Study	Reason for exclusion
Ackerman 2006	Not randomised
Arias 1989	Not randomised
Catala 1994	Sympathetic blockade versus intravenous lidocaine for postherpetic neuralgia
Dellemijn 1994	Sympathetic blockade versus phentolamine infusion
Erickson 1993	Not randomised
Farcot 1990	Not randomised
Fukusaki 1995	Nerve blocks (including sympathetic blocks) for cervical radiculopathy
Garrido 2005	Not randomised
Glynn 1993	Not randomised
Hartrick 2004	Not randomised
ISRCTN71968956	Not randomised
Kastler 2013	Not randomised
Linson 1983	Not randomised
Malmqvist 1992	Not randomised
Meier 2009	< 48 h follow‐up postblock
Perrigot 1982	Not a local sympathetic block
Quevedo 2005	Not randomised
Raja 1991	< 48 h follow‐up postblock
Schurmann 2001	Not randomised
Steinbrocker 1953	Not randomised
Tran 2000	Sympathetic blockade plus iohexol versus sympathetic blockade plus saline; evaluating the effect of the contrast agent iohexol
Verdugo 1995	<48 h follow‐up postblock
Wang 1985	Not randomised
Wehnert 2002	<48 h follow‐up postblock
Yucel 2009	Not randomised