What do systematic reviews say?

Multiple vs single‐injection technique

Multiple showed no clear difference in intravascular injection compared with single‐injection technique (moderate certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 1.35 [0.2, 9.06]
  4 studies · 352 participants
  Moderate

Multiple vs double‐injection technique

Multiple showed no clear difference in intravascular injection compared with double‐injection technique (moderate certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.69 [0.32, 1.49]
  7 studies · 676 participants
  Moderate

Double vs single‐injection technique

Double showed no clear difference in intravascular injection compared with single‐injection technique (low certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 4.15 [0.46, 37.13]
  2 studies · 90 participants
  Low

Adverse effects of pharmacological intervention vs control

Adverse effects of pharmacological intervention showed no clear difference in pain on injection compared with control (low certainty).

• Pharmacological and non‐pharmacological interventions for reducing rocuronium bromide induced pain on injection in… 2016 · Cochrane Headline outcomes only
  RR 0.47 [0.09, 2.46]
  1 study · 118 participants
  Low

Plain lidocaine vs buffered lidocaine

• Adjusting the pH of lidocaine for reducing pain on injection 2010 · Cochrane Headline outcomes only
  no estimate extracted
  7 studies · 685 participants
  Moderate

Intervention not reported

• Peripheral nerve blocks for hip fractures in adults 2020 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 75 participants
  Moderate

Peribulbar vs retrobulbar

Peribulbar showed no clear difference in need for additional injection Number of additional injections compared with retrobulbar (low certainty).

• Peribulbar versus retrobulbar anaesthesia for cataract surgery 2015 · Cochrane Headline outcomes only
  RR 1.54 [0.91, 2.6]
  4 studies · 1029 participants
  Low

Infraclavicular block vs all other brachial plexus blocks

• Infraclavicular brachial plexus block for regional anaesthesia of the lower arm 2013 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 391 participants
  High

Double vs single‐injection technique

Double leads to lower primary anaesthesia failure (incomplete sensory block) compared with single‐injection technique (high certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.55 [0.34, 0.89]
  9 studies · 527 participants
  High

Multiple vs single‐injection technique

Multiple showed no clear difference in secondary analgesia failure ‐ tourniquet pain compared with single‐injection technique (high certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.97 [0.3, 3.11]
  4 studies · 379 participants
  High

Multiple vs single‐injection technique

Multiple showed no clear difference in complete failure of block1 compared with single‐injection technique (moderate certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.31 [0.03, 2.71]
  7 studies · 484 participants
  Moderate

Multiple vs single‐injection technique

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 206 participants
  Low

Multiple vs single‐injection technique

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 244 participants
  Low

Multiple vs double‐injection technique

Multiple leads to lower primary anaesthesia failure compared with double‐injection technique (high certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.27 [0.19, 0.39]
  12 studies · 966 participants
  High

Multiple vs double‐injection technique

Multiple showed no clear difference in secondary analgesia failure ‐ intraoperative sedation required compared with double‐injection technique (high certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.75 [0.55, 1.03]
  7 studies · 716 participants
  High

Multiple vs double‐injection technique

Multiple leads to lower secondary analgesia failure ‐ tourniquet pain compared with double‐injection technique (high certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.53 [0.33, 0.84]
  7 studies · 719 participants
  High

Multiple vs double‐injection technique

Multiple showed no clear difference in complete failure of block1 compared with double‐injection technique (low certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.24 [0.04, 1.41]
  9 studies · 630 participants
  Low

Multiple vs double‐injection technique

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  no estimate extracted
  5 studies · 524 participants
  Moderate

Double vs single‐injection technique

Double showed no clear difference in secondary analgesia failure ‐ intraoperative sedation required compared with single‐injection technique (moderate certainty).

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  RR 0.64 [0.31, 1.31]
  2 studies · 129 participants
  Moderate

Multiple vs double‐injection technique

• Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults… 2016 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 510 participants
  Low