Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Aug 2023
Pharmacodynamic effect of gabapentin on central nervous system in patients with chronic low back pain: a [99mTc]Tc-ECD SPECT study.
Gabapentin is an effective therapeutic alternative for chronic low back pain, indicated in several guidelines for treating neuropathic pain as first-line medication. This study aimed to describe the pharmacodynamics of gabapentin in the central nervous system of patients with chronic low back pain (CLBP) by using single-photon emission CT (SPECT) with [99mTc]Tc-ECD. ⋯ A lack of improvement in some patients with gabapentin may be associated with an activated affective circuit of pain, evidenced by the increase of rCBF of the anterior cingulate cortex. A maladaptive brain state in chronic pain can explain the decrease of rCBF in the default mode network structures. Gabapentin acts directly or indirectly on neurons of periaqueductal gray substance by increasing the pain threshold and decreasing the rCBF of this structure.
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Reg Anesth Pain Med · Aug 2023
There remains a role for neuraxial anesthesia for hip fracture surgery in the post-REGAIN era.
Two recent, large-scale, randomized controlled trials comparing neuraxial anesthesia with general anesthesia for patients undergoing surgical fixation of a hip fracture have sparked interest in the comparison of general and neuraxial anesthesia. These studies both reported non-superiority between general and neuraxial anesthesia in this patient cohort, yet they have limitations, like their sample size and use of composite outcomes. We worry that that if there is a perception among surgeons, nurses, patients and anesthesiologists that general and spinal anesthesia are equivalent (which is not what the authors of the studies conclude), it may become difficult to argue for the resources and training to provide neuraxial anesthesia to this patient population. In this daring discourse, we argue that despite the recent trials, there remain benefits of neuraxial anesthesia for patients who have suffered hip fractures and that abandoning offering neuraxial anesthesia to these patients would be an error.
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Reg Anesth Pain Med · Aug 2023
Modified thoracoabdominal nerve block through perichondrial approach (M-TAPA): an anatomical study to evaluate the spread of dye after a simulated injection in soft embalmed Thiel cadavers.
There is still no consensus on the analgesic range and mechanisms of action of modified thoracoabdominal nerve block through perichondrial approach (M-TAPA). This cadaveric study aimed to determine the spread of an injectate following simulated M-TAPA. ⋯ Our findings suggest that M-TAPA most likely involves the T9, T10 and T11 segmental nerves and that the local anesthetic may not spread to the intercostal space in the thoracic cage in M-TAPA. Further studies are required to confirm the precise mechanism of action and efficacy of M-TAPA in a large sample of human participants.
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Reg Anesth Pain Med · Aug 2023
Serum concentrations of local anesthetics after unilateral interpectoral-pectoserratus plane block in breast cancer surgery: a pharmacokinetic study.
The ultrasound-guided interpectoral-pectoserratus plane block is a fascial plane block for superficial surgery of the anterolateral chest wall. This technique involves injecting a relatively large volume of local anesthetics (typically 30 mL of 0.25%-0.50%, ie, 75-150 mg ropivacaine) underneath the major and minor pectoral muscles of the anterior thoracic wall. There is a potential risk of toxic serum concentrations of local anesthetics due to systemic absorption. ⋯ This pharmacokinetic study demonstrated that a 2.5 mg/kg ropivacaine interpectoral-pectoserratus plane block may result in exceeding the threshold for local anesthetic systemic toxicity.