Professor Joel Starkopf, MD, PhD, University of Tartu
Juri Karjagin, MD, PhD, University of Tartu
Vladimir Cerny, MD, PhD, Charles University in Prague
Approximately 10000 patients are hospitalised to intensive care unit every year in Estonia. One third of them develop elevated intra-abdominal pressure (IAP) i.e. intra-abdominal hypertension (IAH). IAH can lead to severe abdominal organ's dysfunction and is therefore a reason for elevated mortality. According to the severity, IAH is graded into four levels. Grade I refers to IAP levels from 12 to 15 mmHg, Grade II 16 to 20, Grade III 21 to 25, and Grade IV above 25 mmHg, respectively. The most severe form of IAH (IAP over 20 mmHg) is life-threatening abdominal compartment syndrome (ACS). Treatment of ACS is self-evident - fast and aggressive. Consequences of grade I and II IAH are not uniformly understood and the treatment recommendations are either absent or un-precisely defined.
The main aim of present study was to investigate whether grade I and II IAH causes alterations in tissue perfusion and metabolism which are not detectable with conventional methods. Early treatment of mild to moderate IAH would be necessary if tissue perfusion and metabolism are deteriorated. Tissue perfusion was evaluated in sublingual area with videomicroscope. Several researches have previously shown that gastrointestinal and sublingual region microcirculation reacts similarly and that sublingual changes describe the situation in gastrointestinal region. For tissue metabolism evaluation we used microdialysis in the abdominal rectus muscle.
Altogether 37 patients we included. Main finding of our work was that grade I or II IAH does not influence sublingual microcirculation in previously fluid-resuscitated critically ill patients. But the microcirculation was significantly altered in surgical patients, who were not allowed to eat-drink prior the elective surgery. The main finding of microdialysis study was the prevalence of anaerobic metabolism in RAM tissue during grade I and II IAH. This indicates to possible tissue hypoperfusion.
In conclusion, the results of present work accentuate, that the tissue metabolism is severely altered during grade I and II IAH, despite the lack of clearly identified clinical symptoms and therefore IAH cannot be ignored in critically ill patients.