In this episode, I’ll discuss what dose of norepinephrine is safe for patient mobilization.
While patient mobilization is important to avoiding complications of an ICU stay, the use of vasopressors like norepinephrine is often perceived as a reason to not mobilize a patient since it indicates hemodynamic instability.
A recent systematic review concluded that evidence determining specific doses of vasoactive drugs that would allow safe mobilization of patients in critical care is lacking. In response to this, a group of researchers at a university hospital in Germany decided to publish their experience mobilizing ICU patients on norepinephrine in the form of a retrospective cohort study. While this is a single center study it does encompass 16 different ICUs.
The authors analyzed over 800 patients who were mobilized over 3300 times while on a continuous infusion of norepinephrine. An ICU mobilization score was used to identify which patients qualified for in-bed only mobilization vs out-of-bed mobilization. Compared with other patients in the cohort who were mobilized while not on a vasopressor, there was no significant difference in mortality between groups. Adverse events related to mobilization on norepinephrine such as hypotension and tachycardia were rare occurring at a rate of 1%.
There was no interaction between the dose of norepinephrine or the type of mobilization (in bed vs out of bed) in terms of adverse event rate. There was a single severe adverse event where a patient on 0.14 mcg/kg/min needed to be resuscitated after an attempt at out-of-bed mobilization and the resuscitation was successful. Furthermore in a sensitivity analysis it did not appear like norepinephrine had any effect at all on the development of an adverse event.
The authors concluded that:
Mobilisation with norepinephrine can be done safely when considering the status of the patient and safety guidelines. We demonstrated that safe mobilisation was possible with norepinephrine doses up to 0.20 µg/kg/min for out-of-bed (IMS ≥ 2) and 0.33 µg/kg/min for in-bed (IMS 0–1) mobilisation.
This represents some very detailed information on a large cohort of patients mobilized while on norepinephrine and until prospective data is available it is reasonable to consider mobilization for patients on norepinephrine using the same criteria described in this article.
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