Gastric tonometry: in vivo comparison of saline and air tonometry in patients with cardiogenic shock.

Measurement of gastric intramucosal pH (pHi) has been advocated to assess gastric perfusion. Regional PCO2 (rPCO2) values are measured using saline tonometry (rsPCO2) and more recently using air tonometry (raPCO2). We compared 237 measurements of saline and air tonometry in 19 consecutive, severely ill patients (mean age 59 (range 31-76) yr, 19 males, APACHE II 22 +/- 7) with cardiogenic shock. Equilibration period was set to 90 min. Nineteen independent paired samples of mean raPCO2 and mean rsPCO2 of each patient showed good correlation (r = 0.93, P < 0.001). Mean raPCO2 was 6.5 (1.8) kPa and mean rsPCO2 6.8 (2.4) kPa. PCO2 measured by saline was significantly higher than that measured by air (P < 0.05). Bland and Altman analysis showed a bias (mean rsPCO2-mean raPCO2) of 0.3 kPa and a precision of 1.2 kPa. Agreement between the two methods decreased with increasing rPCO2 concentrations. Although air tonometry of rPCO2 is a promising technique, a systematic disagreement with saline tonometry at high rPCO2 values requires further investigation and cautious interpretation of these values.

[1]  J. Vincent,et al.  Monitoring Gastric Mucosal Carbon Dioxide Pressure Using Gas Tonometry: In Vitro and in Vivo Validation Studies , 1997, Anesthesiology.

[2]  I. Jousela,et al.  Validation of air tonometric measurement of gastric regional concentrations of CO2 in critically ill septic patients , 1997, Intensive Care Medicine.

[3]  S. Mostafa,et al.  pHi: a review of the literature , 1996 .

[4]  G. Settergren,et al.  Dopexamine and dopamine in the prevention of low gastric mucosal pH following cardiopulmonary by-pass. , 1995, Acta anaesthesiologica Scandinavica.

[5]  G. Knichwitz,et al.  Improved P CO2 measurement in six standard blood gas analysers using a phosphate‐buffered solution for gastric tonometry , 1995, Anaesthesia.

[6]  R. Fiddian-Green.  Gastric intramucosal pH, tissue oxygenation and acid-base balance. , 1995, British journal of anaesthesia.

[7]  J. Fee,et al.  Correction of Splanchnic Oxygen Deficit in the Intensive Care Unit: Dopexamine and Colloid versus Placebo , 1995, Anaesthesia and intensive care.

[8]  P. Marik,et al.  The contrasting effects of dopamine and norepinephrine on systemic and splanchnic oxygen utilization in hyperdynamic sepsis. , 1994, JAMA.

[9]  E. Ruokonen,et al.  Saline Pco2 is an important source of error in the assessment of gastric intramucosal pH , 1994, Critical care medicine.

[10]  J. Bion,et al.  Measuring carbon dioxide tension in saline and alternative solutions: Quantification of bias and precision in two blood gas analyzers , 1994, Critical care medicine.

[11]  A. Webb,et al.  Postoperative multiple organ dysfunction syndrome associated with gut mucosal hypoperfusion, increased neutrophil degranulation and C1-esterase inhibitor depletion. , 1993, British journal of anaesthesia.

[12]  P. Lawler,et al.  Potential hazards in estimation of gastric intramucosal pH , 1992, The Lancet.

[13]  J. Bion,et al.  Potential hazards in estimation of gastric intramucosal pH , 1992, The Lancet.

[14]  M. H. Lee.  Gastric mucosal pH as a prognostic index of mortality in critically ill patients. , 1992, Critical care medicine.

[15]  G. Gutierrez,et al.  Comparison of gastric intramucosal pH with measures of oxygen transport and consumption in critically ill patients , 1992, Critical care medicine.

[16]  A. Dubin,et al.  Gastric intramucosal pH as a therapeutic index of tissue oxygenation in critically ill patients , 1992, The Lancet.

[17]  S. Baker,et al.  Predictive value of the stomach wall pH for complications after cardiac operations: comparison with other monitoring. , 1987, Critical care medicine.

[18]  S. Baker,et al.  Prediction of the development of sigmoid ischemia on the day of aortic operations. Indirect measurements of intramural pH in the colon. , 1986, Archives of surgery.

[19]  D. Altman,et al.  STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT , 1986, The Lancet.

[20]  G. Pittenger,et al.  Predictive value of intramural pH and other risk factors for massive bleeding from stress ulceration. , 1983, Gastroenterology.

[21]  G. Pittenger,et al.  Back-diffusion of CO2 and its influence on the intramural pH in gastric mucosa. , 1982, The Journal of surgical research.