William C. Upshaw

Purpose of Review Total knee replacement (TKR) is a common procedure to alleviate pain in patients with severe osteoarthritis of the knee after failed conservative treatment. While generally safe, postoperative pain is a significant issue many patients experience following surgery. Recent Findings To control postoperative pain, numerous treatments may be administered which may be given preoperatively, intraoperatively, or postoperatively. These treatments include medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and opioids. Additionally, peripheral nerve blocks (PNB) may be performed prior to total knee replacement to limit pain after the surgery. A specific type of PNB done prior to total knee replacement is the genicular nerve block (GNB) which targets five genicular nerves that innervate different parts of the knee joint. This type of block is designed to prevent pain impulses from being sent to the central nervous system from the knee without affecting movement of the lower extremity by sparing efferent nerves innervating muscles. PubMed was used to identify the studies found in this review that are less than 5 years old using the search term “genicular nerve block clinical studies.” Most studies compared GNB alone compared to other blocks, however some used GNB in combination with other blocks, most at a maximum of 48 h postoperative. Summary GNB is typically performed by anesthesiologists under ultrasound guidance to ensure accurate placement of the block. Clinical studies have shown that GNB is effective in controlling pain following TKR leading to lower pain scores following surgery as well as a reduced level of opioid consumption. Additionally, GNB has shown reduced motor weakness following TKR compared to other types of PNBs allowing earlier mobilization of patients. However, more studies are needed to further investigate the efficacy of GNB compared to other PNBs to treat postoperative pain following TKR.

Purpose of Review Peripheral nerve blocks are performed using local anesthetics that are commonly performed prior to surgery to either be the sole anesthetic and/or for postoperative pain management. Interscalene blocks are a specific type of nerve block that targets the superior and middle trunks of the brachial plexus inhibiting transmission of pain signals from the upper extremities to the central nervous system making them useful in mitigating pain following surgeries involving the shoulder, upper arm, and elbow. Recent Findings Previously, interscalene blocks were performed with a nerve stimulator, which is an instrument designed to generate a twitch in surrounding muscles to verify the anesthetic block was placed in the correct location. However, this approach with a nerve stimulator alone is being done less frequently as physicians now often employ ultrasound either by itself or in conjunction with a nerve stimulator to in the block. Several clinical studies have shown that the use of ultrasound leads to improved safety and effectiveness of the interscalene block as compared to performing the block using a nerve stimulator alone. Clinical studies comparing interscalene blocks done with ultrasound versus ultrasound in conjunction with a nerve stimulator have shown the combination to be slightly safer and more efficacious with reduced side effects, though the difference in these metrics between the two is small. Summary Interscalene blocks are highly effective for postoperative pain related to shoulder and upper extremity surgeries. Ultrasound guided blocks are more effective with reduced adverse effects when compared to nerve stimulation alone. The combination of both ultrasound and nerve stimulation allows for increased efficacy and decreaed side effects in limited clinical investigations. Therefore, more studies are needed to further compare and determine best practice interscalene techniques for shoulder and upper extremity surgeries.

Etizolam is a thienodiazepine derivative which produces an anxiolytic effect similar to benzodiazepines such as alprazolam (Xanax). Like classic benzodiazepines, etizolam has a high affinity towards the GABA_A receptor, and allosterically potentiates the effects of GABA resulting in neuronal hyperpolarization related to chloride influx. When taken in therapeutic doses, etizolam produces a similar effect to Xanax. Counterfeit Xanax tablets contain variable amounts of etizolam. Tablets with high amounts of etizolam can cause toxicity if ingested, especially when combined with other substances. When toxic symptoms occur in patients, they may include severe sedation, unconsciousness, and depression of the medullary respiratory center. In this regard, there is the potential for death. Additionally, the rise in fake Xanax tablets containing etizolam and other counterfeit medications has been exacerbated by the difference in regulations regarding these substances in different countries as well as the illegal drug trade. Healthcare providers may also play a role through the over- or underprescribing of certain medications. Thus, in order to combat the rise in counterfeit medications such as fake Xanax, international cooperation, regulation, and enforcement of laws pertaining to the manufacture, prescription, and distribution of these substances are needed.

Purpose of Review Patients often experience a significant degree of knee pain following total knee replacement (TKR). To alleviate this pain, nerve blocks may be performed such as the adductor canal block (ACB). However, ACBs are unable to relieve pain originating from the posterior region of the knee. A new type of nerve block known as the IPACK block may be used in conjunction with ACBs as it is designed to inhibit nerve branches innervating this area. In this article, we examine the rationale behind the IPACK procedure, how it is performed, and clinical trials examining its efficacy. Recent Findings 5 of the 7 clinical trials examined in this article showed the IPACK + ACB block to show superior efficacy in treating pain following TKR compared to other blocks. These blocks included PMDI+ACB, SPANK+ACB, PAI+ACB, ACB alone, and SCAB. 2 of the 7 clinical trials showed the IPACK + ACB to be less effective in managing patients pain following TKR compared to other blocks which included the CACB and 4 in 1 block. Summary In most instances, the IPACK + ACB showed superior efficacy in managing patients’ pain following TKR when compared to other types of nerve blocks. This was determined by measuring usage of opioids, reported postoperative pain, and length of hospital stays following TKR. Thus, we suppose the IPACK block may be used in conjunction with the ACB to effectively reduce patient’s pain following TKR.