Assessment of Gut Mucosal Perfusion and Colonic Tissue Blood Flow During Abdominal Aortic Surgery with Gastric Tonometry and Laser Doppler Flowmetry

Abstract

The objective of this study was to investigate the effect of infrarenal aortic cross-clamping and unclamping on gut mucosal perfusion by gastric tonometry and on sigmoid colonic tissue blood flow by laser Doppler flowmetry during abdominal aortic surgery. This was a prospective before-and-after intervention comparison study in a university hospital of 8 male patients, aged 57-87, undergoing elective infrarenal abdominal aortic surgery. Each patient was pretreated with ranitidine. Following general anesthesia, a nasogastric tonometer was inserted into the stomach. The balloon of the tonometer was filled with 2.5 mL of normal saline for gas tension and pH analysis. This process was repeated before and after aortic cross-clamping and unclamping. Gastric mucosal pHi was calculated with the Henderson-Hasselbalch equation from the arterial Hco₃ and the tonometrically measured mucosal Pco₂. A laser Doppler flow probe was placed in contact with the serosa of the sigmoid colon against the mesentery after the abdomen was opened. Sigmoid colonic tissue blood flow (SCBF) was assessed by the laser Doppler flowmeter. Gastric mucosal pHi by gastric tonometry and colonic tissue blood flow by laser Doppler flowmetry were measured before and after aortic cross-clamping and unclamping. Gastric mucosal pHi decreased significantly 30 minutes after aortic cross-clamping (7.37 +0.07) (p<0.0 1), 60 minutes after aortic cross-clamping (7.39 +0.08) (p<0.05), and 30 minutes after aortic unclamping (7.37 ±0.08) (p < 0.01), compared with pHi before aortic cross-clamping (7.50 ±0.06). Gastric mucosal pHi increased to the original level 60 minutes after aortic unclamping (7.46 ±0.08). Since a gastric mucosal pH above 7.35 is considered normal, these mean values of pHi were clinically insignificant. However, gastric mucosal pHi decreased below 7.32 in 5 patients during abdominal aortic surgery. Gastric mucosal pHi decreased further to 7.30 in 1 patient following aortic cross-clamping and below 7.30 in 3 patients 30 minutes after aortic unclamping. SCBF decreased significantly after aortic cross-clamping (28.1 ±4.8 mL/min/l 100 g) compared with the value before aortic cross-clamping (51.9 ± 11.3 mL/min/l 00 g) (p<0.01). Following aortic unclamping, SCBF returned to 41.7 ±7.4 mL/min/100 g.

It is concluded that transient episodes of significant intestinal mucosal ischemia may have been encountered occasionally in patients undergoing abdominal aortic surgery, but a sigmoid

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References

1. Nakatsuka M , Gupta AK , Posner MP : The effects of fluid loading on hemodynamic changes and right ventricular function with aortic unclamping during abdominal aortic surgery. Vascular Surgery 27:282-287, 1993.

2. Shoemaker WC , Appel PL , Kramm HB , et al: Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients. Chest 94:1176-1186, 1988.

3. Dahn MS , Lang MP , Jacobs LA : Central mixed and splanchnic venous oxygen saturation monitoring. Intensive Care Med 14:373-378, 1988.

4. Gilmour DG , Aitkenhead AR , Hothersall AP , et al: The effect of hypovolemia on colonic blood flow in the dog. Br J Surg 67:82-84, 1980.

5. Davidson D , Stalcup SA : Systemic circulatory adjustments to acute hypoxia and reoxygenation in unanesthetized sheep. J Clin Invest 73:317-320, 1984.

6. Hartmann M , Montgomery A , Johnson K , et al: Tissue oxygenation in hemorrhagic shock measured as transcutaneous oxygen tension, subcutaneous oxygen tension, and gastrointestinal intramucosal pH in pigs. Crit Care Med 19:205-210, 1991.

7. Fiddian-Green RG , Amelin PM , Hermann JB , et al: Prediction of the development of sigmoid ischemia on the day of aortic operations: Indirect measurements of intramural pH in the colon. Arch Surg 121:654-660, 1986.

8. Fiddian-Green RG : Gut mucosal ischemia during cardiac surgery. Semin Thorac Cardiovasc Surg 2:389-399, 1990.

9. Soong CV , Halliday MI , Hood JH , et al: The relationship between bowel ischemia and organ impairment in elective abdominal aortic surgery repair. Br J Surg 80:517-532, 1992.

10.

10. Ivatury RR , Simon RJ , Havriliak D , et al: Gastric mucosal pH and oxygen delivery and oxygen consumption indicies in the assessment of adequacy of resuscitation after trauma: A prospective randomized study. J Trauma 39:128-134, 1995.

11.

11. Mythen MG , Webb AR : Intraoperative gut mucosal hypoperfusion is associated with increased postoperative complications and cost. Intensive Care Med 20:99-104, 1994.

12.

12. Fiddian-Green RG : Should measurements of tissue pH and P02 be included in the routine monitoring of intensive care unit patients? Crit Care Med 19:141-143, 1991.

13.

13. Gutierrez G , Brown, SD : Gastric tonometry: A new monitoring modality in the intensive care unit. J Intensive Care Med 10:34-44, 1995.

14.

14. Fiddian-Green RG : Assessment of the adequacy of mucosal oxygenation in patients with intraluminally located silicone tonometers. In: Microcirculation in Circulatory Disorders, ed. by Manage H , Zweifach BW , Messmer K . Tokyo: Springer-Verlag, 1998, pp 481-487.

15.

15. Hobson RW , Wright CB , O'Donnell JA , et al: Determination of intestinal viability by Doppler ultrasound. Arch Surg 114:165-168, 1979.

16.

16. Stein JH , Lappe DL , Bowen PD , et al: Continuous measurement of tissue blood flow by laser Doppler spectroscopy. Am J Physiol 232:H441-H448, 1977.

17.

17. Stern MD , Bowen PD , Palma R , et al: Measurement of renal cortical and medullary blood flow by laser Doppler spectroscopy in the rat. Am J Physiol 236:F80-F87, 1979.

18.

18. Kauchi Y ., Esato K , Fuzioka K , et al: Assessment of laser Doppler flowmetry during abdominal aortic aneurysmectomy. Vascular Surgery 29:371-377, 1995.

19.

19. Heard SO , Helsmoortel CM , Kent JC , et al: Gastric tonometry in healthy volunteers: Effect of ranitidine on calculated intramural pH. Crit Care Med 22:1877-1879, 1994.

20.

20. Takala J , Parvianinen I , Siloaho M , et al: Saline Pco2 is an important source of error in the assessment of gastric intramucosal pH. Crit Care Med 22:1877-1879, 1994.

21.

21. Price HL , Deutsch S , Marshall BE , et al: Hemodynamic and metabolic effects of hemorrhage in man, with particular reference to the splanchnic circulation. Circ Res 18:469-474, 1966.

22.

22. Grum CM , Fiddian-Green RG , Pittenger GL , et al: Adequacy of tissue oxygenation in intact dog intestine. J Appl Physiol 56:1065-1069, 1984.

23.

23. Michie HR , Guillous PJ , Wilmore DW : Tumor necrosis factor and bacterial sepsis. Br J Surg 76:670-671, 1989.

24.

24. Movat HZ , Cybulsky MI , Colditz IG , et al: Acute inflammation in gram-negative infection: Endotoxin, interleukin 1, tumor necrosis factor, and neutrophils. Fed Proc 46:97-104, 1987.

25.

25. Fink MP : Gastrointestinal mucosal injury in experimental models of shock, trauma, and sepsis. Crit Care Med 19:627-641, 1991.

26.

26. Fiddian-Green RG , Baker S : Predictive value of the stomach wall pH for complications after cardiac operations: Comparison with other monitoring. Crit Care Med 15:153-156, 1987.

27.

27. Kuttila K , Niinikoski J , Hagland U : Visceral and peripheral tissue perfusion after cardiac surgery. Scand J Thorac Cardiovasc Surg 25:57-62, 1991.

28.

28. Diebel LN , Dulchavasky SA , Wilson RF : Effect of increased intra-abdominal pressure on mesenteric arterial and intestinal mucosal blood flow. J Trauma 33:45-48, 1992.

29.

29. Porter JM , Sussman MS , Bulkly GB : Splanchnic vasospasm in circulatory shock. In: Splanchnic Ischemia and Multiple Organ Failure, ed. by Marston A , Bulkly GB , Fiddian-Green RG . London: Edward Arnold, 1989, pp 73-88.

30.

30. Fiddian-Green RG : A sensitive and specific diagnosis test for intestinal ischemia using silastic tonometers. Eur Surg Res 62:32-32, 1984.

31.

31. Schwartz LB , Gewertz BL : The renal response to low dose dopamine. J Surg Res 45:574-579, 1988.