title: Validation of an acoustic gastrointestinal surveillance biosensor for postoperative ileus.
abstract: BACKGROUND
  Postoperative ileus (POI) can worsen outcomes, increase cost, and prolong hospitalization. An objective marker could help identify POI patients who should not be prematurely fed. We developed a disposable, non-invasive acoustic gastro-intestinal surveillance (AGIS) biosensor. We tested whether AGIS can distinguish healthy controls from patients recovering from abdominal surgery.
  
  
  METHODS
  AGIS is a disposable plastic device embedded with a microphone that adheres to the abdominal wall and connects to a computer that measures acoustic event rates. We compared intestinal rates of healthy subjects using AGIS for 60 min after a standardized meal to recordings of two postoperative groups: (1) patients tolerating standardized feeding and (2) POI patients. We compared intestinal rates among groups using ANOVA and t tests.
  
  
  RESULTS
  There were 8 healthy controls, 7 patients tolerating feeding, and 25 with POI; mean intestinal rates were 0.14, 0.03, and 0.016 events per second, respectively (ANOVA p < 0.001). AGIS separated patients from controls with 100 % sensitivity and 97 % specificity. Among patients, rates were higher in fed versus POI subjects (p = 0.017).
  
  
  CONCLUSIONS
  Non-invasive, abdominal acoustic monitoring distinguishes POI from non-POI subjects. Future research will test whether AGIS can identify patients at risk for development of POI and assist with postoperative feeding decisions.
authors.affiliation: Department of Medicine, VA Greater Los Angeles Healthcare System, Los Angeles, USA, bspiegel@mednet.ucla.edu.
authors.forename: Brennan M R
authors.initials: BM
authors.lastname: Spiegel
authors.forename: Marc
authors.initials: M
authors.lastname: Kaneshiro
authors.forename: Marcia M
authors.initials: MM
authors.lastname: Russell
authors.forename: Anne
authors.initials: A
authors.lastname: Lin
authors.forename: Anish
authors.initials: A
authors.lastname: Patel
authors.forename: Vartan C
authors.initials: VC
authors.lastname: Tashjian
authors.forename: Vincent
authors.initials: V
authors.lastname: Zegarski
authors.forename: Digvijay
authors.initials: D
authors.lastname: Singh
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Cohen
authors.forename: Mark W
authors.initials: MW
authors.lastname: Reid
authors.forename: Cynthia B
authors.initials: CB
authors.lastname: Whitman
authors.forename: Jennifer
authors.initials: J
authors.lastname: Talley
authors.forename: Bibiana M
authors.initials: BM
authors.lastname: Martinez
authors.forename: William
authors.initials: W
authors.lastname: Kaiser
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000328:Adult; D000368:Aged; D015374:Biosensing Techniques / Q000592:standards*; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D045823:Ileus / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D011184:Postoperative Period; D015203:Reproducibility of Results
references.citation: Cochrane Database Syst Rev. 2006 Oct 18;(4):CD004080
references.pmid: 17054196
references.citation: Gastroenterology. 1999 Aug;117(2):489-92
references.pmid: 10419931
references.citation: J Manag Care Pharm. 2009 Jul-Aug;15(6):485-94
references.pmid: 19610681
references.citation: Nutr Clin Pract. 2011 Apr;26(2):115-25
references.pmid: 21447763
references.citation: J Am Coll Surg. 2007 Jul;205(1):43-51
references.pmid: 17617331
references.citation: Am J Gastroenterol. 1999 Feb;94(2):374-81
references.pmid: 10022632
references.citation: J Am Coll Surg. 2010 Feb;210(2):228-31
references.pmid: 20113944
references.citation: World J Surg. 2014 Aug;38(8):1966-77
references.pmid: 24682277
references.citation: Gastroenterology. 2009 Mar;136(3):842-7
references.pmid: 19135997
references.citation: Stroke. 2011 Aug;42(8):2246-50
references.pmid: 21636815
references.citation: IEEE J Biomed Health Inform. 2014 May;18(3):1015-25
references.pmid: 24107984
references.citation: Dig Surg. 2010;27(5):422-6
references.pmid: 20948217
references.citation: BMJ. 2001 Oct 6;323(7316):773-6
references.pmid: 11588077
references.citation: Am J Surg. 2001 Nov;182(5A Suppl):3S-10S
references.pmid: 11755891
references.citation: Medsurg Nurs. 2012 May-Jun;21(3):146-50
references.pmid: 22866434
references.citation: J Gastrointest Surg. 2009 Mar;13(3):569-75
references.pmid: 18629592
references.citation: Ther Clin Risk Manag. 2008 Oct;4(5):913-7
references.pmid: 19209273
references.citation: Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6901-5
references.pmid: 19964452
references.citation: Surg Clin North Am. 2012 Apr;92(2):259-72, viii
references.pmid: 22414412
references.citation: World J Surg. 1997 Oct;21(8):806-9; discussion 809-10
references.pmid: 9327670