Table 1.
Study characteristics.
| Author, year | Country | Groups and interventions | (n) | Age (y), % males | Time of treatment | Anesthesia | Intra/postoperative analgesia | Main outcomes |
|---|---|---|---|---|---|---|---|---|
| Al-Metwalli, 2008 | Saudi Arabia | 1. DEX 1 μg/kg + saline to 20 ml 2. Saline 20 ml |
20 20 |
40.2, 55% 38.2, 65% |
Before tourniquet release | General | Fentanyl/diclofenac | Pain VAS at 1–24 h, diclofenac use 0–24 h, time to first analgesia, PONV, hypotension, and bradycardia |
| Alipour, 2014 | Iran | 1. DEX 1 µg/kg + saline to 25 ml 2. Saline 25 ml |
21 23 |
30.8, 71.4% 29.4, 73.9% |
Before tourniquet release | General | Fentanyl/tramadol | Pain VAS at 1–24 h, tramadol use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and pruritus |
| Cao, 2016 | China | 1. DEX 100 µg + saline to 15 ml 2. DEX 50 µg + saline to 15 ml 3. Saline 15 ml |
20 20 20 |
42.1, 50% 44.1, 35% 42.2, 40% |
Before the end of surgery | General | Fentanyl/flurbiprofen | Pain VAS at 1–24 h, flurbiprofen use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and somnolence |
| Cui, 2014 | China | 1. DEX 1 µg/kg + 0.25% bupivacaine to 20 ml 2. 0.25% bupivacaine 20 ml |
20 20 |
40.2, 40% 39.4, 4% |
Before the end of surgery | General | Fentanyl/PCA with fentanyl | Pain VAS at 1–24 h, fentanyl use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and somnolence |
| Elbadawy, 2015 | Egypt | 1. DEX 1 µg/kg + 0.25% bupivacaine to 25 ml 2. 0.25% bupivacaine 25 ml |
25 25 |
36.5, 56% 33.6, 64% |
Before tourniquet release | General | Fentanyl/paracetamol | Pain VAS at 0.5–12 h, paracetamol use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and hallucination |
| Lei, 2014 | China | 1. DEX 1 μg/kg + saline to 20 ml 2. Saline 20 ml |
20 20 |
40.0, 40% 39.0, 45% |
Before the end of surgery | General | Fentanyl/lornoxicam | Pain VAS at 1–24 h, lornoxicam use 0–24 h, time to first analgesia, PONV, hypotension, and bradycardia |
| Panigrahi, 2015 | India | 1. DEX 1 µg/kg + 0.2% ropivacaine to 20 ml 2. DEX 2 µg/kg + 0.2% ropivacaine to 20 ml 3. 0.2% ropivacaine 20 ml |
20 20 20 |
31.7, 75% 32.3, 65% 30.8, 70% |
Before tourniquet release | Spinal | Bupivacaine/diclofenac | Pain VAS at 1–24 h, diclofenac use 0–24 h, time to first analgesia, PONV, hypotension, and bradycardia |
| Panigrahi, 2016 | India | 1. DEX 1 µg/kg + 0.2% ropivacaine to 20 ml 2. 0.2% ropivacaine 20 ml |
20 20 |
31.7, 75% 30.8, 70% |
Before tourniquet release | Spinal | Bupivacaine/diclofenac | Pain VAS at 1–24 h, diclofenac use 0–24 h, time to first analgesia, PONV, hypotension, and bradycardia |
| Paul, 2010 | India | 1. DEX 100 µg + 0.25% ropivacaine to 20 ml 2. 0.25% ropivacaine 20 ml |
30 30 |
41.4, 70% 39.8, 73% |
Before arthroscope removal | General | Fentanyl/PCA with fentanyl | Pain VAS at 1–18 h, fentanyl use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and somnolence |
| Wang, 2014 | China | 1. DEX 1 µg/kg + 0.25% ropivacaine to 20 ml 2. 0.25% ropivacaine 20 ml |
30 30 |
40.0, 46% 40.0, 56% |
Before tourniquet release | General | Fentanyl/fentanyl | Pain VAS at 1–24 h, fentanyl use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and hypoxemia |
| Yao, 2012 | China | 1. DEX 0.7 μg/kg + saline to 15 ml 2. Saline 15 ml |
20 20 |
40.2, 55% 39.2, 65% |
Before tourniquet release | General | Fentanyl/tramadol | Pain VAS at 1–12 h, tramadol use 0–24 h, time to first analgesia, PONV, hypotension, and bradycardia |
| Zhang, 2015 | China | 1. DEX 100 µg + 0.25% ropivacaine to 20 ml 2. 0.25% ropivacaine 20 ml |
30 30 |
40.4, 63% 38.9, 66% |
Before the end of surgery | General | Fentanyl/PCA with fentanyl | Pain VAS at 1–24 h, fentanyl use 0–24 h, time to first analgesia, PONV, hypotension, bradycardia, and somnolence |
DEX, dexmedetomidine; VAS, visual analogue scale score; PONV, postoperative nausea and vomiting; PCA, patient controlled analgesia.