Ocular microvascular changes in patients with sepsis: a prospective observational study

Abstract

Background: The aim of the study was to detect differences in the conjunctival microcirculation between septic patients and healthy subjects and to evaluate the course of conjunctival and retinal microvasculature in survivors and non-survivors over a 24-h period of time. Methods: This single-center prospective observational study was performed in mixed ICU in a tertiary teaching hospital. We included patients with sepsis or septic shock within the first 24 h after ICU admission. Conjunctival imaging, using an IDF video microscope, and retinal imaging, using portable digital fundus camera, as well as systemic hemodynamic measurements, were performed at three time points: at baseline, 6 h and 24 h. Baseline conjunctival microcirculatory parameters were compared with healthy controls. Results: A total of 48 patients were included in the final assessment and analysis. Median APACHE II and SOFA scores were 16[12-21] and 10[7-12], respectively. Forty-four (92%) patients were in septic shock, 48 (100%) required mechanical ventilation. 19 (40%) patients were discharged alive from the intensive care unit. We found significant reductions in all microcirculatory parameters in the conjunctiva when comparing septic and healthy subjects. In addition, we observed a significant lower microvascular flow index (MFI) of small conjunctival vessels during all three time points in non-survivors compared with survivors. However, retinal arteriolar vessels were not different between survivors and non-survivors. Conclusions: Conjunctival microvascular blood flow was altered in septic patients. In the 24-h observation period conjunctival small vessels had a significantly higher MFI, but no difference in retinal arteriolar diameter in survivors in comparison with non-survivors.

Sepsis and the microcirculation: the impact on outcomes

“…Significantly, a MFI less than 2.6 combined with tachycardia more than 90 was found to be an independent risk factor for increased in-hospital mortality in acutely ill patients [31]. While the sublingual microcirculation has been a focus of much evaluation, examination of the conjunctival and retinal microcirculation has also revealed improved microcirculatory parameters in sepsis survivors vs. nonsurvivors [32].…”

Audinių Perfuzijos Vertinimas Šoko Metu

“…Nors techniškai panaudojant videomikroskopiją galima ištirti kraujotaką bet kurioje gleivinėje ar organų paviršiuje, mikrocirkuliacija šiuo metodu dažniausiai vertinama poliežuvio srityje ar akies junginėje [39]. Poliežuvio sritis labiausiai ištirta, lengvai pasiekiama ir pokyčiai joje turi ryšį su organų nepakankamumo progresavimu bei mirštamumu [40,41].…”

Retinal blood flow in critical illness and systemic disease: a review

“…The choriocapillaris is derived from the short posterior ciliary arteries, which also branch off the ophthalmic artery. The conjunctiva covers the sclera and lines the inside of the eyelids, and is also supplied by the ophthalmic artery [ 34 ].…”

“…IDF uses a green light source that is absorbed by haemoglobin to detect RBC [ 34 ] with devices optimised for surface microcirculatory visualisation and may have better image quality than SDF imaging [ 111 ]. Portable IDF (Cytocam®-IDF device) demonstrated reductions in all microcirculatory parameters of the conjunctiva, including microvascular flow index (MFI) and total and perfused vessel density, in septic patients compared with healthy individuals [ 34 ].…”

“…IDF uses a green light source that is absorbed by haemoglobin to detect RBC [ 34 ] with devices optimised for surface microcirculatory visualisation and may have better image quality than SDF imaging [ 111 ]. Portable IDF (Cytocam®-IDF device) demonstrated reductions in all microcirculatory parameters of the conjunctiva, including microvascular flow index (MFI) and total and perfused vessel density, in septic patients compared with healthy individuals [ 34 ]. Similarly, in the ovine septic and haemorrhagic shock model, functional capillary density and MFI of the conjunctiva capillary microcirculation were significantly reduced in septic shock, with alterations correlating with sublingual capillary microcirculation [ 112 ].…”