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Intraabdominal hypertension (IAH) is negative for outcome after intensive care. Little research has focused on medical intervention to improve visceral circulation during IAH. A nitric oxide (NO)-donor was compared with placebo in 25 pigs; each pig was randomized into three groups: PDNO (NO-donor), Control (placebo), or Sham. IAH was induced by CO2 insufflation to 30 mmHg. Sham group had surgical preparation only. Blood gases, invasive venous and arterial blood pressure, intestinal microcirculation and superior mesenteric blood flow were measured. The PDNO group had significantly increased intestinal microcirculation compared with Controls during IAH (last hour, P = 0.009). The mean arterial pressure and abdominal perfusion pressures (APP) were decreased, and the cardiac index were increased in the PDNO group. Also, systemic and pulmonary vascular resistances were lower in the PDNO group compared with Controls. These experimental findings indicate that NO should be further explored with potential application to improve intestinal microcirculation in IAH patients. [ABSTRACT FROM AUTHOR]

Objective: The distribution of postoperative gastrointestinal (GI) dysfunction and its association with outcome were investigated in cardiac surgery patients. Gastrointestinal function was evaluated using the Acute Gastrointestinal Injury (AGI) grade proposed by the European Society of Intensive Care Medicine. Design: Prospective observational study at a single center. Setting: University hospital. Patients: Consecutive patients presenting for elective cardiac surgery with extracorporeal circulation (ECC). Interventions: None. Results: Daily assessment using the AGI grade was performed on the first 3 postoperative days in addition to standard care. For analysis, 3 groups were formed based on the maximum AGI grade: AGI 0, AGI 1, and AGI ≥2. Five hundred and one patients completed the study; 32.7%, 65.1%, and 2.2% of the patients scored a maximum AGI 0, AGI 1, and AGI ≥2, respectively. Patients with AGI grade ≥2 had more frequently undergone thoracic aortic surgery and had longer surgery duration and time on ECC. Patients with AGI grade ≥2 had statistically significant higher frequency of GI complications within 30 days (63.6% vs 1.2% and 5.5% in patients with AGI 0 and AGI 1) and higher 30-day mortality (9.1% vs 0.0% and 1.8% in patients with AGI 0 and AGI 1). Conclusions: Early GI dysfunction following cardiac surgery was associated with an unfavorable outcome. Increased attention to GI dysfunction in cardiac surgery patients is warranted and the AGI grade could be a helpful adjunct to a structured approach. [ABSTRACT FROM AUTHOR]

Background and Aim: Gastrointestinal complications post cardiac surgery are infrequent but difficult to diagnose and carry a high mortality. Plasma intestinal fatty acid‐binding protein (I‐FABP) concentrations and the relationship between I‐FABP, gastrointestinal dysfunction, and postoperative outcomes were investigated in patients who developed gastrointestinal dysfunction (acute gastrointestinal injury [AGI] grade ≥2) and those with normal gastrointestinal function. Methods: Patients with (AGI 2 group, n = 11) and without (matched controls, AGI 0 group, n = 22) early postoperative gastrointestinal dysfunction were extracted from a larger single‐center prospective observational study, including adults undergoing elective cardiac surgery with extracorporeal circulation, and investigated in this nested case‐control analysis. Results: Both groups displayed variations in I‐FABP concentrations with higher I‐FABP on postoperative Day 1 compared to baseline and postoperative Days 2 and 3 (p <.001 and p =.005, respectively). The AGI 2 group had higher I‐FABP concentrations on Day 2 compared to the AGI 0 group (p =.024). I‐FABP on Day 2 correlated positively with AGI grade over the first 3 days (p =.036, p =.021 and p =.018, respectively). High I‐FABP (defined as fourth quartile concentrations) on Day 1 was associated with more prolonged surgical procedures (p <.05). Furthermore, fourth quartile I‐FABP on Day 1 and early gastrointestinal dysfunction were associated with higher frequencies of postoperative organ dysfunction (p <.05) and gastrointestinal complications (p <.05), and higher 365‐day mortality. Conclusion: The present study indicates an association between intraoperative gastrointestinal injury, postoperative gastrointestinal dysfunction and gastrointestinal complications. A high‐powered study is needed to further explore this relationship and the interpretation of I‐FABP concentrations in individual cardiac surgery patients. [ABSTRACT FROM AUTHOR]

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) causes physiological, metabolic, end-organ and inflammatory changes that need to be addressed for better management of severely injured patients. The aim of this study was to investigate occlusion time-dependent metabolic, end-organ and inflammatory effects of total REBOA in Zone I in a normovolemic animal model.Methods: Twenty-four pigs (25-35 kg) were randomized to total occlusion REBOA in Zone I for either 15, 30, 60 min (REBOA15, REBOA30, and REBOA60, respectively) or to a control group, followed by 3-h reperfusion. Hemodynamic variables, metabolic and inflammatory response, intraperitoneal and intrahepatic microdialysis, and plasma markers of end-organ injuries were measured during intervention and reperfusion. Intestinal histopathology was performed.Results: Mean arterial pressure and cardiac output increased significantly in all REBOA groups during occlusion and blood flow in the superior mesenteric artery and urinary production subsided during intervention. Metabolic acidosis with increased intraperitoneal and intrahepatic concentrations of lactate and glycerol was most pronounced in REBOA30 and REBOA60 during reperfusion and did not normalize at the end of reperfusion in REBOA60. Inflammatory response showed a significant and persistent increase of pro- and anti-inflammatory cytokines during reperfusion in REBOA30 and was most pronounced in REBOA60. Plasma concentrations of liver, kidney, pancreatic and skeletal muscle enzymes were significantly increased at the end of reperfusion in REBOA30 and REBOA60. Significant intestinal mucosal damage was present in REBOA30 and REBOA60.Conclusion: Total REBOA caused severe systemic and intra-abdominal metabolic disturbances, organ damage and inflammatory activation already at 30 min of occlusion. [ABSTRACT FROM AUTHOR]

Background: Cardiopulmonary bypass and postoperative cardiac dysfunction cause splanchnic hypoperfusion resulting in intra-abdominal anaerobic metabolism and risk for gastrointestinal complications. The intra-abdominal metabolism can be monitored by intraperitoneal measurement of relevant metabolites using microdialysis. The aim of this study was to investigate the intraperitoneal metabolism using microdialysis during and after cardiopulmonary bypass at 34°C. Methods: In six patients undergoing elective coronary artery bypass grafting or aortic valve replacement under cardiopulmonary bypass, microdialysis was used to measure intraperitoneal and subcutaneous glucose, lactate, pyruvate, glycerol and glutamate concentrations, intraoperatively and up to 36 hours postoperatively. Arterial and central venous blood gases were analysed as were haemodynamics and the development of complications. Results: All patients had an ordinary perioperative course and did not develop gastrointestinal complications. The arterial, intraperitoneal and subcutaneous lactate concentrations changed during the perioperative course with differences between compartments. The highest median (interquartile range) concentration was recorded in the intraperitoneal compartment at 1 hour after the end of cardiopulmonary bypass (2.1 (1.9–2.5) mM compared to 1.3 (1.2–1.7) mM and 1.5 (1.0–2.2) mM in the arterial and subcutaneous compartments, respectively). In parallel with the peak increase in lactate concentration, the intraperitoneal lactate/pyruvate ratio was elevated to 33.4 (12.9–54.1). Conclusion: In cardiac surgery, intraperitoneal microdialysis detected changes in the abdominal metabolic state, which were more pronounced than could be shown by arterial blood gas analysis. Despite an uneventful perioperative course, patients undergoing low-risk surgery under cardiopulmonary bypass might be subjected to a limited and subclinical intra-abdominal anaerobic state. [ABSTRACT FROM AUTHOR]

The impact of acute cardiac dysfunction on the gastrointestinal tract was investigated in anesthetized and instrumented pigs by sequential reductions of cardiac output (CO). Using a cardiac tamponade (n = 6) or partial inferior caval vein balloon inflation (n = 6), CO was controllably reduced for 1 h each to 75% (CO75%), 50% (CO50%), and 35% (CO35%) of the baseline value. Cardiac output in controls (n = 6) was not manipulated and maintained. Mean arterial pressure, superior mesenteric arterial blood flow, and intestinal mucosal perfusion started to decrease at CO50% in the intervention groups. The decrease in superior mesenteric arterial blood flow was non-linear and exaggerated at CO35%. Systemic, venous mesenteric, and intraperitoneal lactate concentrations increased in the intervention groups from CO50%. Global and mesenteric oxygen uptake decreased at CO35%. In conclusion, gastrointestinal metabolism became increasingly anaerobic when CO was reduced by 50%. Anaerobic gastrointestinal metabolism in low CO can be detected using intraperitoneal microdialysis. [ABSTRACT FROM AUTHOR]