Ask the patient (6 cases) | Wrong patient | 1 | – | – |
| Wrong side | – | 2 | 2 |
| Failed block | – | – | 1 |
Local anaesthetic toxicity (11 cases) | Fitting | 2 | | – |
| Nausea | 1 | – | – |
| Other effects | 8 | | |
Assess level of block (30 cases) | Overdose, n = 20 | | | 3 |
| Total spinal | 14 | – | – |
| High block/prolonged recovery | 3 | – | – |
| Underdose/failed block, n = 10 | | | |
| Incorrect infusion rate | 3 | – | – |
| Communication error | 1 | – | – |
| Not stated | 6 | – | – |
Catheter/needle problems (76 cases) | | | |
Inadvertent intravascular placement or injection (20 cases) | 7 | 13 | – |
| Fitting (5 brachial plexus blocks) | | | |
| Other effects (8 brachial plexus blocks) | | | |
Inadvertent intrathecal placement or injection (35 cases) | | | |
| Inadvertent subarachnoid injection | 1 | – | – |
| Dural puncture (17 with headache§; 10 without headache; 6 not stated) | 33 | – | – |
| Migration of epidural catheter | 1 | – | – |
Inadvertent subdural placement or injection (3 cases) | | | |
| Subdural drug effect | 3 | – | – |
Blocked/kinked/split catheter, or catheter pulled out (4 cases) | 4 | – | – |
Trauma (7 cases) | Pneumothorax | – | 1 | – |
| Epidural haematoma | 1 | – | – |
| Bloody spinal tap | 2 | – | – |
| Haematoma/haemorrhage after ophthalmic block | – | – | 2 |
| Corneal damage | – | – | 1 |
Infection (2 cases) | Epidural abscess | 1 | – | – |
| Positive catheter tip culture | 1 | – | – |
Pain (5 cases) | Dural puncture headache after spinal block§ | 4 | – | – |
| Backache after epidural block | 1 | – | – |
Consequences of sensory/motor blockade (1 case) | Fall post-spinal block | 1 | – | – |
Miscellaneous | Hypothermia after epidural block | 2 | – | – |
Remaining (6 cases) | Other | – | – | 4 |