Advanced airway management and respiratory care in decompensated pulmonary hypertension.

Meticulous risk stratification is essential when considering intubation of a patient with decompensated pulmonary hypertension (dPH). It is paramount to understand both the pathophysiology of dPH (and associated right ventricular failure) and the complications related to a high-risk intubation before attempting the procedure. There are few recommendations in this area and the literature, guiding these recommendations, is limited to expert opinion and very few case reports/case series. This review will discuss the complex pathophysiology of dPH, the complications associated with intubation, the debates surrounding induction agents, and the available options for the intubation procedure, with specific emphasis on the emerging role for awake fiberoptic intubation. All patients should be evaluated for candidacy for veno-arterial extracorporeal membrane oxygen as a bridge to recovery, lung transplantation, or pulmonary endarterectomy prior to intubation. Only an experienced proceduralist who is both comfortable with high-risk intubations and the pathophysiology of dPH should perform these intubations.

Diagnostic Point-of-Care Ultrasound: Recommendations From an Expert Panel.

Diagnostic point-of-care ultrasound (PoCUS) has emerged as a powerful tool to help anesthesiologists guide patient care in both the perioperative setting and the subspecialty arenas. Although anesthesiologists can turn to guideline statements pertaining to other aspects of ultrasound use, to date there remains little in the way of published guidance regarding diagnostic PoCUS. To this end, in 2018, the American Society of Anesthesiologists chartered an ad hoc committee consisting of 23 American Society of Anesthesiologists members to provide recommendations on this topic. The ad hoc committee convened and developed a committee work product. This work product was updated in 2021 by an expert panel of the ad hoc committee to produce the document presented herein. The document, which represents the consensus opinion of a group of practicing anesthesiologists with established expertise in diagnostic ultrasound, addresses the following issues: (1) affirms the practice of diagnostic PoCUS by adequately trained anesthesiologists, (2) identifies the scope of practice of diagnostic PoCUS relevant to anesthesiologists, (3) suggests the minimum level of training needed to achieve competence, (4) provides recommendations for how diagnostic PoCUS can be used safely and ethically, and (5) provides broad guidance about diagnostic ultrasound billing.

Secondary-Sphere Chlorolanthanide(III) Complexes with a 1,3,5-Triazine-Based Ligand Supported by Anion-π, π-π, and Hydrogen-Bonding Interactions.

2,4,6-Dipicolylamine-functionalized 1,3,5-triazine (dpat) was isolated. When reacted with LaCl3, compound [(LaCl6)(H3dpat)][H2O]2 (1) formed, which crystallized in the monoclinic P21/n space group with parameters a = 11.47 Å, b = 19.22 Å, c = 20.98 Å, V = 4652.02 Å, and ß = 90.53°. When reacted with NdCl3, the complex [NdCl3(H2O)4(H3dpat)][Cl]3(MeOH)2 (2) crystallized in the monoclinic P21/n space group with unit cell parameters a = 20.05 Å, b = 12.81 Å, c = 20.64 Å, V = 5004.40 Å, and ß = 110.20°. In both cases, the dpat ligand forms a bowl-shaped cavity that partially envelops the LnIII-containing central unit, which is anionic in 1 and neutral in 2. The formation of these outer-sphere complexes is supported by secondary interactions, including π-π stacking, hydrogen bonding, and anion-π between the chlorolanthanide(III) fragment and the electron-deficient 1,3,5-triazine ring. Evidence of protonation of the pyridine rings in dpat was substantiated through the isolation of [H2dpat][Cl]2 (3). This compound crystallized in the monoclinic C2/c space group with parameters a = 11.93 Å, b = 20.22 Å, c = 15.28 Å, V = 3664.97 Å, and ß = 94.35°. Four pyridine rings are pairwise protonated in 3. dpat showed a moderate ability to extract LaIII from an aqueous to an organic phase, indicating its potential, through judicious manipulation of secondary-sphere interactions, as the starting point for efficient extractants for LnIII ions.

Echocardiography-Guided Dual-Lumen Venovenous Extracorporeal Membrane Oxygenation Cannula Placement in the ICU-A Retrospective Review.

OBJECTIVE: The most effective method of image guidance for venovenous extracorporeal membrane oxygenation is not known. The authors' objectives were to define the frequency of successful initial cannulation using echocardiographic guidance in the intensive care unit, as well as to determine the frequency of subsequent adjustments. Additional aims were to illustrate cannula malposition problems and to describe features associated with difficult cannulation. DESIGN: Retrospective consecutive case series analysis. SETTING: Single tertiary care university hospital. PARTICIPANTS: Forty-five patients treated with venovenous extracorporeal membrane oxygenation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The most common causes of respiratory failure were pneumonia, aspiration, and inhalational burn injury. Sixty-two percent survived to discharge. Initial cannulation was successful in 39 cases (87%). Adverse events included 5 cases of cannula malposition and 1 case of hemorrhagic shock. During the course of extracorporeal membrane oxygenation, 17 patients (38%) required echo-guided cannula position adjustments. There were no fatal complications. Factors associated with difficult cannulation included extremes of size, a prominent Eustachian valve, and an anterior guidewire bending in the right atrium. Younger age was associated positively with survival. There was no significant association between adverse events during cannulation and survival. CONCLUSIONS: Dual-lumen venovenous extracorporeal membrane oxygenation cannulation in the intensive care unit under echo guidance has a high initial success rate, but many patients require subsequent repositioning. Echocardiography can define cannula position in sufficient detail to identify malposition precisely and to guide repositioning.

Strain Imaging: An Everyday Tool for the Perioperative Echocardiographer.

Strain analysis allows for global and regional analysis of myocardial function and has been shown to be an independent predictor of outcomes after cardiac surgery. Strain imaging offers advantages over traditional EF measurements in that it is relatively angle independent, it is less dependent upon loading conditions, it is reproducible, it does not rely on geometric assumptions, and it can detect subclinical systolic dysfunction. Limitations of strain analysis include high temporal resolution requirements, a strong dependence on image quality, and inter-vendor variability. In addition, there is a paucity of data on the intraoperative applications of strain. The ASE has defined a global longitudinal strain of -20% measured by transthoracic echocardiography to be considered normal, with less negative values considered abnormal. Presently, there are no published guidelines on the normal values of strain with transesophageal echocardiography (TEE). However, multiple studies have shown that a reduction in intraoperative strain assessed with TEE has been shown to be an independent predictor of complications during cardiac surgery. Accordingly, further incorporation of intraoperative strain analysis with TEE could aid in prognostication for patients undergoing cardiac surgery. As perioperative strain analysis continues to advance, an understanding of these concepts is imperative for perioperative echocardiographers. It is the authors' goal to show that strain imaging can provide a reliable and objective measure that can be performed in real time to aid in decision-making and perioperative risk stratification.

The Year in Perioperative Echocardiography: Selected Highlights From 2019.

This article is the fourth of an annual series reviewing the research highlights of the year pertaining to the subspecialty of perioperative echocardiography for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board, for the opportunity to continue this series. In most cases, these were research articles that were targeted at the perioperative echocardiography diagnosis and treatment of patients after cardiothoracic surgery; but in some cases, these articles targetted the use of perioperative echocardiography in general.

Anion-π and H-Bonding Interactions Supporting Encapsulation of [Ln(NO3)6/5]3-/2- (Ln = Nd, Er) with a Triazine-Based Ligand.

Reaction of NdIII and ErIII nitrate salts with a 1,3,5-tris(dipicolylamine)-triazine (dpat) ligand yielded two unprecedented examples of [Ln(NO3)6/5]3-/2- (Ln = Nd, Er) moieties completely encapsulated by the ligands. They are found in the two new complexes, [(H3dpat)2][(Nd(NO3)6)2]·2CH3CN (1), and the related [(H3dpat)2][(Er(NO3)5)3]·3CH3CN·2H2O (2). The structures of the complexes are similar and they crystallize in the triclinic P-1 space group with a = 12.1630(3), b = 12.2694(3), c = 17.6357(5) Å, V = 2611.10(12) Å3, and a = 14.3372(4), b = 17.1271(4), c = 25.2207(7) Å, V = 5934.7(3) Å3, respectively. Anion-π interactions, which are reported here for the first time for LnIII ion complexes, hydrogen bonding interactions and π-π stacking support the formation of the encapsulated species. Evidence of the protonated dpat ligand in 1 and 2 was found through isolation of (H2dpat)(NO3)2. Finally, the pH-dependent ability of the ligand to extract LaIII and nitrate ions from aqueous into toluene solution is demonstrated.

Transesophageal Echocardiography: Guidelines for Point-of-Care Applications in Cardiac Arrest Resuscitation.

Cardiac arrest is one of the most challenging patient presentations managed by emergency care providers, and echocardiography can be instrumental in the diagnosis, prognosis, and treatment guidance in these critically ill patients. Transesophageal echocardiography has many advantages over transthoracic echocardiography in a cardiac arrest resuscitation. As transesophageal echocardiography is implemented more widely at the point of care during cardiac arrest resuscitations, guidelines are needed to assist emergency providers in acquiring the equipment and skills necessary to successfully incorporate it into the management of cardiac arrest victims.

Implementation of national practice guidelines to reduce waste and optimize patient value.

BACKGROUND: The financial health care crisis has provided the platform to drive operational improvements at US health care facilities. This has led to adoption of lean operation principles by many health care organizations as a means of eliminating waste and improving operational efficiencies and overall value to patients. We believe that standardized implementation of national practice guidelines can provide the framework to help to reduce financial waste. MATERIALS AND METHODS: We analyzed our institutional preoperative electrocardiogram (ECG) ordering practices for patients undergoing elective surgery at our institution from February-March, 2012 to identify utilization and review compliance with American Heart Association guidelines. We then implemented an ECG ordering algorithm based on these guidelines and studied changes in ordering patterns, associated cost savings and hospital billing for the same period in 2013. RESULTS: From February-March 2012, 677 noncardiac surgical procedures were performed at our institution, and 312 (46.1%) had a preoperative ECG. After implementation of our evidence-based ECG ordering algorithm for the same period in 2013, 707 noncardiac surgical cases were performed, and 120 (16.9%) had a preoperative ECG. Preoperative ECG utilization dropped 63% with an annual institutional cost savings of $72,906 and $291,618 in total annual health care savings. Based on our data, US-wide implementation of our evidence-based ECG ordering algorithm could save the US health care system >$1,868,800,000 per year. CONCLUSIONS: Here, we demonstrate that standardized application of a national practice guideline can be used to eliminate nearly $2 billion per year in waste from the US health care system.

A review of 364 perioperative rescue echocardiograms: findings of an anesthesiologist-staffed perioperative echocardiography service.

OBJECTIVE: Review the findings and use of rescue echocardiography performed by the Division of Perioperative Echocardiography and its impact on patient management. DESIGN: Retrospective observational study. SETTING: Single institution, tertiary care hospital. PARTICIPANTS: Three hundred sixty-four consecutive rescue echocardiograms in the perioperative setting. INTERVENTIONS: Rescue transesophageal or rescue transthoracic echocardiography. MEASUREMENTS AND MAIN RESULTS: Of a total of 1,675 perioperative echocardiograms performed in a 28-month period, 364 (21.8%) were rescue studies. Of these, 95.9% were transesophageal and 4.1% were transthoracic. Location at time of rescue echocardiography was intraoperative (55.5%), postoperative (44.2%), and preoperative (0.3%). No single diagnosis predominated the intraoperative or postoperative environment, and the frequency of common etiologies did not allow for assumption. There was a change in management for 214 patients (59%) as the result of findings. The methods used in performing rescue echocardiography at the authors' institution are reported. CONCLUSIONS: The heterogeneity of diagnoses and the frequency with which rescue echocardiography changed management further supports the growing body of evidence that the hemodynamically unstable perioperative patient benefits from its use.

Cervical Spine Fracture Presenting as an Orthostatic Headache Secondary to Cerebral Spinal Fluid Leak.

BACKGROUND: Head injuries are a common chief complaint encountered in the emergency department (ED). A cerebrospinal fluid (CSF) leak resulting from such injuries is uncommon, but has potentially debilitating consequences if undiagnosed. CASE REPORT: A 34-year-old male patient presented to the ED with complaints of an orthostatic headache after a bicycle accident that occurred 5 days prior to presentation. He presented with a nonfocal neurologic examination. Computed tomography (CT) of the head was without significant pathology. CT angiography of the neck, performed due to a concern about traumatic arterial dissection, revealed C7 spinal fractures, but no evidence of dissection or occlusion of the arteries in the neck. Lying flat, he appeared comfortable but became quite symptomatic upon sitting upright or standing. Based on this finding, a CSF leak was suspected and he was admitted for symptom control and more detailed imaging to rule out such a leak. He was found, on magnetic resonance imaging, to have epidural CSF collections consistent with the suspected leak. In addition to immobilization for the cervical spine fracture, he was treated for orthostatic headaches conservatively with good outcomes. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although this syndrome is still considered rare compared to other posttraumatic injuries, there is a growing body of evidence suggesting it may be underdiagnosed. Additionally, the signs and symptoms of this syndrome are nonspecific, with the exclusion of the orthostatic headache, and may be readily attributed to other diagnoses.

Development and validation of a machine learning method to predict intraoperative red blood cell transfusions in cardiothoracic surgery.

Accurately predicting red blood cell (RBC) transfusion requirements in cardiothoracic (CT) surgery could improve blood inventory management and be used as a surrogate marker for assessing hemorrhage risk preoperatively. We developed a machine learning (ML) method to predict intraoperative RBC transfusions in CT surgery. A detailed database containing time-stamped clinical variables for all CT surgeries from 5/2014-6/2019 at a single center (n = 2410) was used for model development. After random forest feature selection, surviving features were inputs for ML algorithms using five-fold cross-validation. The dataset was updated with 437 additional cases from 8/2019-8/2020 for validation. We developed and validated a hybrid ML method given the skewed nature of the dataset. Our Gaussian Process (GP) regression ML algorithm accurately predicted RBC transfusion amounts of 0 and 1-3 units (root mean square error, RMSE 0.117 and 1.705, respectively) and our GP classification ML algorithm accurately predicted 4 + RBC units transfused (area under the curve, AUC = 0.826). The final prediction is the regression result if classification predicted < 4 units transfused, or the classification result if 4 + units were predicted. We developed and validated an ML method to accurately predict intraoperative RBC transfusions in CT surgery using local data.

The bed nucleus of the stria terminalis is required for the expression of contextual but not auditory freezing in rats with basolateral amygdala lesions.

Previous data suggest that overtraining can overcome fear conditioning deficits in rats with lesions of the basolateral complex of the amygdala (BLA). We have previously shown that the central nucleus of the amygdala (CEA) is essential for the acquisition and expression of conditional fear to both contextual and auditory conditioned stimuli (CSs) after overtraining. This provides strong evidence that the CEA can compensate for the loss of the BLA. Another brain area that may compensate for the loss of the BLA is the bed nucleus of the stria terminalis (BNST). We explored this possibility by examining the consequences of lesions or reversible inactivation of the BNST on the expression of overtrained fear in rats with BLA lesions. We demonstrate that lesions or inactivation of the BNST block the expression of freezing to the conditioning context, but not to an auditory conditional stimulus. These results reveal that the BNST has a critical role in the expression of contextual fear, but not fear to an auditory CS, and is therefore not the essential locus of compensation for fear learning in the absence of the BLA.

PKMzeta maintains spatial, instrumental, and classically conditioned long-term memories.

How long-term memories are stored is a fundamental question in neuroscience. The first molecular mechanism for long-term memory storage in the brain was recently identified as the persistent action of protein kinase Mzeta (PKMzeta), an autonomously active atypical protein kinase C (PKC) isoform critical for the maintenance of long-term potentiation (LTP). PKMzeta maintains aversively conditioned associations, but what general form of information the kinase encodes in the brain is unknown. We first confirmed the specificity of the action of zeta inhibitory peptide (ZIP) by disrupting long-term memory for active place avoidance with chelerythrine, a second inhibitor of PKMzeta activity. We then examined, using ZIP, the effect of PKMzeta inhibition in dorsal hippocampus (DH) and basolateral amygdala (BLA) on retention of 1-d-old information acquired in the radial arm maze, water maze, inhibitory avoidance, and contextual and cued fear conditioning paradigms. In the DH, PKMzeta inhibition selectively disrupted retention of information for spatial reference, but not spatial working memory in the radial arm maze, and precise, but not coarse spatial information in the water maze. Thus retention of accurate spatial, but not procedural and contextual information required PKMzeta activity. Similarly, PKMzeta inhibition in the hippocampus did not affect contextual information after fear conditioning. In contrast, PKMzeta inhibition in the BLA impaired retention of classical conditioned stimulus-unconditioned stimulus (CS-US) associations for both contextual and auditory fear, as well as instrumentally conditioned inhibitory avoidance. PKMzeta inhibition had no effect on postshock freezing, indicating fear expression mediated by the BLA remained intact. Thus, persistent PKMzeta activity is a general mechanism for both appetitively and aversively motivated retention of specific, accurate learned information, but is not required for processing contextual, imprecise, or procedural information.

Tridentate N(2)S ligand from 2,2'-dithiodibenzaldehyde and N,N-dimethylethylenediamine: Synthesis, structure, and characterization of a Ni(II) complex with relevance to Ni Superoxide Dismutase.

Nickel Superoxide Dismutase (NiSOD) and the A-cluster of Carbon Monoxide Dehydrogenase/Acetyl Coenzyme A Synthase (CODH/ACS) both feature active sites with Ni coordinated by thiolate and amide donors. It is likely that the particular set of donors is important in tuning the redox potential of the Ni center(s). We report herein an expansion of our efforts involving the use of 2,2'-dithiodibenzaldehyde (DTDB) as a synthon for metal-thiolate complexes to reactions with Ni complexes of N,N-dimethylethylenediamine (dmen). In the presence of coordinating counterions, these reactions result in monomeric square-planar complexes of the tridentate N(2)S donor ligand derived from the Schiff-base condensation of dmen and DTDB. In the absence of a coordinating counterion, we have isolated a Ni(II) complex with an asymmetric N(2)S(2) donor set involving one amine and one imine N donor in addition to two thiolate donors. This latter complex is discussed with respect to its relevance to the active site of NiSOD.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part II: recommendations.

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine Society (ASRA) commissioned this narrative review to provide recommendations for POCUS. The recommendations were written by content and educational experts and were approved by the guidelines committee and the Board of Directors of the ASRA. In part II of this two-part series, learning goals and objectives were identified and outlined for achieving competency in the use of POCUS, specifically, airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma exam, and focused cardiac ultrasound, in the perioperative and chronic pain setting. It also discusses barriers to POCUS education and training and proposes a list of educational resources. For each POCUS section, learning goals and specific skills were presented in the Indication, Acquisition, Interpretation, and Medical decision-making framework.