What do systematic reviews say?

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

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

Double vs single‐injection technique

Double showed no clear difference in secondary analgesia failure ‐ tourniquet pain 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 0.58 [0.22, 1.52]
  2 studies · 104 participants
  Moderate

Double vs single‐injection technique

Double showed no clear difference in complete failure of block3 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 1.29 [0.33, 5.01]
  7 studies · 368 participants
  Low

Double 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
  0 studies · 0 participants
  GRADE not reported

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

Double 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 · 119 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

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

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

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

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 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 single‐injection technique

Multiple leads to lower primary anaesthesia failure 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 0.25 [0.14, 0.42]
  9 studies · 712 participants
  High