Table 1 The major characters of these included studies
| Studies | Publish year | sample size (n) | Age (yr) | Type of surgery | Dexmedetomidine doses | Control | Delirium assessment methods | Time of CPB (min) | Primary Outcomes | Secondary Outcomes |
|---|---|---|---|---|---|---|---|---|---|---|
| Azeem | 2018 | 60 |
DEX: 65.3 ± 4.8 CON: 66.7 ± 5.6 | MIX | infusion 0.4–0.7 μg/kg/h postoperatively | MOR | CAM-ICU | ND | POD incidence | HR, SBP, DBP, Duration of intubation and mechanical ventilation |
| Balkanay | 2015 | 88 | Mean age: 60.5 ± 8.6 | CABG |
High-dose DEX group: 0.04–0.50 mg/kg/h Low-dose DEX group: 0.04–0.50 mg/kg/h | NS | ND |
NS: 91.1 ± 32.1 DEX1: 98.6 ± 34.7 DEX2: 100.7 ± 29.5 | Renal function | POD incidence, length of ICU stay, hospital stay, bradycardia, hypotension, AF, postoperative agitation, furosemide need |
| Corbett | 2005 | 89 |
DEX: 63.6 ± 10.1 PRO: 62.4 ± 10.7 | CABG | 1 mg/kg loading dose, then 0.4 mg/kg/h during MV | PRO | Modified Hewitt questionnaire | ND | Patients’ satisfaction | POD incidence, length of ICU stay, hospital stay, MV, in-hospital mortality, pain, etc |
| Djaiani | 2016 | 183 |
DEX: 72.7 ± 6.4 PRO: 72.4 ± 6.2 | MIX | 0.4 μg/kg infusion over a period of 10-20 min followed by 0.2–0.7 μg/kg/h infusion | PRO | CAM and CAM-ICU |
DEX: 100 (71–127) PRO: 98 (77.5–133) | POD incidence | POD duration, length of ICU stay, hospital stay, time to extubation, in-hospital mortality, AF, etc |
| Li | 2017 | 285 |
DEX: 66.4 ± 5.4 NS: 67.5 ± 5.3 | MIX | 0.6 μg/kg infusion for 10 min, then 0.4 μg/kg/h until the end of surgery, 0.1 μg/kg/h after surgery | NS |
CAM and CAM-ICU MMSE |
DEX: 105 (84 to 129) NS: 101 (81 to 130) | POD incidence | POD duration, length of ICU stay, hospital stay, MV, 30-day mortality, bradycardia, etc |
| Liu | 2016 | 61 |
DEX: 53 (48–63) PRO: 55 (48–62) | Cardiac valve surgery | 0.2–1.5 mg/kg/h after arrival on ICU before extubation | PRO | CAM-ICU |
DEX: 73 (60–88) PRO: 68 (54–80) | microcirculatory variables and clinical parameters | POD incidence, bradycardia, hypotension, nausea, vomiting, AF |
| Maldonado | 2009 | 90 |
DEX: 55 ± 16 PRO: 58 ± 18 MID: 60 ± 16 | Cardiac valve surgery | Loading dose: 0.4μg/kg, followed by a maintenance drip of 0.2 μg/kg/h– 0.7μg/kg/h | PRO and MID | Diagnostic and Statistical Manual of Mental Disorders |
DEX: 165 ± 62 PRO: 162 ± 57 MID: 163 ± 51 | POD incidence | Length of stay in ICU and hospital, use of postoperative rescue medications |
| Massoumi | 2019 | 88 |
DEX: 61.80 ± 7.90 NS: 61.30 ± 8.90 | CABG | 1 μg/kg subcutaneously treated within 10 min and 0.2–0.7 μg/kg/h in hour infusion by the syringe pum | NS | RASS CAM-ICU | ND | POD incidence | laboratory variables and vital signs |
| Park | 2014 | 142 |
DEX: 51.09 ± 16.10 REM: 54.35 ± 13.97 | MIX | 0.5 mg/kg loading dose after arrival on ICU, then 0.2–0.8 mg/kg/h until discharged from ICU | REM | CAM-ICU |
DEX: 159.55 ± 56.55 REM: 173.19 ± 79.56 | POD incidence | POD duration, length of ICU stay, hospital stay, time to extubation; bradycardia,etc |
| Priye | 2015 | 64 |
DEX: 45.1 ± 14.7 NS: 41.4 ± 11.9 | MIX | 0.4 mg/kg/h arrival on ICU for 12 h | NS | RASS |
DEX: 98.22 ± 30.61 NS: 95.00 ± 35.51 | VAS scores | POD incidence, awakening time |
| Shehabi | 2009 | 299 |
DEX: 71.5 (66 to 76) MOR: 71.0 (65 to 75) | MIX | 0.1–0.7 mg/kg/h until removal of chest drain | MOR | CAM-ICU |
DEX: 98 (80 to 128) MOR: 100 (77 to 120) | POD incidence | Length of stay in ICU and hospital, time to extubation, in-hospital mortality, bradycardia, hypotension, tachycardia, AF, VF, etc |
| Shi | 2019 | 164 |
DEX: 74.7 ± 7.2 PRO: 74.2 ± 7.7 | MIX | 0.4–0.6 μg/kg/h maintenance syringe pump intravenous infusion during operation | PRO | CAM |
DEX:110.8 (25.2) PRO: 115.1 (28.9) | POD incidence | POD onset, POD duration, length of stay in ICU and in Hospital |
| Shokri | 2019 | 286 |
DEX: 63.75 ± 3.29 CLO: 64.38 ± 4.81 | CABG | 0.7–1.2 μg/kg/h with an increment of 0.1–0.2 μg/kg/h every 30 min, up to 1–1.4 μg/kg body-weight/h | clonidine | CAM-ICU | ND | POD incidence | Extubation time, lengths of intensive care unit (ICU) and hospital stay, need for inotropic support or vasopressors |
| Subramaniam | 2019 | 120 |
DEX: 64 (63–72) and 79 (63–74) PRO: 70 (66–75) and 71 (64–79) | MIX |
0.5–1 μg/kg during chest closure 0.1–1.4 μg/kg per h infusion continued to 6 h | PRO | CAM or CAM-ICU | ND | POD incidence | Duration of POD, postoperative cognition at discharge, 48-h break-through analgesic requirements, and ICU and hospital lengths of stay |
| Turan | 2020 | 794 |
DEX: 63 ± 11 NS: 62 ± 12 | MIX | 0·1 μg/kg per h before the surgical incision 0·2 μg/kg per h at the end of bypass, 0·4 μg/kg per h maintained until 24 h postoperatively | NS | RASS CAM-ICU | ND | POD incidence Atrial arrhythmia | Kidney function; 90-daypersistent incisional pain |