surgical challenges in the treatment of ciai (complicated intraabdominal infection) reno rudiman...
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Surgical Challengesin the treatment of cIAI (complicated Intraabdominal Infection)
Reno Rudiman
Hasan Sadikin General Hospital, Bandung, Indonesia
DefinitionInfections that spread beyond the hollow viscus of origin into the peritoneal space and are associated with:
Abscess formation or
Peritonitis
PeritonitisPrimary = spontaneous 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 cIAIDifficult to diagnose in the critically ill patient because history is usually unobtainable and physical signs usually masked by decreased conscious level
Clinical features of cIAIConsider 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
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
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
Term Definition
Source controlAll 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
FistulaAbnormal communication between two epithelial
cell-lined surfaces
AbcessFluid-filled collection of tissue fluid, tissue debris,
neutrophis, and bacteria contained within a fibrous capsule
Drainage Creation of a controlled sinus or fistula
DebridementRemoval 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
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
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
DebridementNecrotic 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
DebridementRetroperitoneum
• Peripancreatic retroperitoneal necrosis is well tolerated
• Blind exploration of retroperitoneum - risk of uncontrollable hemorrhage
• Delayed debridement is preferred for suspected infected necrosis
DebridementForeign body
• 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
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
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
Diffuse Peritonitis
• 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
Source Control
Should be individualized based on:
Diagnostic uncertainty
Physiologic stability
Premorbid health status
Previous surgical interventions
Surgeon’s experience & skill
Available surgical facilities
AntibioticsHigh 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
AntibioticsSuitable regimes include:
imipenem/cilastin, meropenem, doripenem
3rd or 4th generation cephalosporin plus metronidazole
ciprofloxacin plus metronidazole
aztreonam plus metronidazole
piperacillin/tazobactam
Risk Factors for Treatment Failure
Patient factors
• Age, comorbidity, malnutrition
• Prolonged hospital stay, Antibiotic resistance
• Severity of illnessSurgical factors
• Inadequate source control
Ineffective antibiotic therapy
ModifiableRisk
Factors
Surg Inf 2002(3):175-233
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