1. Prevention and Treatment of Postoperative Ileus
Gum chewing
Prevention and Treatment of Postoperative Ileus
Lacey N. LaGrone, MD
Neuraxial Catheter
NSAIDs
Ambulation
Laparoscopy
Opioid antagonists
Limit opiates
NGT
Investigational therapies . . .

2. Definition
Prevention / Treatment
Pathophysiologic target
Evidence: Yes / No / Maybe

3. Definition of problem < 12 – 24 hr 5.9 +/- 1.5 d < 12 – 24 hr
What gut function is to be expected after laparotomy?
< 12 – 24 hr
5.9 +/- 1.5 d
Passing flatus / stool correlated well w/ return of colonic myoelectric activity.
< 12 – 24 hr
Estimated direct health care costs in 2000:
> $1,000,000,000

4. Intervention
Neuraxial Catheter
Evidence?
Yes / No / Maybe

5. Pathophysiology of ileus:
Inhibitory neural reflexes: Noxious spinal afferent signals increase inhibitory sympathetic activity in the GI tract (rats)
Limit opiate use
Evidence:
Midthoracic epidural with local anesthetics, 48-72h postop.
22 trials.
Epidural w/ local anesthetics mean time for return of bowel function 24 v. 37h
Unclear whether epidural opiates slow bowel function

6. Nasogastric decompression
Intervention
Nasogastric decompression
Evidence?
Yes / No / Maybe

7. Nasogastric Decompression
Pathophysiology of ileus
Symptom management
Evidence
2010 Cochrane review, 37 studies, 5711 patients.
Open procedures, randomization prior to OR
Patients w/o routine NGT use had:
Earlier return of bowel function [time to flatus] (p< )
Trend toward increased pulmonary complications (p=0.09)
Trend toward increased wound infection (p=0.39)
Trend toward increased ventral hernia (p=0.09)
Anastomotic leak rate the same (p=0.70)
Cochrane review. 37 studies.

8. Intervention
Gum chewing
Evidence?
Yes / No / Maybe

9. Pathophysiology of ileus
Cephalic-vagal stimulation of digestion
Increase promotility neural and humoral factors
Evidence

10. Pathophysiology of ileus
Cephalic-vagal stimulation of digestion
Increase promotility neural and humoral factors
Evidence

11. Intervention
Ambulation
Evidence?
Yes / No / Maybe

12. Ambulate Control Pathophysiology of ileus “Prokinetic”? Evidence
Patients were assigned randomly to one of two groups.
Ten patients (group A) followed an ambulatory regimen Transverse
starting 12 to 24 hours after operation and the other 25 Tran
patients served as controls (group C) and did not ambulate Colon
until postoperative day 4. Patients in group A underwent
an initial 30- to 45-minute recording session, which was
immediately followed by ambulation with assistance.
Then they underwent another 60- to 90-minute postambulation
recording session. Patients attempted to walk at
least 75 yards during the ambulation session, but the distance
varied with each patient's condition.
Ambulate
Control

13. Intervention
Rocking-chair
Evidence?
Yes / No / Maybe

14. Pathophysiology of ileus
“gentle, rhythmic, repetitive motion of rocking stimulates the vestibular nerves to send signals of pleasure and alertness to the Reticular Activating System, which is the body's “flight or fight” response center”
Evidence:

15. Intervention
Opioid antagonists
Evidence?
Yes / No / Maybe

16. Pathophysiology of Ileus
Opioids
Increase resting tone, decrease gastric motility and emptying, increase small intestinal periodic spasms, decrease colonic propulsive movements (5)
Receptor specific, mediated at level of enteric nervous system.
Evidence:
Alvimopan, oral peripherally acting mu-opioid receptor antagonist that has limited ability to cross blood-brain barrier (57), hastens postoperative GI recovery after bowel surgery and TAH (58-62)
Time to first passage of stool, tolerance of regular diet, length of hospital stay (63)
Concern for cardiovascular or neoplastic complications. FDA: accelerate time to upper and lower GI recovery following partial large or small bowel resection w/ primary anastamosis. Inpatients. (64)

17. Methylnaltrexone (PAM-OR) (65-67)
Approved for opioid-induced constipation. Two phase III trials found no improvement in recovery of gut function or time to discharge (68)

18. Antiinflammatory pharmacotherapy
Intervention
Antiinflammatory
pharmacotherapy
Evidence?
Yes / No / Maybe

19. Pathophysiology of Ileus
Inflammation
Local macrophages are activated by intestinal manipulation, produce inflammatory response that results in muscle dysfunction.
Degree of intestinal manipulation of both small and large intestine is directly related to both amount of dysmotility and degree of neutrophil infiltration into intestinal muscularis.
Field effect affecting entire GI tract.
Evidence . . .

20. Highly selective competitive COX-2 antagonist
Muscarinic antagonist
Bethanechol: muscarinic agonist
DFU: Highly selective competitive COX-2 antagonist
Increases COX-2, which decreases jejunal contractility
Blocked by administration of COX-2 inhibitors

21. Mast cells play a role
Mast cell stabilizers prevent intestinal inflammation and dysmotility, and mast cell deficiencies limit intestinal leukocyte migration

24. Minimally invasive surgery
Intervention
Minimally invasive surgery
Evidence?
Yes / No / Maybe

25. 1 v. 5 cm abdominal muscle-fascia incision
Minimally invasive surgery
In animals, length of laparotomy correlates w/ ileus.
Confounded by decreased postoperative opioid use, tendency towards earlier postoperative feeding.
1 v. 5 cm abdominal muscle-fascia incision
1 v. 5 cm laparotomy
Laparotomy with intestinal manipulation

27. Intervention
Duration of operation
Evidence?
Yes / No / Maybe

29. Intervention
Estimated blood loss
Evidence?
Yes / No / Maybe

31. Preemptive anesthesia
Intervention
Preemptive anesthesia
Initiate before surgical injury, adequate to prevent central sensitization, must be maintained postoperatively to prevent inflammatory changes assoc. w/ post-injury hypersensitivity.
Gabapentin, dexamethasone, APAP, COX-2 inhibitors, subcu anesthesia
Evidence?
Yes / No / Maybe

32. Intervention
Bran
Bran x 8-10 days preop, more likely to pass flatus w/in 24h (78 v. 5 %)

33. Intervention
Coffee
Evidence?
Yes / No / Maybe

34. Pathophysiology of Ileus
Cup of coffee stimulates colonic motor activity to the same degree as a high-calorie meal.

35. Intervention Metoclopramide Evidence? Yes / No / Maybe
100 patients. Scheduled reglan. Average time to PO intake: 3.5 v. 5.0 days. P>0.05.

36. Intervention
Suggestion
Evidence?
Yes / No / Maybe

37. P<0.05

38. Intervention
Investigational . . .
Evidence?
Yes / No / Maybe

39. Neurohumoral peptides
Nitric oxide, vasoactive intestinal polypeptide, substance P act as inhibitory neurotransmitters in the gut which slow gut motility.
NO knock-out mice do not get ileus after intestinal manipulation
In rats, selective antagonists to VIP, substance P improve ileus (6)

40. References