Cardiorespiratory capacity in tetra- and paraplegia shortly after injury

In one hundred patients (86 males, 14 females) with relatively recent spinal cord injuries the oxygen supporting system was evaluated during graded arm ergometry. The patients were assigned according to injury level to 5 subgroups with complete, and to 2 additional groups with incomplete injuries. Mean peak oxygen uptake (VO2) was found to be as low as 0.74 l/min in males with complete tetraplegia and 1.9 l/min in patients with conus and cauda lesions. Peak VO2 was closely correlated (r = 0.74) to the injury level. Peak VO2 was also closely correlated to peak minute ventilation (VE) in all groups. In patients with higher injury levels most of the increase in VE during maximal exercise was due to an increase in respiratory frequency (fR). In patients with tetraplegia and high paraplegia, arm cranking revealed deficient sympathetic regulation of cardiovascular functions resulting in hypotension. In both the complete and incomplete tetraplegic patients there was a relatively low peak heart rate (fH). Peak fH and VO2 varied more in patients with incomplete tetraplegia than in those with complete tetraplegia. Peak VO2 in females with mid-level thoracic paraplegia was on the average lower than in males with corresponding injury levels (16 ml/kg/min against 22 ml/kg/min, respectively). Evaluation of cardiorespiratory functions in spinal cord injured patients during high intensity endurance work performed shortly after the injury adds diagnostic and functionally useful information for the design of rehabilitation and should be recommended as clinical routine.