Polydistrectual resistance index evaluation is an assessment of vascular compliance in patients with septic shock treated with vasopressinA Barile1, A Recchia2, G Paternoster3, M Copetti4, L Mirabella5, G Cinnella5, A Del Gaudio2 1University of Foggia, Departement of Medical and Surgical Servic,Intensive Care Unit, FOGGIA, Italy, 2IRCCS “Casa Sollievo della Sofferenza“, Anesthesia and Intensive Care 2, San Giovanni Rotondo, Italy, 3Cardiovascular Anaesthesia and ICU, Potenza, Italy, 4IRCCS “Casa Sollievo della Sofferenza“, Unit of Biostatistics, San Giovanni Rotondo, Italy, 5University of Foggia, Department of Anesthesia and Intensive Care, FOGGIA, Italy

Critical Care 2023, 27(S1): P189

Introduction: Surviving Sepsis Campaign recomends using norepinephrine (NE) as the first-line vasopressor to restore mean arterial pressure [1]. If mean arterial pressure remains inadeguate SSC suggests adding vasopressin (VA) [2]. Resistance Index (RI) is a power Doppler ultrasound assessment of vascular compliance to detect organ perfusion.

Methods: Aim of this study is to compare RI in septic shock patients treated with NE (Group1), NE plus VA since the beginning of vasopressor therapy (Group2) and VA plus NE where VA is added if NE dosage was 20 mcg/min (Group3). RI were measured in renal artery (ARE), radial artery (AR), central retinal artery (CRA),superior mesenteric artery (AMS) at three different time points (T0) before vasopressor therapy, (T1) at 1 h, T2 at 24 h and T3 at 48 h.

Results: 48 patients were divided into three groups. 17 patients Group 1; 16 Group 2, 15 Group 3. In Group 1 RI increased from T0 in CRA R[0.90(0.57–1.12)] and ARE L [0.74(0.56–0.92) to T3 in CRA R[0.97(0.97–1.14)] and ARE L [0.96(0.82–1.17)]. In Group 2 RI reduced in AMS, from T0[0.84(0.70,1.02)] to T3[0.75(0.59,0.81)],in CRA R, from T0[0.90(0.57,1.09] to T3[0.79(0.58, 0.87)], in CRA L, from T0[0.91(0.43,1.53)] to T3[0.76(0.58, 0.89]and in ARE L, from T0[0.79(0.58, 0.92)] to T3[0.72(0.59, 0.83)]. In Group 3 RI reduced in AMS, from t0[0.86(0.71,0.93)] to T3 [0.68(0.64,0.81)], in CRA R, from T0 [0.90(0.75,1.12)] to T3 [0.78(0.66,0.88)],in CRA L,from T0[0.96(0.76,1.33)] to T3 [0.96(0.76,1.33)], in ARE L, from T0[0.77(0.66, 0.99)] to T3[0.67(0.61,0.85], in ARE R, from T0[0.82[0.64, 0.90]]to T3[0.70(0.62,0.82)] and in AR R, from T0[1,10(0.81,1.30)] to T3 [0.87(0.64,1.22)].

Conclusions: Resistence Index was significantly reduced in patients treated with early synergic administration of NE and VA (Fig. 1). This strategy optimized multiorgan perfusion.

References

1.

Evans L. Intesnive Care Med 2021;47:1181–1247.

2.

Sacha GL. Crit Care Med. 2022;50:614–623.

Fig. 1 (abstract P189). Correlations between all the variables analyzed at T0, T2 and T3 (a,b,c). Intensity of Red indicates inverse correlations, Blue indicates direct. There is a greater direct correlation at T3 between the dose of norepinephrine and the Resistance Index. The hypothesis that can be made to explain this is linked to "receptor desensitization", meaning that the dosage of norepinephrine must be increased over time to produce the desired effect (MAP > 65 mmHg), also causing an increase in side effects such as tachyphylaxis, vasoconstriction and therefore the increase in Resistance Indices. IR MES SUP = AMS; IR O right/left = CRA R/L; KIDNEY IR right/left = ARE R/L; IR snuff right/left = AR R/L; NORA DOSE = Ne dose