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Myoelectric assessment of bowel viability
October
ABSTRACTS
1986
MYOELECTRIC ASSESSMENT OF BOWEL VIABILITY. R.E. Brolin, J.L. Seamlow R.A. Koch. W.T. Reddell. B.A. Mast, J.W. Mackenzie -0 Dept.of Surgery, DMDNJ-Rutgers Medical School, CN 19, New Brunswick, NJ 08903. There are no reliable objective methods available for We designed a device clinical diagnosis of bowel viability. capable of quantitative measurement of intestinal ischenic damage. The device employs a clip-on strain gauge probe that delivers a precisely controlled electrical stimulus. Threshold stimulus level (TSL) is the stimulus current in qilliamps (mA) necessary to produce a clearly defined smooth muscle contraction. TSL was used to establish viability boundaries in ischemlc bowel segments in 30 dogs. Bowel viability was assessed using TSL compared with gross features (color. peristalsis) and Doppler ultrasound at 2ca intervals in normal and ischemic small bowel. Doppler readings were taken from the bowel wall (BW) and marginal artery (MA) at TSL ranged from a low of 22 + 2nA in each 2cn interval. normal howeJ (outside ischemic segment) to 97 2 4mA in necrotic bowel. Resection and anastomosis was perforred in 3 groups of 10 dogs at TSL measurements of 3OmA, 40mA and 50mA Dogs were killed on the 10th postop day. respectively. Table shows correlations between gross features and Doppler data at each TSL. LASTI+IDOPPLER VISIBLE PERISTALSIS iN’MA 17/20* 3omA 12/20*
TSL
40nA 50mA
13/20* 8/20*
8/20* f3/20*
COLOR
ANASTOMOTIC
PINK DUSKY u 7 13 5
9
6
11
9
j&& o/10 l/IO
4/10 (P(O.04) were
N =20*: two observations per dog as measurements taken from proximal and distal ends of each ischemic segment. At TSL= 30aA. Doppler signal was present in 17/20 (MA) cases, peristalsis observed in 12/20. color pink in 7. dusky in remaining 13, etc. The number of leaks at TSL= 50mA was significantly greater than at TSL=30mA by Fisher’s exact test. These results show that the quantitative nyoelectric parameters established by this device provide a reliable in viva assessment of bowel viability. The device is easy to use and may have clinical applicability.
DIFFERENTIAL EFFECTS OF PGEZ ON MYOELECTRIC AND CONTRACTILE ACTIVITY OF THE COLON IN IN VIVO RABBIT MODEL. R. Burakoff, &. Braunstein, M. Aaronson, B. Ganek, P. Gannon. University Hospital, Boston, MA. Variable effects of PGEZ have been reported on the motility of the colon. The purpose of this study was to determine the effect of PGEZ on the contractility and myoelectric activity of the colon in an in viva rabbit model. Methods: 4-5 kg New Zealand White rabbits fasted for 24 hours, were anesthetized with ketamine and pentobarbital. Arterial line placed above level of the SMA and BP and respiration monitored. Bipolar electrodes and strain gages were sutured to distal and proximal colon and oriented to the circular muscle. Doses of PGEZ from 0.1 to 0.8 uglkglmin. infused intraarterially in different experiments for 30 min. Signals recorded on a Beckman R611 and a FM tape recorder. Data analyzed for spikes potentials, electrical slow wave frequency and change in contractility visually and by compResults: The baseline recordings of the myouter programs. electric activity revealed a regular slow wave pattern without prolonged spontaneous spike bursts from the proximal colon whereas the distal colon exhibited an irregular slow wave pattern with spontaneous spike bursts occurring periDistal colon: 1. With increasing doses of PGE2 odically. there was a statistically significant increase in the 2. There was a statistically number of spike potentials. significant increase in slow wave frequency with increas3. With increasing doses of PGE2 there ing doses of PGEP. was a statistically significant increase in the number of propagating contractions associated with diarrhea1 movements Proximal colon: The lowest dose 0.1 uglkglmin. resulted in a statistically significant decrease in spike potentials. HOWeVer,with the highest dose infused of 0.8ug/kg/min. there was a statistically significant increase in spike At all doses no propagating contractions were potentials. noted during the recording period (6 hours). Conclusion: PGE2 have differential effects on the myoelectric activity and contractility of the proximal and distal colon. This may indicate a predominant inhibitory effect on the proximal circular smooth muscle and predominant stimulatory effect on longitudinal muscle of the distal colon.
OF PAPERS
1047
EFFECT OF INDOMETHACIN AND PGF2 ON ILEAL AND COLONIC MOTILITY IN AN IN VIVO RABBIT MODEL. R. Burakoff, E. Nastos, M. Aaronson, P. Gannon, S. Won. University Hospital, Boston, Winthrop-University Hospital, New York. Introduction: Prostaglandin F20( (PGFZa ) has been shown to increase contractility of colonic muscle in vitro and may h important in regulating colonic motility. Indomethacin has a variable effect on intestinal motility, but its effect on colonic motility in viva has not been studied. Purpose: To determine the effects of PGF2d and indomethacin on ileal, proximal and distal colonic motility in an in vivo rabbit model. Methods: 4-5 kg New Zealand White rabbits are anesthetized with pentobarbital and ketamine. Arterial line is placed above the level of the SMA to record BP and infuse drugs. Bipolar electrodes are sewn onto the serosa of the bowel. Signals recorded on Beckman R611 and FM rape and analyzed for spike potentials. Results: Terminal ileum: In the arterial infusion of PGF2a with 0.5 to 4.0 ((g/kg/min. for 30 min. resulted in increased spike potentials at all doses but the effect was greatest at 0.5 and i.Oug. IV bolus of 5 mg/kg@ indomethacin also increased spike potential. Proximal colon: 0.5ug and l.Oxg of IA PGF2a increased spike potentials but 2.0 and 4.0 ug significantly decreased spike potentials. IV bolus indomethacin increased spike potentials and reversed the inhibitory effect of PGFZo( . Distal colon: 0.5 to 4.0 xg IA infusion of PGF2a. resulted in an increased of spike potentials at all doses. IV indomethacin significantly'decrkased spike potentials and inhibited the increase of spike potentials 2' to PGF2cx . an increase in myoelectric activity summary : 1. PGF2gcauses of the ileum and colon. However, high dose PGF2a( resulted in inhibition of spike potentials in the proximal colon. 2. IV infusion of indomethacin resulted in increase myoelectrical activity in the ileum and proximal colon. 3. IV indomethatin reversed the effect of PGF2d on the colon but not the terminal ileum. Conclusion: Intravenous infusion of indomethacin at a dose that inhibits endogenous synthesis of PG modulates myoelectric activity in the ileum and colon in viva. PGF2c.xalso modulates ileal and colonic myoelectric activity. Since, in the colon, indomethacin antagonizes the effect of exogenousPGF2R thiseffectisn't rtodepletioncfmdog. FG'S.
POST-PRANDIAL COLONIC SPIKE POTENTIAL ACTIVITY IN THE INFANT RHESUS PRIMATE SIMULATES ADULT PATTERNS. Robert Cannon, Julie Mathews and Anthony Cheung. of Pediatrics, Univ. of California, Davis and Dept. CalIf. Primate Research Center, Davis, California. Developmental changes in gastrointestinal motility during infancy are poorly understood in the human. We have utilized the infant rhesus primate as a model to study responses of the distal colon to enteral feeding. 6 infant rhesus (ages: 4-7 mos) and 6 adult rhesus primates were studied following administration of ketamlne for immobilization. Colonic slow wave activity and spike potentials were obtalned from an intraluminal Ag-AgCI bipolar electrode pair (spacing: 1.5 mm) afixed to mucosa by suction. Myosleclric activity was recorded using a Beckman R511 recording system with 0.16 Hz to 30 Hz bandpass filtering. Followlng a 6 to 8 hour fast and 10 mln of stable baseline recordings, a standard liquid meal (6.7 Cal/kg: 1.5% pro, 3.8% fat, 6.9% CHO) of was admlnistercd via a nasogasrric tube. Spike activity was visually quantitatad from spike potentials superimposed on recorded slow wave signals. The results in each group of were expressed as mean # spikes / 5 minute recording interval to facilitate 1) both infant and adult animals comparison. Results: responded to meal stimulation with increased colonic spiking. 2) the time period of maximal spike activity was lo-15 minutes post-prandial In all animals. 3) spike activity returned to near baseline values by 30 to 40 minures in both groups. Conclusions: Rhesus primate5 manifest increases In meal stimulated colonic motility similar to human adults. In this modal, infantile responses arc identical to adult patterns, suggesting early maturation of colonic responses to feeding. This response has direct application to developmental gastrointestinal motility in the human infant.
ABSTRACTS
1986
MYOELECTRIC ASSESSMENT OF BOWEL VIABILITY. R.E. Brolin, J.L. Seamlow R.A. Koch. W.T. Reddell. B.A. Mast, J.W. Mackenzie -0 Dept.of Surgery, DMDNJ-Rutgers Medical School, CN 19, New Brunswick, NJ 08903. There are no reliable objective methods available for We designed a device clinical diagnosis of bowel viability. capable of quantitative measurement of intestinal ischenic damage. The device employs a clip-on strain gauge probe that delivers a precisely controlled electrical stimulus. Threshold stimulus level (TSL) is the stimulus current in qilliamps (mA) necessary to produce a clearly defined smooth muscle contraction. TSL was used to establish viability boundaries in ischemlc bowel segments in 30 dogs. Bowel viability was assessed using TSL compared with gross features (color. peristalsis) and Doppler ultrasound at 2ca intervals in normal and ischemic small bowel. Doppler readings were taken from the bowel wall (BW) and marginal artery (MA) at TSL ranged from a low of 22 + 2nA in each 2cn interval. normal howeJ (outside ischemic segment) to 97 2 4mA in necrotic bowel. Resection and anastomosis was perforred in 3 groups of 10 dogs at TSL measurements of 3OmA, 40mA and 50mA Dogs were killed on the 10th postop day. respectively. Table shows correlations between gross features and Doppler data at each TSL. LASTI+IDOPPLER VISIBLE PERISTALSIS iN’MA 17/20* 3omA 12/20*
TSL
40nA 50mA
13/20* 8/20*
8/20* f3/20*
COLOR
ANASTOMOTIC
PINK DUSKY u 7 13 5
9
6
11
9
j&& o/10 l/IO
4/10 (P(O.04) were
N =20*: two observations per dog as measurements taken from proximal and distal ends of each ischemic segment. At TSL= 30aA. Doppler signal was present in 17/20 (MA) cases, peristalsis observed in 12/20. color pink in 7. dusky in remaining 13, etc. The number of leaks at TSL= 50mA was significantly greater than at TSL=30mA by Fisher’s exact test. These results show that the quantitative nyoelectric parameters established by this device provide a reliable in viva assessment of bowel viability. The device is easy to use and may have clinical applicability.
DIFFERENTIAL EFFECTS OF PGEZ ON MYOELECTRIC AND CONTRACTILE ACTIVITY OF THE COLON IN IN VIVO RABBIT MODEL. R. Burakoff, &. Braunstein, M. Aaronson, B. Ganek, P. Gannon. University Hospital, Boston, MA. Variable effects of PGEZ have been reported on the motility of the colon. The purpose of this study was to determine the effect of PGEZ on the contractility and myoelectric activity of the colon in an in viva rabbit model. Methods: 4-5 kg New Zealand White rabbits fasted for 24 hours, were anesthetized with ketamine and pentobarbital. Arterial line placed above level of the SMA and BP and respiration monitored. Bipolar electrodes and strain gages were sutured to distal and proximal colon and oriented to the circular muscle. Doses of PGEZ from 0.1 to 0.8 uglkglmin. infused intraarterially in different experiments for 30 min. Signals recorded on a Beckman R611 and a FM tape recorder. Data analyzed for spikes potentials, electrical slow wave frequency and change in contractility visually and by compResults: The baseline recordings of the myouter programs. electric activity revealed a regular slow wave pattern without prolonged spontaneous spike bursts from the proximal colon whereas the distal colon exhibited an irregular slow wave pattern with spontaneous spike bursts occurring periDistal colon: 1. With increasing doses of PGE2 odically. there was a statistically significant increase in the 2. There was a statistically number of spike potentials. significant increase in slow wave frequency with increas3. With increasing doses of PGE2 there ing doses of PGEP. was a statistically significant increase in the number of propagating contractions associated with diarrhea1 movements Proximal colon: The lowest dose 0.1 uglkglmin. resulted in a statistically significant decrease in spike potentials. HOWeVer,with the highest dose infused of 0.8ug/kg/min. there was a statistically significant increase in spike At all doses no propagating contractions were potentials. noted during the recording period (6 hours). Conclusion: PGE2 have differential effects on the myoelectric activity and contractility of the proximal and distal colon. This may indicate a predominant inhibitory effect on the proximal circular smooth muscle and predominant stimulatory effect on longitudinal muscle of the distal colon.
OF PAPERS
1047
EFFECT OF INDOMETHACIN AND PGF2 ON ILEAL AND COLONIC MOTILITY IN AN IN VIVO RABBIT MODEL. R. Burakoff, E. Nastos, M. Aaronson, P. Gannon, S. Won. University Hospital, Boston, Winthrop-University Hospital, New York. Introduction: Prostaglandin F20( (PGFZa ) has been shown to increase contractility of colonic muscle in vitro and may h important in regulating colonic motility. Indomethacin has a variable effect on intestinal motility, but its effect on colonic motility in viva has not been studied. Purpose: To determine the effects of PGF2d and indomethacin on ileal, proximal and distal colonic motility in an in vivo rabbit model. Methods: 4-5 kg New Zealand White rabbits are anesthetized with pentobarbital and ketamine. Arterial line is placed above the level of the SMA to record BP and infuse drugs. Bipolar electrodes are sewn onto the serosa of the bowel. Signals recorded on Beckman R611 and FM rape and analyzed for spike potentials. Results: Terminal ileum: In the arterial infusion of PGF2a with 0.5 to 4.0 ((g/kg/min. for 30 min. resulted in increased spike potentials at all doses but the effect was greatest at 0.5 and i.Oug. IV bolus of 5 mg/kg@ indomethacin also increased spike potential. Proximal colon: 0.5ug and l.Oxg of IA PGF2a increased spike potentials but 2.0 and 4.0 ug significantly decreased spike potentials. IV bolus indomethacin increased spike potentials and reversed the inhibitory effect of PGFZo( . Distal colon: 0.5 to 4.0 xg IA infusion of PGF2a. resulted in an increased of spike potentials at all doses. IV indomethacin significantly'decrkased spike potentials and inhibited the increase of spike potentials 2' to PGF2cx . an increase in myoelectric activity summary : 1. PGF2gcauses of the ileum and colon. However, high dose PGF2a( resulted in inhibition of spike potentials in the proximal colon. 2. IV infusion of indomethacin resulted in increase myoelectrical activity in the ileum and proximal colon. 3. IV indomethatin reversed the effect of PGF2d on the colon but not the terminal ileum. Conclusion: Intravenous infusion of indomethacin at a dose that inhibits endogenous synthesis of PG modulates myoelectric activity in the ileum and colon in viva. PGF2c.xalso modulates ileal and colonic myoelectric activity. Since, in the colon, indomethacin antagonizes the effect of exogenousPGF2R thiseffectisn't rtodepletioncfmdog. FG'S.
POST-PRANDIAL COLONIC SPIKE POTENTIAL ACTIVITY IN THE INFANT RHESUS PRIMATE SIMULATES ADULT PATTERNS. Robert Cannon, Julie Mathews and Anthony Cheung. of Pediatrics, Univ. of California, Davis and Dept. CalIf. Primate Research Center, Davis, California. Developmental changes in gastrointestinal motility during infancy are poorly understood in the human. We have utilized the infant rhesus primate as a model to study responses of the distal colon to enteral feeding. 6 infant rhesus (ages: 4-7 mos) and 6 adult rhesus primates were studied following administration of ketamlne for immobilization. Colonic slow wave activity and spike potentials were obtalned from an intraluminal Ag-AgCI bipolar electrode pair (spacing: 1.5 mm) afixed to mucosa by suction. Myosleclric activity was recorded using a Beckman R511 recording system with 0.16 Hz to 30 Hz bandpass filtering. Followlng a 6 to 8 hour fast and 10 mln of stable baseline recordings, a standard liquid meal (6.7 Cal/kg: 1.5% pro, 3.8% fat, 6.9% CHO) of was admlnistercd via a nasogasrric tube. Spike activity was visually quantitatad from spike potentials superimposed on recorded slow wave signals. The results in each group of were expressed as mean # spikes / 5 minute recording interval to facilitate 1) both infant and adult animals comparison. Results: responded to meal stimulation with increased colonic spiking. 2) the time period of maximal spike activity was lo-15 minutes post-prandial In all animals. 3) spike activity returned to near baseline values by 30 to 40 minures in both groups. Conclusions: Rhesus primate5 manifest increases In meal stimulated colonic motility similar to human adults. In this modal, infantile responses arc identical to adult patterns, suggesting early maturation of colonic responses to feeding. This response has direct application to developmental gastrointestinal motility in the human infant.