Complications Associated With Eye Blocks and Peripheral Nerve Blocks: An American Society of Anesthesiologists Closed Claims Analysis

Complications associated with three brachial plexus blocking techniques: Systematic review and meta-analysis

BACKGROUND

Brachial plexus block has become one of the most widely-used anaesthetic techniques in the world for upper limb anaesthesia. There are three different brachial blocks techniques: supraclavicular, infraclavicular and axillary block. However, its execution is not exempt from possible clinical complications, and it is not clear which of these is associated with a lower complication rate and greater anaesthetic success.

MATERIALS AND METHODS

Systematic review and meta-analysis following the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify controlled clinical trials reporting the three techniques. The main outcome was the incidence of anaesthetic complications, and the secondary ones were an anaesthetic success, time of performance and anaesthetic latency.

RESULTS

25 controlled clinical trials, with 2012 patient, were included. The methodological quality of the included studies is moderate to high. For the main outcome, the main complication reported was a vascular puncture, followed by transient neurological injury, symptomatic diaphragmatic paralysis and pneumothorax. No differences were found in complications associated with the three anaesthetic techniques. Additionally, no differences were found regarding anaesthetic success.

CONCLUSIONS

Anesthetic complications associated with the three brachial block techniques are low, with no medium and long-term sequelae; however, none of the three techniques seems to be superior among them to reduce these complications. All three techniques are highly successful when performed using ultrasound imaging.

Perianesthetic neurological adverse events in children: A review of the Wake-Up Safe Database

BACKGROUND

Perianesthetic neurological adverse events are rare in children and have been studied in detail in the settings of cardiac surgery and regional anesthesia. Our study aims to characterize perianesthetic neurological adverse events in children in the setting of all types of surgery and diagnostic or interventional procedures, to evaluate anesthesia's role, and to identify factors amenable to prevention.

METHODS

We conducted a retrospective study by reviewing all the anesthetic encounters reported in the Wake-Up Safe database between January 2010 and December 2017.

RESULTS

The rate of perianesthetic neurological adverse events was 0.49 per 10 000 pediatric anesthetic encounters. The odds of NAE were significantly higher in children who were older than 6 months; had American Society of Anesthesiologists physical status (ASA PS) of 3, 4, or 5; or had American Society of Anesthesiologists Emergency (ASA E) status. Seizures were the most common NAE. Overall, 23 (18.1%) children with neurological adverse events died, and 33 (26%) experienced permanent or severe permanent harm. The risk of death was higher in infants and in children with ASA PS of 3, 4, or 5; ASA E status; preexisting neurological abnormality; or preexisting neurological deficit and in events associated with cardiac arrest or trauma. Anesthesia contributed to 24 (18.9%) events; patient disease was the primary causative factor in 95 (74.8%) adverse events, and 37 (29.1%) events were preventable, including 2 deaths. Preventable factors broadly included inadequate preoptimization, complications during airway management and central venous catheter placement, and suboptimal patient positioning.

CONCLUSION

Perianesthetic neurological adverse events are rare in children and have a poor outcome. Our study has described pediatric perianesthetic neurological injury in detail and identified contributing factors that can be optimized during various phases of perianesthetic care. This information can be utilized during the informed consent process and to enhance the quality of care in children receiving anesthesia.

Identification and economic burden of main adverse events of nerve injuries caused by regional anesthesia: a systematic review

BACKGROUND AND OBJECTIVES

Anesthesiologists and hospitals are increasingly confronted with costs associated with the complications of Peripheral Nerve Blocks (PNB) procedures. The objective of our study was to identify the incidence of the main adverse events associated with regional anesthesia, particularly during anesthetic PNB, and to evaluate the associated healthcare and social costs.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic search on EMBASE and PubMed with the following search strategy: ("regional anesthesia" OR "nerve block") AND ("complications" OR "nerve lesion" OR "nerve damage" OR "nerve injury"). Studies on patients undergoing a regional anesthesia procedure other than spinal or epidural were included. Targeted data of the selected studies were extracted and further analyzed.

RESULTS

Literature search revealed 487 articles, 21 of which met the criteria to be included in our analysis. Ten of them were included in the qualitative and 11 articles in the quantitative synthesis. The analysis of costs included data from four studies and 2,034 claims over 51,242 cases. The median claim consisted in 39,524 dollars in the United States and 22,750 pounds in the United Kingdom. The analysis of incidence included data from seven studies involving 424,169 patients with an overall estimated incidence of 137/10,000.

CONCLUSIONS

Despite limitations, we proposed a simple model of cost calculation. We found that, despite the relatively low incidence of adverse events following PNB, their associated costs were relevant and should be carefully considered by healthcare managers and decision makers.

Pharmacokinetic and clinical effects of two bupivacaine concentrations on axillary brachial plexus block

Introduction

The risk of systemic bupivacaine toxicity is a persistent problem, which makes its pharmacokinetic study fundamental for regional anesthesia safety. There is little evidence of its influence on plasma peak at different concentrations. The present study compares two bupivacaine concentrations to establish how the concentration affects this drug plasma peak in axillary brachial plexus block. Postoperative latency and analgesia were also compared.

Methods

30 patients were randomized. In the 0.25% Group, 0.25% bupivacaine (10 mL) was injected per nerve. In the 0.5% Group, 0.5% bupivacaine (5 mL) was injected per nerve. Peripheral blood samples were collected during the first 2 h after the blockade. For sample analyses, high performance liquid chromatography mass spectrometry was used.

Results

Plasma peak occurred 45 min after the blockade, with no difference between groups at the assessed time-points. Plasma peak was 933.97 ± 328.03 ng.mL⁻¹ (mean ± SD) in 0.25% Group and 1022.79 ± 253.81 ng.mL⁻¹ in 0.5% Group (p = 0.414). Latency was lower in 0.5% Group than in 0.25% Group (10.67 ± 3.71 × 17.33 min ± 5.30, respectively, p = 0.004). No patient had pain within the first 4 h after the blockade.

Conclusion

For axillary brachial plexus block, there was no difference in bupivacaine plasma peak despite the use of different concentrations with the same local anesthetic mass. The concentration inversely influenced latency.

Local anesthetics

Local anesthetics are used broadly to prevent or reverse acute pain and treat symptoms of chronic pain. This chapter, on the analgesic aspects of local anesthetics, reviews their broad actions that affect many different molecular targets and disrupt their functions in pain processing. Application of local anesthetics to peripheral nerve primarily results in the blockade of propagating action potentials, through their inhibition of voltage-gated sodium channels. Such inhibition results from drug binding at a site in the channel's inner pore, accessible from the cytoplasmic opening. Binding of drug molecules to these channels depends on their conformation, with the drugs generally having a higher affinity for the open and inactivated channel states that are induced by membrane depolarization. As a result, the effective potency of these drugs for blocking impulses increases during high-frequency repetitive firing and also under slow depolarization, such as occurs at a region of nerve injury, which is often the locus for generation of abnormal, pain-related ectopic impulses. At distal and central terminals the inhibition of voltage-gated calcium channels by local anesthetics will suppress neurogenic inflammation and the release of neurotransmitters. Actions on receptors that contribute to nociceptive transduction, such as TRPV1 and the bradykinin B2 receptor, provide an independent mode of analgesia. In the spinal cord, where local anesthetics are present during epidural or intrathecal anesthesia, inhibition of inotropic receptors, such as those for glutamate, by local anesthetics further interferes with neuronal transmission. Activation of spinal cord mitogen-activated protein (MAP) kinases, which are essential for the hyperalgesia following injury or incision and occur in both neurons and glia, is inhibited by spinal local anesthetics. Many G protein-coupled receptors are susceptible to local anesthetics, with particular sensitivity of those coupled via the Gq alpha-subunit. Local anesthetics are also infused intravenously to yield plasma concentrations far below those that block normal action potentials, yet that are frequently effective at reversing neuropathic pain. Thus, local anesthetics modify a variety of neuronal membrane channels and receptors, leading to what is probably a synergistic mixture of analgesic mechanisms to achieve effective clinical analgesia.