The Abdomen in Critical Care
Introduction
Need for HDU / ICU
Specific Complications
The Surgeon in ICU
Introduction

The abdomen causes many critical illness
- via infection / inflammation, obstruction or heamorrhage of its viscera +/- sepsis.
Once ICU support is required, mortality approaches 70%.
Diagnosis can be very difficult.
Surgeons are required to provide experise on drains, wounds and stomas in the ICU environment.

Some important points
Pts became unwell quickly and frequent reassessment is important
Pts can sequester large quantities of fluid in their abdomen
Any pt with an acute abdomen needing ongoing fluids to maintain urine, and O2, is at high risk and needs senior input and HDU/ICU care.
The Need for HDU / ICU Care

Use the pt assessment framework to be thorough and structured.
- assess the pt on the ward as thoroughly as you would in the emergency room.

Anticipate need from risk factors:
- age
- severity of acute illness
- comorbidity
- acute physiological status
- close monitoring to minimise delay

Deterioration
Establish early and frequent obs monitoring
- look for frequent trends of change that need early action
Pts that do not progress quickly also fit this category.
--> resuscitate ABCs
--> transfer to ICU safely and appropriately
--> assess notes and the pt carefully
--> diagnose clinically and with investigations
--> treat and consult appropriately.

Investigations
Haematology
- WCC<2 is a sin of a profoundly impaired host response
- WCC >20-25 may indicate infarction
- Anaemia may signal an unknown neoplasm, or bleeding / sepsis / DIC.
Biochemistry
Look for renal failure
Acidosis should be detected.
Scoring systems
Eg APACHE II, POSSUM, Ranson's
- offer comparative indices of pt severity
- limited individual use in prognosis
Imaging
Early CT or USS may reveal a source of sepsis or infection
- they also can easily miss collections
Gastrografin enema or meal can show anastomotic leaks
Plain XRs are rarely if ever useful.
Specific Complications

Anastomotic Leak

Post-op Bleeding

GI Stress Ulceration

PE
- do not forget DVT prophylaxis

Necrotising Fasciitis

Burst Abdomen
A historical condition
- now mass cloured using non-absorbable synthetic monofilaments delays this.
Heralded by the 'pink sign'
- a serosanguinous discharge eight to ten days after surgery
Keep exposed viscera warm and moist with sterile saline packs and arrange for closure within 3-4 hrs.
- there is little systemic upset when the abdomen bursts...
... but mortality is as high as 30%.
In certain pts conservative management may be chosen; the worse outcome being a large hernia.

The Surgeon in ICU

A vital part of the MDT
Remain informed and lead surgical decisions: nutrition, drainage, gut use, wound and stoma care.
- recognise and treat abdominal concerns.
- frequently review your patients and attend when requested.
- maintain a daily record of progress and management plans.
- twice daily ICU review can help recognise complications early.

Assessing the ICU pt's abdomen
Consider new problems and ongoing problems
Make your own full and thorough assessment
- review charts, results, notes, and examine the pt.
The stakes are high: missed abdo sepsis is almost always fatal.
--> in the face of sedation diagnosis is difficult and laparotomy may be considered for MODs.
- distension, drain effluent, wounds and stomas may provide clues.
- signs are often systemic, eg O2 requirement, inotrope requirement, onset of acute renal failure, or thrombocytopaenia.
- a higher than expected degree of support required by ICU adjuncts should be suspicious.
- WCC may be less reliable due to steroids or other diseases
- investigations can be difficult.
Keep discussing with ICU colleagues.

Consider these clinical questions
- could this be bleeding? perf? gangrene? sepsis?
- where from?
Use clinical judgement and investigations to decide
- CT is usually the best form of imaging
- USS is difficult and can be unreliable.
Consider line sepsis, urinary sepsis and pulmonary sepsis by bacteria or fungi.
Put proposals to relatives
... sometimes they may decide the pt has had 'enough' if the chances of death are significant.

Principles of Reoperative Surgery
Prepare the pt as well as reasonable possible first
Anticipate difficult - senior surgeon
Deal with problem as definitively as possible
Exteriorise leaking bowel where possible
Remove dead tissue
Culture pus and drain sepsis
Consider gastrostomy or jejunostomy for ease of future management.

Other surgery notes
When all dead tissue has not been removed, undertake a further look at 24-72 hrs.
- however the use of 'routine' repeat looks is harmful and without benefit
Sometimes the abdo wall may not be closen without undue tension
- may need to leave it open with moist packing ('laparostomy')
- change packing every 24hrs or so (surgeon should do this)
- and relavage abdo in the ICU if required.
--> these heal remarkably well if the underlying problem is fixed.
Beware the abdominal compartment syndrome
Intestinal fistula management can be complex

The intact gut as a focus of sepsis
Starved or hypoperfused gut may liberate factors into the circulation to promote MODs
- especially after trauma
- particularly at risk of colonisation with aerobic gram -ve bacilli
--> high mortality, eg pneumonia, urinary infection, soft-tissue infections.
Upper GI colonisation is encouraged by intubation and PPIs.
--> this adds to the difficulties of enteral nutrition.
Sucralfate is a gastric mucosal cytoprotective agent
- keeps gastric pH low.
- however makes gastric decompression difficult as it blocks the NG tube.
- problems with resistence may yet emerge
--> early enteral feeding by jejunostomy or fine-bore gastric tubes may be an advantage.

Stoma, Wound and Drain Care
Stomas
Feeding gastrostomy or jejunostomy: start stomal feeding in accordance with bowel function, remove after 10 dats at least (allows a suitable seal to form).
Faecal stomas: temporary, loop, or end-in.  small bowel effluent irritates skin and should be spouted.  large bowel effluent is firmer and less irritant.
- Do't forget to protect nearby wounds early and provide psychological support.
Drains
There is little evidence they work beyond 24-48hrs.
- may cause tissue reaction and persistant drainage.
- whether they reduce risks of complications or infection is open to doubt.
May be passive or suction and are mostly expensive.
- protect anastomoses, drain potential fluid collections.
- patency and function of suction drains can be improved by using a sump drain.
Wounds
Most wounds are closed primarily even when contaminated.
- safe when source of infection treated and antibiotics given.
Sometimes a laparotomy wound may be left open.
- eg after faecal peritonitis
- kept moist with saline or dilute aqueous antiseptic
- suture is done after granulation is established and clean.