management of severe sepsis and septic shock: An evidence-based review

2. Abstract • Source control represents a key component of success in therapy of sepsis. • It includes drainage of infected fluids, debridement of infected soft tissues, removal of infected devices or foreign bodies, and finally, definite measures to correct anatomic derangement resulting in ongoing microbial contamination and to restore optimal function.

3. Drainage • Question: What is the optimal approach to abscess drainage in the patient with severe sepsis or septic shock? • Recommendation: As a general principle, the optimal method of drainage is that which accomplishes full drainage of the collection with the least degree of anatomic and physical trauma to the patient; not only does such an approach minimize the immediate morbidity associated with drainage, it also ensures the broadest range of options for subsequent reconstructive surgery.(Grade E)

4. Drainage • Drainage is most likely to be successful when the abscess occurs as a postoperative complication, whereas failure is most common with very small abscesses, pancreatic abscesses, and abscesses from which fungi are isolated • Laparoscopic drainage of abdominal abscesses has been reported, although it is unclear whether laparoscopic techniques have any significant advantage over open surgery or percutaneous radiographic drainage.

5. Debridement • In patients with necrotizing soft-tissue infections, the extension of tissue necrosis is rapid, and because the necrotic tissues are exposed, control of areas of bleeding can be readily accomplished using electrocautery. • Early aggressive debridement is associated with an improved clinical outcome • for patients with retroperitoneal necrosis secondary to pancreatitis, extension of tissue necrosis is more gradual, whereas injudicious exploration can result in bleeding from retroperitoneal vessels that are not readily controlled.

6. Debridement • At the time of laparotomy for peritonitis, neither irrigation of the peritoneal cavity nor the careful removal of fibrinous exudates adherent to loops of bowel have been shown to improve outcome or decrease rates of recurrence. • In summary, then, the optimal timing of debridement is a tradeoff between the infectious process and the morbidity associated with intervention • Although early therapy is desirable, the benefits must be weighed against the risks of hemorrhage in tissues that are not readily amenable to surgical control.

7. Foreign body • for example, a colonized intravascular catheter or infected prosthetic heart valve) can serve as an ongoing reservoir of microorganisms that trigger a systemic inflammatory response. • Question: Can an infected vascular catheter be safely exchanged over a guidewire? • Recommendation: An infected intravascular catheter can be safely exchanged over a guidewire, provided there is no significant evidence of soft-tissue infection at the exit site.(Grade B)

8. Foreign body • Rationale: A systematic review of 12 randomized trials comparing catheter changes over a guidewire with catheter replacement at a separate site in patients with central venous catheter infections found that guidewire exchange was associated with fewer mechanical complications (relative risk, 1.72; 95% confidence interval, 0.89–3.33) and a modestly increased rate of catheter exit-site infection (relative risk, 1.52; 95% confidence interval, 0.34–6.73).

9. Question: How is the need for abdominal source control best established? • Recommendation: The need for abdominal source control measures is typically suggested by the history and physical examination; radiographic examination should be performed to establish or confirm the diagnosis in the majority of cases and to aid in deciding on the optimal source control method. Radiographic definition of an intraabdominal infection facilitates operative planning if surgery is contemplated and is a prerequisite for the use of percutaneous drainage. • Grade E

10. Abdominal source control • Rationale: Abdominal pain is the cardinal symptom; its location and characteristics generally provide insight into its cause. Additional historical features may point to specific causes—a history of peptic ulcer disease suggesting a perforated ulcer; a history of peripheral vascular disease, atrial fibrillation, or acute myocardial infarction suggesting the possibility of intestinal ischemia; or a history of abdominal surgery raising the possibility of strangulating intestinal obstruction.

11. Question: What is the optimal approach to source control when sepsis results from a perforation of the gastrointestinal tract? • Recommendation: The therapeutic objective in managing a perforation at any level of the gastrointestinal tract is to eliminate ongoing leakage of luminal contents through removal of the perforation or through the creation of a controlled sinus or fistula. How this objective is best accomplished depends on the anatomic site and extent of the perforation, the degree of localization, and the physiologic stability of the patient. • Grade E; except Grade C for gastrointestinal perforations secondary to diverticulitis

12. GI perforation secondary to diverticulitis • The sigmoid colon is the most common site of intestinal perforation, usually as a result of underlying diverticular disease • Several therapeutic options are available. For the patient with a walled-off perforation resulting in a peridiverticular abscess, percutaneous CT-guided drainage converts the abscess to a controlled colocutaneous fistula and so permits resolution of the acute inflammatory process; resection of the involved colon can then be undertaken electively at a later date

13. Question: What is the optimal mode of source control when sepsis results from the biliary tract? • Recommendation: The objective of therapy when sepsis arises from obstruction of the gall bladder or biliary tree is the relief of intraluminal pressure through the creation of a controlled fistula with the skin or intestinal tract. Timely intervention after stabilization of the patient is indicated. For the patient with gangrenous acute cholecystitis or acalculous cholecystitis, source control options include PTCD or operative cholecystectomy. Cholangitis necessitates decompression of the biliary tree by ERCP with papillotomy or nasobiliary drainage, transhepatic decompression, or operative exploration of the common bile duct. • Grade D

14. Question: What is the optimal mode of source control when sepsis results from intestinal ischemia or infarction? • Recommendation: Intestinal infarction is a surgical emergency because gangrenous intestine produces rapid physiologic decompensation, and in the absence of surgical resection, is almost invariably lethal. On the other hand, intestinal ischemia in the absence of infarction is potentially reversible with hemodynamic support and correction of the circumstances that produced the ischemia. Thus, early diagnosis and timely surgical intervention are critical to a successful outcome for patients with severe sepsis secondary to intestinal ischemia.(Grade E)

15. Question: What is the optimal source control approach for patients with infected pancreatic necrosis? • Recommendation: Infection of necrotic pancreas or retroperitoneal fat is a common complication of severe acute pancreatitis. When the process is limited to infection of a collection of pancreatic fluid, percutaneous drainage alone may be sufficient. More typically, however, variable amounts of infected necrotic tissue must be debrided to achieve adequate source control. Data from case series and a single randomized trial suggest that delaying surgical debridement for at least 2–3 wks results in fewer procedure-related complications and improved clinical outcome. • Grade C

16. Infective pancreatic necrosis • Most authorities recommend operative debridement only for patients with infected pancreatic necrosis and prefer to manage noninfected necrosis expectantly • In contrast, infected necrosis is an indication for intervention, although successful nonoperative management of infected necrosis has been reported • Delayed surgery permits better demarcation of planes between viable and nonviable retroperitoneal tissues and so reduces the morbidity of surgery

17. Question: What is the role of open-abdomen or serial laparotomy approaches in the patient with complicated abdominal infection? • Recommendation: Although open-abdomen approaches are sometimes unavoidable in patients with significant abdominal wall soft-tissue loss or intraabdominal compartment syndrome, there is no convincing evidence that such approaches offer increased survival, and case series suggest they may result in higher rates of intestinal fistulization. • Grade E

18. Question: Is there a role for diagnostic laparotomy or abdominal washout in the patient with a possible intraabdominal focus but negative radiographic investigations? • No; Grade E • Recommendation: Advances in diagnostic imaging techniques have essentially eliminated the radiographically occult but clinically important focus on intraabdominal infection. Provided the clinician has access to resources for CT, it is very unlikely that surgical exploration will reveal treatable foci of infection that cannot be detected radiologically, and there is no evidence that blind laparotomy results in improved clinical outcomes.

19. Source control in infections of the chest and mediastinum • Question: What is the role of diagnostic sampling in the diagnosis of intrathoracic or sinus infection? • Recommendation: Access to fluid collections for diagnosis and potential therapeutic drainage is a priority. Sampling of intraparenchymal, intrapleural, mediastinal, or sinus collections, either blindly or by ultrasound or CT-guided needle aspiration, is usually diagnostic. Patients receiving antibiotics may have sterile aspirates. • Grade E

20. Empyema • The prevalence of empyema related to tube thoracostomy is unknown, but it seems to be less than 3% to 5% • Empyemas are commonly diagnosed by aspiration of pus from the pleural space. The diagnosis is suggested by chest radiographic findings of retained, loculated intrapleural fluid with or without air–fluid levels • If noninvasive investigations are nondiagnostic, aspiration under ultrasound or CT guidance is indicated

21. Empyema • The optimal timing of surgery for empyema in the nonseptic patient is also uncertain. • In the physiologically stable patient, attempts at aspiration or chest tube drainage may be appropriate; in the septic patient, however, aggressive, definitive intervention is probably warranted. • If simple tube thoracostomy drainage fails, a video-assisted thoracic surgical approach is preferred by most practitioners, particularly early in the course of the infectious process before the development of a thick, fibrous peel

22. Question: What is the role of fibrinolytics in treatment of empyema? • Recommendation: The use of fibrinolytics via tube thoracostomy for retained infected loculations, when administered early before the fibrotic phase of disease, decreases length of stay, time to resolution, and necessity for surgical intervention. • Grade C

23. Fibrinolytics for empyema • The best results occur when the enzyme is used early in the disease process, before onset of the fibroblastic phase. • Enzyme is instilled daily through the chest tube, which is then clamped for 6–8 hrs, and continued for a week or as long as drainage is productive. • Even with this approach, as many as 20% of empyemas will fail to resolve and will require open thoracotomy.

24. Lung abscess • Lung abscesses can develop after necrotizing bacterial infections, aspiration, retained foreign bodies, septic emboli, and infected injury • The diagnosis can usually be made by routine chest radiography, showing an intraparenchymal air-fluid level with loss of parenchymal markings, and confirmed by chest CT

25. Lung abscess • In the patient who deteriorates or is unstable, CT- or ultrasound-guided aspiration with placement of percutaneous drains is feasible and frequently successful • In progression of disease, formal thoracotomy with resection of involved pulmonary parenchyma may be required to resolve the infectious process. • Surgery is rarely required, except for the management of lung abscesses associated with hemoptysis.

26. Mediastinitis • Mediastinitis is most commonly seen after surgical intervention for cardiac procedures, after which its prevalence is 1–3% • More than 70% of episodes are caused by S. aureus • The diagnosis can be made either by needle aspiration of the previous surgical area using a parasternal approach or by CT-guided aspiration of loculated fluid collections • Reopening of the surgical site and debridement and drainage of the mediastinum is frequently required for definitive care.

27. Sinusitis • Indwelling nasogastric or nasotracheal tubes are associated with a significant rate of acute mechanical and gravitational sinusitis • The most common organisms are Streptococci, Haemophilus influenzae, and S. aureus • The diagnosis may be confirmed by direct aspiration or CT-guided puncture of the sinuses. • Treatment is drainage to prevent the highly morbid secondary complication of subdural abscess or pulmonary complications from ongoing aspiration

28. Skin and soft tissue infection • Question: Does bacteriology influence source control management (streptococcal, mixed, clostridial)? • Recommendation: Different bacterial etiologies for necrotizing soft-tissue infections do not require different operative management. All affected tissue should be exposed, and all dead tissue should be removed. • Grade E

29. Question: How is the need for source control determined? • Recommendation: Clinical suspicion is important.. Any infection with skin necrosis, bullae, evidence of gas in tissue either by physical or radiologic exam, or ecchymosis should be inspected either in the operating room with the option to continue to full operative management or by biopsy and frozen section with the option to proceed to operative management if findings warrant it. • Grade E

30. Question: What is the role of ultrasound, CT, or magnetic resonance imaging in the diagnosis of necrotizing soft-tissue infections? • Recommendation: Ultrasound seems to be relatively sensitive and less specific for revealing that the process being observed externally extends to the deeper tissues where necrotizing soft-tissue infections usually occur. It may also be helpful in guiding needle aspiration of suspicious areas. MRI is very sensitive but very nonspecific for revealing the same type of information described for ultrasound above. • Grade E

31. Question: What is the role for biopsy and frozen section examination in the diagnosis of necrotizing soft-tissue infections? • Recommendation: Biopsy and frozen section examination may be helpful but only if the suspicion of necrotizing soft-tissue infection and then primarily if an experienced surgeon is not available. • Grade E

32. Question: How do you determine the extent of excision, and when should amputation be performed? • Recommendation: A combination of incision and blunt dissection are used to expose the entire extent of involved tissue. Amputation is performed only when it is required to remove all dead tissue or when previous operative management has made the limb nonfunctional. • Grade E

33. Question: What is the role of reoperation for necrotizing soft tissue infection? • Recommendation: Any patient who has been operated on for necrotizing soft-tissue infection should be scheduled for a follow-up procedure in the operating room at a specific time in the future between 6 and 48 hrs later, regardless of how well he or she seems to be doing at that time. If the patient’s condition deteriorates or the infection is obviously extending before the scheduled reoperation, then the next procedure should be done at that time. • Grade E

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