A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?

BACKGROUND: Chronic pain is a recognized complication of surgery, and it has been hypothesized that regional anesthesia might reduce the risk of development of chronic pain after upper extremity surgery. METHODS: A systematic literature review was performed to assess whether in patients undergoing elective upper extremity surgery (P), regional anesthesia (I), compared to general anesthesia (C), would result in lower long-term (>3 months) postoperative pain intensity (O). We included randomized and nonrandomized controlled trials (RCTs). Our primary outcome was numerical rating score or visual analogue scale for pain, at >3 months postoperatively. The Embase, Medline ALL, Web of Science Core Collections, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for all reports assessing pain at >3 months after upper extremity surgery under general versus regional anesthesia. Secondary outcomes were: opioid prescription filling, complex regional pain syndrome (CRPS) incidence, the Mayo Wrist Score (MWS), and scores on the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Quality (or certainty) of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Risk-of-bias was assessed using the Cochrane tool for randomized trials (RoB 2.0) and nonrandomized trials (ROBINS-I). RESULTS: This review included 14 studies, comprising 7 RCTs and 7 nonrandomized studies. Six of the 7 studies (4 RCTs, N = 273; 2 nonrandomized studies, N = 305) using a pain score, our primary outcome, report comparable long-term postoperative pain scores after regional and general anesthesia. Six of the 7 studies using our secondary outcomes report comparable long-term outcomes in terms of opioid prescription filling (2 retrospective cohort studies [RCSs], N = 89,256), CRPS incidence (1 RCT, N = 301), MWS (1 RCT and 1 RCS, N = 215), and DASH score (1 RCT, N = 36). Comparable outcomes were reported in all 7 RCTs (N = 778) and in 5 of the 7 nonrandomized studies, comprising 5 RCSs (N = 89,608). Two prospective observational studies (POSTs), comprising 279 patients, report a statistically significant difference in outcomes, with less pain and better DASH scores after brachial plexus anesthesia. All 14 studies provided moderate to very low certainty evidence, and there was a serious risk of bias due to confounding bias in 5 of the 7 nonrandomized studies (N = 631). CONCLUSIONS: The results of this review indicate that upper extremity regional anesthesia, compared to general anesthesia, is unlikely to change pain intensity at >3 months postoperatively.

Incidence of Chronic Postsurgical Pain after Upper Extremity Surgery and its Correlation with Preoperative Pain.

The incidence of chronic postsurgical pain (CPSP) after upper extremity surgery is not known. The goal was to study CPSP at 5 years postoperative and to investigate patient, surgical, and anesthetic risk factors. Methods: Patients scheduled for elective upper extremity surgery were included, and numeric rating scale (NRS) score for pain was obtained preoperatively and at 5 years postoperatively. According to the International Association for the Study of Pain definition, CPSP was defined as an increase in NRS compared with preoperatively. Results: A total 168 patients were contacted at 5 years postoperatively. Incidence of CPSP was 22%, and 35% had an NRS score of 4 or more. The number of patients with an NRS score of 0 and with an NRS score of 4 or more preoperatively was higher in the no-CPSP group, with P values of 0.019 and 0.008, respectively. Of the patients with no preoperative pain, 34% developed CPSP. Regional anesthesia was associated with a lower CPSP incidence (P = 0.001) and was more frequently applied in surgery on bony structures and in patients with a preoperative NRS score of 4 or more. Conclusions: The incidence CPSP was 22%. Patients with no pain or an NRS score of 4 or more preoperatively were less likely to develop CPSP, but individual susceptibility to pain and success of the surgery may be of influence. One-third of the patients with no preoperative pain developed CPSP. More studies are needed to reveal the exact relation between brachial plexus anesthesia and CPSP.

Is It the Surgery or the Block? Incidence, Risk Factors, and Outcome of Nerve Injury following Upper Extremity Surgery.

Although numerous studies have addressed the topic of postoperative nerve injury, debate continues to exist on its exact incidence, risk factors, etiology, and functional outcome. The aim of this study is to investigate the incidence of nerve injury and to identify patient, anesthetic, and surgical factors pertaining to perioperative nerve injury. Also, long-term nerve injury outcomes were assessed in terms of functionality. METHODS: A total of 297 patients, scheduled for elective distal upper extremity surgery, were prospectively included. At various time points, patients were screened for new onset nerve injury by means of clinical examination and questionnaires (including the Quick Disabilities of the Arm, Shoulder and Hand functionality measure). RESULTS: New nerve injury was diagnosed in 14 patients [4.7% (95% CI, 2.8-7.8)], but no causative risk factors were identified. The exact origin of nerve injury is suspected to be surgical in 11 cases. At 4 years postoperatively, 5 of the 14 patients with nerve injury (36%) were still symptomatic and had reduced functionality relative to preoperative status. CONCLUSIONS: This study demonstrates an incidence of all cause nerve injury of 4.7%. No specific patient, anesthetic, or surgical risk factors are identified and, importantly, patients who received regional anesthesia are not at more risk of nerve injury than those who received general anesthesia. The exact origin of nerve injury is very difficult to determine, but is suspected to be caused by direct surgical trauma in most cases. Four years following the nerve injury, approximately 40% of the patients with new onset nerve injury have reduced functionality.

Regional anaesthesia is associated with less patient satisfaction compared to general anaesthesia following distal upper extremity surgery: a prospective double centred observational study.

BACKGROUND: Patient satisfaction is a well-established indicator to evaluate the quality of medical care and there is an increasing support for the use of patient-reported experience measures (PREMs) to evaluate satisfaction. To anesthetize the upper limb for surgery, both general and regional plexus anaesthesia are appropriate techniques. However, the best technique in the anaesthesiologist's perspective might not necessarily result in the highest patient satisfaction. The aim of this study is to investigate patient satisfaction following general and regional anaesthesia, and to identify areas where anaesthesiologists can focus on improving patient care. METHODS: Patients scheduled for elective distal upper extremity surgery under either general or regional plexus anaesthesia were prospectively included. On the first postoperative day, patient satisfaction and main reason for dissatisfaction with the anaesthesia technique were investigated during a telephone interview. RESULTS: Of the 243 patients included in the current study, 79.8% report being "fully satisfied" with their anaesthesia technique. 32.1% of the patients who received regional anaesthesia reported not feeling "fully satisfied". This figure is 5.5% following general anaesthesia. Main reason for dissatisfaction following regional anaesthesia are reported as "insufficient anaesthesia prior to surgery", and "the discomfort of having a long-lasting insensate extremity postoperatively". CONCLUSIONS: Following regional plexus anaesthesia, a third of the patients are not "fully satisfied". To optimize patient satisfaction following regional anaesthesia techniques, we advocate stronger focus on patient counselling preoperatively, addressing the issues of block failure and prolonged postoperative sensory and motor block.

Individual duration of axillary brachial plexus block is unpredictable: a prospective double centered observational study.

BACKGROUND: The duration of effect for axillary plexus block using ropivacaine is highly variable. The available literature does not offer any plausible means of predicting time of block offset for individual patients, making it difficult to give accurate information and plan postoperative analgesics. This study was designed to identify factors influencing axillary plexus block offset time. METHODS: A total of 92 patients participated in this prospective double centred observational study. All patients were scheduled for axillary plexus block with ropivacaine 0.75% and subsequent block duration was recorded. RESULTS: Mean time of axillary plexus block offset was 13.5 hours, with a range of 4.8 to 25.4 hours. No statistical significant differences in offset time was seen with regard to gender, age, body weight, BMI and ASA-classification. A trend for increasing duration of blocks associated with increasing age was observed. No statistically significant difference was identified in block duration between blocks performed with nerve stimulator guidance versus ultrasound guidance. Similarly, neither dose nor volume of ropivacaine 0.75% was identified as a factor influencing block duration. CONCLUSIONS: This prospective study demonstrates a large inter individual variation in time of axillary plexus block offset using ropivacaine 0.75%. The lack of association between offset time and both demographic and block performance factors, makes predictability of individual duration of axillary plexus blocks in clinical practice extremely difficult. We suggest that all patients should be made aware of such variability in duration prior to block placement.

Comparison of bilateral pulse arrival time before and after induced vasodilation by axillary block.

The propagation time of arterial pulse waves provides information about arterial stiffness. Pulse arrival time (PAT) is calculated as the time between the R-wave (ECG) and three reference points on photoplethysmographic (PPG) pulse waves: foot, first derivative and peak. Because large variation in PAT-values between patients exists, measurements of the contra-lateral arm as reference could be a solution. However, anatomical differences between arteries of the arms could introduce an offset of PAT. Furthermore, when arterial stiffness decreases (e.g. after axillary blockade (AxB)) and pulse wave amplitude increases (vasodilation), the pulse waveform can change. The aim of this study was to investigate whether there is a difference between the PAT of both arms and to evaluate the effect of vasodilation after AxB on PAT. ECG and PPG was measured on both hands in 34 patients, starting 2 min before the injection of local anaesthetic of an AxB and continuing for a period of 30 min after block placement. PAT of the baseline and after AxB were calculated and compared. The mean-PAT of both arms were not significantly different for the three reference points. After AxB, PAT significantly increased for all reference points. PAT can be used for intra-subject comparison.

A randomized prospective study comparing the Cobra Perilaryngeal Airway and Laryngeal Mask Airway-Classic during controlled ventilation for gynecological laparoscopy.

BACKGROUND: An increasing number of noninvasive, supraglottic airway devices are currently available. In this randomized single-blind study, we compared the Cobra Perilaryngeal Airway (CobraPLA) to the [Laryngeal Mask Airway (LMA)-Classic] during gynecological laparoscopy. METHODS: Forty patients received either an LMA-Classic or a CobraPLA. Insertion, ventilation and removal characteristics were noted, as well as any throat morbidity. RESULTS: Devices were similar for insertion characteristics, adverse events, and throat morbidity. Before pneumoperitoneum, peak airway pressures were 20.3 +/- 4.9 cm H2O in the LMA-Classic group versus 25.5 +/- 7.9 cm H2O in the CobraPLA group, P = 0.01. This difference was maintained during pneumoperitoneum; LMA-Classic (22.8 +/- 6.1 cm H2O) and CobraPLA (28.1 +/- 8.5 cm H2O), P = 0.04. Macroscopic blood occurred only on the CobraPLA, seen on 40% of the devices after removal, P = 0.001. CONCLUSION: During gynecological laparoscopy, the CobraPLA provides similar insertion characteristics, but higher airway sealing pressures than the LMA-Classic. The usefulness of this finding requires further investigation.

Peripheral flow index is a reliable and early indicator of regional block success.

We investigated the usefulness of peripheral flow index (PFI) measurement using a standard pulse oximetry digit probe for early prediction of successful regional blocks. Sixty-six patients scheduled for limb surgery underwent either axillary or sciatic block using a nerve stimulator technique with mepivacaine 1.5%. PFI, which is the ratio of the pulsatile versus the nonpulsatile component of the pulse oximetry signal, was recorded from 10 min before block insertion until 30 min afterwards. PFI recordings of the unblocked limb were similarly recorded. Pinprick and cold sensation were assessed at 5-min intervals until 30 min after blockade. An increase in PFI by a factor of 1.55 at 10 min after axillary block placement (P = 0.006), and 12 min after sciatic block placement (P = 0.001) was required to predict a successful block. The sensitivity and specificity of PFI was 100% for predicting axillary block outcomes at this time. Positive predictive value was 95% and negative predictive value was 93%. For sciatic blocks, sensitivity and specificity were 90% and 100%, respectively. The calculated positive predictive value at time 12 min for sciatic blocks was 94% and negative predictive value was 92%. At 15 min after block placement, cold and pinprick sensations had the same calculated values for sensitivity and specificity at 71% and 100%, respectively, for axillary blocks. For sciatic blocks, cold sensation had a sensitivity of 77% and a specificity of 100%, whereas pinprick had a sensitivity of just 20% with a specificity of 100%. We conclude that PFI provides a simple, early, and objective assessment of the success and failure of nerve blocks.

Thermographic temperature measurement compared with pinprick and cold sensation in predicting the effectiveness of regional blocks.

We designed this study to evaluate the usefulness of thermographic temperature measurement with an infrared camera, compared with patient response to cold and pinprick, as a means of assessing the success or failure of axillary blockades. Axillary blocks were performed on 25 patients undergoing surgery on the hand or forearm using a nerve stimulator technique with mepivacaine 1.5%. Pinprick and cold sensation were assessed on the operative site at 5-min intervals for 30 min. A thermographic image of the operative limb was recorded at similar time intervals. Thermographic images of the unblocked limb were taken before block placement and at 30 min. Temperature values at the operative site and unblocked limb were calculated from the thermographic images. Results revealed that thermography had higher combined values for sensitivity, specificity, and positive and negative predictive values than both cold and pinprick at all time intervals, with statistically significant differences at 15 min (thermography versus cold, P = 0.006; thermography versus pinprick, P = 0.026) and 30 min (thermography versus cold, P = 0.038; thermography versus pinprick, P = 0.040). For thermography as a method of block assessment, an optimal time of 15 min after mepivacaine local anesthetic injection gives the highest combined values for predicting a successful block (P = 0.004). We conclude that thermography provides an early and objective assessment of the success and failure of axillary regional blockades.

Remifentanil as a single drug for extracorporeal shock wave lithotripsy: a comparison of infusion doses in terms of analgesic potency and side effects.

UNLABELLED: This randomized, double-blind study was designed to evaluate analgesic effectiveness and side effects of two remifentanil infusion rates in patients undergoing extracorporeal shock wave lithotripsy (ESWL) for renal stones. We included 200 patients who were administered remifentanil either 0.05 microg x kg(-1) x min(-1) (n = 100) or 0.1 microg x kg(-1) x min(-1) (n = 100) plus demand bolus of 10 microg of remifentanil via a patient-controlled analgesia (PCA) device. No other sedating drugs were given. The frequencies of PCA demands and deliveries were recorded. Arterial blood pressure, oxygen saturation, and respiratory rate were recorded throughout the procedure; postoperative nausea and vomiting (PONV), dizziness, itching, agitation, and respiratory depression were measured posttreatment. Visual analog scale (VAS) scores were taken preoperatively, directly postoperatively, and 30 min after finishing the procedure. There were no statistically significant differences in the frequency of PCA demands and delivered boluses or among perioperative VAS scores. The extent of PONV and frequency of dizziness and itching immediately after and dizziness 30 min after the end of treatment were significantly reduced in the smaller dose group. We conclude that a remifentanil regimen of 0.05 microg x kg(-1) x min(-1) plus 10 microg demands is superior to 0.1 microg x kg(-1) x min(-1) plus demands, as there was no difference in the VAS scores recorded between groups and it has a less frequent incidence of side effects in patients receiving ESWL. IMPLICATIONS: Remifentanil is an appropriate analgesic choice for patients undergoing extracorporeal shock wave lithotripsy (ESWL) therapy, as it has both fast onset and offset times. We studied remifentanil as a sole drug for ESWL and have shown that an infusion rate of 0.05 microg x kg-1 x min-1 plus patient-controlled analgesia demands of 10 microg provides adequate analgesia and has significantly less side effects than a dose of 0.1 microg x kg-1 x min-1 plus 10 microg demands.