Summary of findings for adult patients having single shot versus continuous catheter adductor canal block for total knee arthroplasty
| Outcomes | Single shot ACB mean (SD) or events/total patients | Continuous ACB mean (SD) or events/total patients | Standardized mean difference or OR (HKSJ 95% CI) | No of participants (studies) | Strength or certainty of the evidence (GRADE) | Comments |
| Primary outcomes | ||||||
| Analgesic consumption between 0 and 48 hours postoperatively (mg) | 123.09 (168.19) | 106.17 (164.18) | 0.28 (–0.47 to 1.03) | 711 (8) | High | High inconsistency with I2 of 85%; however, resolved with sensitivity analysis |
| AUC rest pain scores between 0 and 48 hours postoperatively (cm.h) | 13.99 (7.52) | 9.46 (5.13) | 2.18 (–2.38 to 6.74) | 325 (4) | Low | Unresolved inconsistency with I2 of 96% High risk of small study effects |
| Secondary outcomes | ||||||
| Rest pain at PACU, assessed with NRS score: 0–10 cm (worst) | 2.42 (2.84) | 1.24 (1.58) | 0.70 (–0.32 to 1.72) | 325 (4) | Moderate | High inconsistency (I2 of 85%) |
| Rest pain at 6 hours, assessed with NRS score: 0–10 cm (worst) | 3.95 (2.69) | 2.63 (1.82) | 1.52 (0.05 to 2.99) | 584 (7) | Low | High inconsistency (I2 of 96%) Imprecision due to MCID being met with upper bound of CI |
| Rest pain at 12 hours, assessed with NRS score: 0–10 cm (worst) | 3.36 (2.11) | 2.73 (1.70) | 0.46 (–0.41 to 1.33) | 504 (5) | Moderate | High inconsistency (I2 of 92%) |
| Rest pain at 24 hours, assessed with NRS score: 0–10 cm (worst) | 3.05 (1.82) | 2.48 (1.69) | 0.78 (–0.10 to 1.67) | 809 (9) | Moderate | High inconsistency (I2 of 91%) |
| Rest pain at 48 hours, assessed with NRS score: 0–10 cm (worst) | 2.86 (1.70) | 2.10 (1.74) | 1.19 (0.56 to 2.32) | 856 (9) | Moderate | High inconsistency (I2 of 93%) |
| AUC rest pain scores between 24 and 48 hours postoperatively (cm.hour) | 2.87 (2.03) | 2.20 (2.01) | 0.75 (–0.09 to 1.59) | 761 (8) | Moderate | High inconsistency (I2 of 89%) |
| Analgesic consumption at PACU (mg) | N/A | N/A | N/A | 44 (1) | N/A | No difference observed between the two groups |
| Analgesic consumption between 0 and 24 hours postoperatively (mg) | 67.45 (102.62) | 57.28 (93.08) | 0.25 (–0.40 to 0.90) | 796 (9) | Moderate | High inconsistency (I2 of 85%) |
| Analgesic consumption between 24 and 48 hours postoperatively (mg) | 48.20 (130.08) | 37.72 (105.20) | 0.12 (–0.19 to 0.43) | 711 (8) | Moderate | High inconsistency (I2 of 52%) |
| Time to analgesic request (hour) | N/A | N/A | N/A | 236 (2) | N/A | Both studies did not identify differences between the two groups |
| Functional recovery (high log odds=better function)* | N/A | N/A | 0.04 (–0.79 to 0.89) | 776 (10) | Low | High inconsistency (I2 of 86%) Several functional tools used and possibility of indirectness |
| Duration of PACU stay (hour) | N/A | N/A | N/A | 105 (1) | N/A | No difference observed between the two groups |
| Duration of hospital stay (days) | 4.14 (2.19) | 4.10 (2.16) | 0.21 (0.00 to 0.42) | 715 (8) | High | Low risk of bias, inconsistency, indirectness, and small study effects |
| Block procedure time (minutes) | N/A | N/A | N/A | 48 (1) | N/A | Quicker procedural time reported with sACB |
| Opioid related side effect of nausea/vomiting | 56/384 | 39/328 | 0.79 (0.5 to 1.25) | 712 (8) | High | Low risk of bias, inconsistency, indirectness, and small study effects |
| Opioid-related side effect of drowsiness | N/A | N/A | N/A | 60 (1) | N/A | 1/30 events of drowsiness with sACB; 0/30 events with cACB |
| Nerve block-related side effects | 0/469 | 8/415 | 0.24 (0.14 to 0.41) | 884 (10) | High | Low risk of bias, inconsistency, indirectness, and small study effects |
*No individual effect measures since log (OR) calculated.
.ACB, adductor canal block; AUC, area under the curve; cACB, continuous ACB; GRADE, Grades of Recommendation, Assessment, Development and Evaluation; HKSJ, Hartung-Knapp-Sidik-Jonkman; MCID, minimal clinically important difference; N/A, not applicable; NRS, Numeric Rating Scale; PACU, postanesthesia care unit.