Surgical Challenges in the treatment of cIAI (complicated Intraabdominal Infection) Reno Rudiman Hasan Sadikin General Hospital, Bandung, Indonesia

Definition Infections that spread beyond the hollow viscus of origin into the peritoneal space and are associated with: Abscess formation or Peritonitis

Peritonitis Primary = spontaneous bacterial peritonitis spontaneous bacterial peritonitisspontaneous bacterial peritonitis arises without a breach in the peritoneal cavity or GI tract Secondary spillage of gut organisms through a physical hole in the GI tract or through a necrotic gut wall community acquired or healthcare associated Tertiary peritonitis in a critically ill patient which persists or recurs at least 48 h after apparently adequate management of primary or secondary peritonitis

Microbiology: Abscesses or secondary peritonitis Health care associated intra-abdominal infection Community acquired infections Infections derived from stomach, duodenum, biliary system and proximal small bowel: Gram positive and Gram negative aerobic and facultative bacteria Distal small bowel: Gram negative facultative and aerobic bacteria Anaerobes Large bowel: Facultative and obligate anaerobic bacteria Streptococi and enterococci commonly present

Clinical features of cIAI Difficult to diagnose in the critically ill patient because history is usually unobtainable and physical signs usually masked by decreased conscious level

Clinical features of cIAI Consider diagnosis in the appropriate clinical setting in patients with otherwise unexplained signs of sepsis or organ dysfunction: recent abdominal surgery source of arterial emboli peripheral vascular disease thrombotic disorder recent arteriography history of reduced splanchnic blood flow (eg use of vasopressors or prolonged shock)

Clinical features of cIAI Suspicion of intra-abdominal infection Unexpected shortness of breath supraventricular tachycardia occurring 3-4 days after an abdominal operation new onset renal dysfunction elevated bilirubin or transaminases

InvestigationsMicrobiological Blood cultures often negative polymicrobial or anaerobic bacteraemia should raise possibility of anaerobic infection Community acquired infections: Gram stain of no value Healthcare associated infections: Gram stain may be valuable in S.aureus or Enterococcus spp. infections

AXR

Ultrasound

CT abdomen

Invasive Investigations in ICU Probing of surgical wounds with sterile culture swab or gloved finger can often identify collections of infected material immediately adjacent to incision Diagnostic peritoneal lavage may reveal bacteria, white cells, bile or intestinal contents bloody lavage return suggests acute intestinal ischaemia Bedside laparoscopy difficult experience in critically ill patients largely anecdotal

Management of cIAI Physiological resuscitation Systemic antibiotics Source control

Physiologic resuscitation: Early Goal Directed Therapy

What is Source Control? All those physical measures that are undertaken To eliminate a focus of infection To control ongoing contamination To restore premorbid anatomy & function

What is Source Control? Not always surgical procedures, also include Radiologically directed drainage of abscess Removal of colonized urinary or vascular catheter Removal of devitalized tissue by frequent dressing changes

TermDefinition Source control All physical measures undertaken to eliminate a source of infection, control ongoing contamination, and restore premorbid anatomy and function SinusAbnormal communication to an epithelial cell-lined surface Fistula Abnormal communication between two epithelial cell-lined surfaces Abcess Fluid-filled collection of tissue fluid, tissue debris, neutrophis, and bacteria contained within a fibrous capsule DrainageCreation of a controlled sinus or fistula Debridement Removal of devitalized tissue, foreign bodies, or other areas advantageous to bacterial growth

Principles of Source Control Drainage of abscess Debridement of nonviable of infected tissue Definitive management of the anatomic abnormality responsible for ongoing microbial contamination & restoring normal function and anatomy

Drainage Converting a contained collection to a controlled fistula (to exterior) or sinus Drain must permit free flow of the abscess Minimum risk and physiologic derangement: percutaneous drainage Modern imaging: all collections can be visualized preoperatively In unstable and ill patient – surgery for controlled sinus/fistula & removal of dead tissue only Converting a contained collection to a controlled fistula (to exterior) or sinus Drain must permit free flow of the abscess Minimum risk and physiologic derangement: percutaneous drainage Modern imaging: all collections can be visualized preoperatively In unstable and ill patient – surgery for controlled sinus/fistula & removal of dead tissue only

Drainage CT guided abcess drainage Drainage CT guided abcess drainage

Debridement The process of removing nonviable tissue Directed against solid components that promote bacterial growth Demarcation between viable and nonviable tissue maybe not absolute at early stage Gentle debridement - use wet to dry saline dressing The process of removing nonviable tissue Directed against solid components that promote bacterial growth Demarcation between viable and nonviable tissue maybe not absolute at early stage Gentle debridement - use wet to dry saline dressing

Debridement Remove all necrotic tissue but minimize the resulting defects for easier reconstruction Bleeding from viable tissue is better than fail to debride necrotic material Remove all necrotic tissue but minimize the resulting defects for easier reconstruction Bleeding from viable tissue is better than fail to debride necrotic material

Debridement Necrotic bowel Excision for necrotic bowel is more complex The benefits of resection must be weighed against the consequences of loss of bowel length The dilemma is usually best resolved by a planned second-look laparotomy Excision for necrotic bowel is more complex The benefits of resection must be weighed against the consequences of loss of bowel length The dilemma is usually best resolved by a planned second-look laparotomy

Debridement Retroperitoneum Peripancreatic retroperitoneal necrosis is well tolerated Blind exploration of retroperitoneum - risk of uncontrollable hemorrhage Delayed debridement is preferred for suspected infected necrosis Peripancreatic retroperitoneal necrosis is well tolerated Blind exploration of retroperitoneum - risk of uncontrollable hemorrhage Delayed debridement is preferred for suspected infected necrosis

Debridement Foreign body Risks are minimal when urinary or vascular catheter is infected Risks are high when aortic graft or heart valve is infected Risks are minimal when urinary or vascular catheter is infected Risks are high when aortic graft or heart valve is infected

Definitive management The ultimate aim of therapy: to restore function with the least risk To correct the abnormality that created the infection The ultimate aim of therapy: to restore function with the least risk To correct the abnormality that created the infection

Extent of Surgical Therapy The more extensive the initial intervention, the greater is the challenge of subsequent reconstruction The optimal intervention is that which accomplishes the source control objectives in the simplest manner The more extensive the initial intervention, the greater is the challenge of subsequent reconstruction The optimal intervention is that which accomplishes the source control objectives in the simplest manner

Failed Source Control Failure of source control is more important than antibiotic failure Cause of failure: Poor choice of operation Correct operation performed poorly Poor timing Consequences of failure: Nosocomial infections Nutritional and metabolic disorders Multiple organ dysfunction syndrome Failure of source control is more important than antibiotic failure Cause of failure: Poor choice of operation Correct operation performed poorly Poor timing Consequences of failure: Nosocomial infections Nutritional and metabolic disorders Multiple organ dysfunction syndrome

Diffuse Peritonitis Aggressive initial surgical source control : intraoperative lavage If source control not possible Continuous lavage Laparostomy Planned reexploration Or combination of above Aggressive initial surgical source control : intraoperative lavage If source control not possible Continuous lavage Laparostomy Planned reexploration Or combination of above

Complications of Source Control Complications from Technical error Local factors that impair healing Complications from Technical error Local factors that impair healing

Source Control Should be individualized based on: Diagnostic uncertainty Physiologic stability Premorbid health status Previous surgical interventions Surgeon’s experience & skill Available surgical facilities

Antibiotics High risk patients should be given antibacterials with a wider spectrum of activity Risk factors: higher APACHE II poor nutritional status significant cardiovascular disease inability to obtain adequate source control immunosuppression

Antibiotics Should be active against enteric Gram negative aerobic and facultative bacilli and ß-lactam susceptible Gram positive cocci For distal small bowel and colon-derived infections antibacterials should cover anaerobes Same recommendation also applies to more proximal GI perforations when obstruction is present

Antibiotics Suitable regimes include: imipenem/cilastinimipenem/cilastin, meropenem, doripenem meropenem imipenem/cilastinmeropenem 3rd or 4th generation cephalosporin3rd or 4th generation cephalosporin plus metronidazole 3rd or 4th generation cephalosporin ciprofloxacinciprofloxacin plus metronidazole ciprofloxacin aztreonam plus metronidazole piperacillin/tazobactam

Risk Factors for Treatment Failure Patient factors Age, comorbidity, malnutrition Prolonged hospital stay, Antibiotic resistance Severity of illness Surgical factors Inadequate source control Ineffective antibiotic therapy Modifiable Risk Factors Modifiable Risk Factors Surg Inf 2002(3):

Conclusion Management of cIAI includes: physiologic resuscitations, systemic antibiotics and source control The key to success when treating surgical infections is timely intervention to stop the delivery of bacteria and adjuvants of inflammation/infection into the peritoneal cavity All others are useless if source control failed