In patients supported with peripheral veno-arterial extracorporeal membrane oxygenation, what factors are associated with the development of spinal cord ischaemia?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in patients supported with peripheral veno-arterial extracorporeal membrane oxygenation, what factors are associated with the development of spinal cord ischaemia'? Altogether, more than 22 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Of the 28 patients reported by included studies, the thoracic spinal cord was most commonly affected. Twenty patients (71%) survived to hospital discharge and 7 (25%) were reported to have neurological recovery. Potential confounders included coronary angiography, cardiac arrest requiring chest compressions and concomitant intra-aortic balloon pump. Consequently, all papers highlighted the likely multifactorial aetiology of spinal cord infarction in these patients. We propose that close neurological observation, particularly in patients who have received chest compressions, and management of potential aetiological factors is crucial to aid in timely diagnosis and potential prevention of this rare complication. Limiting sedation and neuromuscular blockade to enable neurologic assessment of the lower limbs may allow more timely diagnosis.

Six-minute walk test distance at time of hospital discharge is strongly and independently associated with all-cause mortality following cardiac surgery.

We investigated the impact of distance covered in the six-minute walk test (6mWT) before being discharged from the hospital after cardiac surgery on the risk of all-cause mortality. Our study included 1127 patients who underwent cardiac surgery and then took part in a standardised physiotherapist-supervised inpatient rehabilitation programme during 2007-2017. The percentage of the predicted 6mWT distance, and the lower limit of normal distance was calculated based on individual patients' age, sex, and body mass index. We used Cox regression with adjustment for confounders to determine multivariable-adjusted hazard ratios (HRs) for mortality. Over a median follow-up period of 6.4 (IQR: 3.5-9.2) years, 15% (n = 169) patients died. We observed a strong and independent inverse association between 6mWT distance and mortality, with every 10 m increase in distance associated to a 4% reduction in mortality (HR: 0.96, 95% CI 0.94-0.98, P < 0.001). Those in the top tertile for predicted 6mWT performance had a 49% reduced risk of mortality (HR: 0.51, 95% CI 0.33-0.79) compared to those in the bottom tertile. Patients who met or exceeded the minimum normal 6mWT distance had 36% lower mortality risk (HR: 0.64, 95% CI 0.45-0.92) compared to those who did not meet this benchmark. Subgroup analysis showed that combined CABG and valve surgery patients walked less in the 6mWT compared to those undergoing isolated CABG or valve surgeries, with a significant association between 6mWT and mortality observed in the isolated procedure groups only. In conclusion, the longer the distance covered in the 6mWT before leaving the hospital, the lower the risk of mortality.