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Rib fractures, in particular those involving various levels, are frequent in multi-trauma patients. These injuries are typically seen after blunt thoracic trauma, most commonly involving motor vehicle accidents. Rib fractures alone are associated with significant morbidity and mortality as well as long-term disability without appropriate management. Patients with rib fractures require safe, effective analgesia to prevent respiratory compromise. Choosing an effective pain management strategy for this patient population can prove to be challenging due to a spectrum of additional injuries, body habitus, coagulation status, and preexisting comorbidities. Many strategies have been implemented to provide appropriate pain control. These range from opioid treatment as sole therapy to multimodal approaches which often include regional anesthesia. Regional anesthesia techniques have consisted of midline neuraxial procedures as well as a variety of truncal nerve blocks. Successful pain management and favorable outcomes rely on a prompt and accurate diagnosis, along with an integrated team approach which includes providers skilled in performing regional anesthesia.

Background Both wound infiltration (WI) with local anaesthetic and Erector Spinae Plane block (ESPB) have been described for post-operative analgesia after abdominal surgery. This study compared the efficacy of WI versus ESPB for post-operative analgesia after laparoscopic assisted colonic surgery. Methods Seventy-two patients between 18 and 85 years of age undergoing elective surgery were randomised to receive either WI or ESPB. In the WI group a 40 ml bolus of 0.5% Ropivacaine, infiltrated at the ports and minimally invasive wound at subcutaneous and fascia layers. In the ESPB group at T8 level, under ultrasound guidance, a 22-gauge nerve block needle was passed through the Erector Spinae muscle to reach its fascia. A dose up to 40 ml of 0.5% Ropivacaine, divided into two equal volumes, was injected at each side. Both groups had a multimodal analgesic regime, including regular Paracetamol, dexamethasone and patient-controlled analgesia (PCA) with Fentanyl. The primary end point was a post-operative pain score utilising a verbal Numerical Rating Score (NRS, 0–10) on rest and coughing in the post anaesthetic care unit (PACU) and in the first 24 h. Secondary outcomes measured were: opioid usage, length of stay and any clinical adverse events. Results There was no significant treatment difference in PACU NRS at rest and coughing (p-values 0. 382 and 0.595respectively). Similarly, there were no significant differences in first 24 h NRS at rest and coughing (p-values 0.285 and 0.431 respectively). There was no significant difference in Fentanyl use in PACU or in the first 24 h (p- values 0.900 and 0.783 respectively). Neither was there a significant difference found in mean total Fentanyl use between ESPB and WI groups (p-value 0.787). Conclusion Our observations found both interventions had an overall similar efficacy. Trial registration The study was registered with the Australian New Zealand Clinical Trial Registry (ACTRN: 12619000113156).

BackgroundThere is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques.MethodsWe conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement.ResultsSixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified.ConclusionsHarmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

Purpose of review Thoracic myofascial plane blocks have gained popularity because of their ease of performance and relative safety. This review highlights current research demonstrating the efficacy of these blocks for specific surgical procedures and provides a brief description of how these techniques are performed. Recent findings Fascial plane blocks of the thorax and chest wall have been shown to be beneficial in providing perioperative analgesia for a variety of surgical procedures. Studies discussed in this review compare thoracic fascial plane blocks to systemic analgesia alone, contrast these novel methods of pain control to more traditional techniques, such as paravertebral nerve blocks and epidural anesthesia, and attempt to determine, which fascial plane blocks provide optimal postsurgical analgesia. Summary Thoracic fascial plane blocks provide the anesthesiologist a number of techniques to address postsurgical pain. The relative ease of performance and safety profile of these blocks make them an appealing option for pain control for many patients undergoing thoracic or chest wall surgery. Further research is needed to not only define additional indications for each of these blocks, but also explore optimal dosing including the use of continuous catheter techniques.

NaV1.8 channels play a crucial role in regulating the action potential in nociceptive neurons. A single nucleotide polymorphism in the human NaV1.8 gene SCN10A, A1073V (rs6795970, G>A), has been linked to the diminution of mechanical pain sensation as well as cardiac conduction abnormalities. Furthermore, studies have suggested that this polymorphism may result in a “loss-of-function” phenotype. In the present study, we performed genomic analysis of A1073V polymorphism presence in a cohort of patients undergoing sigmoid colectomy who provided information regarding perioperative pain and analgesic use. Homozygous carriers reported significantly reduced severity in postoperative abdominal pain compared with heterozygous and wild-type carriers. Homozygotes also trended toward using less analgesic/opiates during the postoperative period. We also heterologously expressed the wild-type and A1073V variant in rat superior cervical ganglion neurons. Electrophysiological testing demonstrated that the mutant NaV1.8 channels activated at more depolarized potentials compared with wild-type channels. Our study revealed that postoperative abdominal pain is diminished in homozygous carriers of A1073V and that this is likely due to reduced transmission of action potentials in nociceptive neurons. Our findings reinforce the importance of NaV1.8 and the A1073V polymorphism to pain perception. This information could be used to develop new predictive tools to optimize patient pain experience and analgesic use in the perioperative setting. NEW & NOTEWORTHY We present evidence that in a cohort of patients undergoing sigmoid colectomy, those homozygous for the NaV1.8 polymorphism (rs6795970) reported significantly lower abdominal pain scores than individuals with the homozygous wild-type or heterozygous genotype. In vitro electrophysiological recordings also suggest that the mutant NaV1.8 channel activates at more depolarizing potentials than the wild-type Na+ channel, characteristic of hypoactivity. This is the first report linking the rs6795970 mutation with postoperative abdominal pain in humans.

The erector spinae plane (ESP) block is an ultrasound-guided regional anesthesia technique that has enjoyed unprecedented popularity since its description in 2016. This review summarizes the applied anatomy, technical performance, and clinical application of the ESP block. Dissection and imaging studies indicate that paravertebral local anesthetic spread is a primary mechanism of action of the ESP block. A large volume of case report literature supports its efficacy in myriad clinical settings, including thoracic surgery, thoracic trauma, cardiac surgery, abdominal surgery, spine surgery, and painful conditions of the upper and lower limbs. Several randomized controlled trials have also been published that report significant analgesic benefit compared with systemic analgesia alone. The ESP block is a highly effective and versatile technique for the management of acute and chronic pain. Further studies are needed to definitively determine its efficacy compared with more established techniques.

Over 300,000 patients are hospitalized annually following hip fractures in the USA. Many patients experienced inadequate analgesia. We will review the perioperative effects of the fascia iliaca compartment block (FICB) in hip fracture patients. FICB by injecting local anesthetics beneath the fascia iliaca results in significant pain relief in hip fractures. Neuropathies and vascular injuries are almost unlikely. Single-shot FICB is faster to place, yet providing about 8 h of analgesia when bupivacaine is used. Continuous FICB provides prolonged titratable analgesia, improved patient satisfaction, and leads to faster hospital discharge. FICB reduces opioid consumption, decreases morbidity and mortality, reduces hospital stay, reduces delirium, and improves satisfaction. FICB should form part of a multimodal analgesic regime, in the context of a multidisciplinary approach to the management of hip fracture patients. More clinical investigations are needed to validate the long-term outcome benefits of FICB in hip fracture patients.

Thoracic myofascial plane blocks have gained popularity because of their ease of performance and relative safety. This review highlights current research demonstrating the efficacy of these blocks for specific surgical procedures and provides a brief description of how these techniques are performed.Fascial plane blocks of the thorax and chest wall have been shown to be beneficial in providing perioperative analgesia for a variety of surgical procedures. Studies discussed in this review compare thoracic fascial plane blocks to systemic analgesia alone, contrast these novel methods of pain control to more traditional techniques, such as paravertebral nerve blocks and epidural anesthesia, and attempt to determine, which fascial plane blocks provide optimal postsurgical analgesia.Thoracic fascial plane blocks provide the anesthesiologist a number of techniques to address postsurgical pain. The relative ease of performance and safety profile of these blocks make them an appealing option for pain control for many patients undergoing thoracic or chest wall surgery. Further research is needed to not only define additional indications for each of these blocks, but also explore optimal dosing including the use of continuous catheter techniques.

Supplemental Digital Content is available in the text., Current evidence suggests that Coronavirus Disease 2019 (COVID-19) spread occurs via respiratory droplets (particles >5 µm) and possibly through aerosol. The rate of transmission remains high during airway management. This was evident during the 2003 severe acute respiratory syndrome epidemic where those who were involved in tracheal intubation had a higher risk of infection than those who were not involved (odds ratio 6.6). We describe specific airway management principles for patients with known or suspected COVID-19 disease for an array of critical care and procedural settings. We conducted a thorough search of the available literature of airway management of COVID-19 across a variety of international settings. In addition, we have analyzed various medical professional body recommendations for common procedural practices such as interventional cardiology, gastroenterology, and pulmonology. A systematic process that aims to protect the operators involved via appropriate personal protective equipment, avoidance of unnecessary patient contact and minimalization of periprocedural aerosol generation are key components to successful airway management. For operating room cases requiring general anesthesia or complex interventional procedures, tracheal intubation should be the preferred option. For interventional procedures, when tracheal intubation is not indicated, cautious conscious sedation appears to be a reasonable approach. Awake intubation should be avoided unless it is absolutely necessary. Extubation is a high-risk procedure for aerosol and droplet spread and needs thorough planning and preparation. As updates and modifications in the management of COVID-19 are still evolving, local guidelines, appraised at regular intervals, are vital in optimizing clinical management.

To provide an update on new strategies for pain management after rib fractures utilizing regional analgesia.Pain management for patients with rib fractures can be very challenging. Traditionally, intravenous patient-controlled analgesia (IVPCA) with opioids, epidural, and paravertebral blocks have been used. These techniques, however, may be contraindicated or have limited application in certain patient populations. Recently, ultrasound-guided myofascial plane blocks such as the erector spinae plane (ESP) block and the serratus anterior plane (SAP) block have emerged as alternatives; providing excellent analgesia with minimal side effects. These blocks have the flexibility to be employed in a wide variety of circumstances where epidural and paravertebral approaches may not be feasible such as in anticoagulated patients and in patients with vertebral fractures where positioning options are limited. Myofascial blocks are less invasive and allow for broader and earlier application (e.g. in the emergency department). Further research on myofascial plane blocks is a priority.Until recently, epidural, paravertebral, and intercostal blocks have been advocated as primary management techniques for pain associated with rib fractures. Newer myofascial plane blocks may play a key role in the future as part of alternative pain management strategies.

Background and Aims: Cadaveric studies have shown that injectate from transmuscular quadratus lumborum block (QLB) can spread to the lumbar plexus. Our aim was to compare analgesic efficacy of transmuscular QLB with lumbar plexus block (LPB) for patients undergoing total hip arthroplasty (THA). Material and Methods: Thirty patients receiving transmuscular QLB were propensity score matched with 30 patients receiving LPB for age, sex, ASA score, BMI, operative time, preoperative oxycodone, and intraoperative opioid use. The primary outcome was postoperative opioid consumption during the first 24 postoperative hours. Secondary outcomes included static pain scores at 0–12, 12–24, and 24–48 h intervals, opioid consumption at 0–12, 12–24, and 24–48 h intervals and the length of hospital stay. The incidence of severe adverse events was also compared. Results: Opioid consumption (median [IQR]) in the first 24 h was similar between the transmuscular QLB and LPB patient groups—33.6 mg (22.9–48.5) versus 32.8 mg (24.8–58.3) intravenous morphine equivalents. There was no difference between groups in static pain scores or opioid consumption during any time interval up to 48 h postoperatively. Length of hospital stay (median [IQR]) was similar between the transmuscular QLB and LPB groups—55.6 h (53.7–60.3) versus 57.9 h (54.3–79.1). Conclusions: This study suggests that transmuscular QLB provides similar analgesia to LPB following THA. Prospective studies are needed to confirm this.

Post-operative pain after minimally invasive video-assisted thoracoscopic surgery (VATS) in adults is commonly managed with oral and parenteral opioids and invasive regional techniques such as thoracic epidural blockade. Emerging research has shown that the novel erector spinae plane (ESP) block, can be employed as a simple and safe alternative analgesic technique for acute post-surgical, post-traumatic and chronic neuropathic thoracic pain in adults. We illustrate this by presenting a paediatric case of VATS, in which an ESP block provided better analgesia, due to greater dermatomal coverage, as well as reduced side-effects when compared with a thoracic epidural that had previously been employed on the same patient for a similar procedure on the opposite side.

The field of pharmacogenomics seeks to understand how an individual's unique gene sequence can affect their response to certain drugs. It is particularly relevant in anesthesia when the interindividual response to pain medication is essential. Codeine and tramadol are prodrugs metabolized by CYP2D6, polymorphisms of which can cause dangerous or even fatal levels of their metabolites, or decrease the level of metabolites to decrease their analgesic effect. Many other opioids are metabolized by CYP2D6 or CYP3A5, of which loss-of-function variants can cause dangerous levels of these drugs. The OCT1 transporter facilitates the movement of drugs into hepatocytes for metabolism, and variants of this transporter can increase serum levels of morphine and O-desmethyltramadol. Many NSAIDs are metabolized by CYP2C9, and there is concern that variants of this enzyme may lead to high serum levels of these drugs, causing gastrointestinal bleeding, however the data does not strongly support this. The ABCB1 gene encodes for P-glycoprotein which facilitates efflux of opioids away from their target receptors. The C3435T SNP may increase the concentration of opioids at target receptors, although the data is not conclusive. Catechol-O-Methyltransferase (COMT) is shown to indirectly upregulate opioid receptors. Certain haplotypes of COMT have been demonstrated to have an effect on opioid requirements. The OPRM1 gene codes for the mu-opioid receptor, and there is conflicting data regarding its effect on analgesia and opioid requirements. Overall, there is a fair amount of conflicting data in the above topics, suggesting that there is still a lot of research to be done on these topics, and that pain perception is multifactorial, likely including many common genetic variants.

The erector spinae plane (ESP) block has been described in the successful management of both thoracic and abdominal pain. Since the erector spinae muscle extends to the cervical spine, the ESP block may be potentially useful in painful conditions of the shoulder girdle. We performed a series of ESP blocks at the T2/T3 level in an elderly male patient with chronic shoulder pain. Immediate and profound analgesia with improved range of motion was consistently observed following the block. There was detectable sensory block in the congruent cervico-thoracic dermatomes with no motor block. Computed tomography imaging showed the spread of radiocontrast up to the C3 level in the vicinity of the neural foramina. Clinical analgesia generally outlasted the expected duration of conduction blockade and significantly contributed to overall improvement in the patient’s symptoms. The ESP block may be a promising alternative to other interventional procedures in the management of chronic shoulder pain and deserves further study.

Background and aims Post thoracotomy pain syndrome (PTPS) remains a common complication of thoracic surgery with significant impact on patients’ quality of life. Management usually involves a mul¬tidisciplinary approach that includes oral and topical analgesics, performing appropriate interventional techniques, and coordinating additional care such as physiotherapy, psychotherapy and rehabilitation. A variety of interventional procedures have been described to treat PTPS that is inadequately managed with systemic or topical analgesics. Most of these procedures are technically complex and are associated with risks and complications due to the proximity of the targets to neuraxial structures and pleura. The ultrasound-guided erector spinae plane (ESP) block is a novel technique for thoracic analgesia that promises to be a relatively simple and safe alternative to more complex and invasive techniques of neural blockade. We have explored the application of the ESP block in the management of PTPS and report our preliminary experience to illustrate its therapeutic potential. Methods The ESP block was performed in a pain clinic setting in a cohort of 7 patients with PTPS following thoracic surgery with lobectomy or pneumonectomy for lung cancer. The blocks were performed with ultrasound guidance by injecting 20–30mL of ropivacaine, with or without steroid, into a fascial plane between the deep surface of erector spinae muscle and the transverse processes of the thoracic vertebrae. This paraspinal tissue plane is distant from the pleura and the neuraxis, thus minimizing the risk of complications associated with injury to these structures. The patients were followed up by telephone one week after each block and reviewed in the clinic 4–6 weeks later to evaluate the analgesic response as well as the need for further injections and modification to the overall analgesic plan. Results All the patients had excellent immediate pain relief following each ESP block, and 4 out of the 7 patients experienced prolonged analgesic benefit lasting 2 weeks or more. The ESP blocks were combined with optimization of multimodal analgesia, resulting in significant improvement in the pain experience in all patients. No complications related to the blocks were seen. Conclusion The results observed in this case series indicate that the ESP block may be a valuable therapeutic option in the management of PTPS. Its immediate analgesic efficacy provides patients with temporary symptomatic relief while other aspects of chronic pain management are optimized, and it may also often confer prolonged analgesia. Implications The relative simplicity and safety of the ESP block offer advantages over other interventional procedures for thoracic pain; there are few contraindications, the risk of serious complications (apart from local anesthetic systemic toxicity) is minimal, and it can be performed in an outpatient clinicsetting. This, combined with the immediate and profound analgesia that follows the block, makes it an attractive option in the management of intractable chronic thoracic pain. The ESP block may also be applied to management of acute pain management following thoracotomy or thoracic trauma (e.g. rib fractures), with similar analgesic benefits expected. Further studies to validate our observations are warranted.

Summary Laparoscopic ventral hernia repair is an operation associated with significant postoperative pain, and regional anaesthetic techniques are of potential benefit. The erector spinae plane (ESP) block performed at the level of the T5 transverse process has recently been described for thoracic surgery, and we hypothesised that performing the ESP block at a lower vertebral level would provide effective abdominal analgesia. We performed pre-operative bilateral ESP blocks with 20–30 ml ropivacaine 0.5% at the level of the T7 transverse process in four patients undergoing laparoscopic ventral hernia repair. Median (range) 24-h opioid consumption was 18.7 mg (0.0–43.0 mg) oral morphine. The highest and lowest median (range) pain scores in the first 24 h were 3.5 (3.0–5.0) and 2.5 (0.0–3.0) on an 11-point numerical rating scale. We also performed the block in a fresh cadaver and assessed the extent of injectate spread using computerised tomography. There was radiographic evidence of spread extending cranially to the upper thoracic levels and caudally as far as the L2–L3 transverse processes. We conclude that the ESP block is a promising regional anaesthetic technique for laparoscopic ventral hernia repair and other abdominal surgery when performed at the level of the T7 transverse process. Its advantages are the ability to block both supra-umbilical and infra-umbilical dermatomes with a single-level injection and its relative simplicity.

Ultrasound guidance is used for a variety of surgical needle insertion procedures, but there is currently no standard for the teaching of ultrasound skills. Recently, computer ultrasound simulation has been introduced as an alternative teaching method to traditional manikin and cadaver training because of its ability to provide diverse scenario training, quantitative feedback, and objective assessment. Current computer ultrasound training simulation is limited in its ability to image tissue deformation caused by needle insertions, even though tissue deformation identification is a critical skill in performing an ultrasound-guided needle insertion. To fill this need for improved simulation, a novel method of simulating ultrasound tissue–needle deformation is proposed and evaluated. First, a cadaver study is conducted to obtain ultrasound video of a peripheral nerve block. Then, optical flow analysis is conducted on this video to characterize the tissue movement due to the needle insertion. Tissue movement is characterized into three zones of motion: tissue near the needle being pulled, and zones above and below the needle where the tissue rolls. The rolling zones were centered 1.34 mm above and below the needle and 4.53 mm behind the needle. Using this characterization, a vector field is generated mimicking these zones. This vector field is then applied to an ultrasound image using inverse mapping to simulate tissue movement. The resulting simulation can be processed at 3.1 frames per second. This methodology can be applied through future optimized graphical processing to allow for accurate real time needle tissue simulation.

Medical simulation training is widely used to effectively train for invasive medical procedures such as peripheral nerve blocks. Traditionally, accurate haptic training relies on expensive cadavers, manikins, or advanced haptic robots. Proposed herein is a novel concept for haptic training called the low-cost haptic force needle insertion simulator (LCNIS), which uses material fracture inside disposable cartridges to accurately replicate the force of inserting a needle into tissue. Cadaver and material fracture experiments were performed to develop and determine the accuracy of the LCNIS. The material testing showed that polycarbonate had the highest maximum needle puncture force of the materials tested, 9.85 N, and that fluorinated ethylene propylene had the lowest maximum puncture force, 0.84 N. The cadaver results showed that the error between the three peak forces in a cadaver and a cadaver mimicking cartridge was 1.00 N, 0.01 N, and 1.54 N. The standard deviation of these peaks was 0.60 N, 0.55 N, and 0.41 N. This novel method of haptic simulation can easily be adapted to recreate any type of force and, therefore, could be utilized to train for a wide variety of medical procedures.

A 68-year-old female with a history of sporadic type and presumably secondary erythromelalgia with chronic intractable pain presented for foot surgery. The procedure was performed with combined general anesthesia and regional anesthesia consisting of the placement of a popliteal pain catheter for postoperative pain management. Subsequent whole-genome sequencing revealed that the patient was a homozygous carrier of the common missense mutation in the SCN9A gene coding for voltage-gated sodium channel (NaV1.7) - dbSNP rs6746030 (R1150W). The occurrence of this single nucleotide polymorphism (SNP) was previously suggested not to be associated with erythromelalgia but rather thought to be part of quantitative changes in the pain threshold in different cohorts of patients. The placement of the pain catheter, although controversial in patients with erythromelalgia, provided effective postoperative pain relief without any side effects.

Regional anaesthesia is often helpful in improving respiratory function and analgesia following multiple rib fractures. The erector spinae plane block has become the technique of choice in our institution due to its relative simplicity and purported safety. The aim of this retrospective cohort study was to determine its effectiveness in improving respiratory and analgesic outcomes. We reviewed electronic medical records of patients with traumatic rib fractures admitted to a level-one trauma centre between January 2016 and July 2017, who also received erector spinae plane blocks. We analysed the following outcomes before and up to 72 h after erector spinae plane blockade: incentive spirometry volume; maximum numerical rating scale static pain scores; and 12-h opioid consumption. Pre- and post-block data were compared. We included 79 patients, 77% of whom received continuous erector spinae plane block for a mean (SD) of 3.7 (1.9) days. The majority (85%) had other associated injuries. Incentive spirometry volumes improved from 784 (694) to 1375 (667) ml (p < 0.01) during the first 24 h following erector spinae plane blockade. Pain scores were reduced from 7.7 (2.5) to 4.7 (3.2) in the first three hours (p < 0.01). Reductions in opioid consumption were observed but did not achieve statistical significance. These improvements were largely sustained for up to 72 h. Mean arterial blood pressure remained unchanged from baseline. In conclusion, erector spinae plane blocks were associated with improved inspiratory capacity and analgesic outcomes following rib fracture, without haemodynamic instability. We propose that it should be considered to be a viable alternative to other regional analgesic techniques when these are not feasible.

Of concern in the paper is an analytical study of the left ventricular wall stresses due to cardiac contraction. The study has been performed by developing a mathematical model for the intact heart, where the heart is represented as a volume of revolution of cardiod. The study is based on the consideration that during systole, the interstitial pressure is negligibly small compared to the left ventricular pressure. It is assumed that the shear stress on the outer surface of the heart is zero except in the region where the right ventricle wraps around the left ventricle. The results indicate that the increased diastolic filling contracts the ventricle more forcefully, whereby a larger amount of blood is ejected. This is in agreement with the Frank-Starling principle. Theoretical analysis of another alternative model for the heart, viz. a volume of revolution of lemniscate is also presented.

In this paper, wave propagation in head generated by a local axisymmetric impact on its outer surface is studied. The skull material is treated as isotropic and homogeneous, but presence of the cerebrospinal fluid (considered as a compressible but inviscid irrotational fluid) inside the cranium has been accounted for in the analysis. Some numerical results obtained on the basis of the analytical study, are also presented.

Background Higher body mass index (BMI) has been associated with postoperative complications in total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, the association of incremental increases of BMI and its effects on postoperative complications has not been well studied. We hypothesize that there is a BMI cutoff at which there is a significant increase of the risk of postoperative complications. Methods We studied the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2013. The final cohort included 77,785 primary TKA and 49,475 primary THA subjects, respectively. Patients were separated into 7 groups based on BMI (18.5-24.9 kg/m 2 , 25.0-29.9 kg/m 2 , 30.0-34.9 kg/m 2 , 35.0-39.9 kg/m 2 , 40.0-44.9 kg/m 2 , 45.0-49.9 kg/m 2 , and >50.0 kg/m 2 ). We analyzed data on five 30-day composite complication variables, including any complication, major complication, wound infection, systemic infection, and cardiac and/or pulmonary complication. Results The odds ratio for 4 (any complication, major complication, wound infection, and systemic infection) of 5 composite complications started to increase exponentially once BMI reached 45.0 kg/m 2 or higher in TKA. Similarly, the odds ratio in 3 (any complication, systemic infection, and wound infection) of 5 composite complications showed similar trends in THA patients. These findings were further confirmed with propensity score matching and entropy balancing. Conclusions Our study suggested that there was a positive correlation between BMI and incidences of 30-day postoperative complications in both TKA and THA. The odds of complications increased dramatically once BMI reached 45.0 kg/m 2 .

The ultrasound-guided erector spinae plane (ESP) block is a newly described technique for providing thoracic analgesia. It is simple to perform and relatively noninvasive compared with thoracic epidural analgesia. In addition, the anatomy lends itself well to catheter insertion for continuous blockade. In this report, we describe the use of the ESP block as a rescue analgesic technique for postthoracotomy analgesia in a patient with failed thoracic epidural analgesia.

IntroductionInterscalene regional anesthesia is effective for pain management but is not without complications. To determine whether postoperative neurologic findings were related to the surgery versus the regional catheter, we developed the dry catheter technique where patients could be examined after the surgery prior to dosing the catheter. The purpose of the study was to assess the utility of the dry catheter block in recognizing neurological deficits associated with regional anesthesia.MethodsAn interscalene catheter was placed but not started. After the surgery, a neurovascular examination was performed. If the examination was normal, the regional anesthesia was started. Throughout the patient’s hospitalization, pain levels were collected.ResultsA total of 125 shoulders were studied. There were 9 postoperative nerve-related complications. The patients experienced the most pain relief in the first 12 hours.ConclusionThe dry catheter technique allows differentiation between complications associated with regional anesthesia versus those associated with the surgery. Although interscalene anesthesia provided effective pain control, we stopped using it because we felt its complication rate was too high.

Background We recently described a lateral-to-medial approach for transversus abdominis plane (LM-TAP) block, which may permit preoperative initiation of the block. Objective Our objective was to evaluate the feasibility of continuous LM-TAP blocks in clinical practice in comparison with thoracic epidural analgesia (TEA). Design A randomised, open-label study. Setting University Hospital, London Health Sciences Centre, London, Ontario, Canada from July 2008 to August 2012. Patients Fifty adult patients undergoing open abdominal surgery via laparotomy were allocated randomly to receive preoperative catheter-congruent TEA or ultrasound-guided continuous bilateral LM-TAP block for 72 h postoperatively. Reasons for noninclusion were American Society of Anesthesiologists' physical status more than 4, known allergy to study drugs, chronic pain/opioid dependence, spinal abnormalities or psychiatric illness. Interventions In the TEA group (n = 24), patient-controlled epidural analgesia was maintained using bupivacaine 0.1% with hydromorphone 10 μg ml⁻¹ after establishment of the initial block. In the LM-TAP group (n = 26), ultrasound-guided LM-TAP catheters were inserted on each side preoperatively after a bolus of 30 ml of ropivacaine 0.5% (20 ml subcostal and 10 ml subumbilical injections on both sides). Analgesia was maintained with an infusion of ropivacaine 0.35% at a rate of 2 to 2.5 ml h⁻¹ through each catheter, along with rescue intravenous patient-controlled analgesia. Main outcome measures The primary outcome was pain score on coughing 24 h after the end of surgery. Secondary outcomes were pain scores from 24 to 72 h, intraoperative and postoperative opioid consumption, time to onset of bowel movement and side effect profiles. Results Mean [95% confidence interval (95% CI)] pain scores at rest ranged from 1. 7 (0.9 to 2.5) to 2.3 (1.1 to 3.4) in TEA vs. 1.5 (0.7 to 2.2) to 2.2 (1.3 to 3.0) in LM-TAP (P = 0.829). The dynamic pain scores ranged from 2.9 (1.5 to 4.4) to 3.8 (2.8 to 4.8) in TEA vs. 3.3 (2.4 to 4.3) to 3.8 (2.7 to 4.9) in LM-TAP (P = 0.551). The variability in pain scores was lower in the LM-TAP group than in the TEA group in the first 24 h postoperatively. Patient satisfaction and other secondary outcomes were similar. Conclusion Continuous bilateral LM-TAP block can be initiated preoperatively and may provide comparable analgesia to TEA in patients undergoing laparotomy. Clinical trials registry not registered because registration was not mandatory at the time of starting the trial.

Background and Aims: Ultrasound (US)-guided infraclavicular approach for axillary vein (AXV) cannulation has gained popularity in the last decade. Material and Methods: In this manikin study, we evaluated the feasibility of a training model for teaching AXV cannulation. The learning pattern with this technique was assessed among attending anesthesiologists and residents in training. Results: A faster learning pattern was observed for AXV cannulation among the attending anesthesiologists and residents in training, irrespective of their prior experience with US. It was evident that a training modality for this technique could be easily established with a phantom model and that hands-on training motivates trainees to embrace US-based central venous cannulation. Conclusion: A teaching model for US-guided infraclavicular longitudinal in-plane AXV cannulation can be established using a phantom model. A focused educational program would result in an appreciable change in preference in embracing US-based cannulation techniques among residents.

Enhanced recovery protocols frequently use multimodal postoperative analgesia to improve postoperative outcomes in patients undergoing colorectal surgery.The purpose of this study was to evaluate liposomal bupivacaine use in transversus abdominis plane blocks on postoperative pain scores and opioid use after colorectal surgery.This was a retrospective cohort study comparing outcomes between patients receiving nonliposomal anesthetic (n = 104) and liposomal bupivacaine (n = 303) blocks.The study was conducted at a single tertiary care center.Patients included those identified within an institutional database as inpatients undergoing colorectal procedures between 2013 and 2015 who underwent transversus abdominis plane block for perioperative analgesia.The study measured postoperative pain scores and opioid requirements.Patients receiving liposomal bupivacaine had significantly lower pain scores for the first 24 to 36 postoperative hours. Pain scores were similar after 36 hours. The use of intravenous opioids among the liposomal bupivacaine group decreased by more than one third during the hospitalization (99.1 vs 64.5 mg; p = 0.040). The use of ketorolac was also decreased (49.0 vs 18.3 mg; p0.001). In subgroup analysis, the decrease in opioid use was observed between laparoscopic and robotic procedures but not with laparotomies. No significant differences were noted in the use of oral opioids, acetaminophen, or ibuprofen. Postoperative length of stay and total cost were decreased in the liposomal bupivacaine group but did not achieve statistical significance.The study was limited by its retrospective, single-center design and heterogeneity of block administration.Attenuated pain scores observed with liposomal bupivacaine use were associated with significantly lower intravenous opioid and ketorolac use, suggesting that liposomal bupivacaine-containing transversus abdominis plane blocks are well aligned with the opioid-reducing goals of many enhanced recovery protocols.

Supplemental Digital Content is available in the text, Background: Pharmacologic angiotensin axis blockade (AAB) has been associated with profound hypotension following anesthetic induction with propofol. To combat this problem, investigators have attempted to withhold angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) preoperatively, or evaluated the effects of different induction agents in conferring greater hemodynamic stability. To date, methohexital has not been compared with the most commonly used induction agent, propofol. Hence, the primary objective was to study the hypothesis that methohexital confers a better hemodynamic profile than propofol for anesthetic induction, in patients receiving AAB. The secondary objective was to investigate the postinduction levels of serum neurohormones in an attempt to explain the mechanisms involved. Methods: Forty-five adult, hypertensive patients taking ACEi or ARB and scheduled for elective, noncardiac surgery completed the study. Patients were randomized to receive equi-anesthetic doses of either propofol or methohexital for anesthetic induction. Hemodynamic variables were measured and blood samples were drawn before induction and for 15 minutes afterwards. Results: Methohexital resulted in less hypotension compared with propofol (P = .01), although the degree of refractory hypotension was similar (P = .37). The postinduction systolic blood pressure (P = .03), diastolic blood pressure (P

Background People with the Ehlers-Danlos Syndromes (EDS), a group of heritable disorders of connective tissue, often report experiencing dental procedure pain despite local anesthetic (LA) use. Clinicians have been uncertain how to interpret this apparent LA resistance, as comparison of EDS and non-EDS patient experience is limited to anecdotal evidence and small case series. The primary goal of this hypothesis-generating study was to investigate the recalled adequacy of pain prevention with LA administered during dental procedures in a large cohort of people with and without EDS. A secondary exploratory aim asked people with EDS to recall comparative LA experiences. Methods We administered an online survey through various social media platforms to people with EDS and their friends without EDS, asking about past dental procedures, LA exposures, and the adequacy of procedure pain prevention. Among EDS respondents who both received LA and recalled the specific LA used, we compared agent-specific pain prevention for lidocaine, procaine, bupivacaine, mepivacaine, and articaine. Results Among the 980 EDS respondents who had undergone a dental procedure LA, 88% (n = 860) recalled inadequate pain prevention. Among 249 non EDS respondents only 33% (n = 83) recalled inadequate pain prevention (P < 0.001 compared to EDS respondents). The agent with the highest EDS-respondent reported success rate was articaine (30%), followed by bupivacaine (25%), and mepivacaine (22%). Conclusions EDS survey respondents reported nearly three times the rate of LA non-response compared to non-EDS respondents, suggesting that LAs were less effective in preventing their pain associated with routine office dental procedures.

Background Postoperative hypertension is a common problem in patients undergoing surgical procedures, and the modification of this response could result in improved surgical outcome. Although it is recognized that the incidence of postoperative hypertension is higher in neurosurgical procedures, mechanisms behind this are not well understood. Oxidative stress is an important component of brain injury, and free radicals can influence blood pressure by a number of mechanisms. This study examined the effect of pretreatment with antihypertensive agents on postoperative hypertension in patients undergoing neurosurgery for supratentorial brain tumors and the role of oxidative stress in the process. Methods Forty-nine consecutive patients who underwent surgery for supratentorial brain tumors were divided in to three groups (control, Tab. Glucose; atenolol; and lisinopril groups). Blood was drawn at three time points (1 d before the surgery, at the time of dura opening, and at the time of extubation). Hemodynamic parameters in all three groups and levels of malondialdehyde, protein carbonyl content, nitrate, and α-tocopherol in serum at various time points were analyzed. Results The results showed that perioperative hemodynamic changes were highly associated with oxidative stress parameters in all the three groups. It was seen that atenolol and lisinopril significantly decreased levels of malondialdehyde, protein carbonyl content, and nitrate in the intraoperative period ( P Conclusions The results demonstrate that pretreatment with β-receptor blocker (atenolol) or angiotensin-converting enzyme inhibitor (lisinopril) reduces postoperative hypertension in patients undergoing neurosurgery, and inhibition of oxidative stress may be a potential mechanism for this effect.

BACKGROUND: Controversy exists regarding the increased safety profile when ultrasound is used for central venous catheters inserted in the subclavian or axillary vein. The critically ill neurosurgical patient presents unique considerations for the optimal central line approach. METHODS: This report is a retrospective chart review of 6 neurosurgical intensive care patients in whom an ultrasound-guided, transpectoral, axillary vein catheterization was attempted. A sterile technique was observed. The anatomy was confirmed using combined transverse, longitudinal, and Doppler flow images. The needle tip was advanced into the axillary vein under real-time ultrasound using an in-plane technique. The central venous catheter was inserted using the Seldinger technique. A chest radiograph was obtained after each line. RESULTS: Five of the 6 central lines were inserted easily, without complications. The sixth central line was inserted without complications but more proximally because of difficulty in visualizing the axillary vein on account of the patient's morbid obesity and severe hypovolemia. CONCLUSIONS: This series illustrates new and useful aspects of ultrasound use in transpectoral axillary vein catheterization: it requires minimal additional training; it combines the real time, in-plane technique with transverse, longitudinal, and Doppler color flow images; and it is used safely in the critically ill neurosurgical patient. The data on infraclavicular central venous catheters indicate decreased line sepsis, arterial punctures, and venous thrombosis while improving nursing care and patient comfort. This technique's potential for decreasing the risk of pneumothorax may make it a reasonable option for many critically ill patients in whom other central venous catheter approaches may not be ideal.

Thoracic neuropathic pain is a debilitating condition that is often poorly responsive to oral and topical pharmacotherapy. The benefit of interventional nerve block procedures is unclear due to a paucity of evidence and the invasiveness of the described techniques. In this report, we describe a novel interfascial plane block, the erector spinae plane (ESP) block, and its successful application in 2 cases of severe neuropathic pain (the first resulting from metastatic disease of the ribs, and the second from malunion of multiple rib fractures). In both cases, the ESP block also produced an extensive multidermatomal sensory block. Anatomical and radiological investigation in fresh cadavers indicates that its likely site of action is at the dorsal and ventral rami of the thoracic spinal nerves. The ESP block holds promise as a simple and safe technique for thoracic analgesia in both chronic neuropathic pain as well as acute postsurgical or posttraumatic pain.

We performed bilateral transmuscular quadratus lumborum blocks in six cadavers using iodinated contrast and methylene blue. Computed tomography imaging was performed in four cadavers and anatomical dissection was completed in five. This demonstrated spread to the lumbar paravertebral space in 63% of specimens, laterally to the transversus abdominis muscle in 50% and caudally to the anterior superior iliac spine in 63% of specimens. There was no radiographic evidence of spread to the thoracic paravertebral space. Anatomical dissection revealed dye staining of the upper branches of the lumbar plexus and the psoas major muscle in 70% of specimens. Further clinical studies are required to confirm if the quadratus lumborum block might be a suitable alternative to lumbar plexus block.

A patient undergoing elective total shoulder arthroplasty had an Arrow Stimucath™ (Arrow International Reading, PA, USA) stimulating catheter inserted in the region of the interscalene brachial plexus using an ultrasound-guided in-plane approach. There was subsequent difficulty in removing the catheter and traction was associated with painful paraesthesia in the patient's thumb. Plain X-ray revealed a hook-shaped deformity of the tip and surgical exploration was required to remove the catheter, the tip of which appeared to be trapped within the sheath of the brachial plexus. We speculate that the mechanism for entrapment in this case was deformation of the catheter tip into a hook-like shape. The subsequent catheter-neural interaction prevented asymptomatic removal. We recommend that removal of peripheral nerve catheters be attempted only after resolution of sensory block so as to enable patients to report pain or paraesthesia. Imaging with ultrasound or X-rays may help ascertain catheter tip location and confirm whether deformity is present. We also recommend a low threshold for proceeding to surgical extraction, particularly if neurological symptoms are present.