Diagnosis and management in Rubinstein-Taybi syndrome: first international consensus statement.

Rubinstein-Taybi syndrome (RTS) is an archetypical genetic syndrome that is characterised by intellectual disability, well-defined facial features, distal limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in either of two genes (CREBBP, EP300) which encode for the proteins CBP and p300, which both have a function in transcription regulation and histone acetylation. As a group of international experts and national support groups dedicated to the syndrome, we realised that marked heterogeneity currently exists in clinical and molecular diagnostic approaches and care practices in various parts of the world. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria for types of RTS (RTS1: CREBBP; RTS2: EP300), molecular investigations, long-term management of various particular physical and behavioural issues and care planning. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimisation of diagnostics and care.

Congenital Heart Defects in Patients with Anorectal Malformations: A Retrospective Cohort Study of 281 Patients.

In patients born with anorectal malformations (ARM), additional congenital heart defects (CHD) can occur. We aimed to provide an overview on disease and treatment details of CHD identified in patients born with ARM, from a unique large cohort of a very rare disease. We performed a retrospective single-center cohort study between January 2000 and July 2023. All consecutive patients with ARM were included. Outcomes were the number of patients with CHD, and screening percentage and percentage of patients diagnosed with CHD over 3 time periods (2000-2006, 2007-2014, 2015-2023). We used uni- and multi-variable logistic regression analyses to search for associations between CHD present and baseline characteristics. In total, 281 patients were included. Some 241 (85.8%) underwent echocardiography, of whom 80 (33.2%) had CHD. Screening percentage with echocardiography increased (74.1% vs. 85.7% vs. 95.9%, p < 0.001) and percentage of patients diagnosed with CHD remained similar over time (30.2% vs. 34.5% vs. 34.0%, p = 0.836). Atrial and ventricular septal defects (n = 36, n = 29), and persistent left superior vena cava (n = 17) were most identified. The presence of VACTERL-association or a genetic syndrome was independently associated with the presence of CHD. CHD were present in 33% of patients with ARM that underwent echocardiography. Over time, the number of CHD identified through screening remained similar. Patients with the presence of VACTERL-association or a genetic syndrome had a higher risk of having CHD. Therefore, acknowledging the potential presence of CHD in patients with ARM remains important.

The Maxillary Nerve Block in Cleft Palate Care: A Review of the Literature and Expert's Opinion on the Preferred Technique of Administration.

INTRODUCTION: Although the maxillary nerve block (MNB) provides adequate pain relief in cleft palate surgery, it is not routinely used globally, and reported techniques are heterogeneous. This study aims to describe relevant anatomy and to present the preferred technique of MNB administration based on the current literature and the expert opinion of the authors. METHOD AND MATERIALS: First, a survey was sent to 432 registrants of the International Cleft Palate Master Course Amsterdam 2023. Second, MEDLINE (PubMed interface) was searched for relevant literature on maxillary artery (MA) anatomy and MNB administration in pediatric patients. RESULTS: Survey response rate was 18% (n=78). Thirty-five respondents (44.9%) used MNB for cleft palate surgery before the course. A suprazygomatic approach with needle reorientation towards the ipsilateral commissure before incision was most frequently reported, mostly without the use of ultrasound. Ten and 20 articles were included on, respectively, MA anatomy and MNB administration. A 47.5% to 69.4% of the MA's run superficial to the lateral pterygoid muscle and 32% to 52.5% medially. The most frequently described technique for MNB administration is the suprazygomatic approach. Reorientation of the needle towards the anterior aspect of the contralateral tragus appears optimal. Needle reorientation angles do not have to be adjusted for age, unlike needle depth. The preferred anesthetics are either ropivacaine or (levo)bupivacaine, with dexmedetomidine as an adjuvant. CONCLUSION: Described MNB techniques are heterogeneous throughout the literature and among survey respondents and not routinely used. Further research is required comparing different techniques regarding efficacy and safety.

Impact of surgery and anesthesia during early brain development: A perfect storm.

Neonatal surgery and concomitant anesthesia coincide with a timeframe of rapid brain development. The speed and complexity of early brain development superimposed on immature regulatory mechanisms that include incomplete cerebral autoregulation, insufficient free radical scavenging and an immature immune response puts the brain at risk. Brain injury may have long-term consequences for multiple functional domains including cognition, learning skills, and behavior. Neurodevelopmental follow-up studies have noted mild-to-moderate deficits in children who underwent major neonatal surgery and related anesthesia. The present review evaluates neonatal surgery against the background of neurobiological processes that unfold at a pace unparalleled by any other period of human brain development. First, a structured summary of early brain development is provided in order to establish theoretical groundwork. Next, literature on brain injury and neurodevelopmental outcome after neonatal surgery is discussed. Special attention is given to recent findings of structural brain damage reported after neonatal surgery. Notably, high-quality imaging data acquired before surgery are currently lacking. Third, mechanisms of injury are interrogated taking the perspective of early brain development into account. We propose a novel disease model that constitutes a triad of inflammation, vascular immaturity, and neurotoxicity of prolonged exposure to anesthetic drugs. With each of these components exacerbating the other, this amalgam incites the perfect storm, resulting in brain injury. When examining the brain, it seems intuitive to distinguish between neonates (i.e., <60 postconceptional weeks) and more mature infants, multiple and/or prolonged anesthesia exposure and single, short surgery. This review culminates in an outline of anesthetic considerations and future directions that we believe will help move the field forward.

Perioperative apnea in infants with hypertrophic pyloric stenosis: A systematic review.

BACKGROUND: Infantile hypertrophic pyloric stenosis (IHPS) leads to excessive vomiting and metabolic alkalosis, which may subsequently cause apnea. Although it is generally assumed that metabolic derangements should be corrected prior to surgery to prevent apnea, the exact incidence of perioperative apneas in infants with IHPS and the association with metabolic alkalosis are unknown. We performed this systematic review to assess the incidence of apnea in infants with IHPS and to verify the possible association between apnea and metabolic alkalosis. METHODS: We searched MEDLINE, Embase, and Cochrane library to identify studies regarding infants with metabolic alkalosis, respiratory problems, and hypertrophic pyloric stenosis. We conducted a descriptive synthesis of the findings of the included studies. RESULTS: Thirteen studies were included for analysis. Six studies described preoperative apnea, three studies described postoperative apnea, and four studies described both. All studies were of low quality or had other research questions. We found an incidence of 27% of preoperative and 0.2%-16% of postoperative apnea, respectively. None of the studies examined the association between apnea and metabolic alkalosis in infants with IHPS. CONCLUSIONS: Infants with IHPS may have a risk to develop perioperative apnea. However, the incidence rates should be interpreted with caution because of the low quality and quantity of the studies. Therefore, further studies are required to determine the incidence of perioperative apnea in infants with IHPS. The precise underlying mechanism of apnea in these infants is still unknown, and the role of metabolic alkalosis should be further evaluated.

Molecular mechanisms of action of systemic lidocaine in acute and chronic pain: a narrative review.

Systemic administration of the local anaesthetic lidocaine is antinociceptive in both acute and chronic pain states, especially in acute postoperative and chronic neuropathic pain. These effects cannot be explained by its voltage-gated sodium channel blocking properties alone, but the responsible mechanisms are still elusive. This narrative review focuses on available experimental evidence of the molecular mechanisms by which systemic lidocaine exerts its clinically documented analgesic effects. These include effects on the peripheral nervous system and CNS, where lidocaine acts via silencing ectopic discharges, suppression of inflammatory processes, and modulation of inhibitory and excitatory neurotransmission. We highlight promising objectives for future research to further unravel these antinociceptive mechanisms, which subsequently may facilitate the development of new analgesic strategies and therapies for acute and chronic pain.

The emergency paediatric surgical airway: A systematic review.

BACKGROUND: Although an emergency surgical airway is recommended in the guidelines for a paediatric cannot intubate, cannot oxygenate (CICO), there is currently no evidence regarding the best technique for this procedure. OBJECTIVE: To review the available literature on the paediatric emergency surgical airway to give recommendations for establishing a best practice for this procedure. DESIGN: Systematic review: Considering the nature of the original studies, a meta-analysis was not possible. DATA SOURCES: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Google Scholar and LILACS databases. ELIGIBILITY CRITERIA: Studies addressing the paediatric emergency surgical airway and reporting the following outcomes: time to tracheal access, success rate, complications and perceived ease of use of the technique were included. Data were reported using a Strengths, Weaknesses, Opportunities and Threats analysis. Strengths and Weaknesses describe the intrinsic (dis)advantages of the techniques. The opportunities and threats describe the (dis)advantage of the techniques in the setting of a paediatric CICO scenario. RESULTS: Five studies described four techniques: catheter over needle, wire-guided, cannula or scalpel technique. Mean time for placement of a definitive airway was 44 s for catheter over needle, 67.3 s for the cannula and 108.7 s for the scalpel technique. No time was reported for the wire-guided technique. Success rates were 43 (10/23), 100 (16/16), 56 (87/154) and 88% (51/58), respectively. Complication rates were 34 (3/10), 69 (11/16), 36 (55/151) and 38% (18/48), respectively. Analysis shows: catheter over needle, quick but with a high failure rate; wire-guided, high success rate but high complication rate; cannula, less complications but high failure rate; scalpel, high success rate but longer procedural time. The available data are limited and heterogeneous in terms of reported studies; thus, these results need to be interpreted with caution. CONCLUSION: The absence of best practice evidence necessitates further studies to provide a clear advice on best practice management for the paediatric emergency surgical airway in the CICO scenario.

Local Anesthetic-Induced Neurotoxicity.

This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor.

Teaching concepts in ultrasound-guided regional anesthesia.

PURPOSE OF REVIEW: Ultrasound-guided regional anesthesia is a challenging, complex skill and requires competence in teaching. The aim of this study was to review current literature on identification of education and learning of ultrasound-guided regional anesthesia and to summarize recent findings on teaching concepts. RECENT FINDINGS: Several teaching programs have been described and implemented into daily routine. Factors relevant to current practice are the knowledge of sonoanatomy, the acquisition of manual skills, the teaching ability, and the feedback given to the trainee. Simulation is a rapidly growing field and is supported by the development of phantoms. Needle visualization is one of the core competencies that is necessary for successful ultrasound-guided procedures and could be supported by technical developments in the future to improve teaching concepts. SUMMARY: Although a lot of key questions cannot be answered by the latest study results, some interesting findings were able to improve existing education programs. These results should be tailored to the individual need of a trainee, and the effects of improved training programs on patient safety and quality of care have to be investigated. The see one, do one, teach one approach is obsolete and should be abandoned.

Influence of arm position on ultrasound visibility of the axillary brachial plexus.

BACKGROUND: Contemporary axillary brachial plexus block is performed by separate injections targeting radial, median, ulnar and musculocutaneous nerve. These nerves are arranged around the axillary artery, making ultrasound visualisation sometimes challenging. In particular, the radial nerve can be difficult to localise deep to the artery. OBJECTIVES: The primary aim of this study was to investigate which arm position optimises the visibility of the radial nerve. Secondary aims were the visibility and position of the other nerves during varying arm positions. DESIGN: A prospective observational study. SETTING: University teaching hospital, November 2012. PARTICIPANTS: Twenty volunteers, recruited by an advertisement on the Department's bulletin board. Inclusion criterion age more than 18 years. EXCLUSION CRITERIA: refusal of ultrasound examination, restricted shoulder movement, local infection, BMI greater than 30 kg m⁻². INTERVENTION: One anaesthesiologist performed bilateral ultrasound examinations of the axillary brachial plexus on 20 volunteers. Each arm was placed in different positions [shoulder (S) 90° or 180° abduction, elbow (E) 0° or 90° extension] and scans were performed proximally in the axilla, and additionally 5 cm distally to this point [proximal (P) vs. distal (D)], resulting in eight different scans stored for off-line analysis performed by two blinded anaesthesiologists. MAIN OUTCOME MEASURES: For radial, median, ulnar and musculocutaneous nerve, visibility was assessed on a six-point visibility scale. Distances and angles of the nerves relative to the axillary artery and distances relative to the skin were measured. RESULTS: No significant differences between arm positions were found in the visibility score of radial (P = 0.359) and musculocutaneous nerves (P = 0.073). Visibility of the median nerve was improved in positions S90°/E0°/D and S180°/E0°/P (P = 0.02). The ulnar nerve was more visible in position S180°/E 0°/P and D (P = 0.007). The greatest distance between artery and radial nerve was 7.4 ±â€Š4.7 mm at an angle of 120 ±â€Š14° in position S180°/E 0°/D. CONCLUSION: The visibility of the radial nerve was not improved by varying positions of the arm. S180°/E0° provided the best overall visibility and accessibility of nerves. TRIAL REGISTRATION: https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm Identifier: NL42116.018.12.

Different Analgesia Techniques for Postoperative Pain in Children Undergoing Abdominal Surgery for Intractable Constipation: A Retrospective Cohort Study in a Single Tertiary Children's Hospital.

Functional constipation in the pediatric population is a prevalent issue that is usually well managed. However, in rare cases, conservative treatment fails, and surgical intervention is necessary. This retrospective cohort study aimed to describe and compare different perioperative analgesic techniques in children undergoing major abdominal surgery for intractable constipation. Conducted between 2011 and 2021, this study enrolled patients under 18 years old who underwent initial major abdominal surgery for intractable constipation (i.e., creation of ostomy or subtotal colectomy). Patients were categorized according to the perioperative analgesic technique (i.e., systemic, neuraxial, or truncal block). Of 65 patients, 46 (70.8%) were female, and the median age was 13.5 [8.8-16.1] years during initial major abdominal surgery. Systemic analgesia was used in 43 (66.2%), neuraxial in 17 (26.2%), and truncal blocks in 5 (7.7%) of the surgeries. Patients with neuraxial analgesia reported less postoperative pain (median [interquartile range] numeric rating scale (NRS) 2.0 [0-4.0]), compared to systemic analgesia (5.0 [2.0-7.0], p < 0.001) and to truncal blocks (5.0 [3.0-6.5], p < 0.001). In this preliminary investigation, neuraxial analgesia appears to be the most effective approach to reducing acute postoperative pain in pediatric patients undergoing major abdominal surgery for intractable functional constipation. However, well-designed studies are warranted.

Intercostal Nerve Cryoablation or Epidural Analgesia for Multimodal Pain Management after the Nuss Procedure: A Cohort Study.

BACKGROUND: Nuss procedure for pectus excavatum is a minimally invasive, but painful procedure. Recently, intercostal nerve cryoablation has been introduced as a pain management technique. MATERIALS AND METHODS: In this cohort study, we compared the efficacy of multimodal pain management strategies in children undergoing a Nuss procedure. The effectiveness of intercostal nerve cryoablation combined with patient-controlled systemic opioid analgesia (PCA) was compared with continuous epidural analgesia (CEA) combined with PCA. The study was conducted between January 2019 and July 2022. Primary outcome was length of stay (LOS), and secondary outcomes were operation room time, postoperative pain, opioid consumption, and gabapentin use. RESULTS: Sixty-six consecutive patients were included, 33 patients in each group. The cryoablation group exhibited lower Numeric Rating Scale (NRS) pain scores on postoperative day 1 and 2 (p = 0.002, p = 0.001) and a shorter LOS (3 vs. 6 days (p < 0.001). Cryoablation resulted in less patients requiring opioids at discharge (30.3 vs. 97.0%; p < 0.001) and 1 week after surgery (6.1 vs. 45.4%; p < 0.001)). In the CEA group, gabapentin use was more prevalent (78.8 vs. 18.2%; p < 0.001) and the operation room time was shorter (119.4 vs. 135.0 minutes; p < .010). No neuropathic pain was reported. CONCLUSIONS: Intercostal nerve cryoablation is a superior analgesic method compared with CEA, with reduced LOS, opioid use, and NRS pain scores. The prophylactic use of gabapentin is redundant.

Hyperbaric oxygen does not improve cerebral function when started 2 or 4 hours after cerebral arterial gas embolism in swine.

OBJECTIVE: Hyperbaric oxygenation is the accepted treatment for cerebral arterial gas embolism. Although earlier start of hyperbaric oxygenation is associated with better outcome, it is unknown how much delay can be tolerated before start of hyperbaric oxygenation. This study investigates the effect of hyperbaric oxygenation on cerebral function in swine when initiated 2 or 4 hours after cerebral arterial gas embolism. DESIGN: Prospective interventional animal study. SETTING: Surgical laboratory and hyperbaric chamber. SUBJECTS: Twenty-two Landrace pigs. INTERVENTIONS: Under general anesthesia, probes to measure intracranial pressure, brain oxygen tension (PbtO2), and brain microdialysis, and electrodes for electroencephalography were placed. The electroencephalogram (quantified using temporal brain symmetry index) was suppressed during 1 hour by repeated injection of air boluses through a catheter placed in the right ascending pharyngeal artery. Hyperbaric oxygenation was administered using U.S. Navy Treatment Table 6 after 2- or 4-hour delay. Control animals were maintained on an inspiratory oxygen fraction of 0.4. MEASUREMENTS AND MAIN RESULTS: Intracranial pressure increased to a mean maximum of 19 mm Hg (SD, 4.5 mm Hg) due to the embolization procedure. Hyperbaric oxygenation significantly increased PbtO2 in both groups treated with hyperbaric oxygenation (mean maximum PbtO2, 390 torr; SD, 177 torr). There were no significant differences between groups with regard to temporal brain symmetry index (control vs 2-hr delay, p = 0.078; control vs 4-hr delay, p = 0.150), intracranial pressure, and microdialysis values. CONCLUSIONS: We did not observe an effect of hyperbaric oxygenation on cerebral function after a delay of 2 or 4 hours. The injury caused in our model could be too severe for a single session of hyperbaric oxygenation to be effective. Our study should not change current hyperbaric oxygenation strategies for cerebral arterial gas embolism, but further research is necessary to elucidate our results. Whether less severe injury benefits from hyperbaric oxygenation should be investigated in models using smaller amounts of air and clinical outcome measures.

Comparison of Patient-Controlled versus Continuous Epidural Analgesia in Adult Surgical Patients: A Systematic Review.

BACKGROUND: The advantages of PCEA over CEA have been demonstrated in obstetric patients. Whether a similar benefit applies to surgical patients is unclear. METHODS: Embase, PubMed, and Cochrane Library were searched, enabling a systematic review of studies comparing PCEA and CEA in adult surgical patients (PROSPERO: CRD42018106644). The study quality was assessed using the Cochrane risk-of-bias tool (RoB2). The primary outcome was pain scores on postoperative day one (POD1). Secondary outcomes were 24 or 48 h epidural or intravenous total analgesic dose, systemic analgesics, manual top-ups, side effects, and patient satisfaction. RESULTS: Six randomized controlled trials with high heterogeneity of study characteristics were identified with a moderate risk of bias. Two studies showed significantly reduced resting pain scores on POD1 in PCEA compared with CEA patients (36-44%, p < 0.05). Four studies found comparable pain scores between these groups. PCEA use reduced epidural medication (28% to 40% reduction, p < 0.01) in four studies. One study found a 23% reduction (p < 0.001) of top-ups in PCEA; intravenous morphine use by PCEA patients was reduced (0.16 vs. 3.45 mg per patient, p < 0.05) in one study. PCEA patients were more satisfied with analgesia (p < 0.001) in two studies. Nausea and vomiting were reduced in PCEA (p = 0.01). CONCLUSIONS: Regarding the reduction in pain scores, the effects of PCEA were not significant or clinically not relevant. However, regarding the amount of epidural drug use, the amount of required rescue systemic analgesics, patient satisfaction, and the number of required top-ups, PCEA had advantages over CEA in surgical patients.

Perioperative Hypoxemia and Postoperative Respiratory Events in Infants with Hypertrophic Pyloric Stenosis.

BACKGROUND: Normalization of metabolic alkalosis is an important pillar in the treatment of infantile hypertrophic pyloric stenosis (IHPS) because uncorrected metabolic alkalosis may lead to perioperative respiratory events. However, the evidence on the incidence of respiratory events is limited. We aimed to study the incidence of peroperative hypoxemia and postoperative respiratory events in infants undergoing pyloromyotomy and the potential role of metabolic alkalosis. MATERIALS AND METHODS: We retrospectively reviewed all patients undergoing pyloromyotomy between 2007 and 2017. All infants received intravenous fluids preoperatively to correct metabolic abnormalities close to normal. We assessed the incidence of perioperative hypoxemia (defined as oxygen saturation [SpO2] < 90% for > 1min) and postoperative respiratory events. Additionally, the incidence of difficult intubations was evaluated. We performed a multivariate logistic regression analysis to evaluate the association between admission or preoperative serum pH values, bicarbonate or chloride, and peri- and postoperative hypoxemia or respiratory events. RESULTS: Of 406 included infants, 208 (51%) developed 1 or more episodes of hypoxemia during the perioperative period, of whom 130 (32%) experienced it during induction, 43 (11%) intraoperatively, and 112 (28%) during emergence. About 7.5% of the infants had a difficult intubation and 17 required more than 3 attempts by a pediatric anesthesiologist. Three patients developed respiratory insufficiency and 95 postoperative respiratory events were noticed. We did not find a clinically meaningful association between laboratory values reflecting metabolic alkalosis and respiratory events. CONCLUSIONS: IHPS frequently leads to peri- and postoperative hypoxemia or respiratory events and high incidence of difficult tracheal intubations. Preoperative pH, bicarbonate, and chloride were bad predictors of respiratory events.

Accuracy of abdominal organ motion estimation in radiotherapy using the right hemidiaphragm top as a surrogate during prolonged breath-holds quantified with MRI.

BACKGROUND: Respiratory motion presents a challenge in radiotherapy of thoracic and upper abdominal tumors. Techniques to account for respiratory motion include tracking. Using magnetic resonance imaging (MRI) guided radiotherapy systems, tumors can be tracked continuously. Using conventional linear accelerators, tracking of lung tumors is possible by determining tumor motion on kilo voltage (kV) imaging. But tracking of abdominal tumors with kV imaging is hampered by limited contrast. Therefore, surrogates for the tumor are used. One of the possible surrogates is the diaphragm. However, there is no universal method for establishing the error when using a surrogate and there are particular challenges in establishing such errors during free breathing (FB). Prolonged breath-holding might address these challenges. PURPOSE: The aim of this study was to quantify the error when using the right hemidiaphragm top (RHT) as surrogate for abdominal organ motion during prolonged breath-holds (PBH) for possible application in radiation treatments. METHODS: Fifteen healthy volunteers were trained to perform PBHs in two subsequent MRI sessions (PBH-MRI1 and PBH-MRI2). From each MRI acquisition, we selected seven images (dynamics) to determine organ displacement during PBH by using deformable image registration (DIR). On the first dynamic, the RHT, right and left hemidiaphragm, liver, spleen and right and left kidney were segmented. We used the deformation vector fields (DVF), generated by DIR, to determine the displacement of each organ between two dynamics in inferior-superior (IS), anterior-posterior (AP), left-right (LR) direction and we calculated the 3D vector magnitude (|d|). The displacements of the RHT, both hemidiaphragms and the abdominal organs were compared using a linear fit to determine the correlation (R2 of the fit) and the displacement ratio (DR, slope of the fit) between displacements of the RHT and each organ. We quantified the median difference between the DRs of PBH-MRI1 and PBH-MRI2 for each organ. Additionally, we estimated organ displacement in the second PBH by applying the DR from the first PBH to the displacement of the RHT measured during the second PBH. We compared the estimated organ displacement to the measured organ displacement during the second PBH. The difference between the two values was defined as the estimation error of using the RHT as a surrogate and assuming a constant DR over MRI sessions. RESULTS: The linear relationships were confirmed by the high R2 values of the linear fit between the displacements of the RHT and the abdominal organs (R2 > 0.96) in the IS and AP direction and |d|, and high to moderate correlations in the LR direction (0.93 > R2 > 0.64). The median DR difference between PBH-MRI1 and PBH-MRI2 varied between 0.13 and 0.31 for all organs. The median estimation error of the RHT as a surrogate varied between 0.4 and 0.8 mm/min for all organs. CONCLUSION: The RHT could serve as an accurate surrogate for abdominal organ motion during radiation treatments, for example, in tracking, provided the error of the RHT as motion surrogate is taken into account in the margins. TRIAL REGISTRATION: The study was registered in the Netherlands Trial Register (NL7603).

Lipophilicity but not stereospecificity is a major determinant of local anaesthetic-induced cytotoxicity in human T-lymphoma cells.

BACKGROUND AND OBJECTIVES: Local neurotoxicity of local anaesthetics is a well known phenomenon which is determined by lipophilicity. Recent reports have indicated the relevance of local anaesthetic-induced cytotoxicity also in nonneuronal tissues. This study re-evaluates the role of lipophilicity in local anaesthetic cytotoxicity in nonneuronal cells. In addition, the toxicities of pipecoloxylidine S(-) enantiomers were investigated. METHODS: Local anaesthetic-induced cytotoxicity was investigated in vitro in T-lymphoma cells (Jurkat). Cells were incubated with each of eight different local anaesthetics, two esters and six amides. Annexin V-fluorescein isothiocyanate and 7-aminoactinomycin D double staining followed by flow cytometry were used to investigate the fraction of early apoptotic cells as well as the overall cell death. The concentrations leading to 50% cell death (LC50) were calculated and compared. In a second step, we compared the toxicities of S(-) bupivacaine and the racemate as well as R(+) and S(-) ropivacaine. RESULTS: Concentration-dependent cytotoxicity was observed for all investigated local anaesthetics. Apoptosis was seen at low concentrations, whereas necrosis was observed at higher concentrations. LC50 values of the different local anaesthetics yielded the following decreasing order of toxicity: tetracaine, bupivacaine, ropivacaine, prilocaine, procaine, lidocaine, articaine and mepivacaine. Toxicity correlated with octanol/buffer partition coefficients, but was independent of the ester or amide linkage. There was no effect of stereoisomerism on apoptosis and necrosis. CONCLUSION: Moderate correlations for cytotoxicity with lipophilicity and clinical potency of local anaesthetics can be found in nonneuronal cells that are less than those reported previously with neuronal cells. Structural factors such as ester or amide linkage or stereospecificity do not have any influence on cytotoxicity. Although S(-) enantiomers may be advantageous with regard to systemic toxicity, they have no advantage in respect of local cytotoxicity in vitro.

The Options for Neuraxial Drug Administration.

Neuraxial drug administration, i.e., the injection of drugs into the epidural or intrathecal space to produce anesthesia or analgesia, is a technique developed more than 120 years ago. Today, it still is widely used in daily practice in anesthesiology and in acute and chronic pain therapy. A multitude of different drugs have been introduced for neuraxial injection, only a part of which have obtained official approval for that indication. A broad understanding of the pharmacology of those agents is essential to the clinician to utilize them in a safe and efficient manner. In the present narrative review, we summarize current knowledge on neuraxial anatomy relevant to clinical practice, including pediatric anatomy. Then, we delineate the general pharmacology of neuraxial drug administration, with particular attention to specific aspects of epidural and intrathecal pharmacokinetics and pharmacodynamics. Furthermore, we describe the most common clinical indications for neuraxial drug administration, including the perioperative setting, obstetrics, and chronic pain. Then, we discuss possible neurotoxic effects of neuraxial drugs, and moreover, we detail the specific properties of the most commonly used neuraxial drugs that are relevant to clinicians who employ epidural or intrathecal drug administration, in order to ensure adequate treatment and patient safety in these techniques. Finally, we give a brief overview on new developments in neuraxial drug therapy.

Contralateral surgical exploration during inguinal hernia repair in infants (HERNIIA trial): study protocol for a multi-centre, randomised controlled trial.

BACKGROUND: The incidence of metachronous contralateral inguinal hernia (MCIH) is high in infants with an inguinal hernia (5-30%), with the highest risk in infants aged 6 months or younger. MCIH is associated with the risk of incarceration and necessitates a second operation. This might be avoided by contralateral exploration during primary surgery. However, contralateral exploration may be unnecessary, leads to additional operating time and costs and may result in additional complications of surgery and anaesthesia. Thus, there is no consensus whether contralateral exploration should be performed routinely. METHODS: The Hernia-Exploration-oR-Not-In-Infants-Analysis (HERNIIA) study is a multicentre randomised controlled trial with an economic evaluation alongside to study the (cost-)effectiveness of contralateral exploration during unilateral hernia repair. Infants aged 6 months or younger who need to undergo primary unilateral hernia repair will be randomised to contralateral exploration or no contralateral exploration (n = 378 patients). Primary endpoint is the proportion of infants that need to undergo a second operation related to inguinal hernia within 1 year after primary repair. Secondary endpoints include (a) total duration of operation(s) (including anaesthesia time) and hospital admission(s); (b) complications of anaesthesia and surgery; and (c) participants' health-related quality of life and distress and anxiety of their families, all assessed within 1 year after primary hernia repair. Statistical testing will be performed two-sided with α = .05 and according to the intention-to-treat principle. Logistic regression analysis will be performed adjusted for centre and possible confounders. The economic evaluation will be performed from a societal perspective and all relevant costs will be measured, valued and analysed. DISCUSSION: This study evaluates the effectiveness and cost-effectiveness of contralateral surgical exploration during unilateral inguinal hernia repair in children younger than 6 months with a unilateral inguinal hernia. TRIAL REGISTRATION: ClinicalTrials.gov NCT03623893 . Registered on August 9, 2018 Netherlands Trial Register NL7194. Registered on July 24, 2018 Central Committee on Research Involving Human Subjects (CCMO) NL59817.029.18. Registered on July 3, 2018.

Benzethonium increases the cytotoxicity of S(+)-ketamine in lymphoma, neuronal, and glial cells.

INTRODUCTION: Ketamine has been demonstrated to be neurotoxic in animals as well as in patients. Preservatives added to ketamine have been accused to induce this neurotoxicity. Therefore, we investigated whether the most widely used preservative of ketamine-benzethonium chloride-enhances the toxicity of S(+)-ketamine in vitro in lymphoma, neuroblastoma cells and primary astrocytes. METHODS: Human Jurkat T-lymphoma- and neuroblastoma cells (SHEP) were incubated for 24 hours with commercially available S-ketamine containing benzethonium, pure S-ketamine and pure benzethonium chloride. The rate of early- and late-apoptotic cells was evaluated by flowcytometry. In a second step the combined toxicity of benzethonium and ketamine was investigated in neuroblastoma cells and primary rat astrocytes in a mitochondrial activity assay (XTT). The additivity of the toxicities was evaluated by employing isobolographic analysis. RESULTS: In Jurkat T-lymphoma and neuroblastoma cells benzethonium increased the toxicity of ketamine from 32% to 80% and from 64% to 84% cell deaths, respectively. In neuroblastoma cells as well as in primary rat astrocytes the measured combined toxicity was within the confidence interval of the calculated pure additive toxicity as seen in the isobolograms. CONCLUSIONS: We conclude that benzethonium increases the local toxicity of ketamine in cells of hematopoietic, neuronal and glial origin in an additive manner. Therefore, caution is recommended especially when using preservative containing S-ketamine as an additive for long-term neuraxial analgesia.