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Kontinuirano praćenje srčanoga minutnog volumena (CO) i održavanje normovolemije primarni su ciljevi optimizacije hemodinamskog (HD) statusa svakoga kritičnog bolesnika. Za razliku od samo invazivnog nadzora i intermitentne termodilucijske procjene CO-a s pomoću plućnog arterijskog katetera, danas se puno više primjenjuju minimalno invazivne i potpuno neinvazivne metode. Minimalno invazivne metode koje se s pomoću transpulmonalne termodilucije (TD) pri procjeni CO-a služe analizom krivulje tlaka pulsa dijele se na starije, kalibrirane i novije, nekalibrirane. Dinamički parametri kao što su varijacija udarnog volumena (SVV) i varijacija pulsnog tlaka (PPV), koji se kontinuirano prate ovim metodama, puno preciznije odražavaju potrebu za ciljanom optimalnom volumnom nadoknadom (GDVT) u odnosu prema tradicionalnim, statičkim parametrima (CVP i PCWP). Suvremenije neinvazivne kontinuirane metode koje još nisu dovoljno validirane u kliničkim uvjetima jesu aplanacijska tonometrija, pletizmografija, metoda djelomičnoga ponovnog udaha parcijalnog CO2 i procjena CO-a temeljena na tranzicijskom vremenu pulsnog vala. Torakalna električna bioimpedancija i bioreaktancija koriste se slabom naizmjeničnom strujom koja prolaskom kroz prsni koš kontinuirano u sistoli prati fazne pomake napona i analizira krivulju udarnog volumena (SV). Poznato je da primjenom volumena u oko 50% kritičnih bolesnika neće doći do povećanja SV-a, stoga je važno prije primjene volumena kontinuiranim praćenjem SV-a/CO-a procijeniti hoće li biti prikladnoga HD odgovora na volumen. Danas postoji više metoda kojima se može procijeniti odgovor na volumnu nadoknadu poput mjerenja varijacije dijametra donje i gornje šuplje vene, okluzijskog testa na kraju ekspirija, testa respiratorne sistoličke varijacije, SVV-a i PPV-a. Pasivno podizanje nogu (PLR) ima najveću prediktivnu vrijednost u dinamičkoj procjeni volumnog statusa kod hemodinamski nestabilnog bolesnika., Continuous monitoring of cardiac output (CO) and maintenance of normovolaemia are the primary aims of haemodynamic (HD) optimization in every critical care patient. Previously, invasive monitoring and intermittent thermodilution with pulmonary artery catheterization were the main methods for determining CO. However, the methods more commonly used today are either minimally invasive or non-invasive. Minimally invasive methods of transpulmonary thermodilution (TD) in CO monitoring analyze the pulse pressure curve and are divided into older, calibrated and newer, non-calibrated systems. Dynamic parameters such as stroke volume variation (SVV) and pulse pressure variation (PPV) which can be continuously monitored, are far more precise in determining the optimal goal-directed volume therapy (GDVT) in comparison to the traditional static parameters such as CVP and PCWP. Modern non-invasive continuous methods, that are still not fully validated in clinical circumstances are: applanation tonometry, plethysmography, partial CO2 rebreathing technique, and pulse wave transit time measurements of CO. Thoracic electrical bioimpedance and bioreactance uses a weak alternating current, and through the phasic variations in the charge of the current during a systolic cycle, enables continuous analysis of the stroke volume (SV) curve. It is known that volume administration will not increase SV in roughly 50% of critically ill patients (fluid non-responders), therefore, prior to volume administration, through continuous SV/CO monitoring, it is important to assess whether a patient will have an adequate haemodynamic response to fluid administration (responders). There are some methods available for predicting the response to fluid administration, like measurement of variation in the diameter of the superior and inferior vena cava, the end-expiratory occlusion test, respiratory systolic variation test, SVV and PPV. The passive leg raising (PLR) test has the highest predictive score in dynamic assessment of the volume status in a haemodynamically unstable patient.

Sažetak. U posljednjih nekoliko desetljeća dostupan nam je velik izbor enteralnih formula za različite indikacije. Koncept kliničke prehrane s vremenom je evoluirao od nutritivne potpore koja ima cilj samo zadovoljiti energetske potrebe bolesnika do one koja može utjecati i na sam tijek bolesti. Iako za određene farmakološki aktivne tvari u enteralnim pripravcima, kao što su različite aminokiseline i njihovi metaboliti, ω-3 masne kiseline, nukleotidi i antioksidansi, postoje dokazi da mogu utjecati na upalne i imunološke funkcije, pozitivan utjecaj imunomodulirajućih nutrijenata na klinički ishod u određenim je uvjetima bilo vrlo teško dokazati, usprkos velikom broju kliničkih istraživanja u ovom području. Moguća objašnjenja za ove proturječnosti kriju se u nedovoljno precizno utvrđenim mehanizmima djelovanja, vremenu i načinu davanja, dozi, a napose vrsti i tijeku bolesti u kojoj su se primjenjivali. Svrha je ovog pregleda objasniti potencijalno korisne fiziološke mehanizme djelovanja najčešće upotrebljavanih farmakonutrijenata i prezentirati kliničke dokaze o njihovoj uporabi., Summary. Enteral nutrition formulas have been created over the past several decades with a variety of intended uses. Over the past two decades, the focus has shifted to the administration of pharmacologically active substances, such as different amino acids and their metabolites, ω-3 fatty acids, nucleotides and antioxidants in an attempt to modulate the inflammatory or immune response and affect clinical outcomes. Although some pharmaconutrients have clearly demonstrated the ability to potentiate, antagonize, or otherwise modify metabolic functions, despite the large volume of clinical research in this area, undoubted benefit of immunomodulating diets in certain clinical settings was difficult to prove. Potential explanations for discrepancies include variable effects of individual nutrients dependent on dose, nutrient interactions, timing of delivery and different metabolic needs of heterogeneous patient population. The purpose of this review is to cover potential beneficial physiological mechanisms for some common individual pharmaconutrients and briefly describe some of the current clinical data regarding their use.

To determine whether elevated intra-abdominal pressure (IAP) is associated with a higher rate of enteral nutrition-related gastrointestinal (GI) complications, to assess the value of IAP as a predictor of enteral nutrition (EN) intolerance. Intensive Care Unit (ICU) patients on mechanical ventilation requiring at least 5 days of EN were recruited for a prospective, observational, non-interventional, multicenter study. EN was performed and GI complications were managed with an established protocol. IAP was determined via a urinary catheter. Patients who developed any GI complications were considered as presenting EN intolerance. Variables related to EN, IAP and GI complications were monitored daily. Statistical analysis compared patients without GI complications (group A) vs. GI complications (group B). 247 patients were recruited from 28 participating ICUs (group A: 119, group B: 128). No differences between groups were recorded. Patients in group B (p &lt, 0.001) spent more days on EN (8.1 ± 8.4 vs. 18.1 ± 13.7), on mechanical ventilation (8.0 ± 7.7 vs. 19.3 ± 14.9) and in the ICU (12.3 ± 11.4 vs. 24.8 ± 17.5). IAP prior to the GI complication was (14.3 ± 3.1 vs. 15.8 ± 4.8) (p &lt, 0.003). The best IAP value identified for EN intolerance was 14 mmHg but it had low sensitivity and specificity. Although a higher IAP was associated with EN intolerance, IAP alone did not emerge as a good predictor of EN intolerance in critically ill patients.