Table 6. Summary of secondary adverse events.
| Adverse events | No. of studies | DEX group no./total (%) | Saline group no./total (%) | Effect size# (95% CI) | I2 test (%) | P value | NNH/NNT |
| Nausea | 8 | 22/227 (9.69) | 20/192 (10.42) | 0.99 (0.51, 1.89) | 0 | 0.97 | — |
| Vomiting | 7 | 9/223 (4.04) | 11/170 (6.47) | 0.70 (0.28, 1.76) | 0 | 0.45 | — |
| Itching | 4 | 2/125 (1.60) | 2/89 (2.25) | 0.76 (0.12, 4.87) | 0 | 0.77 | — |
| Respiratory depression | 4 | 0/135 (0) | 0/99 (0) | NE | NA | NA | — |
| Urine retention | 3 | 1/80 (1.25) | 3/80 (3.75) | 0.49 (0.09, 2.74) | 0 | 0.41 | — |
| Additional sedation | 3 | 5/79 (6.33) | 12/77 (15.58) | 0.15 (0.03, 0.64) | NA | 0.01 | NNT 11.1 |
| Shivering | 3 | 8/79 (10.13) | 6/77 (7.79) | 1.28 (0.42, 3.85) | 0 | 0.66 | — |
| Hypoxemia | 2 | 4/49 (8.16) | 5/47 (10.64) | 0.64 (0.14, 2.92) | NA | 0.56 | — |
| Cardiac arrhythmia | 1 | 0/30 (0) | 0/30 (0) | NE | NA | NA | — |
| Agitation | 1 | 2/30 (6.67) | 8/30 (26.67) | 0.20 (0.04, 1.02) | NA | 0.05 | — |
# Effect size: odd ratios for adverse events.
Abbreviations: NA, not applicable; NE, not estimable, NNH, number need to harm; NNT, number need to treat.