Excluded studies
| Reference | Intervention | Reason for exclusion |
| Tawfic et al 29 | Ketamine | Case report |
| Heartsill and Brown30 | Gabapentin | Case report |
| Fletcher et al 31 | Locally applied transdermal nitrate patches | Patients had ‘distal limb ischaemia’ but the paper did not provide sufficient information to confirm that patients had critical limb ischaemia |