Equation of Marinho et al for Predicting 6-Minute Walking Distance (6MWD) in an Adult with Sickle Cell Anemia

Patient selection: Brazilian adult with sickle cell anemia

Parameters:

(1) hemoglobin in g/dL

(2) FVC (forced vital capacity) as percent of predicted (from 0 to 100)

(3) tricuspid regurgitant velocity (TRV) in meters per second (m/s)

(4) acute chest syndrome (ACS, with 0 if absent and 1 if present)

6MWD as percent of predicted =

= (7.46 * (hemoglobin)) + (0.296 * (percent of predicted FVC)) - (6.102 * (TRV)) - (2.148 * (points for ACS)) + 8.11

The equation reflects factors that negatively affect the six-minute walking distance:

(1) anemia

(2) reduced pulmonary function

(3) elevated TRV (>= 2.5 m/s)

(4) acute chest syndrome (ACS)