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Background In patients with remarkably enlarged cardiac chambers and history of implantation of older types of mitral valve prosthesis, the considerations for reoperative tricuspid valve surgery are not limited to the risks of sternal reentry but also include the dilemma of whether to carry out prophylactic replacement of the normal functioning but outdated prosthesis or leave it in situ. Methods We reviewed our surgical strategy and postoperative 5-year follow-up findings in two patients who underwent redo tricuspid surgery 3 to 4 decades after mechanical mitral valve replacement. Both patients presented with significant symptoms of progressive right heart failure due to severe tricuspid regurgitation, despite optimal medical therapy. Results We found the beating-heart approach to be an effective and safe method for redo tricuspid surgery. Both first-generation mitral mechanical prostheses were not replaced and have remained well functional upon the patients’ postoperative 5-year follow-up, respectively. Conclusion For patients with normal functioning first-generation mechanical mitral prostheses, whether to prophylactically replace the prosthesis should be based on an individualized risk-benefit analysis.

Background: Selective neonatal left mainstem bronchial intubation to treat right lung disease is typically achieved with elaborate maneuvers, instrumentation and devices. This is often attributed to bronchial geometry which favors right mainstem entry of an endotracheal tube deliberately advanced beyond the carina. Case summary: A neonate with severe bullous emphysema affecting the right lung required urgent non-ventilation of that lung. We achieved left mainstem bronchial intubation by turning the endotracheal tube 180° such that the Murphy's eye faced the left instead of the right, and simulated a left-handed intubation by slightly orientating the endotracheal tube such that its concavity faced the left instead of the right as in a conventional right-handed intubation. Conclusion: Urgent intubation of the left mainstem bronchus with an endotracheal tube can be easily achieved by recognizing that it is the position of the endotracheal tube tip and the direction of its concavity that are the chief determinants of which bronchus an endotracheal tube goes when advanced. This is important in critically ill neonates as the margin of safety and time window are small, and the absence of double-lumen tubes. Use of fiberoptic bronchoscope and blockers should be reserved as backup plans. Resumo: Justificativa: A intubação seletiva neonatal do brônquio principal esquerdo para tratar a doença pulmonar direita é tipicamente realizada com elaboradas manobras, instrumentação e dispositivos. Isso é frequentemente atribuído à geometria brônquica que favorece a entrada principal direita de um tubo endotraqueal (TET) deliberadamente avançado para além da carina. Resumo do caso: Recém-nascido com enfisema bolhoso grave afetando o pulmão direito que precisou com urgência da não ventilação desse pulmão. Conseguimos a intubação brônquica esquerda fazendo uma rotação de 180° do TET, de forma que o olho de Murphy ficasse voltada para a esquerda e não para a direita, e simulamos uma intubação à esquerda orientando ligeiramente o TET, de modo que sua concavidade virasse para a esquerda em vez de para a direita, como em uma intubação convencional à direita. Conclusão: A intubação urgente do brônquio principal esquerdo com um TET pode ser facilmente obtida reconhecendo-se que é a posição da ponta do TET e a direção de sua concavidade que determinam para qual brônquio o TET irá quando avançado. Isso é importante em neonatos criticamente doentes diante da margem de segurança e janela de tempo pequenas e na ausência de tubos de duplo lúmen. O uso de broncofibroscópio e bloqueadores deve ser considerado como planos de segurança. Keywords: Bullous emphysema, Endobronchial intubation, Neonate, Palavras-chave: Enfisema bolhoso, Intubação endobrônquica, Recém-nascido

Resumo Justificativa A intubacao seletiva neonatal do bronquio principal esquerdo para tratar a doenca pulmonar direita e tipicamente feita com elaboradas manobras, instrumentacao e dispositivos. Isso e frequentemente atribuido a geometria bronquica que favorece a entrada principal direita de um tubo endotraqueal (TET) deliberadamente avancado para alem da carina. Resumo do caso Recem‐nascido com enfisema bolhoso grave que afetava o pulmao direito e precisou com urgencia da nao ventilacao desse pulmao. Para conseguir a intubacao bronquica esquerda fizemos uma rotacao de 180° do TET, de forma que o olho de Murphy ficasse voltado para a esquerda, e nao para a direita, e para simular uma intubacao a esquerda orientamos ligeiramente o TET, de modo que sua concavidade virasse para a esquerda em vez de para a direita, como em uma intubacao convencional a direita. Conclusao A intubacao urgente do bronquio principal esquerdo com um TET pode ser facilmente obtida se reconhecermos que e a posicao da ponta do TET e a direcao de sua concavidade que determinam para qual bronquio o TET ira quando avancado. Isso e importante em neonatos criticamente doentes diante da margem de seguranca e janela de tempo pequenas e na ausencia de tubos de duplo lumen. O uso de broncofibroscopio e bloqueadores deve ser considerado como planos de seguranca.

Outside of anesthesia, lumbar puncture (LP) is commonly performed for diagnostic and therapeutic purposes. Patients with leukemia and lymphoma need multiple LPs for diagnosis and intrathecal chemotherapy. Thrombocytopenia, sometimes complicated by coagulopathy, is frequently present in this patient

Background: Postoperative pain represents an important concern when remifentanil is used for total intravenous anesthesia because of its ultrashort half-life. Longer acting opioids, such as sufentanil, have been used during induction of remifentanil-based total intravenous anesthesia as a means to overcome this shortcoming. However, the effectiveness and safety of such strategy still lacks evidence from randomized clinical trials. Hence, we aimed to assess the postoperative analgesic efficacy and safety of a single dose of sufentanil administered during the induction of remifentanil-based total intravenous anesthesia. Methods: Forty patients, scheduled for elective open abdominal surgery, were randomized to receive remifentanil-based total intravenous anesthesia with or without a single dose of sufentanil upon induction. We assessed the postoperative morphine consumption administered through a patient-controlled analgesia pump. Self-reported pain scores and the occurrence of nausea, vomiting, pruritus, agitation, somnolence and respiratory depression were also assessed up to 2 days after surgery. Results: The mean difference between the sufentanil and control groups regarding morphine consumption in the post-anesthetic care unit and at 12, 24 and 48 h after surgery were −7.2 mg (95%CI: −12.5 to −2.1, p

Prophylactic administration of a vasopressor to mitigate the hypotensive effect of propofol (and/or other co-induction agents) during sedation/anesthesia immediately prior to tracheal intubation in frail patients in the intensive care unit and emergency and operating rooms appears to be not an uncommon practice. We submit that this practice is unnecessary and potentially harmful. Despite restoring the blood pressure, phenylephrine, for instance, may have an additive or synergistic effect with propofol in reducing the cardiac output and, ultimately, organ perfusion. Airway instrumentation often leads to sympathetic activation and hypertension (thereby increasing myocardial oxygen consumption) which may be exacerbated by an arbitrary prophylactic dose of phenylephrine. Finally, in spite of the well-recognized need to reduce dosages of propofol in frail patients, excessive doses are commonly given, leading to hypotension. We herein discuss each of these points and suggest alternative techniques to promote a stable induction in frail patients.

Background and objectives: Focused Cardiac Ultrasound (FoCUS) has proven instrumental in guiding anesthesiologists’ clinical decision-making process. Training residents to perform and interpret FoCUS is both feasible and effective. However, the degree of knowledge retention after FoCUS training remains a subject of debate. We sought to provide a description of our 4-week FoCUS curriculum, and to assess the knowledge retention among anesthesia residents at 6 months after FoCUS rotation. Methods: A prospective analysis involving eleven senior anesthesia residents was carried out. At end of FoCUS Rotation (EOR) participants completed a questionnaire (evaluating the number of scans completed and residents’ self-rated knowledge and comfort level with FoCUS), and a multiple-choice FoCUS exam comprised of written- and video-based questions. Six months later, participants completed a follow-up questionnaire and a similar exam. Self-rated knowledge and exam scores were compared at EOR and after 6 months. Spearman correlations were conducted to test the relationship between number of scans completed and exam scores, perceived knowledge and exam scores, and number of scans and perceived knowledge. Results: Mean exam scores (out of 50) were 44.1 at EOR and 43 at the 6-month follow-up. Residents had significantly higher perceived knowledge (out of 10) at EOR (8.0) than at the 6-month follow-up (5.5), p = 0.003. At the EOR, all trainees felt comfortable using FoCUS, and at 6 months 10/11 still felt comfortable. All the trainees had used FoCUS in their clinical practice after EOR, and the most cited reason for not using FoCUS more frequently was the lack of perceived clinical need. A strong and statistically significant (rho = 0.804, p = 0.005) correlation between number of scans completed during the FoCUS rotation and 6-month follow-up perceived knowledge was observed. Conclusion: Four weeks of intensive FoCUS training results in adequate knowledge acquisition and 6-month knowledge retention. Resumo: Justificativa e objetivos: A ultrassonografia cardíaca no local de atendimento (USCLA) provou ser importante para orientar o processo de tomada de decisão clínica dos anestesiologistas. Treinar os residentes para fazer e interpretar uma USCLA é viável e eficaz. No entanto, o grau de retenção do conhecimento após o treinamento permanece um assunto de debate. Procuramos fornecer uma descrição do currículo de quatro semanas do treinamento de USCLA e avaliar a retenção do conhecimento entre os residentes de anestesia seis meses após a rotação em USCLA. Métodos: Uma análise prospectiva foi realizada com 11 residentes seniores de anestesia. Ao final da rotação em USCLA, os participantes preencheram um questionário (avaliando o número de exames ultrassonográficos concluídos, o conhecimento adquirido e o nível de conforto dos residentes com a USCLA) e fizeram um exame de múltipla escolha para USCLA, composto por perguntas escritas e baseadas em vídeo. Seis meses depois, os participantes preencheram um questionário de acompanhamento e um exame similar. A autoavaliação do conhecimento e os escores do exame foram comparados no final da rotação e após seis meses. Correlações de Spearman foram usadas para testar a relação entre o número de exames concluídos e os escores dos exames, o conhecimento percebido, os escores dos exames, o número de exames e o conhecimento percebido. Resultados: Os escores médios dos exames (50) foram: 44,1 no final da rotação e 43 após seis meses. Os residentes tiveram conhecimento percebido significativamente maior (10) no final da rotação (8,0) que após seis meses (5,5), p = 0,003. No final da rotação, todos os residentes se sentiram confortáveis usando o aparelho de USCLA e, aos seis meses, 10/11 ainda se sentiam confortáveis. Todos os residentes haviam usado o USCLA em sua prática clínica após o final da rotação e a razão mais citada para não usar o USCLA com mais frequência foi a falta de necessidade clínica percebida. Uma correlação forte e estatisticamente significativa (rho = 0,804, p = 0,005) foi observada entre o número de exames realizados durante a rotação em USCLA e o conhecimento percebido em seis meses de seguimento. Conclusão: Quatro semanas de treinamento intensivo de USCLA resultaram em aquisição e retenção adequadas do conhecimento por seis meses. Keywords: POCUS, FoCUS, Knowledge retention, Education, Anesthesia, Palavras-chave: POCUS, USCLA, Retenção de conhecimento, Educação, Anestesia

We conducted a small pilot observational study of the effects of bilateral thoracic paravertebral block (BTPB) as an adjunct to perioperative analgesia in coronary artery bypass surgery patients. The initial ropivacaine dose prior to induction of general anaesthesia was 3 mg/kg, which was followed at the end of the surgery by infusion of ropivacaine 0.25% 0.1 ml/kg/hour on each side (e.g. total 35 mg/hour for a 70 kg person). The BTPB did not eliminate the need for supplemental opioids after CABG in the eight patients studied. Moreover, in spite of boluses that were within the manufacturer's recommendation for epidural and major nerve blocks, and an infusion rate that was only slightly higher than what appeared to be safe for epidural infusion, potentially toxic total plasma ropivacaine concentrations were common. We also could not exclude the possibility that the high ropivacaine concentrations were contributing to postoperative mental state changes in the postoperative period. Also, one patient developed local anaesthetic toxicity after the bilateral paravertebral dose. As a result, the study was terminated early after four days. The question of whether paravertebral block confers benefits in cardiac surgery remains unanswered. However, we believe that the bolus dosage and the injection rate we used for BTPB were both too high, and caution other clinicians against the use of these doses. Future studies on the use of BTPB in cardiac surgery patients should include reduced ropivacaine doses injected over longer periods.

From the *Department of Anesthesiology and Perioperative Medicine, Queen’s University, Kingston, Ontario, Canada; †Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, Columbus, OH; and ‡Department of Anaesthesia, The Tweed Hospital, Tweed Heads, Australia. Address reprint requests to Anthony M.-H. Ho, MD, FRCPC, FCCP, Department of Anesthesiology and Perioperative Medicine, Victory 2, Kingston General Hospital, Queen’s University, 76 Stuart Street, Kingston, Ontario, Canada, K7L 2V7. E-mail: hoamh@hotmail.com © 2016 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.04.005

The optimal approach to postoperative analgesia in patients with bilateral diaphragmatic paralysis undergoing abdominal surgery remains unclear. We report a 69-year-old woman with bilateral diaphragmatic paralysis who underwent a laparoscopic hernia repair and an open laparotomy for reversal of a Hartmann procedure under general anesthesia. Postoperative analgesia was provided by intravenous opioid and epidural local anesthetic and opioid, respectively. The patient's trachea was successfully extubated at the end of both surgical procedures. Epidural analgesia was associated with better pain control and shorter intensive care unit stay.

During this COVID-19 pandemic, at increased risk of infection are clinicians involved in aerosol-generating procedures such as endotracheal intubation.1 We herein describe a technique to mitigate aerosolisation. As shown in the figure 1A, the rubber bung of a 20 mL syringe plunger is used to occlude the connector of the endotracheal tube (ETT) figure 1B, preventing aerosolised particles (eg, during coughing) from being directed towards the operator. Once the ETT tip has passed the larynx and its cuff has been inflated to ensure seal, a clamp is applied to the ETT (not shown) prior to removal of the …

Background: Chronic pain is a highly prevalent and complex health problem that is associated with a severe symptom burden, as well as substantial economic and social impact. Many patients with chronic pain still suffer from unrelieved or undertreated pain due to the incomplete efficacy and dose-limiting adverse effects of current therapies. Long-term and high-dose opioid use has considerably increased in the past 20 years despite limited evidence supporting its effectiveness in several chronic pain conditions, and serious concerns have emerged regarding adverse effects and potential misuse. Until recently, the steady increase in opioid prescribing rates has been associated with rising opioid-related mortality and other serious problems, emphasizing the need for better nonopioid therapies. Emerging evidence supports the safe use of magnesium in controlling chronic pain, but its overall efficacy and safety is still unclear. Objective: This paper aims to assess the efficacy and safety of magnesium compared with a placebo for the treatment of chronic noncancer pain. Methods: We will conduct a detailed search on Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from their inception until the date the searches are run to identify relevant randomized controlled trials. The reference lists of retrieved studies as well as Web-based trial registries will also be searched. We will include randomized double-blind trials comparing magnesium (at any dose, frequency, or route of administration) with placebo using participant-reported pain assessment. Two reviewers will independently evaluate studies for eligibility, extract data, and assess trial quality and potential bias. Risk of bias will be assessed using criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. Primary outcomes for this review will include any validated measure of pain intensity or pain relief. Dichotomous data will be used to calculate the risk ratio and number needed to treat or harm. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. Results: This protocol is grant-funded and has undergone a peer-review process through the Queen’s University Department of Anesthesiology and Perioperative Medicine Vandewater Endowed Studentship. This project is also supported, in part, by the Chronic Pain Network of the Canadian Institutes of Health Research Strategy for Patient-Oriented Research. The electronic database search strategies are currently being developed and modified. The entire review is expected to be completed by January 1, 2019. Conclusions: The completion of this review is expected to identify available high-quality evidence describing the efficacy and safety of magnesium for the treatment of chronic noncancer pain. International Registered Report Identifier (IRRID): PRR1-10.2196/11654

Postoperative pain represents an important concern when remifentanil is used for total intravenous anesthesia because of its ultrashort half-life. Longer acting opioids, such as sufentanil, have been used during induction of remifentanil-based total intravenous anesthesia as a means to overcome this shortcoming. However, the effectiveness and safety of such strategy still lacks evidence from randomized clinical trials. Hence, we aimed to assess the postoperative analgesic efficacy and safety of a single dose of sufentanil administered during the induction of remifentanil-based total intravenous anesthesia.Forty patients, scheduled for elective open abdominal surgery, were randomized to receive remifentanil-based total intravenous anesthesia with or without a single dose of sufentanil upon induction. We assessed the postoperative morphine consumption administered through a patient-controlled analgesia pump. Self-reported pain scores and the occurrence of nausea, vomiting, pruritus, agitation, somnolence and respiratory depression were also assessed up to 2 days after surgery.The mean difference between the sufentanil and control groups regarding morphine consumption in the post-anesthetic care unit and at 12, 24 and 48h after surgery were -7.2mg (95%CI: -12.5 to -2.1, p0.001), -3.9mg (95%CI: -11.9 to 4.7, p=0.26), -0.6mg (95%CI: (-12.7 to 12.7, p=0.80), and -1.8mg (95%CI: (-11.6 to 15.6, p=0.94), respectively. Neither self-reported pain nor the incidence of adverse events were significantly different between groups at any time point.Our findings suggest that the administration of sufentanil during induction of remifentanil-based total intravenous anesthesia is associated with decreased early postoperative opioid consumption.

BACKGROUND Chronic pain is a highly prevalent and complex health problem that is associated with a severe symptom burden, as well as substantial economic and social impact. Many patients with chronic pain still suffer from unrelieved or undertreated pain due to the incomplete efficacy and dose-limiting adverse effects of current therapies. Long-term and high-dose opioid use has considerably increased in the past 20 years despite limited evidence supporting its effectiveness in several chronic pain conditions, and serious concerns have emerged regarding adverse effects and potential misuse. Until recently, the steady increase in opioid prescribing rates has been associated with rising opioid-related mortality and other serious problems, emphasizing the need for better nonopioid therapies. Emerging evidence supports the safe use of magnesium in controlling chronic pain, but its overall efficacy and safety is still unclear. OBJECTIVE This paper aims to assess the efficacy and safety of magnesium compared with a placebo for the treatment of chronic noncancer pain. METHODS We will conduct a detailed search on Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from their inception until the date the searches are run to identify relevant randomized controlled trials. The reference lists of retrieved studies as well as Web-based trial registries will also be searched. We will include randomized double-blind trials comparing magnesium (at any dose, frequency, or route of administration) with placebo using participant-reported pain assessment. Two reviewers will independently evaluate studies for eligibility, extract data, and assess trial quality and potential bias. Risk of bias will be assessed using criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. Primary outcomes for this review will include any validated measure of pain intensity or pain relief. Dichotomous data will be used to calculate the risk ratio and number needed to treat or harm. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS This protocol is grant-funded and has undergone a peer-review process through the Queen’s University Department of Anesthesiology and Perioperative Medicine Vandewater Endowed Studentship. This project is also supported, in part, by the Chronic Pain Network of the Canadian Institutes of Health Research Strategy for Patient-Oriented Research. The electronic database search strategies are currently being developed and modified. The entire review is expected to be completed by January 1, 2019. CONCLUSIONS The completion of this review is expected to identify available high-quality evidence describing the efficacy and safety of magnesium for the treatment of chronic noncancer pain. INTERNATIONAL REGISTERED REPOR PRR1-10.2196/11654

Hyperbilirubinemia is a known risk factor in patients undergoing open heart operations. Infective endocarditis often leads to valvular injury, such as rupture of chordae tendineae or leaflet perforation, which can cause acute heart failure in association with pulmonary hypertension and liver dysfunction. Here we present a patient with massive liver congestion, reflected by extreme hyperbilirubinemia, secondary to acute heart failure following mitral valve endocarditis that was successfully treated by emergency mitral and tricuspid valve repair.

Traditional transfusion guidelines suggest that fresh frozen plasma (FFP) should be given based on laboratory or clinical evidence of coagulopathy or acute loss of 1 blood volume. This approach tends to result in a significant lag time between the first units of erythrocytes and FFP in trauma requiring massive transfusion. In severe trauma, observational studies have found an association between increased survival and aggressive use of FFP and platelets such that FFP:platelet:erythrocyte ratio approaches 1:1:1 to 2 from the first units of erythrocytes given. There are considerable concerns over either approach, and no randomized controlled trials have been published comparing the 2 approaches. Nowadays, trauma clinicans are incorporating the strenghts of both approaches and are no longer treating them as a dichotomy. Specifically, "1:1:1" proponents have devised 1:1:1 activation criteria to minimize unnecessary FFP and platelet transfusion and are prepared to deactivate the protocol as soon as patient is stabilized. Similarly, 1:1:1 skeptics are more mindful of the need to be proactive about trauma coagulopathy and the inherent delays in FFP administration in trauma patients.

Focused Cardiac Ultrasound (FoCUS) has proven instrumental in guiding anesthesiologists' clinical decision-making process. Training residents to perform and interpret FoCUS is both feasible and effective. However, the degree of knowledge retention after FoCUS training remains a subject of debate. We sought to provide a description of our 4-week FoCUS curriculum, and to assess the knowledge retention among anesthesia residents at 6 months after FoCUS rotation.A prospective analysis involving eleven senior anesthesia residents was carried out. At end of FoCUS Rotation (EOR) participants completed a questionnaire (evaluating the number of scans completed and residents' self-rated knowledge and comfort level with FoCUS), and a multiple-choice FoCUS exam comprised of written- and video-based questions. Six months later, participants completed a follow-up questionnaire and a similar exam. Self-rated knowledge and exam scores were compared at EOR and after 6 months. Spearman correlations were conducted to test the relationship between number of scans completed and exam scores, perceived knowledge and exam scores, and number of scans and perceived knowledge.Mean exam scores (out of 50) were 44.1 at EOR and 43 at the 6-month follow-up. Residents had significantly higher perceived knowledge (out of 10) at EOR (8.0) than at the 6-month follow-up (5.5), p=0.003. At the EOR, all trainees felt comfortable using FoCUS, and at 6 months 10/11 still felt comfortable. All the trainees had used FoCUS in their clinical practice after EOR, and the most cited reason for not using FoCUS more frequently was the lack of perceived clinical need. A strong and statistically significant (rho=0.804, p=0.005) correlation between number of scans completed during the FoCUS rotation and 6-month follow-up perceived knowledge was observed.Four weeks of intensive FoCUS training results in adequate knowledge acquisition and 6-month knowledge retention.

Background Efficient airway management is paramount in emergency medicine. Our experience teaching tracheal intubation has consistently identified gaps in the understanding of important issues. Here we discuss the importance of the endotracheal tube (ETT) bevel in airway management. Discussion The ETT bevel orientation is the main determinant of which mainstem bronchus the ETT enters when advanced too distally, despite a common belief that attributes a higher incidence of right mainstem bronchial intubation to the straighter angle sustained by the right mainstem bronchus. Likewise, a bougie- or fiberscope-assisted tracheal intubation can be impeded by the ETT tip hooking onto laryngeal structures; a 90-degree counterclockwise turn of the ETT (such that the bevel is facing posteriorly) prior to advancing it toward the larynx produces a first-pass success rate of 100%. Similarly, a posterior-facing bevel is believed to improve the ease of passage through the back of the nasal cavity when performing nasotracheal intubation. If resistance is met after the ETT tip has reached the laryngeal vicinity, further counterclockwise rotation may change the plane and incident angle of the ETT tip, facilitating passage through the vocal cords. Clockwise twisting of the ETT reduces the incident angle in the sagittal plane, thereby facilitating videolaryngoscopy-assisted tracheal intubation. Finally, a posterior-facing ETT bevel is the least likely to intubate a tracheoesophageal fistula. Conclusions Understanding the implications of the ETT bevel direction may significantly change the efficiency of deliberate endobronchial, nasal, and bougie/fiberscope-, and videolaryngoscope-assisted intubations, and while managing the patient with a tracheoesophageal fistula.

Before-after study designs are effective research tools and in some cases, have changed practice. These designs, however, are inherently susceptible to bias (ie, systematic errors) that are sometimes subtle but can invalidate their conclusions. This overview provides examples of before-after studies relevant to anesthesiologists to illustrate potential sources of bias, including selection/assignment, history, regression to the mean, test-retest, maturation, observer, retrospective, Hawthorne, instrumentation, attrition, and reporting/publication bias. Mitigating strategies include using a control group, blinding, matching before and after cohorts, minimizing the time lag between cohorts, using prospective data collection with consistent measuring/reporting criteria, time series data collection, and/or alternative study designs, when possible. Improved reporting with enforcement of the Enhancing Quality and Transparency of Health Research (EQUATOR) checklists will serve to increase transparency and aid in interpretation. By highlighting the potential types of bias and strategies to improve transparency and mitigate flaws, this overview aims to better equip anesthesiologists in designing and/or critically appraising before-after studies.

Efficient implementation of machine learning applications on FPGAs often requires non-linear numerical functions with a non-standard numerical precision that is not readily available from vendor provided standard libraries. While application-specific designs of such functions can result in superior numerical accuracy and area efficiency when compared to ad-hoc composition using vendor-provided primitives, the effort devoted to this challenging task can hardly be portable to other similar applications. In this work, we present an open source generator, NnCore, for floating-point non-linear operator cores built using fixed-point piecewise polynomial segments. The proposed framework takes advantage of properties such as oddness/evenness and intercept-at-origin, often found in the numerical functions commonly used in machine learning applications, and applied an improved segmentation algorithm that specifically handles “outlier” segments, to reduce the required memory size for storing polynomial coefficients. Experimental results show that, at single-precision setting, NnCore generated cores use up to 65% fewer BRAMs, 63% fewer shift-registers, and runs at up to 2.2 χ the clock speed, compare with cores generated from a previous generic function generator. At half-precision, cores can run around 1.2 χ higher clock speed while requiring higher resource usage, or use a comparable number of resource but run at 12% to 45% lower clock speed. The use of HLS C++ as output format allows core integration into modern high-level workflow such as Xilinx SDAccel.

We report a case of severe respiratory distress in a neonate who was not endotracheally intubated soon after esophageal atresia/tracheoesophageal fistula (EA/TEF) repair. In this serious situation, any form of emergency respiratory support or definitive airway management may compromise the esophageal anastomosis and fistula repair. The cause of respiratory distress in the early postoperative period after EA/TEF is multifactorial, and in this case, included symptomatic tracheomalacia, which is commonly associated with EA/TEF.

Neural network applications on FPGAs at times require arithmetic operators that are either not available in the manufacturer's core library, or are complex operators made up of several elementary functions, requiring more resources than if they were built as single operators. In this work, we built an open-source, parameterized floating-point core generator named NnCore, for operators used as activation functions, and their derivatives. We propose a binary search algorithm to search for minimax-polynomial segments, with adjusting steps for ensuring monotonicity between different segments.

A 73-year-old man underwent urgent coronary artery bypass grafting after an acute myocardial infarction. An angiogram had revealed multivessel disease with a circumflex artery lesion suspected as the primary culprit. On separation from cardiopulmonary bypass, transesophageal echocardiography revealed a new mobile mass in the aortic root. Cardiopulmonary bypass was reinstituted and a large thrombus emanating from the left coronary ostium was surgically removed. We hypothesize that the thrombus had originated from coronary retrograde extrusion during venous grafting. This case illustrates an unusual source of emboli during coronary artery bypass grafting and emphasizes the importance of perioperative transesophageal echocardiography for the prevention of potentially catastrophic outcomes.

To the Editor, When performing nerve blocks or vascular cannulation under ultrasound (US) guidance, the depth of the target nerve/vessel and/or the defining landmark ( d US cm; [figure 1][1]) is seen on the US screen and noted by the practitioner. This depth serves as a guide for determining the

To determine the dose-dependent effects of testosterone administration on cognition in women with low testosterone levels.71 hysterectomized women with or without oophorectomy with total testosterone31 ng/dl and/or free testosterone3.5 pg/ml received a standardized transdermal estradiol regimen during the 12-week run-in period and were then randomized to receive weekly intramuscular injections of placebo, 3, 6.25, 12.5, or 25 mg testosterone enanthate for 24 weeks. Total testosterone was measured in serum by LC-MS/MS, and free testosterone levels were measured by equilibrium dialysis. Cognitive function was evaluated using a comprehensive battery of standardized neuropsychological tests at baseline and 24 weeks.46 women who had baseline and end-of-treatment cognitive function data constituted the analytic sample. The five groups were similar at baseline. Mean on-treatment nadir total testosterone concentrations were 15, 89, 98, 134, and 234 ng/dl in the placebo, 3, 6.25, 12.5, and 25 mg groups, respectively. No significant changes in spatial ability, verbal fluency, verbal memory, or executive function were observed in any treatment arm compared to placebo even after adjustment for baseline cognitive function, age, and education. Multiple regression analysis did not show any significant relation between changes in testosterone concentrations and change in cognitive function scores.Short-term testosterone administration over a wide range of doses for 24 weeks in women with low testosterone levels was neither associated with improvements nor worsening of cognitive function.

To describe the use of cerebral oximetry to detect a lack of right cerebral perfusion resulting from a malpositioned catheter used for antegrade cerebral perfusion during deep hypothermic circulatory arrest (DHCA). The simple corrective surgical adjustment that followed averted a potentially serious complication.A 57-yr-old male with a type-A aortic dissection undergoing DHCA required antegrade cerebral perfusion for cerebral protection. Catheters were placed accordingly in the left common carotid and brachiocephalic arteries. Whereas frontal cerebral oximetry immediately improved on the left, it did not improve on the right. It was immediately suspected that the tip of the brachiocephalic cannula had advanced into the right subclavian artery, thus depriving the right common carotid artery of blood flow. The problem resolved upon slight withdrawal of the cannula.Vigilance in anesthesia should not stop during DHCA or cardiopulmonary bypass. Cerebral oximetry may provide important information leading to actions that improve brain protection. Vigilances proved important in this case where the cannula tip used for antegrade cerebral perfusion was advanced too far into the right subclavian artery.

Study objectives Inattentional blindness is the psychological phenomenon of inability to see the unexpected even if it is in plain view. We hypothesized that anesthesiologists may overlook unexpected intraoperative events whereas medical students, lacking in intraoperative monitoring experience and knowledge, may be more likely to notice such events. Design A simulation study using a video of a simulated septic patient undergoing abdominal surgery. Setting A large academic center. Participants 31 certified anesthesiologists and 46 upper-year medical students. Interventions None. Participants watched a video of a simulated surgery and scored the abnormalities they saw. Measurements These abnormalities included abnormal physiologic parameters consistent with the condition of the simulated septic patient, and two unexpected but plausible events: head movement and a leaky central line catheter. Main results Students were significantly more likely than anesthesiologists to notice head movement (p

Selective neonatal left mainstem bronchial intubation to treat right lung disease is typically achieved with elaborate maneuvers, instrumentation and devices. This is often attributed to bronchial geometry which favors right mainstem entry of an endotracheal tube deliberately advanced beyond the carina.A neonate with severe bullous emphysema affecting the right lung required urgent non-ventilation of that lung. We achieved left mainstem bronchial intubation by turning the endotracheal tube 180° such that the Murphy's eye faced the left instead of the right, and simulated a left-handed intubation by slightly orientating the endotracheal tube such that its concavity faced the left instead of the right as in a conventional right-handed intubation.Urgent intubation of the left mainstem bronchus with an endotracheal tube can be easily achieved by recognizing that it is the position of the endotracheal tube tip and the direction of its concavity that are the chief determinants of which bronchus an endotracheal tube goes when advanced. This is important in critically ill neonates as the margin of safety and time window are small, and the absence of double-lumen tubes. Use of fiberoptic bronchoscope and blockers should be reserved as backup plans.

A system that augments the Apache Spark data processing framework with FPGA accelerators is presented as a way to model and deploy FPGA-assisted applications in large-scale clusters. In our proposed framework, FPGAs can optionally be used in place of the host CPU for Resilient distributed datasets (RDDs) transformations, allowing seamless integration between gateware and software processing. Using the case of training an Support Vector Machine (SVM) cell image classifier as a case study, we explore the feasibilities, benefits and challenges of such technique. In our experiments where data communication between CPU and FPGA is tightly controlled, a consistent speedup of up to 1.6x can be achieved for the target SVM training application as the cluster size increases. Hardware-software techniques that are crucial to achieve acceleration such as the management of data partition size are explored. We demonstrate the benefits of the proposed framework, while also illustrate the importance of careful hardware-software management to avoid excessive CPU-FPGA communication that can quickly diminish the benefits of FPGA acceleration.