Pumps
Small Bowel Enema Pump
 
MINIPULS 3 (MANDEL) FLUID FLOW RATES

This peristaltic infusion pump is used for small bowel enema and CT enteroclysis.

Flow rate selections and adjustment will determine the flow rate of liquids.
  1. Selection of Flow Rates:
     
    • This is dependent upon the tube diameter and pump speed (revolutions per minute)
    • The tube size and material will also determine the flow rate.
    • There are five flow charts with different tube sizes.
    • It is manufacturer’s suggestion to use middle range tube sizes to get a middle range speed and flow rate.

  1. Cam Pressure (Adjustment):
     
    • Adjusting the cam pressure on the tubing to a MINIMUM is necessary to ensure pumping of fluid.
    • The compression cam pressure can be adjusted using the adjustment screw.
       
    • Method:
       
      • Slowly tighten the screw until the pump starts pumping liquid inside the peristaltic tubing
      • Then tighten again approximately 1/8 of a turn.
      • Do not over tighten the screws.

 
Minipuls Infusion Pump Flow Rate - Large Tube Sizing.pdf

Minipuls Infusion Pump Flow Rate - Large Silicone Tube.pdf

 

Small bowel enema table setup

CO2 Insufflation Pump
 

Infusion pump with air filter


 

CO2 infusion pump setup


 

Colonic Insufflation - Precautions regarding Pressurized Insufflation

Cadaver Studies

  • Burt studied pneumatic rupture of the colon in cadavers found that:
    • Pressure at which colonic serosal laceration occurs depends on the location in the colon.
    • Rupture pressure ranged from 99 mmHg in the rectum to 40 mmHg in the cecum.
       
  • Kozarek et al. published similar findings with cadaver studies:
    • Serosal tearing of the colon occurred:
      • With intraluminal pressures beginning at 52 mmHg
      • The cecum requiring lowest pressure for perforation


Double Contrast Barium Enema

  • Diner et al. studied intracolonic pressures during filled column and air contrast barium enema:
    • Colonic pressure during filling with contrast ranged from 20-25 mmHg at the sigmoid to 30-33 mmHg at the ascending colon.
    • Increases in colonic pressure were reported as follows:
      • Straight leg raising resulted in pressures averaging 40-43 mmHg
      • Valsalva maneuvers 57-63 mmHg, and patient motion 43-50 mmHg
         
  • Short et al. measured the intracolonic pressure of 100 patients during double contrast enema, and found:
    • The onset of uncomfortable fullness corresponded to an average pressure of 23 mmHg.
    • Pressure levels 30 mmHg often result in unsolicited complaint of pain.
    • The onset of uncomfortable fullness, when associated with steady intracolonic pressure usually corresponds to a well-filled colon.


Colonoscopy

  • Kozarek et al. reported during colonoscopy:
    • An average sustained intraluminal pressure of 22 mmHg.
    • The maximum intraluminal pressure ranging between 34-138 mmHg.
    • Intermittent pressure increases were due to patient movement, patient performance of a Valsalva maneuver, and manual pressure of the abdomen.


Conclusion

  • An intracolonic pressure of 0-25 mmHg for colonic insufflation is consistent for a safe examination and not associated with injury to the colon. (for barium enema and colonoscopy)


References:

Burt CA. Pneumatic rupture of the intestinal canal with experimental data showing the mechanism of perforation and the pressure required. Archives of Surgery 1931;22:875-902.

Kozarek RA, Earnest DL, Silverstein ME, Smith RG. Air pressure-induced colon injury during diagnostic colonoscopy. Gastroenterology 1980; 78:7-14.

Diner WC, Patel G, Texter EC Jr., et al. Intraluminal pressure measurements during barium enema: full column vs. air contrast. Am J Roentgenol 1981;137:217-221.

Short WF. Moss G. Crowther JC. Friedman RC. Horwitz RL. Manco LG. Silk PR. Manometrically guided colon insufflation during double-contrast barium enemas. Gastrointestinal Radiology. 10(1):85-8, 1985