Kjell Jansson

Human intraperitoneal microdialysis : increased lactate/pyruvate ratio suggests early visceral ischaemia

BACKGROUND Previous studies suggest that visceral ischaemia precedes shock and multiple organ failure, though methods for studying humans are lacking. We aimed to evaluate intraperitoneal microdialysis, a new technique for detecting splanchnic ischaemia in clinical practice. METHODS Right-sided hemicolectomy was performed in eight patients who were studied by microdialysis postoperatively for glucose, lactate, pyruvate and glycerol levels. RESULTS Six of the eight patients showed a normal postoperative course and had lactate/pyruvate ratios between 7.1 and 21.7, glucose between 4.5 and 14.3 mmol/L and glycerol between 10.4 and 296 micromol/L. In one patient, intraperitoneal lactate/pyruvate ratio and glycerol increased and glucose decreased 5 h before low oxygenation appeared. Another patient exhibited a period of increased lactate/pyruvate ratio before a period of atrial fibrillation. CONCLUSION Intraperitoneal microdialysis was performed safely. Two out of the eight patients exhibited changes of metabolic markers followed by clinical symptoms that were probably related to transient visceral ischaemia. Our findings suggest that intraperitoneal microdialysis may become a useful tool for monitoring splanchnic ischaemia in clinical practice.Background: Previous studies suggest that visceral ischaemia precedes shock and multiple organ failure, though methods for studying humans are lacking. We aimed to evaluate intraperitoneal microdialysis, a new technique for detecting splanchnic ischaemia in clinical practice. Methods: Right-sided hemicolectomy was performed in eight patients who were studied by microdialysis postoperatively for glucose, lactate, pyruvate and glycerol levels. Results: Six of the eight patients showed a normal postoperative course and had lactate/pyruvate ratios between 7.1 and 21.7, glucose between 4.5 and 14.3 r mmol/L and glycerol between 10.4 and 296 r 7 mol/L. In one patient, intraperitoneal lactate/pyruvate ratio and glycerol increased and glucose decreased 5 r h before low oxygenation appeared. Another patient exhibited a period of increased lactate/pyruvate ratio before a period of atrial fibrillation. Conclusion: Intraperitoneal microdialysis was performed safely. Two out of the eight patients exhibited changes of metabolic markers followed by clinical symptoms that were probably related to transient visceral ischaemia. Our findings suggest that intraperitoneal microdialysis may become a useful tool for monitoring splanchnic ischaemia in clinical practice.

Is Early Detection of Anastomotic Leakage Possible by Intraperitoneal Microdialysis and Intraperitoneal Cytokines After Anterior Resection of the Rectum for Cancer

PurposeThis prospective study assessed methods of detecting intraperitoneal ischemia and inflammatory response in patients with and without postoperative complications after anterior resection of the rectum.MethodsIn 23 patients operated on with anterior resection of the rectum for rectal carcinoma, intraperitoneal lactate, pyruvate, and glucose levels were monitored postoperatively for six days by using microdialysis with catheters applied in two locations: intraperitoneally near the anastomosis, and in the central abdominal cavity. A reference catheter was placed subcutaneously in the pectoral region. Cytokines, interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-a, were measured in intraperitoneal fluid by means of a pelvic drain for two postoperative days.ResultsThe intraperitoneal lactate/pyruvate ratio near the anastomosis was higher on postoperative Day 5 (P--.029) and Day 6 (P--.009) in patients with clinical anastomotic leakage (n--) compared with patients without leakage (n--6). The intraperitoneal levels of IL-6 (P--.002; P--.012, respectively) and IL-10 (P--.002; P--.041, respectively) were higher on postoperative Days 1 and 2 in the leakage group, and TNF-a was higher in the leakage group on Day 1 (P--.011). In-hospital clinical anastomotic leakage was diagnosed on median Day 6, and leakage after hospital discharge on median Day 20.ConclusionsThe intraperitoneal lactate/pyruvate ratio and cytokines, IL-6, IL-10, and TNF-α, were increased in patients who developed symptomatic anastomotic leakage before clinical symptoms were evident.

Results of intraperitoneal microdialysis depend on the location of the catheter.

Jansson K, Strand I, Redler B, Magnuson A, Ungerstedt U, Norgren L. Results of intraperitoneal microdialysis depend on the location of the catheter. 2004; 64: 63-70. Background and Objective: Intraperitoneal microdialysis was recently described as a method for early detection of visceral ischemia. The method seems safe and accurate. The intra-abdominal catheter used may imply variations in results depending on the location of the catheter. The aim of the study was to investigate possible differences in metabolic parameters obtained depending on various locations of the intra-abdominal catheter, compared with using the subcutaneous reference catheter. Method: After right-sided hemicolectomy in 12 patients, three catheters were placed and fixed intraperitoneally: one at the anastomosis, one in the omentum and one embedded between the small intestinal loops. A subcutaneous catheter placed in the pectoral region was used as reference. Analyses of lactate/pyruvate ratio and glucose and glycerol levels were done during a period of 45 hours postoperatively. Results: Lactate/pyruvate ratio decreased numerically at all three intraperitoneal locations during the study while the subcutaneous lactate/pyruvate ratio increased slightly. Significant differences between intraperitoneal and subcutaneous locations were found as well as differences between the three intraperitoneal locations. Highest values of the lactate/pyruvate ratio were found at the anastomosis, while the widest range was found at the small intestine. Subcutaneous glucose levels were lower while glycerol levels were higher compared with intraperitoneal values. Conclusions: In evaluating postoperative metabolism, intraperitoneal microdialysis is influenced by the location of the microdialysis catheter. The same pattern is, however, recorded over time. The juxta-anastomotic region and the small intestinal loop area seem to be the most reasonable locations for measurements.

Postoperative on‐line monitoring with intraperitoneal microdialysis is a sensitive clinical method for measuring increased anaerobic metabolism that correlates to the cytokine response

Background: Visceral ischaemia and cytokine release are early stages in the development of shock and multiorgan failure. Because of lack of methods to measure anaerobic metabolism or visceral hypoxia in the early phase, diagnosis is not usually established until shock and organ failure are evident. Methods: Nineteen patients were studied postoperatively after major abdominal gastrointestinal surgery. A microdialysis catheter was placed intraperitoneally before closure of the abdomen. Analysis of glucose, pyruvate and lactate was performed every second hour and the ratio between lactate and pyruvate was calculated. Peritoneal fluid was collected from a peritoneal drainage for analysis of tumour necrosis factor alpha (TNF‐α) and interleukin 10 (IL‐10). Results: Sixteen of the patients had a normal postoperative course; the lactate/pyruvate ratio started at the level of 20 immediately postoperatively and decreased significantly during the first 45 postoperative hours (P = 0.007). A similar pattern was recorded for peritoneal TNF‐α, which decreased correspondingly (P = 0.003). A correlation coefficient of 0.303 (P < 0.001) between lactate/pyruvate ratio and TNF‐α was found. After an initial short increase, IL‐10 decreased over time (P < 0.001). Three of the patients had abnormalities in the microdialysis results, cytokines and clinical outcome. These patients are presented separately. Conclusions: A normal postoperative course results in a decrease in the intraperitoneal lactate/pyruvate ratio, TNF‐α and IL‐10. A correlation between the intraperitoneal lactate/pyruvate ratio and TNF‐α was found which suggests that intraperitoneal microdialysis is a sensitive, indirect method in analysing the postoperative intraperitoneal inflammatory response. A complicated postoperative course was preceded by increase of the peritoneal lactate/pyruvate ratio interpreted as splanchnic hypoxia and also an increased TNF‐α level.

Normal values and differences between intraperitoneal and subcutaneous microdialysis in patients after non-complicated gastrointestinal surgery.

Objective. Visceral ischemia is an early event in the development of shock and organ failure. Microdialysis has been presented as a promising method for detection of visceral hypoxia and ischemia. The aim of this study was to investigate differences in the metabolic response measured by microdialysis between intraperitoneal and subcutaneous locations and to estimate normal values of lactate/pyruvate ratio, glucose and glycerol. Material and methods. Intraperitoneal and subcutaneous metabolic responses were compared regarding lacate/pyruvate ratio, glucose and glycerol, during 45 postoperative hours in 33 patients undergoing various non‐complicated elective major gastrointestinal surgery. Results. Intraperitoneal lactate/pyruvate ratio started around 15 and decreased over time, while subcutaneous levels were stable around 9. Glucose levels were higher intraperitoneally and increased rapidly during the first 9 h to 8.6 mM, while the subcutaneous levels increased during 21 h to 7.5 mM. Intraperitoneal glycerol levels were stable around 100 µM, while subcutaneous values started around 230 µM and then increased. Conclusions. In a non‐complicated postoperative course the lactate/pyruvate ratio and glucose levels are higher intraperitoneally, suggesting a higher postoperative intraperitoneal metabolism. Glycerol levels are higher and increase subcutaneously, suggesting increased postoperative energy demand, particularly in the visceral organs, as being responsible for the lipolysis seen in the subcutaneous tissue.

Elevated intraperitoneal matrix metalloproteinases‐8 and ‐9 in patients who develop anastomotic leakage after rectal cancer surgery: a pilot study

Objective  Experimental studies suggest that matrix metalloproteinase (MMP) enzymes mediate the early tissue breakdown that leads to a decrease in intestinal anastomotic strength. Patients with upregulation of MMPs in intestinal biopsies have an increased rate of anastomotic leakage. We measured MMPs and their inhibitors [tissue inhibitors of metalloproteinases (TIMPs)] in postoperative intraperitoneal fluid after rectal cancer surgery, and hypothesized that they would be elevated in patients who later would develop anastomotic leakage.

Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms.

OBJECTIVES This study aims to evaluate intra-peritoneal (ip) microdialysis after endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) in patients developing intra-abdominal hypertension (IAH), requiring abdominal decompression. DESIGN Prospective study. MATERIAL AND METHODS A total of 16 patients with rAAA treated with an emergency EVAR were followed up hourly for intra-abdominal pressure (IAP), urine production and ip lactate, pyruvate, glycerol and glucose by microdialysis, analysed only at the end of the study. Abdominal decompression was performed on clinical criteria, and decompressed (D) and non-decompressed (ND) patients were compared. RESULTS The ip lactate/pyruvate (l/p) ratio was higher in the D group than in the ND group during the first five postoperative hours (mean 20 vs. 12), p = 0.005 and at 1 h prior to decompression compared to the fifth hour in the ND group (24 vs. 13), p = 0.016. Glycerol levels were higher in the D group during the first postoperative hours (mean 274.6 vs. 121.7 μM), p = 0.022. The IAP was higher only at 1 h prior to decompression in the D group compared to the ND group at the fifth hour (mean 19 vs. 14 mmHg). CONCLUSIONS Ip l/p ratio and glycerol levels are elevated immediately postoperatively in patients developing IAH leading to organ failure and subsequent abdominal decompression.

Intraperitoneal glycerol levels and lactate/pyruvate ratio: early markers of postoperative complications

Abstract Objective. We have previously presented microdialysis findings of early intraperitoneal (ip) metabolic disturbances, mainly an increased lactate/pyruvate (l/p) ratio, in surgical patients developing postoperative complications. The aim of the present study was to investigate ip glycerol and l/p ratio after major surgery with and without complications. Material and methods. Sixty patients were followed with microdialysis for 48 h after major abdominal surgery, 44 patients without postoperative complications and 16 patients with major surgical complications. Intraperitoneal and subcutaneous (sc) measurements of glycerol, lactate, pyruvate and glucose were performed, and the l/p ratio was calculated. Results. Intraperitoneal glycerol was significantly lower in the complication group compared with the control group (64 vs. 94.6 μM; p = 0.0015), while the ip l/p ratio was significantly higher in the complication group compared with the control group (13.7 vs. 11.1; p = 0.0073). Conclusions. In this study, ip glycerol levels were lower and ip l/p ratio was higher in the immediate postoperative period in a group of patients with complications. These results might indicate early ip disturbances in fat and carbohydrate metabolism in patients who later developed symptoms of postoperative major complications.

Complications but not obesity or diabetes mellitus have impact on the intraperitoneal lactate/pyruvate ratio measured by microdialysis.

Abstract Objective. Studies have shown a higher risk of postoperative complications in diabetic and obese patients. An increased intraperitoneal lactate/pyruvate ratio as measured by microdialysis has been reported before postoperative complications have been discovered. It is not known whether diabetes or obesity have any influence on the intraperitoneal metabolism (lactate/pyruvate ratio, glucose, glycerol) in relation to major abdominal surgery. The aim of this study was to investigate the postoperative intraperitoneal and subcutaneous carbohydrate and fat metabolism as measured by microdialysis in obese and diabetic patients after major abdominal surgery without postoperative complications. Material and methods. Seven obese patients (body mass index > 30 kg/m2) and six diabetic but non-obese patients were studied up to 48 h after major abdominal surgery and were compared with 31 non-diabetic, non-obese patients, all without complications. Microdialysis was performed to measure glucose, lactate, pyruvate and glycerol intraperitoneally and subcutaneously. The lactate/pyruvate ratio was calculated. Results. The lactate/pyruvate ratio did not differ between the groups. In the diabetic patients, glucose levels were higher intraperitoneally at both Days 1 and 2 compared to controls. Higher glycerol levels were found subcutaneously in obese patients at Day 2. Conclusions. The lactate/pyruvate ratio does not increase intraperitoneally after non-complicated major abdominal surgery in diabetic and obese patients. Obese patients have increased release of free fatty acids and glycerol subcutaneously, while diabetic patients show higher glucose levels intraperitoneally than controls.

Limb ischemia after EVAR: an effect of the obstructing introducer?

Purpose: To evaluate the splanchnic and limb metabolic effects of open repair (OR) of abdominal aortic aneurysms (AAA) versus endovascular aneurysm repair (EVAR) in a pilot study utilizing microdialysis. Methods: Nine AAA patients (8 men; mean age 74 years, range 61–85) were treated with EVAR and 9 had an OR (5 men; mean age 70 years, range 55–85). In the EVAR cases, which were performed percutaneously, the external iliac artery was obstructed by the introducer to a mean functional stenosis of 70% (52%–100%). Catheters for microdialysis were placed subcutaneously above the ankle of the right leg and freely in the abdominal cavity to measure the levels of lactate and pyruvate. The lactate/pyruvate ratio was calculated as a measure of ischemia. Measurements started at the end of surgery and continued for 2 days. Mean values were compared using the Mann-Whitney U test. Results: The mean value of intraperitoneal lactate during the first day after EVAR was 1.5±0.7 mM versus 2.6±0.8 mM after OR (p=0.019). The lactate/pyruvate ratio was 10.2±2.2 after EVAR and 12.3±2.6 after OR (p=0.113). Leg lactate mean values were 4.2±2.0 mM after EVAR versus 1.8±0.6 mM after OR (p<0.001). The lactate/pyruvate ratio was 20.1±8.3 for EVAR and 13.7±3.3 for OR (p=0.040). These differences between EVAR and OR continued for the second day. Conclusion: Intraperitoneally, metabolism was slightly increased after OR; however, it was not suggestive of splanchnic ischemia. Leg findings reflected a more extensive ischemia after EVAR over 48 hours, which was a somewhat unexpected finding that may be related to the introducers impact on blood flow to the limb during the intervention. Although no clinical consequences were recorded, the finding suggests some benefit of minimizing as much as possible the time of reduced perfusion to the limb.