Biomedical subjects

P Kosonen

Publications and source records attributed to P Kosonen.

5 recordsLinked to original sources

PubMed2001

Effect of an acute increase in PCO2 on splanchnic perfusion and metabolism.

OBJECTIVES: To evaluate the acute effects of an increase in PCO2 on splanchnic tissue perfusion and metabolism. DESIGN: Clinical prospective study in the intensive care unit in a university clinic. PATIENTS: Six patients with severe acute lung injury requiring mechanical ventilation. All patients had bilateral infiltrates on chest radiography, a PaO2/FIO2 ratio less than 200 mmHg, and stable hemodynamics without vasoactive drugs. INTERVENTIONS: PCO2 was increased 5-20% by an added dead space from baseline, followed by a return to baseline. MEASUREMENTS AND RESULTS: Splanchnic blood flow was measured using primed continuous infusion of indocyanine green dye with hepatic venous sampling and systemic hemodynamics by routine monitoring; we also determined the gastric mucosal-arterial PCO2 difference and splanchnic lactate/pyruvate exchange. PCO2 was increased by an added dead space; after 60 min all measurements were repeated; after return to baseline a third measurement followed. The increase in PCO2 had no significant effect on splanchnic blood flow or indices of perfusion and metabolism. CONCLUSION: Our results suggest that acute moderate changes in PCO2 have no major effect on splanchnic perfusion and metabolism.

Adolescent↗

PubMed2000

Effect of positive end-expiratory pressure on splanchnic perfusion in acute lung injury.

OBJECTIVE: To evaluate the acute effects of an increased positive end-expiratory pressure (PEEP) on splanchnic tissue perfusion. DESIGN: Clinical prospective study. SETTING: Intensive care unit in a university clinic. PATIENTS: Six patients with severe acute lung injury (ALI) requiring mechanical ventilation. All patients had bilateral infiltrates in chest X-ray, PaO2/FiO2 < 200 mmHg and stable hemodynamics without vasoactive drugs. INTERVENTIONS: PEEP was increased by 5 cmH2O from a clinically selected PEEP level (8/6-11 cmH2O) up to (13/10-14 cmH2O) followed by a return to baseline. MEASUREMENTS AND MAIN RESULTS: Splanchnic blood flow was measured using primed continuous infusion of indocyanine green dye with hepatic venous sampling and systemic hemodynamics by routine monitoring. In addition, we estimated gastric mucosal-arterial PCO2 difference and splanchnic lactate/pyruvate exchange. After a baseline measurement, PEEP was increased. After 60 min all measurements were repeated. PEEP was returned to the baseline level and a third measurement followed. PEEP had no effect on cardiac index (baseline I: 3.2/6.1-2.5 l/min/m2; PEEP: 3.3/5.7-2.3 l/min/m2; baseline II: 3.4/6.0-2.5 l/min/m2); neither did PEEP have any effect on splanchnic blood flow (baseline I: 0.91/1.39-0.62 l/min/m2; PEEP: 1.04/1.75-0.54 l/min/m2; baseline II: 1.07/1.42-0.68 l/min/m2, respectively) or perfusion (gastric mucosal-arterial PCO2 difference baseline I: 2.1/12.8-0.6 kPa; PEEP: 1.7/14.5-0.7 kPa; baseline II: 1.7/8.8-0.1 kPa; lactate uptake baseline I: 0.5/1.1-0.3 mmol/min/m2; PEEP: 0.4/1.0-0.3 mmol/min/m2; baseline II: 0.5/0.9-0.3 mmol/min/m2; hepatic venous lactate/pyruvate baseline I: 9.7/10.6-5.7; PEEP: 9.7/14.2-6.4; baseline II: 8.4/12.4-7.3; respectively). CONCLUSION: PEEP by itself does not have a consistent effect on splanchnic blood flow and metabolism when cardiac index is stable and patients are ventilated within the linear part of the pv curve.

Acute Disease↗

PubMed1999

The Haldane effect--an alternative explanation for increasing gastric mucosal PCO2 gradients?

When venous oxygen saturation increases as a result of increased blood flow, changes in venous blood PCO2 and carbon dioxide content may differ because of the Haldane effect. The Haldane effect may also explain increases in gastric mucosal-arterial PCO2 gradient despite major increases in splanchnic blood flow. We re-analysed data from 22 patients after cardiac surgery who were randomized to receive either dobutamine or placebo, and a separate group of patients who received dobutamine for low cardiac output (n = 6). Three different values of gastric mucosal oxygen extraction at baseline were assumed (0.3, 0.5 and 0.7). In nine of 14 patients with both increasing splanchnic blood flow and mucosal-arterial PCO2 gradient, an equal increase in mucosal and total splanchnic blood flow, oxygen consumption and carbon dioxide production together with the Haldane effect would have caused an increase in mucosal-arterial PCO2 gradients from a mean value of 0.53 (SD 0.88) kPa at baseline to 0.68-0.82 (0.89-0.90) kPa (P < 0.01). In the remaining patients, disproportionate changes in flow and metabolism must have been involved in addition to the Haldane effect. We conclude that whenever major changes in mucosal tissue oxygen extraction are likely to occur, an increase in the mucosal-arterial PCO2 gradient may be explained in part or completely by the Haldane effect, and may therefore not reflect worsening perfusion.

Carbon Dioxide↗

PubMed1997

Venoarterial CO2 gradient after cardiac surgery: relation to systemic and regional perfusion and oxygen transport.

The difference in CO2 tension between venous and arterial blood (delta PCO2) increases in low-flow states. Therefore, delta PCO2 has been suggested as an additional variable in the monitoring of perfusion. We measured CO2 tensions in arterial, mixed venous, hepatic venous, and femoral venous blood in 42 postoperative cardiac surgery patients. Splanchnic and leg blood flow was measured with dye dilution. Forty-three preoperative abdominal surgery patients served as controls. Systemic and femoral delta PCO2 was increased in cardiac patients, whereas there was no difference in splanchnic delta PCO2 between the groups. In cardiac patients, systemic delta PCO2 correlated well with both splanchnic and femoral delta PCO2 (r2 = .74 and r2 = .56, respectively). Femoral delta PCO2 was higher than splanchnic delta PCO2 (1.27 +/- .44 kPa versus .66 +/- .41; p < .001) after cardiac surgery, but not in the control group. The correlation between delta PCO2 and respective blood flow was weak in the whole body, the splanchnic region, and the leg. When splanchnic blood flow was low, systemic and splanchnic delta PCO2 varied widely. In the cardiac patients with an increased systemic delta PCO2 (> .93 kPa), systemic and regional blood flow was low, but there were no differences in systemic or regional oxygen consumption or lactate levels. After cardiac surgery, high systemic delta PCO2 is associated with marginal systemic and regional perfusion. The adequacy of regional blood flow cannot be assessed on the basis of the systemic delta PCO2.

Arteries↗

PubMed1995

The long-term outcome after negative appendix operation.

We evaluated the long-term outcome of "negative appendix" (NA) by analysing the follow-up results of 76 patients identified from a group of 670 appendectomized patients. Randomly selected and histologically proven cases of true acute appendicitis (TA) matched for age and sex were identified to construct case control pairs. Special interest was focused on gender and age, by analysing the results separately in men and women in two age groups (15-39 years and > or = 40 years). The results showed that NA was most common in women aged 15-39 years (21% of appendectomized cases in this age group). At follow-up examination after a mean follow-up of 2.9 years two-thirds of patients were symptomfree. Women aged 15-39 years had significantly more complaints (P < 0.05) and findings (P < 0.05) than patients with TA. In women aged > or = 40 years no significant differences were detected, nor in either age groups in men. Lactose intolerance was the most common finding in symptomatic patients. In conclusion, patients with NA were mostly young women. At long-term follow-up the great majority of patients were symptomfree and appeared not to have developed any serious disease. Routine follow-up for patients with NA does not thus seem necessary.

Adolescent↗