Introduction

Minor hand surgical procedures are often performed in an ambulatory setting with local anesthesia (LA) with or without sedation. LA is safe, fast, and effective, but the injection is painful [1, 12, 13]. In one recent series, about 10 % of patients indicated that they would prefer another form of anesthesia [14]. Sedation can make the procedure more comfortable [23]. The trade-off is the need for a more thorough preoperative medical evaluation, the need for the patient to fast, added medical risks, the risk of orthostatic hypotension, respiratory depression, and nausea, and greater anxiety [5, 17, 23, 29].

The aim of this study was to assess satisfaction with the operative experience and pain intensity in patients undergoing minor hand surgery under LA with or without sedation. Our primary null hypothesis was that there is no difference in satisfaction with surgery between patients treated with and without sedation accounting for other factors. Secondary study questions addressed differences in satisfaction with the anesthesia, pain at enrollment, pain intensity during the operation, and pain with injection accounting for other factors.

Material and Methods

Study Design

The study was IRB-approved. Patients presenting to two hand surgeons were asked to enroll in this prospective observational study. The inclusion criteria were English-speaking patients aged 18 years or older that requested minor hand surgery. Patients were allowed to choose between LA alone and LA with intravenous sedation.

One hundred and one consecutive patients were enrolled between July 2012 and December 2012 after informed consent was obtained. Immediately after enrollment, patients completed a preoperative online questionnaire which included demographic data, current pain intensity, the Patient Health Questionnaire-2 (PHQ-2), a validated two-question measure of depression [3, 15, 16, 19], and the effective coping strategy of pain self-efficacy (the sense that one can accomplish ones goals in spite of pain) with use of the 10-item Pain Self-Efficacy Questionnaire (PSEQ) [6, 21]. Sixteen patients canceled or rescheduled surgery, 8 patients had surgery but could not be contacted after three attempts, 3 patients withdrew from the study, and 1 patient had an axillary block instead of local anesthesia. The excluded patients were more often patients of surgeon A (p = 0.030), but they were otherwise comparable to patients who completed the questionnaires. The final cohort consisted of 73 patients, 40 women and 33 men, with a mean age of 58 years (range 24–89). Thirty-seven patients had carpal tunnel release (bilateral in 3), 22 had release of one or more trigger digits, and 12 had excision of a benign tumor, gouty tophus (1 patient), or foreign body (1 patient) (Table 1). Both hand surgeons used unbuffered 1 % lidocaine and 0.5 % bupivacaine 1:1 mixture with epinephrine injected with a 25-gauge needle straight into the surgical field immediately prior to incision. The anesthesiologists used midazolam, propofol, and fentanyl for sedation.

Table 1 Demographics
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Within 48 h of surgery, patients were contacted by phone and asked to rate the following on an 11-point ordinal scale between 0 and 10: (1) satisfaction with the treating surgeon, (2) satisfaction with the surgery, (3) satisfaction with the anesthesia, (4) pain during the injection, and (5) pain during the procedure. In addition, we asked them who chose the type of anesthesia (reason for anesthesia: perceived doctor’s or patient’s choice). We also recorded time in the operating room, the duration of the operation, and the tourniquet time (Table 2). Thirteen patients did not use a tourniquet or the tourniquet time was not recorded.

Table 2 Perioperative data
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Patients

The 46 patients that chose LA and the 27 that chose LA with sedation were comparable except that patients that had trigger digit release were more likely to have LA only and patients having carpal tunnel release were more likely to have sedation (Table 1). Time in the operating room, duration of the operation, and duration of the tourniquet were about 50 % longer in the group with sedation. Three patients complained about nausea, hypertension was recorded in 2 patients, and hypotension or bradycardia were monitored each in 1 patient during the anesthesia in the sedation group. No intraoperative adverse events were recorded in the LA group.

Statistical Analysis

The Pearson chi-square test was used to analyze differences between two categorical variables and the unpaired t test—or the Mann-Whitney U test if not normally distributed—for differences between a continuous (or ordinal) and a dichotomous variable. As a next step, factors associated with satisfaction with surgery and satisfaction with anesthesia (Table 3) as well as factors associated with pain at enrollment, pain during injection, and pain during operation (Table 4) were sought using bivariate analysis—Mann-Whitney U test, Kruskal-Wallis test, and Spearman’s correlation. Finally, multivariable analysis (linear regression) was performed to assess the impact of significant and nearly significant (p < 0.1) factors on satisfaction and pain (Table 5).

Table 3 Bivariate analysis, satisfaction
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Table 4 Bivariate analysis, pain
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Table 5 Significant predictors
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We performed a power analysis after enrolling 20 patients. We calculated that 72 patients would provide 80 % power to detect a difference in satisfaction with surgery between patients treated with and without sedation given an effect size of 0.68 (calculated by the difference of the mean satisfaction and standard deviation of the enrolled patients and an assumed clinically relevant difference of 1.5 points on an 11-ordinal scale).

The data was collected using Research Electronic Data Capture (REDCap), a free, secure, web-based electronic data capture tool for research studies [9]. Only complete questionnaires could be saved; therefore, we had no missing items.

Results

There was no difference in satisfaction with surgery by the type of anesthesia (Table 2). Greater satisfaction with surgery was associated with older age, reason for anesthesia (perceived doctor’s choice), longer time in the operating room, and longer tourniquet time (Table 3). There was a significant positive correlation between satisfaction with surgery and satisfaction with anesthesia. Satisfaction with surgery was not related to PHQ-2 (depression), PSEQ (pain self-efficacy), the treating doctor, the procedure type, pain during injection, or pain during the procedure. The best multivariable model for satisfaction with surgery included age alone and accounted for 6 % of the variation (Table 5).

Satisfaction with anesthesia was not related to choice of anesthesia, but was associated with no prior surgery for the same condition (Table 3). Higher satisfaction with anesthesia was significantly correlated with less pain during injection as well as less pain during the procedure. The best multivariable model for satisfaction with anesthesia included no prior surgery and accounted for 15 % of the variation (Table 5).

In bivariate analysis, pain during injection was associated with the type of anesthesia, patients that chose LA only had more pain during injection (Table 4). The best multivariable model for pain with injection included anesthesia (LA) and younger age, and accounted for 33 % of the variation (Table  5).

Pain intensity during surgery was associated with anesthesia choice (LA) (Table 4). There were no predictors in the best multivariable model (Table 5).

In bivariate analysis, greater pain intensity at enrollment was associated with more symptoms of depression (higher PHQ-2), less pain self-efficacy (lower PSEQ-2), and the diagnosis (Table 4). There was no correlation between pain intensity at enrollment and pain during injection as well as pain during the procedure. The best multivariable model for greater pain intensity at enrollment included lower PSEQ as well as a carpal tunnel syndrome (vs. benign mass), and accounted for 23 % of the variation (Table 5).

Discussion

Patients that had local anesthesia immediately prior to incision with tourniquet use during surgery had more pain during the procedure, but were equally satisfied with surgery and with anesthesia on average compared to patients that had sedation. In addition, surgery was clearly shorter without sedation.

The reader must be aware that the patients in the current study had relatively rapid injection of local anesthesia immediately prior to incision using a 25-gauge needle. There is some evidence that using a 27-gauge needle, buffered and warmed local anesthesia with epinephrine, no tourniquet, injecting perpendicularly to the skin and subdermally while distracting the patients (talking, pinching), with a slow rate of injection and adequate time to let the local take effect, might have different results [7, 8, 28].

Consistent with our findings, a recent study of patient satisfaction with carpal tunnel decompression under local anesthesia found no relationship between pain with local anesthesia and satisfaction with the surgical hand procedure [2]. Age was the only factor retained in the best multivariable model: Older patients were more satisfied with surgery. This is also consistent with prior studies [11, 24–26]. Also consistent with prior studies, our model explained only 6 % of the variation in satisfaction. Patient satisfaction is complex and poorly understood. Perhaps it is related to overall health status, education level, and participati on in the decision-making process that were not accounted for in our model [11, 25].

Depression (measured with the PHQ-2) and the coping strategy of pain self-efficacy (the sense that one can accomplish ones goals in spite of pain, measured with the PSEQ) had a high impact on pain at enrollment; a prior study about minor hand surgery also found a significant correlation between pain intensity at the time of suture removal and depression [30]. However, depression and the coping strategy of pain self-efficacy did not affect satisfaction with surgery or anesthesia and pain during the injection or the procedure in our study.

Longer surgeries and especially longer tourniquet time might be associated with more pain [10]. We found, however, the opposite—longer operation in sedation were less painful. The explanation may be found in the overall very short procedure times of less than 20 min in our study, since one study showed a well tolerance of tourniquet use up to 20 min [22].

There are several potential shortcomings to take into account when interpreting this study: The small sample size limits generalizability. In spite of the fact that the decision for anesthesia was meant to be the patients, there was a difference in the use of sedation, suggesting that the two surgeons may have presented the options differently. We did not monitor the depth of sedation. We did not study whether the choice of anesthesia affected the long-term outcome. And last, this was not a randomized trial, so we can only comment on the experiences of patients that were given a choice of whether or not to have sedation with their local anesthesia.

In summary, patients having minor hand surgery can be offered the choice of local anesthesia with or without sedation with a high and comparable rate of satisfaction and a low and similar rate of pain. Research to date has demonstrated some benefits of specific technical aspects of local anesthesia, but that is an area that might benefit from additional investigation [13, 18, 20, 28]. We would also consider studies of decision aids to help patients prepare for minor surgery choose a type of anesthesia, screening measures to identify patients likely to be unhappy with local anesthesia alone, and the value of preoperative training and preparation in reducing the unpleasantness of local anesthesia [4, 27].