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E Ruokonen

Publications and source records attributed to E Ruokonen.

At least 37 records · Page 2Linked to original sources
PubMed2000

A prospective, randomized study of goal-oriented hemodynamic therapy in cardiac surgical patients.

UNLABELLED: Organ dysfunction and multiple organ failure are the main causes of prolonged hospital stay after cardiac surgery, which increases resource use and health care costs. Increased levels of oxygen delivery and consumption are associated with improved outcome in different groups of postoperative patients. Cardiac surgical patients are at risk of inadequate perioperative oxygen delivery caused by extracorporeal circulation and limited cardiovascular reserves. The purpose of our study was to test whether increasing oxygen delivery immediately after cardiac surgery would shorten hospital and intensive care unit (ICU) stay. Four hundred three elective cardiac surgical patients were enrolled in the study and randomly assigned to either the control or the protocol group. Goals of the protocol group were to maintain SvO(2) >70% and lactate concentration < or =2.0 mmol/L from admission to the ICU and up to 8 h thereafter. Hemodynamics, oxygen transport data, and organ dysfunctions were recorded. The median hospital stay was shorter in the protocol group (6 vs 7 days, P < 0.05), and patients were discharged faster from the hospital than those in the control group (P < 0.05). Discharge from the ICU was similar between groups (P = 0. 8). Morbidity was less frequent at the time of hospital discharge in the protocol group (1.1% vs 6.1%, P < 0.01). Increasing oxygen delivery to achieve normal SvO(2) values and lactate concentration during the immediate postoperative period after cardiac surgery can shorten the length of hospital stay. IMPLICATIONS: Health care economics has challenged clinicians to reduce costs and improve resource use in cardiac surgery and anesthesia in a patient population increasing in age and in severity of disease. Optimizing cardiovascular function to maintain adequate oxygen delivery during the immediate postoperative period after cardiac surgery can decrease morbidity and reduce length of hospital stay.

Cardiac Surgical Procedures↗
PubMed2000

Time-pattern of lactate and lactate to pyruvate ratio in the first 24 hours of intensive care emergency admissions.

Blood lactate elevation in critically ill patients commonly is taken as a sign of impaired tissue perfusion. Simultaneous elevation of lactate to pyruvate ratio (L/P ratio) may be helpful in discriminating between different mechanisms of hyperlactatemia and thus in determining the relevance of the finding. We studied prospectively the prevalence and the time pattern of hyperlactatemia and simultaneous L/P ratio elevation in 98 consecutive emergency admission patients in a 23-bed surgical-medical University Hospital intensive care unit. Blood lactate, L/P ratio, and blood gases were measured at 2-h intervals during the initial 24 h of intensive care unit admission. Hyperlactatemia (blood lactate over 2 mmol/L) was found in 48 (49%) patients, and the median peak value of the non-survivors was higher than that of the survivors [5.3 (interquartile range 1.9-7.5) vs. 1.9 (1.3-2.9) mmol/L, respectively, p = 0.003]. Hyperlactatemia at admission (n = 31) was associated with a higher hospital mortality than hyperlactatemia developing later (n = 17) (29.0% vs. 5.9%, P = 0.003). Sustained admission hyperlactatemia (>6 h) was associated with higher mortality than short-lasting hyperlactatemia (36.8% vs. 0%, P = 0.008). Simultaneously elevated L/P ratio (L/P ratio > 18; n = 16) was associated with higher mortality than hyperlactatemia with normal L/P ratio (n = 32; 37.5% vs. 12.5%, respectively, P = 0.03) and was found mainly in patients who had severe circulatory failure. The hyperlactatemia of patients with sepsis was not associated with L/P ratio elevation. We conclude that hyperlactatemia is common in emergency admission patients. Hyperlactatemia with L/P ratio elevation and lactic acidosis is likely to be associated with inadequate tissue perfusion. Hyperlactatemia persisting more than 6 h and simultaneous elevation of L/P ratio are associated with increased mortality.

APACHE↗
PubMed2000

Dangers of growth hormone therapy in critically ill patients.

Prolonged stay of patients is the major challenge for modern intensive care because of its effects on morbidity and resource utilization. Severe trauma or infection are associated with the catabolic response, characterized by increased protein turnover and negative nitrogen balance. Severe catabolism leads to end-organ dysfunction and muscular weakness prolonging the need for mechanical ventilation. Catabolism cannot be prevented with standard parenteral or enteral nutritional formulas. In order to prevent the complications of catabolism in intensive care patients, recombinant growth hormone (rhGH) has been applied during two decades as an experimental therapy for patients requiring parenteral nutrition and for those with respiratory failure. Administration of rhGH has resulted in positive nitrogen balance, and studies in mechanically ventilated patients suggest that it may shorten the need for ventilatory support. In contrast to the results of these relatively small studies, a recent multinational randomized controlled trial revealed that the administration of rhGH (with doses 10-20 times higher than those used for replacement therapy) increases the mortality of critically ill patients. This excessive mortality in patients treated with rhGH was related to infections and development of multiple organ failure. Administration of high doses of rhGH to critically ill patients cannot thus be recommended.

APACHE↗
PubMed1999

Increased mortality associated with growth hormone treatment in critically ill adults.

BACKGROUND: The administration of growth hormone can attenuate the catabolic response to injury, surgery, and sepsis. However, the effect of high doses of growth hormone on the length of stay in intensive care and in the hospital, the duration of mechanical ventilation, and the outcome in critically ill adults who are hospitalized for long periods is not known. METHODS: We carried out two prospective, multicenter, double-blind, randomized, placebo-controlled trials in parallel involving 247 Finnish patients and 285 patients in other European countries who had been in an intensive care unit for 5 to 7 days and who were expected to require intensive care for at least 10 days. The patients had had cardiac surgery, abdominal surgery, multiple trauma, or acute respiratory failure. The patients received either growth hormone (mean [+/-SD] daily dose, 0.10 +/- 0.02 mg per kilogram of body weight) or placebo until discharge from intensive care or for a maximum of 21 days. RESULTS: The in-hospital mortality rate was higher in the patients who received growth hormone than in those who did not (P<0.001 for both studies). In the Finnish study, the mortality rate was 39 percent in the growth hormone group, as compared with 20 percent in the placebo group. The respective rates in the multinational study were 44 percent and 18 percent. The relative risk of death for patients receiving growth hormone was 1.9 (95 percent confidence interval, 1.3 to 2.9) in the Finnish study and 2.4 (95 percent confidence interval, 1.6 to 3.5) in the multinational study. Among the survivors, the length of stay in intensive care and in the hospital and the duration of mechanical ventilation were prolonged in the growth hormone group. CONCLUSIONS: In patients with prolonged critical illness, high doses of growth hormone are associated with increased morbidity and mortality.

Adolescent↗
PubMed1999

Procalcitonin concentrations in patients with neutropenic fever.

To assess the usefulness of markers of inflammation in distinguishing bacterial infection from severe systemic nonbacterial inflammation, concentrations of procalcitonin, neopterin, endotoxin, tumor necrosis factor, and interleukin-6 were measured in 28 neutropenic patients at the onset of fever and twice thereafter at 4 h intervals. Infection was found in 11 patients, and 17 patients had fever of undetermined origin. The procalcitonin concentration increased rapidly in patients with infection: the response was detectable within 8 h of the onset of fever. Procalcitonin is a specific but not a sensitive marker of infection in patients with neutropenic fever. Its poor sensitivity was related to an absent or delayed response in patients with gram-positive infections. Considerable overlap between infected and noninfected patients was found in levels of endotoxin, tumor necrosis factor, and interleukin-6.

Adult↗
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↗
PubMed1999

Quality of life after prolonged intensive care.

OBJECTIVE: To assess the subjective health status, quality of life, and functional ability of patients whose intensive care stay was prolonged and to compare their quality of life with that of the general population. DESIGN: Inception cohort study. SETTING: Twenty-three-bed multidisciplinary intensive care unit (ICU) in a tertiary care center. PATIENTS: A consecutive sample of 718 patients aged > or = 18 yrs who required intensive care > or = 4 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The Nottingham Health Profile was used to compare the ICU patients with a random sample (n = 2,595) of the general population. The quality of life and functional ability of 368 respondents (78.3% of 470 survivors) were assessed at 6 months after ICU admission. The length of the ICU stay was 13.6+/-11.8 (median, 9; maximum, 81) days. The quality of life and its various dimensions were influenced by the diagnosis for ICU admission and age. Although problems in physical mobility and energy were prevalent among all patient groups, only a small proportion was dependent on others for the management of daily activities. Patients with trauma or respiratory failure experienced the most limitations. The quality of life of elderly patients and patients who had undergone cardiac surgery was comparable with the general population regarding emotional reactions, social isolation, and pain. CONCLUSIONS: The quality of life of survivors after a prolonged intensive care stay is fairly good, although not comparable with that of the general population. The psychosocial aspects of the quality of life are restored more rapidly than physical performance.

Activities of Daily Living↗
PubMed1999

Acute respiratory distress syndrome: frequency, clinical course, and costs of care.

OBJECTIVE: To define the occurrence rate of acute respiratory distress syndrome (ARDS) using established criteria in a well-defined general patient population, to study the clinical course of ARDS when patients were ventilated using a "lung-protective" strategy, and to define the total costs of care. DESIGN: A 3-yr (1993 through 1995) retrospective descriptive analysis of all patients with ARDS treated in Kuopio University Hospital. SETTING: Intensive care unit in the university hospital. PATIENTS: Fifty-nine patients fulfilled the definition of ARDS: Pao2/Fio2 <200 mm Hg (33.3 kPa) during mechanical ventilation and bilateral infiltrates on chest radiograph. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: With a patient data management system, the day-by-day data of hemodynamics, ventilation, respiratory mechanics, gas exchange, and organ failures were collected during the period that Pao2/Fio2 ratio was <200 mm Hg (33.3 kPa). The frequency of ARDS was 4.9 cases/100,000 inhabitants/yr. Pneumonia and sepsis were the most common causes of ARDS. Mean age was 43+/-2 yrs. At the time of lowest Pao2/Fio2, the nonsurvivors had lower arterial and venous oxygen saturations and higher arterial lactate than survivors, whereas there were no differences between the groups in other parameters. Multiple organ dysfunction preceded the worst oxygenation in both the survivors and nonsurvivors. The intensive care mortality was 37%; hospital mortality and mortality after a minimum 8 months of follow-up was 42%. The most frequent cause of death was multiple organ failure. The effective costs of intensive care per survivor were US $73,000. CONCLUSIONS: The outcome of ARDS is unpredictable at the time of onset and also at the time of the worst oxygenation. Keeping the inspiratory pressures low (30-35 cm H2O [2.94 to 3.43 kPa]) reduces the frequency of pneumothorax, and might lower the mortality. Most patients are young, and therefore the costs per saved year of life are low.

Adolescent↗
PubMed1998

Angiotensin converting enzyme inhibition has no effect on blood pressure and splanchnic perfusion after cardiac surgery.

PURPOSE: The purpose of this study was to study the effect of the angiotensin-converting enzyme inhibitor, enalaprilat, on blood pressure and splanchnic perfusion after cardiac surgery. MATERIALS AND METHODS: Sixteen patients were studied after coronary artery bypass grafting. After admission to the intensive care unit, a 30-minute baseline measurement of systemic hemodynamics, oxygen transport, and gastric tonometry was performed. In 6 of 10 patients receiving enalaprilat and in each of 6 control patients, regional (splanchnic and leg) blood flows were measured also. After the baseline measurement period, 10 patients received a 0.5 mg bolus of enalaprilat and thereafter an incremental infusion of enalaprilat up to a total dose of 10 mg (mean 8.3; range 4 to 10 mg) was continued to reduce the mean arterial pressure (MAP) to 70 to 80 mm Hg. A 30-minute measurement period was repeated 2 to 3 hours after the first measurement period. In the control group, the second measurement was performed at corresponding time points. RESULTS: Though MAP decreased in the enalaprilat group (enalaprilat 99 +/- 14 mm Hg v 89 +/- 21 mm Hg, P < .05; control 95 +/- 13 mm Hg v82 +/- 10 mm Hg, P = NS) in only 4 of 10 patients was the targeted MAP reduction achieved. No significant changes were observed either in systemic or regional blood flows. Systemic, pulmonary, and femoral vascular resistance indices decreased significantly in both groups. Gastric-arterial PCO2 difference did not change in either groups. Angiotensin-converting enzyme activity decreased in the enalaprilat group (10.0 +/- 2.3 v 1.3 +/- 0.3 U x l(-1), P < .01), but plasma renin and endothelin-1 concentrations did not change in either group. CONCLUSIONS: The effect of enalaprilat on blood pressure was poor and it had no beneficial effects on splanchnic circulation. Renin-angiotensin activation is not a major factor in hypertension and splanchnic perfusion after cardiac surgery.

Aged↗
PubMed1998

Epidural analgesia with bupivacaine does not improve splanchnic tissue perfusion after aortic reconstruction surgery.

Inadequate splanchnic tissue perfusion is relatively common during and after aortic surgery. We hypothesized that vasodilation caused by thoracic epidural analgesia improves splanchnic blood flow and tissue perfusion after aortic surgery. In this prospective, randomized, controlled study, we studied 20 patients undergoing elective aortic-femoral or aortic-iliac reconstruction surgery. Gastric and sigmoid colon mucosal PCO2 and pH were measured during surgery. An epidural bolus of bupivacaine 40 mg followed by infusion of 15 mg h-1 was started after operation in 10 patients. After operation, splanchnic blood flow and gastric and sigmoid colon mucosal PCO2 and pH were measured before and 2 h after the start of epidural analgesia. During surgery, the gastric mucosal-arterial PCO2 difference remained stable, whereas the sigmoid mucosal-arterial PCO2 difference increased during aortic clamping but returned to pre-clamping values after declamping. After operation, epidural analgesia had no effect on gastric or sigmoid mucosal-arterial PCO2 differences or on splanchnic blood flow.

Acidosis↗
PubMed1997

The effect of dobutamine infusion on splanchnic blood flow and oxygen transport in patients with acute pancreatitis.

OBJECTIVES: To measure the blood flow distribution and oxygen transport in pancreatitis and to evaluate the regional effects of increased systemic blood flow. DESIGN: Nonrandomized controlled trial. SETTING: A general intensive care unit in a tertiary care center. PATIENTS: 10 patients with pancreatitis requiring mechanical ventilation were studied after fluid resuscitation, and for the response to dobutamine, the patients served as their own controls. For the baseline, 11 patients scheduled for elective abdominal surgery served as a control group. INTERVENTIONS: Systemic and regional hemodynamics were measured after fluid resuscitation to predefined hemodynamic endpoints. In patients with pancreatitis, the measurement was repeated after cardiac output had been increased by at least 25% by dobutamine. MEASUREMENTS AND RESULTS: Hepatosplanchnic blood flow was estimated using regional catheterization and the dye dilution method. In patients with pancreatitis, the cardiac index did not differ from that of the control group (3.9 +/- 0.8 vs 4.1 +/- 0.71.min-1.m-2;NS). Accordingly, there was no difference in the splanchnic blood flow (1.1 +/- 0.4 vs 1.2 +/- 0.51.min-1.m-2;NS). Systemic and splanchnic oxygen consumption was increased in patients with pancreatitis (179 +/- 25 vs 147 +/- 27 ml.min-1.m-2, p < 0.05 and 68 +/- 15 vs 49 +/- 19 ml.min-1.m-2, p < 0.05), and systemic and splanchnic oxygen extraction was higher (0.34 +/- 0.08 vs 23 +/- 0.05, p < 0.01 and 0.46 +/- 0.18 vs 0.28 +/- 0.08, p < 0.05, respectively). Dobutamine had inconsistent effects on splanchnic blood flow: in individual patients, splanchnic blood flow even decreased substantially. CONCLUSIONS: In severe pancreatitis, oxygen consumption is increased in the splanchnic region; increased splanchnic oxygen demand is not always met by adequately increased blood flow. Increasing the systemic blood flow with dobutamine does not improve perfusion in the splanchnic bed.

Acute Disease↗
PubMed1997

Preoperative glutamine loading does not prevent endotoxemia in cardiac surgery.

BACKGROUND: The presence of endotoxemia is relatively common in cardiac surgery patients and it may modify the metabolic and hemodynamic responses peri- and postoperatively. Impaired gut fuel metabolism may contribute to the disturbed function and deterioration of the intestinal mucosal barrier and the development of bacterial translocation and endotoxemia. Glutamine may protect the gut mucosal barrier during marginal or insufficient perfusion. METHODS: We studied the effects of glutamine supplementation on endotoxemia and blood levels of tumor necrosis factor (TNF) during and after extracorporeal circulation (ECC) and the effects of endotoxemia on systemic and regional (splanchnic and leg) hemodynamics and metabolism after cardiac surgery. Nineteen elective coronary bypass patients were randomly assigned to receive preoperatively for 12 h either an infusion of glucose and a balanced amino acid solution (AA-group) or a solution containing 1/5 of total nitrogen as alanyl-glutamine (ALAGLN-group). RESULTS: Glutamine and amino acid loading before ECC did not protect from peri- or postoperative endotoxemia. Endotoxemia was detected in 5 vs. 7 of patients during ECC and 6 vs. 5 of patients postoperatively in the ALAGLN-group vs. AA-group, respectively. More than half of the patients at every measurement had an increased level of TNF. There was no consistent difference between the arterial and hepatic vein endotoxin- or TNF-concentrations. Endotoxemia did not modify systemic or regional hemodynamics and metabolism after cardiac operation. CONCLUSION: Glutamine did not prevent endotoxemia during or after cardiac surgery. An increased level of TNF was common and observed also in some patients without endotoxemia. Endotoxemia did not modify regional or whole-body metabolic patterns or hemodynamics.

Amino Acids↗
PubMed1997

Relationship between intra- and postoperative oxygen transport and prolonged intensive care after cardiac surgery: a prospective study.

BACKGROUND: Prolonged intensive care is a rare but serious complication of cardiac surgery. It is required in less than 10% of operated patients but they use more than 30% of all the intensive care resources needed for cardiac surgery. The aim of our study was to describe the clinical course of the patients who need prolonged intensive care following cardiac surgery and to assess whether the intra- and postoperative oxygen transport variables are different in these patients as compared to patients with an uncomplicated course. METHODS: The study patients were divided into two groups according to the length of stay in the intensive care unit (ICU) after the operation: Group I, n = 241, ICU-stay < 5 days and Group II, n 20, ICU-stay > or = 5 days. Hemodynamic and oxygen transport data were prospectively obtained intra- and postoperatively and postoperative organ dysfunctions were recorded. RESULTS: The patients in the prolonged intensive care group tended to be older, have lower ejection fraction and longer cardiopulmonary bypass time. Postoperatively, this group had significantly increased oxygen extraction rate (P = 0.035, repeated measures for ANOVA). In the logistic regression analysis, increased oxygen extraction (31% in Group I vs. 36% in Group II, P < 0.005) at 6 hours after arrival at the intensive care unit had the strongest independent association with the need for prolonged intensive care. CONCLUSIONS: There was no significant relationship between the factors conventionally assumed to be risk factors for prolonged intensive care. Instead, an increase in whole body oxygen extraction, reflecting a mismatch between the whole body oxygen demand and supply, was associated with the need for prolonged intensive care. Oxygen extraction increased to compensate for the reduced oxygen delivery, which in turn was caused by a lower arterial oxygen content.

Adult↗
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↗
PubMed1996

Effect of nasogastric suction and ranitidine on the calculated gastric intramucosal pH.

OBJECTIVE: To study the effect of nasogastric suction and ranitidine on the determination of gastric intramucosal pH (pHi). DESIGN: Prospective study. SETTING: Clinical research unit at a university hospital intensive care department. SUBJECTS: 12 healthy volunteers. INTERVENTIONS: After a 2-h measurement control period a tonometer was connected to nasogastric suction for 2 h, and thereafter ranitidine was given intravenously and gastric pHi measured. MEASUREMENTS AND RESULTS: During each 2-h measurement period gastric PCO2, gastric pHi, and pH gap were determined every 30 min. Luminal pH was measured after insertion of tonometer and at the end of each study period. Neither nasogastric suction nor ranitidine had an effect on the coefficient of variation for either gastric PCO2 or pHi. Compared to control and nasogastric suction periods, after ranitidine mean gastric pHi was higher (control 7.22 +/- 0.08; nasogastric suction 7.23 +/- 0.07; after ranitidine 7.31 +/- 0.06, p < 0.001) mean gastric PCO2 lower (control 6.4 +/- 1.3; nasogastric suction 6.5 +/- 1.3; after ranitidine 5.3 +/- 0.9, p < 0.001) and pH gap lower (control 0.18 +/- 0.08; nasogastric suction 0.17 +/- 0.05; after ranitidine 0.09 +/- 0.06, p < 0.01). Luminal pH increased after ranitidine in each subject. CONCLUSIONS: H2 blockers have no effect on the reproducibility of gastric pHi measurements, but the use of H2 blockers modifies the normal values for gastric pHi in healthy subjects.

Adult↗
PubMed1996

Splanchnic oxygen transport after cardiac surgery: evidence for inadequate tissue perfusion after stabilization of hemodynamics.

OBJECTIVE: To evaluate the adequacy of visceral oxygen transport and gastric pHi after open heart surgery in patients with stable hemodynamics. DESIGN: Nonrandomized control trial. SETTING: A general intensive care unit in a tertiary care center. PATIENTS: Sixteen postoperative cardiac surgery patients were studied after stabilization of systemic hemodynamics. INTERVENTIONS: The effect of dobutamine infusion (6 mu g kg-1 min-1) on systemic and regional oxygen transport was studied in ten patients, with six patients serving as controls. Systemic oxygen consumption was measured by indirect calorimetry and splanchnic and femoral blood flow, by continuous infusion of indocyanine green using regional catheters and gastric mucosal pHi by gastric tonometer. MEASUREMENTS AND RESULTS: Gastric mucosal acidosis was observed in half of the patients. Dobutamine increased cardiac output (3.2 +/- 0.6 vs 4.4 +/- 0.7 l x min-1 x min-2; P <0.05), splanchnic blood flow (0.68 +/- 0.28 vs 0.91 +/- 0.28 l x min-1 x m-2; p <0.05) and femoral blood flow (0.25 +/- 0.08 vs 0.32 +/- 0.11 l x min-1 x m-2; p <0.05). Changes in splanchnic oxygen delivery and consumption were parallel in the two study groups. In response to dobutamine, gastric pHi did not change (7.30 +/- 0.08 vs 7.31 +/- 0.06; NS), while in the control group, gastric pHi tended to decrease (7.32 +/- 0.04 vs 7.28 +/- 0.06; NS). Systemic oxygen consumption increased in response to dobutamine (141 +/- 11 vs 149 +/- 11 ml x min-1 x m-2; P <0.05) but did not change in the control group. CONCLUSIONS: We conclude that a mismatch between splanchnic oxygen delivery and demand may be present despite stabilization of systemic hemodynamics after cardiac surgery. This is suggested by the parallel changes in splanchnic oxygen delivery and consumption. Dobutamine is likely to improve splanchnic tissue perfusion at this phase.

Acidosis↗
PubMed1996

Sodium nitroprusside after cardiac surgery: systemic and splanchnic blood flow and oxygen transport.

BACKGROUND: Vasoactive drugs may interfere with splanchnic blood flow and tissue oxygenation. Sodium nitroprusside (SNP) is widely used in the treatment of postoperative hypertension after cardiac surgery, but the effects of SNP and other vasodilators on splanchnic blood flow have not been well documented. METHODS: The effects of SNP on systemic blood flow, oxygen transport and gastric intramucosal pH (pHi) were studied in 12 patients with arterial hypertension after coronary artery bypass grafting. In 9 of these patients, the effect on regional (splanchnic and leg) blood flow and oxygen transport was also measured. Hemodynamic and regional blood flow responses were measured before and during SNP infusion (mean 2.8 +/- 1.7 micrograms/kg/min, range 0.6-6.3 micrograms/kg/min), when the goal of the vasodilator treatment, mean arterial pressure 70-80 mmHg, had been reached. RESULTS: SNP increased splanchnic (0.65 +/- 0.22 vs. 0.87 +/- 0.37 L.min-1.m-2, P < 0.01) and femoral blood flow (0.15 +/- 0.04 vs. 0.21 +/- 0.06 L.min-1.m-2, P < 0.05) in parallel with cardiac index (2.6 +/- 0.6 vs. 3.3 +/- 0.7 L.min-1.m-2, P < 0.01). Fractional regional blood flows did not change. Mean gastric intramucosal pH decreased slightly (7.40 +/- 0.07 vs. 7.37 +/- 0.06, P < 0.05). Both systemic (420 +/- 85 vs. 495 +/- 90 mL.min-1.m-2, P < 0.05) and femoral oxygen delivery (25 +/- 5 vs. 32 +/- 10 mL.min-1.m-2, P < 0.05) increased, but neither systemic nor regional oxygen consumption changed. CONCLUSIONS: These results suggest that vasoregulation is well preserved during treatment of early postoperative hypertension with SNP, and that SNP has no adverse effects on splanchnic tissue oxygenation.

Antihypertensive Agents↗