Through clinical cases or retrospective work with small sample size, some authors have observed an improvement in hemodynamic parameters, with a reduction or even withdrawal of norepinephrine after administration of a single dose of hydroxocobolamin (HCB) in refractory vasoplegic shock (cardiac surgery, liver transplantation and septic shock).

HCB produces beneficial alterations in NO metabolism and may be suitable in vasoplegic syndrome. In addition, HCB seems to be involved in the elimination of hydrogen sulfide which also has an endogenous vasodilator function in the vascular endothelium. By these different actions it would cause vasoconstriction in vascular smooth muscle cells. Previous reports demonstrate that HCB was useful for refractory vasoplegic syndrome.

The investigators will conduct a retrospective data collection of patients who was given intravenous HCB for refractory vasoplegic shock since January 2019.

Vasoplegic shock is defined by arterial hypotension, a high cardiac output with a normal or high cardiac index, collapsed systemic vascular resistance (SVR) and high dose of norepinephrine in the absence of hypovolaemia. The drop in secondary organ perfusion pressure ultimately leads to multiple organ failure and death.

Through clinical cases or retrospective work with small sample size, some authors have observed an improvement in hemodynamic parameters, with a reduction or even withdrawal of norepinephrine after administration of a single dose of hydroxocobolamin (HCB) in refractory vasoplegic shock (cardiac surgery, liver transplantation and septic shock).

HCB produces beneficial alterations in NO metabolism and may be suitable in vasoplegic syndrome. In addition, HCB seems to be involved in the elimination of hydrogen sulfide which also has an endogenous vasodilator function in the vascular endothelium. By these different actions it would cause vasoconstriction in vascular smooth muscle cells. Previous reports demonstrate that HCB was useful for refractory vasoplegic syndrome.

The investigators will conduct a retrospective data collection of patients who was given intravenous HCB for refractory vasoplegic shock since January 2019.

Inclusion Criteria:

• All SVR patients over 18 years of age who had received a dose of HCB since January 1 2019 will be included.

Exclusion Criteria:

• Patients who received treatment for another indication were not included.

All SVR (systemic vascular resistance) patients over 18 years of age who had received a dose of HCB since January 1 2019 will be included. Patients who received treatment for another indication were not included.