Hemodynamic challenge to early mobilization after cardiac surgery: A pilot study

Abstract

Background:

Active mobilization is a key component in fast-track surgical strategies. Following major surgery, clinicians are often reluctant to mobilize patients arguing that circulatory homeostasis would be impaired as a result of myocardial stunning, fluid shift, and autonomic dysfunction.

Aims:

We examined the feasibility and safety of a mobilization protocol 12–24 h after elective cardiac surgery.

Setting and Design:

This observational study was performed in a tertiary nonacademic cardiovascular Intensive Care Unit.

Materials and Methods:

Over a 6-month period, we prospectively evaluated the hemodynamic response to a two-staged mobilization procedure in 53 consecutive patients. Before, during, and after the mobilization, hemodynamics parameters were recorded, including the central venous oxygen saturation (ScvO ₂), lactate concentrations, mean arterial pressure (MAP), heart rate (HR), right atrial pressure (RAP), and arterial oxygen saturation (SpO ₂). Any adverse events were documented.

Results:

All patients successfully completed the mobilization procedure. Compared with the supine position, mobilization induced significant increases in arterial lactate (34.6% [31.6%, 47.6%], P = 0.0022) along with reduction in RAP (−33% [−21%, −45%], P < 0.0001) and ScvO ₂ (−7.4% [−5.9%, −9.9%], P = 0.0002), whereas HR and SpO ₂ were unchanged. Eighteen patients (34%) presented a decrease in MAP > 10% and nine of them (17%) required treatment. Hypotensive patients experienced a greater decrease in ScvO ₂ (−18 ± 5% vs. −9 ± 4%, P = 0.004) with similar changes in RAP and HR. All hemodynamic parameters, but arterial lactate, recovered baseline values after resuming the horizontal position.

Conclusions:

Early mobilization after cardiac surgery appears to be a safe procedure as far as it is performed under close hemodynamic and clinical monitoring in an intensive care setting.