| Authors [ref no.] |
Year | Country | Subject no. (intervention/control) |
Age (years) (intervention/control) |
Surgical approach | Intervention (TENS) | Dose of TENS | Frequency (Hz) | Control | Pain scale | Postoperative analgesic regimen | Anesthesia (local/spinal/general) |
Follow-up (day) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gilbert (19) | 1986 | UK | 40 (20/20) | 50/56 | Anterior approach | Conventional | Single | 70 | Sham | VAS | Nothing | 0/40/0 | 3 |
| Smedley (20) | 1988 | UK | 62 (34/28) | 57/55 | Anterior approach | Conventional | Single | 70 | Sham | VAS | Nothing | 0/0/62 | 2 |
| DeSantana (21) | 2008 | USA | 40 (20/20) | 49/42 | Anterior approach | Conventional | Twice | 100 | Sham | NRS | Dipyrone 1 g | 0/40/0 | 1 |
| Ahmed (22) | 2010 | Egypt | 60 (30/30) | 36/34 | Anterior approach | Conventional | Repetitive | 100 | Sham | VAS | Paracetamol 500 mg | 67/0/0 | 5 |
| Dias (23) | 2010 | Brazil | 33 (16/17) | 47/43 | Anterior approach | AL-TENS | Twice | 240 | Sham | VAS | Nothing | 33/0/0 | 14 |
| Dalamagka (24) | 2015 | Greece | 36 (18/18) | 54/53 | Anterior approach | AL-TENS | Repetitive | 2 | Sham | VAS | Pethidine 15 mg | 0/0/36 | 2 |
| Eidy (25) | 2016 | Iran | 66 (33/33) | 34/33 | Anterior approach | Conventional | Single | NR | Sham | VAS | PCA (pethidine 4 mg/hour) | 0/0/66 | 1 |
| Gorganchian (26) | 2016 | Argentina | 24 | NR | Anterior approach | Conventional | Repetitive | 100 | Sham | VAS | Tramadol 50 mg | NR | 1 |
| Yilmaz (27) | 2019 | Turkey | 52 (26/26) | 45/50 | Anterior approach | Conventional | Repetitive | 100 | Sham | VAS | Diclofenac 75 mg | NR | 1 |
| Parseliunas (28), (30) | 2021 | Lithuania | 80 (40/40) | 62/61 | Anterior approach | Conventional | Repetitive | 100 | Sham | VAS | Ketoprofen 100 mg | 0/80/0 | 2 |
| Szmit (29) | 2021 | Poland | 48 (24/24) | 64/61 | Laparoscopy | Conventional | Repetitive | 100 | Sham | VAS | PCA (morphine 1 mg/time) | 0/0/48 | 1 |
| Authors [ref no.] |
Risk of bias 2 tool assessment | |||||
|---|---|---|---|---|---|---|
| Bias arising from the randomization process | Bias due to deviations from the intended interventions | Bias due to missing outcome data | Bias in the measurement of the outcome | Bias in the selection of the reported results | Overall risk of bias | |
| Gilbert (19) | Some concerns | Low | Low | Some concerns | Some concerns | Some concerns |
| Smedley (20) | Some concerns | Low | Low | Some concerns | Some concerns | Some concerns |
| DeSantana (21) | Low | Low | Low | Some concerns | Some concerns | Some concerns |
| Ahmed (22) | Low | Low | Some concerns | Some concerns | Low | Some concerns |
| Dias (23) | Low | Low | Low | Low | Some concerns | Some concerns |
| Dalamagka (24) | Low | Low | Low | Low | Some concerns | Some concerns |
| Eidy (25) | Low | Low | Low | Some concerns | Low | Some concerns |
| Gorganchian (26) | Some concerns | Low | Low | Some concerns | Some concerns | Some concerns |
| Yilmaz (27) | Some concerns | Some concerns | Some concerns | Some concerns | Some concerns | Some concerns |
| Parseliunas (28), (30) | Low | Low | Low | Some concerns | Low | Some concerns |
| Szmit (29) | Low | Low | Low | Some concerns | Low | Some concerns |
| Efficacy and safety of transcutaneous electrical nerve stimulation in patients undergoing inguinal hernia repair | ||||||
|---|---|---|---|---|---|---|
| Patient or Population: Adults, Setting: Inguinal hernia repair, Intervention: TENS, Comparison: Sham | ||||||
| Outcomes | Anticipated Absolute Effects * (95% CI) | Relative Effect (95% CI) |
Patient Number (Studies) |
Certainty of the Evidence (GRADE) |
Comments | |
| Risk with control | Risk with TENS | |||||
| Patients’ pain (POD1) |
- | SMD −1.22 (−1.92 to −0.52) |
- | 559 (11 RCTs) |
Moderate a,b,c | TENS may result in a large reduction in pain at POD 1. |
| Rescue analgesic use | 569 per 1000 | 427 per 1000 (267 to 672) |
RR 0.75 (0.47 to 1.18) |
252 (5 RCTs) |
Low a,b | TENS may result in little to no difference in rescue analgesic use. |
| Patients’ pain (POD 0) |
- | SMD −2.14 (−3.54 to −0.73) |
- | 307 (6 RCTs) |
Moderate a,b,c | TENS likely result in a large reduction in pain at POD 0. |
| Patients’ pain (POD 2) |
- | SMD −0.97 (−2.04 to 0.10) |
- | 275 (5 RCTs) |
Low a,b | TENS may slightly reduce pain at POD 2. |
| Quality of life Assessed with SF-36 |
The mean score was 53.02 | MD 2.58 (−3.61 to 8.77) |
- | 73 (1 RCT) |
Very low b,d | The evidence is very uncertain about the effect of TENS on the quality of life |
| Adverse events | In one patient in the TENS group and two patients in the sham group, skin irritation (redness and itching) was observed. | 242 (3 RCTs) |
Moderate a | No serious adverse events were observed. | ||
