Neurological complications after regional anesthesia: contemporary estimates of risk

Functional outcome of femoral versus obturator nerve block after total knee arthroplasty

Patients undergoing total knee arthroplasty often experience substantial postoperative pain, which may delay functional recovery and hospital discharge. We recently reported the short-term analgesic efficacy of a single-injection femoral nerve block after spinal anesthesia in total knee arthroplasty. We have now followed 30 patients a minimum of 1 year to determine the functional outcome and pain relief after femoral and obturator nerve block after total knee arthroplasty. Patients undergoing primary unilateral total knee arthroplasty were randomized to one of three treatment groups: (1) femoral nerve block; (2) obturator nerve block; or (3) placebo (sham block). At 6 weeks and 1 year, all three groups had similar total Hospital for Special Surgery knee scores and similar subscores such as range of motion, daily function, and resting and dynamic pain. The data support the usefulness of a peripheral nerve blockade in the context of a multimodal analgesic regimen and a tailored rehabilitation program to individual patients and institutions.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Update on the role of paravertebral blocks for thoracic surgery: are they worth it?

PURPOSE OF REVIEW

To consider optimal analgesic strategies for thoracic surgical patients.

RECENT FINDINGS

Recent studies have consistently suggested analgesic equivalence between paravertebral and thoracic epidural analgesia. Complications appear to be significantly less common with paravertebral analgesia.

SUMMARY

There is good evidence that paravertebral block can provide acceptable pain relief compared with thoracic epidural analgesia for thoracotomy. Important side-effects such as hypotension, urinary retention, nausea, and vomiting appear to be less frequent with paravertebral block than with thoracic epidural analgesia. Paravertebral block is associated with better pulmonary function and fewer pulmonary complications than thoracic epidural analgesia. Importantly, contraindications to thoracic epidural analgesia do not preclude paravertebral block, which can also be safely performed in anesthetized patients without an apparent increased risk of neurological injury. The place of paravertebral block in video-assisted thoracoscopic surgery is less clear.

Femoral nerve blocks

Femoral nerve blocks and indeed all peripheral nerve blocks have become a popular, safe and effective method of providing postoperative analgesia. The advantages of a femoral nerve block for lower limb surgery include good postoperative analgesia, a reduction in the need for opioids (thus reducing the associated complications of opioids such as nausea, vomiting, itching and confusion (Allen et al 1998, Wang et al 2002)) and the potential for earlier mobilisation and discharge from the hospital (Wang et al 2002, Ilfeld et al 2008).

Ultrasound-guided regional anesthesia and analgesia: a qualitative systematic review

Ultrasound guidance has become popular for performance of regional anesthesia and analgesia. This systematic review summarizes existing evidence for superior risk to benefit profiles for ultrasound versus other techniques. Medline was systematically searched for randomized controlled trials (RCTs) comparing ultrasound to another technique, and for large (n > 100) prospective case series describing experience with ultrasound-guided blocks. Fourteen RCTs and 2 case series were identified for peripheral nerve blocks. No RCTs or case series were identified for perineural catheters. Six RCTs and 1 case series were identified for epidural anesthesia. Overall, the RCTs and case series reported that use of ultrasound significantly reduced time or number of attempts to perform blocks and in some cases significantly improved the quality of sensory block. The included studies reported high incidence of efficacy of blocks with ultrasound (95%-100%) that was not significantly different than most other techniques. No serious complications were reported in included studies. Current evidence does not suggest that use of ultrasound improves success of regional anesthesia versus most other techniques. However, ultrasound was not inferior for efficacy, did not increase risk, and offers other potential patient-oriented benefits. All RCTs are rather small, thus completion of large RCTs and case series are encouraged to confirm findings.

General health and knee function outcomes from 7 days to 12 weeks after spinal anesthesia and multimodal analgesia for anterior cruciate ligament reconstruction

BACKGROUND

We previously reported that continuous perineural femoral analgesia reduces pain with movement during the first 2 days after anterior cruciate ligament reconstruction (ACLR, n = 270), when compared with multimodal analgesia and placebo perineural femoral infusion. We now report the prospectively collected general health and knee function outcomes in the 7 days to 12 wk after surgery in these same patients.

METHODS

At three points during 12 wk after ACLR surgery, patients completed the SF-36 General Health Survey, and the Knee Outcome Survey (KOS). Generalized Estimating Equations were implemented to evaluate the association between patient-reported survey outcomes and (1) preoperative baseline survey scores, (2) time after surgery, and (3) three nerve block treatment groups.

RESULTS

Two hundred seventeen patients' data were complete for analysis. In univariate and multiple regression Generalized Estimating Equations models, nerve block treatment group was not associated with SF-36 and KOS scores after surgery (all with P > or = 0.05). The models showed that the physical component summary of the SF-36 (P < 0.0001) and the KOS total score (P < 0.0001) increased (improved) over time after surgery and were also influenced by baseline scores.

CONCLUSIONS

After spinal anesthesia and multimodal analgesia for ACLR, the nerve block treatment group did not predict SF-36 or knee function outcomes from 7 days to 12 wk after surgery. Further research is needed to determine whether these conclusions also apply to a nonstandardized anesthetic, or one that includes general anesthesia and/or high-dose opioid analgesia.

[Complications after regional anesthesia]

In recent years, there has been a considerable increase in the number of procedures carried out under regional anesthesia. The techniques used can be associated with a number of complications, which should be understood so that they can be recognized and managed appropriately. The overall incidence of reported complications associated with these techniques is low and therefore, with currently available data, we can only have an approximate idea of their incidence. The objective of this study is to systematically describe the complications that may arise from the use of neuraxial and peripheral regional anesthesia techniques.

Effectiveness and safety of postoperative pain management: a survey of 18 925 consecutive patients between 1998 and 2006 (2nd revision): a database analysis of prospectively raised data

BACKGROUND

Approximately 30-80% of postoperative patients complain about moderate to severe post-surgical pain, indicating that postoperative pain treatment is still a problem.

METHODS

We analysed prospectively collected data on patients in a university hospital receiving systemic and epidural patient-controlled analgesia and continuous peripheral nerve block (CPNB) documented by the acute pain service team in a computer-based system.

RESULTS

Of 18 925 patients visited in the postoperative period between 1998 and 2006, 14 223 patients received patient-controlled epidural analgesia (PCEA), 1591 i.v. patient-controlled analgesia (IV-PCA), 1737 continuous brachial plexus block, and 1374 continuous femoral/sciatic nerve block. Mean dynamic and resting pain scores (VAS 0-100) were significantly lower for peripheral or neuroaxial regional analgesia compared with patient-controlled systemic opioid analgesia (P<0.05). The risk of a symptomatic spinal mass lesion including epidural haematoma (0.02%; 1:4741) or epidural abscess (0.014%; 1:7142) after PCEA was 1:2857 (0.04%). Neurological complications after CPNB occurred in two patients who received interscalene brachial plexus block.

CONCLUSIONS

We demonstrated that PCEA, IV-PCA, and CPNB are safe and efficient. Although all of these treatment strategies provide effective analgesia, PCEA and CPNB provided superior pain relief compared with IV-PCA. We demonstrated that serious complications of analgesic techniques are rare but possibly disastrous necessitating a close supervision by an acute pain service. We found a low rate of adverse effects including hypotension and motor impairment and a low incidence of epidural haematoma for thoracic PCEA compared with lumbar PCEA.

Femoral nerve block for diaphyseal and distal femoral fractures in the emergency department. Surgical technique

BACKGROUND

Diaphyseal and distal femoral fractures are painful injuries that are frequently seen in patients requiring a trauma work-up in the hospital emergency department prior to definitive management. The purpose of this study was to determine whether a femoral nerve block administered in the emergency department could provide better pain relief for patients with femoral fractures than currently used pain management practices.

METHODS

Patients who presented with an acute diaphyseal or distal femoral fracture were identified as potential candidates for this study. Eligible patients were randomized by medical record number to receive either (a) the femoral nerve block (20 mL of 0.5% bupivacaine) along with standard pain management or (b) standard pain management alone (typically intravenous narcotics). The pain was assessed with use of a visual analog scale at the initial evaluation and at five, fifteen, thirty, sixty, and ninety minutes following the initial evaluation. Fifty-four patients were enrolled in the study from April 2005 to May 2006. Thirty-one patients received a femoral nerve block, and twenty-three patients received standard pain management alone.

RESULTS

Baseline scores on the visual analog pain scale did not differ between the groups at the initial evaluation. The patients who received a femoral nerve block (along with standard pain management) had significantly lower pain scores at five, fifteen, thirty, sixty, and ninety minutes following the block than did the patients who received standard pain management alone (p < 0.001). The score on the visual analog pain scale across these time points was an average of 3.6 points less (on a 10-point scale) for those who received the block. There were no infections, paresthesias, or other complications related to the femoral nerve block.

CONCLUSIONS

The acute pain of a diaphyseal or distal femoral fracture can be significantly decreased through the use of a femoral nerve block, which can be administered safely in the hospital emergency department.

Postthoracotomy paravertebral analgesia: will it replace epidural analgesia?

Thoracotomy is associated with significant acute postoperative pain and a high incidence of development of chronic pain. Thoracic epidural analgesia has long been standard treatment for postthoracotomy pain, but recently there has been increased interest in alternative regional techniques, particularly paravertebral analgesia. This article compares the analgesic efficacy, side effects, complications of, and contraindications for thoracic epidural and paravertebral analgesia techniques and discusses their effects on the development of chronic postthoracotomy pain. This information will allow a more considered choice of analgesic technique after thoracotomy.

A patient-based national survey on postoperative pain management in France reveals significant achievements and persistent challenges

We carried out a national survey on postoperative pain (POP) management in a representative sample (public/private, teaching/non-teaching, size) of 76 surgical centers in France. Based on medical records and questionnaires, we evaluated adult patients 24h after surgery, concerning information: pre and postoperative pain, evaluation, treatment and side effects. A local consultant provided information about POP management. Data were recorded for 1900 adult patients, 69.3% of whom remembered information on POP. Information was mainly delivered orally (90.3%) and rarely noted on the patient's chart (18.2%). Written evaluations of POP were frequent on the ward (93.7%) with appropriate intervals (4.1 (4.0)h), but not frequently prescribed (32.7%). Pain evaluations were based on visual analog scale (21.1%), numerical scale (41.2%), verbal scale (13.8%) or non-numerical tool (24%). Pain was rarely a criterion for recovery room discharge (19.8%). Reported POP was mild at rest (2.7 (1.3)), moderate during movement (4.9 (1.9)) and intense at its maximal level (6.4 (2.0)). Incidence of side effects was similar according to patient (26.4%) or medical chart (25.1%) including mostly nausea and vomiting (83.3%). Analgesia was frequently initiated during anesthesia (63.6%). Patient-controlled analgesia (21.4%) was used less frequently than subcutaneous morphine (35.1%) whose prescription frequently did not follow guidelines. Non-opioid analgesics used included paracetamol (90.3%), ketoprofen (48.5%) and nefopam (21.4%). Epidural (1.5%) and peripheral (4.7%) nerve blocks were under used. Evaluation (63.4%) or treatment (74.1%) protocols were not available for all patients. This national, prospective, patient-based, survey reveals both progress and persistent challenges in POP management.

Does patient-controlled continuous interscalene block improve early functional rehabilitation after open shoulder surgery?

BACKGROUND

Early mobilization after shoulder surgery plays a vital role in successful functional rehabilitation. However, postoperative pain often reduces, or even prevents, effective physiotherapy. We investigated the effect of analgesia via patient-controlled interscalene technique on early functional rehabilitation after open shoulder surgery.

METHODS

Eighty-seven patients were randomly assigned to one of two groups: patient-controlled continuous interscalene block (PCISB) and patient-controlled i.v. (opioid) analgesia (PCA). Interscalene block was performed preoperatively; otherwise analgesic protocols were started in the postanesthesia care unit and were continued for 72 h. Physiotherapy was performed for 60 min a day on day 2 and 3 after surgery according to a standardized protocol. Maximum mobility was defined as the range of motion that could be achieved with pain as the limiting factor. Efficiency of functional rehabilitation was evaluated 1 day before and 3 days after surgery with the help of a multimodal scoring system (Constant-Score) that evaluates pain, daily life activity, strength and range of motion. Maximum intensity of pain was also monitored via Visual Analog Scales for the first 72 h after surgery and during in-hospital physiotherapy.

RESULTS

Constant-Score rates were significantly improved by the interscalene block. However, no significant differences in mobility and strength sub-scores were observed between the groups. Compared with PCA, PCISB proved to be beneficial concerning pain at rest at 6 h (P < 0.001), 24 h (P = 0.044), and 72 h (P = 0.013) and for pain during physiotherapy at 48 h after surgery (P = 0.016).

CONCLUSION

Compared with opioid-based PCA, PCISB improved analgesia, but not function, during early rehabilitation of the shoulder joint.

[Electrical nerve stimulation for plexus and nerve blocks]

Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.