Kim 2013a.
Methods | Double‐blind randomized controlled trial | |
Participants | Age (years, mean ± SD): Group C = 38.32 ± 15.73, Group L = 35.52 ± 15.57, Group N = 41.86 ± 15.67, Group LN = 47.26 ± 13.97 Gender (M:F): Group C = 25:25, Group L = 20:30, Group N = 29:21, Group LN = 20:30 Inclusion criteria: Age 18 years to 68 years old, ASA I‐II, undergoing elective surgery Exclusion criteria: if patients met any of the following criteria: the regular use of sedatives or analgesics; an allergy to lidocaine; a pre‐existing movement disorder; pre‐existing drug abuse; inability to co‐operate or give informed consent; any anticipated difficulty in obtaining an airway; thrombophlebitis (or any other pain‐causing lesion); the presence of chronic obstructive pulmonary disease (COPD); or any contraindication to the administration of N2O (e.g. pneumothorax Recruitment: 205 adult patients randomly assigned (200 were analysed) Setting: Korea |
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Interventions |
Pretreatment with venous occlusion A total of 205 adult patients received one of the following combinations: NaCl and 100% O2 (Group C; n = 50); 0.5 mg/kg pretreated lidocaine and 100 % O2 (Group L; n = 50); NaCl and a mixture of 67% N2O/O2 (Group N; n = 50); 0.5 mg/kg lidocaine and a mixture of 67% N2O/O2 (Group LN; n = 50). Vein occlusion was released after 1 min, and 5 ml propofol was injected over 10 sec. The remainder of the induction dose of propofol (with a 3 ml bolus of normal saline and 0.6 mg/kg rocuronium) was then injected. The response to the rocuronium injection was assessed with a 4‐point scale (0–3) |
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Outcomes | Pain intensity assessed on 11‐point scale using a 0‐10, visually enlarged, laminated, Numeric Rating Scale Outcomes reported and used
Outcomes sought but not reported
Outcomes reported but not used
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Notes | Period of the study: dates not reported | |
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | A computer‐generated randomization table |
Allocation concealment (selection bias) | Unclear risk | N/A |
Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | N/A |
Blinding of outcome assessment (detection bias) All outcomes | Low risk | "The investigator recording the pain scores was blinded to the drugs given and to the gas mixture administered to the patients." |
Incomplete outcome data (attrition bias) All outcomes | Low risk | "A total of 205 patients were initially recruited into the study. Three patients were excluded because of difficulty with venous cannulation on the dorsum of the hand. Two patients in group N could not complete the study (one developed excitement and laughing and the other was oversedated)." |
Selective reporting (reporting bias) | Unclear risk | N/A |
Other bias | Low risk | The study appears to be free of other sources of bias |