Action mechanisms in the administration of oxygen via nasal catheters

Uvod: Učinkovitost terapije s kisikom je odvisna od deleža kisika v vdihanem zraku (FIO2), kar pa je odvisno od načina aplikacije kisika. Pri nosnih katetrih je FIO2 težko natančno določiti, zaradi mešanja kisika z atmosferskim zrakom. S pregledom literature smo želeli ugotoviti kakšne vrednosti FIO2 navajajo v raziskavah, kakšen vpliv ima dihanje skozi usta in kako učinkovito je merjenje PETCO2. Metode: Uporabili smo deskriptivno metodo dela. Izvedli smo sistematični pregled literature. Članke smo iskali po podatkovnih bazah: PubMed, ScienceDirect, Web of Science in MEDLINE. Popolna kombinacija iskanja je bila: (»cannula« AND »oxygen concentration« OR »FIO2« AND »breathing pattern«). Rezultati: V podatkovnih bazah smo skupno našli 191 člankov. Po pregledu smo jih v končno analizo vključili 7. Glede na raziskave smo ugotovili, da je bil FIO2 v njihovih primerih nekoliko višji, kot FIO2 izračunan in podan v strokovnih smernicah. Prav tako smo ugotovili, da vlaženje od pretoka 1 do 4 l/min ni potrebno. Ni pa dovolj raziskav, ki bi lahko zagotovo potrdile, da dihanje skozi usta vpliva na večji FIO2. Najboljši način merjenja PETCO2 je s katetrom z ločeni kanili za dovod O2 in merjenje CO2. Razprava: Pri uporabi nosnega katetra je FIO2 odvisen od minutne ventilacije, pretoka, položaja nosnih kanil in morda tudi nosnega in ustnega dihanja. Ob upoštevanju bolnikovih potreb, je vse to potrebno upoštevati tudi pri izbiri sistemov in sami aplikaciji kisika.Introduction: The effectiveness of oxygen therapy depends on the fractional inspired oxygen concentrations (FIO2), which is affected by the method of oxygen delivery. For nasal catheters FIO2 is difficult to determine due to the mixing of oxygen with the atmospheric air. With literature review we wanted to find out what are the values of FIO2 in researches, what is the impact of mouth breathing and how reliable is measurement of PETCO2. Methods: We used a descriptive method of work. We conducted systematic literature review. The articles were searched in databases: PubMed, ScienceDirect, Web of Science in MEDLINE. Complete search strategy was: (»cannula« AND »oxygen concentration« OR »FIO2« AND »breathing pattern«). Results: We found total of 191 articles in databases. After review we included 7 in final analysis. Based on the research, we found that the FIO2 in their studies was slightly higher than FIO2 calculated and given in guidelines. We also found that humidification for flows from 1 to 4 l / min is not necessary. There is not enough research that could certainly confirm that mouth breathing affects a larger FIO2. Nasal cannula with separate nasal prongs for O2 delivery and CO2 sampling is the best way for measuring PETCO2. Discussion: With the use of nasal cannula, FIO2 depends on minute ventilation, flow rate, position of nasal prongs and possibly also nasal and mouth breathing. Taking into account the patient\u27s needs, all this must also be considered when choosing oxygen systems and the oxygen application itself