Management of acute aortic dissection in critical care.

Aortic dissections are associated with significant mortality and morbidity, with rapid treatment paramount. They are caused by a tear in the intimal lining of the aorta that extends into the media of the wall. Blood flow through this tear leads to the formation of a false passage bordered by the inner and outer layers of the media. Their diagnosis is challenging, with most deaths caused by aortic dissection diagnosed at post-mortem. Aortic dissections are classified by location and chronicity, with management strategies depending on the nature of the dissection. The Stanford method splits aortic dissections into type A and B, with type A dissections involving the ascending aorta. De Bakey classifies dissections into I, II or III depending on their origin and involvement and degree of extension. The key to diagnosis is early suspicion, appropriate imaging and rapid initiation of treatment. Treatment focuses on initial resuscitation, transfer (if possible and required) to a suitable specialist centre, strict blood pressure and heart rate control and potentially surgical intervention depending on the type and complexity of the dissection. Effective post-operative care is extremely important, with awareness of potential post-operative complications and a multi-disciplinary rehabilitation approach required. In this review article we will discuss the aetiology and classifications of aortic dissection, their diagnosis and treatment principles relevant to critical care. Critical care clinicians play a key part in all these steps, from diagnosis through to post-operative care, and thus a thorough understanding is vital.

Management of transgender patients in critical care.

As clinicians working in critical care, it is our duty to provide all of our patients with the high-quality care they deserve, regardless of their gender identity. The transgender community continues to suffer discrimination from the media, politicians and general public. As healthcare workers we often pride ourselves on our ability to safely care for all patients. However, there remains a distinct lack of understanding surrounding the care of critically ill transgender patients. This is likely in part because the specific care of transgender patients is not included in the Faculty of Intensive Care Medicine's, Royal College of Anaesthetists', Royal College of Physician's, or Royal College of Emergency Medicine's curriculum. There are several important considerations relevant for transgender patients in critical care including anatomical changes to the airway, alterations to respiratory and cardiovascular physiology and management of hormone therapy. Alongside this, there are simple but important social factors that exist, such as the use of patient pronouns and ensuring admittance to correctly gendered wards. In this review we will address the key points relevant to the care of transgender patients in critical care and provide suggestions on how education on the subject may be improved.

Prognosis of Spontaneous Pneumothorax/Pneumomediastinum in Coronavirus Disease 2019: The CoBiF Score.

Objectives: Pneumothorax and pneumomediastinum are associated with high mortality in invasively ventilated coronavirus disease 2019 (COVID-19) patients; however, the mortality rates among non-intubated patients remain unknown. We aimed to analyze the clinical features of COVID-19-associated pneumothorax/pneumomediastinum in non-intubated patients and identify risk factors for mortality. Methods: We searched PubMed Scopus and Embase from January 2020 to December 2021. We performed a pooled analysis of 151 patients with no invasive mechanical ventilation history from 17 case series and 87 case reports. Subsequently, we developed a novel scoring system to predict in-hospital mortality; the system was further validated in multinational cohorts from ten countries (n = 133). Results: Clinical scenarios included pneumothorax/pneumomediastinum at presentation (n = 68), pneumothorax/pneumomediastinum onset during hospitalization (n = 65), and pneumothorax/pneumomediastinum development after recent COVID-19 treatment (n = 18). Significant differences were not observed in clinical outcomes between patients with pneumomediastinum and pneumothorax (±pneumomediastinum). The overall mortality rate of pneumothorax/pneumomediastinum was 23.2%. Risk factor analysis revealed that comorbidities bilateral pneumothorax and fever at pneumothorax/pneumomediastinum presentation were predictors for mortality. In the new scoring system, i.e., the CoBiF system, the area under the curve which was used to assess the predictability of mortality was 0.887. External validation results were also promising (area under the curve: 0.709). Conclusions: The presence of comorbidity bilateral pneumothorax and fever on presentation are significantly associated with poor prognosis in COVID-19 patients with spontaneous pneumothorax/pneumomediastinum. The CoBiF score can predict mortality in clinical settings as well as simplify the identification and appropriate management of patients at high risk.

The perioperative management of transgender patients: a knowledge gap we can no longer ignore.

Recent years have seen an increase in the number of people openly identifying as transgender in the UK, with current estimates ranging between 200 000 and 600 000 individuals. There has also been an increase in the number of patients undergoing both medical and surgical gender-affirming treatment. There are several important, specific considerations that perioperative clinicians must be aware of when caring for transgender patients, including changes to the airway, potential respiratory and cardiovascular complications, and the management of hormone therapy. Alongside this, important general considerations include the correct use of patient pronouns and ensuring patients are admitted to correctly gendered wards. Despite the need for these considerations, the perioperative management of transgender patients is not covered in the Royal College of Anaesthetists' curriculum; to date, no national guidelines exist on the subject. This article discusses some of the key, specific perioperative considerations relevant to transgender patients, and highlights the need for national guidelines and improved education on the subject.

Catabolism in Critical Illness: A Reanalysis of the REducing Deaths due to OXidative Stress (REDOXS) Trial.

OBJECTIVES: Ongoing risk of death and poor functional outcomes are important consequences of prolonged critical illness. Characterizing the catabolic phenotype of prolonged critical illness could illuminate biological processes and inform strategies to attenuate catabolism. We aimed to examine if urea-to-creatinine ratio, a catabolic signature of prolonged critical illness, was associated with mortality after the first week of ICU stay. DESIGN: Reanalysis of multicenter randomized trial of glutamine supplementation in critical illness (REducing Deaths due to OXidative Stress [REDOXS]). SETTING: Multiple adult ICUs. PATIENTS: Adult patients admitted to ICU with two or more organ failures related to their acute illness and surviving to day 7. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The association between time-varying urea-to-creatinine ratio and 30-day mortality was tested using Bayesian joint models adjusted for prespecified-covariates (age, kidney replacement therapy, baseline Sequential Organ Failure Assessment, dietary protein [g/kg/d], kidney dysfunction, and glutamine-randomization). From 1,021 patients surviving to day 7, 166 (16.3%) died by day 30. After adjustment in a joint model, a higher time-varying urea-to-creatinine ratio was associated with increased mortality (hazard ratio [HR], 2.15; 95% credible interval, 1.66-2.82, for a two-fold greater urea-to-creatinine ratio). This association persisted throughout the 30-day follow-up. Mediation analysis was performed to explore urea-to-creatinine ratio as a mediator-variable for the increased risk of death reported in REDOXS when randomized to glutamine, an exogenous nitrogen load. Urea-to-creatinine ratio closest to day 7 was estimated to mediate the risk of death associated with randomization to glutamine supplementation (HR, 1.20; 95% CI, 1.04-1.38; p = 0.014), with no evidence of a direct effect of glutamine (HR, 0.90; 95% CI, 0.62-1.30; p = 0.566). CONCLUSIONS: The catabolic phenotype measured by increased urea-to-creatinine ratio is associated with increased risk of death during prolonged ICU stay and signals the deleterious effects of glutamine administration in the REDOXS study. Urea-to-creatinine ratio is a promising catabolic signature and potential interventional target.

Effect of intermittent or continuous feeding and amino acid concentration on urea-to-creatinine ratio in critical illness.

BACKGROUND: We sought to determine whether peaks in essential amino acid (EAA) concentration associated with intermittent feeding may provide anabolic advantages when compared with continuous feeding regimens in critical care. METHODS: We performed a secondary analysis of data from a multicenter trial of UK intensive care patients randomly assigned to intermittent or continuous feeding. A linear mixed-effects model was developed to assess differences in urea-creatinine ratio (raised values of which can be a marker of muscle wasting) between arms. To investigate metabolic phenotypes, we performed k-means urea-to-creatinine ratio trajectory clustering. Amino acid concentrations were also modeled against urea-to-creatinine ratio from day 1 to day 7. The main outcome measure was serum urea-to-creatinine ratio (millimole per millimole) from day 0 to the end of the 10-day study period. RESULTS: Urea-to-creatinine ratio trajectory differed between feeding regimens (coefficient -.245; P = .002). Patients receiving intermittent feeding demonstrated a flatter urea-to-creatinine ratio trajectory. With k-means analysis, the cluster with the largest proportion of continuously fed patients demonstrated the steepest rise in urea-to-creatinine ratio. Neither protein intake per se nor serum concentrations of EAA concentrations were correlated with urea-to-creatinine ratio (coefficient = .088 [P = .506] and coefficient <.001 [P = .122], respectively). CONCLUSION: Intermittent feeding can mitigate the rise in urea-to-creatinine ratio otherwise seen in those continuously fed, suggesting that catabolism may have been, to some degree, prevented.

Acute ST-segment elevation myocardial infarction secondary to vaccine-induced immune thrombosis with thrombocytopaenia (VITT).

A 40-year-old man with no cardiac history presented with central chest pain 8 days after receiving the ChAdOx1 nCov-19 vaccine against COVID-19. Initial blood tests demonstrated a thrombocytopaenia (24×109 µg/L) and a raised d-dimer (>110 000 µg/L), and he was urgently transferred to our tertiary referral central for suspected vaccine-induced immune thrombocytopaenia and thrombosis (VITT). He developed dynamic ischaemic electrocardiographic changes with ST elevation, a troponin of 3185 ng/L, and regional wall motion abnormalities. An occlusion of his left anterior descending coronary artery was seen on CT coronary angiography. His platelet factor-4 (PF-4) antibody returned strongly positive. He was urgently treated for presumed VITT with intravenous immunoglobulin, methylprednisolone and plasma exchange, but remained thrombocytopaenic and was initiated on rituximab. Argatroban was used for anticoagulation for his myocardial infarction while he remained thrombocytopaenic. After 6 days, his platelet count improved, and his PF-4 antibody level, troponin and d-dimer fell. He was successfully discharged after 14 days.

The use of critical care echocardiography in peri-arrest and cardiac arrest scenarios: Pros, cons and what the future holds.

Echocardiography is being increasingly deployed as a diagnostic and monitoring tool in the critically ill. This rise in popularity has led to its recommendation as a core competence in intensive care, with several training routes available. In the peri-arrest and cardiac arrest population, point of care focused echocardiography has the potential to transform patient care and improve outcomes. Be it via diagnosis of shock aetiology and reversibility or assessing response to treatment and prognostication. This narrative review discusses current and future applications of echocardiography in this patient group and provides a structure with which one can approach such patients.

A validation study of the identification of haemophagocytic lymphohistiocytosis in England using population-based health data.

We assessed the validity of coded healthcare data to identify cases of haemophagocytic lymphohistiocytosis (HLH). Hospital Episode Statistics (HES) identified 127 cases within five hospital Trusts 2013-2018 using ICD-10 codes D76.1, D76.2 and D76.3. Hospital records were reviewed to validate diagnoses. Out of 74 patients, 73 were coded D76.1 or D76.2 (positive predictive value 89·0% [95% Confidence Interval {CI} 80·2-94·9%]) with confirmed/probable HLH. For cases considered not HLH, 44/53 were coded D76.3 (negative predictive value 97·8% [95% CI 88·2-99·9%]). D76.1 or D76.2 had 68% sensitivity in detecting HLH compared to an established active case-finding HLH register in Sheffield. Office for National Statistics (ONS) mortality data (2003-2018) identified 698 patients coded D76.1, D76.2 and D76.3 on death certificates. Five hundred and forty-one were coded D76.1 or D76.2 of whom 524 (96·9%) had HLH in the free-text cause of death. Of 157 coded D76.3, 66 (42·0%) had HLH in free text. D76.1 and D76.2 codes reliably identify HLH cases, and provide a lower bound on incidence. Non-concordance between D76.3 and HLH excludes D76.3 as an ascertainment source from HES. Our results suggest electronic healthcare data in England can enable population-wide registration and analysis of HLH for future research.

Should nutrition therapy be modified to account for mitochondrial dysfunction in critical illness?

Metabolic dysfunction, and its associated muscle atrophy, remains the most common complication of critical care. At the center of this is mitochondrial dysfunction, secondary to hypoxia and systemic inflammation. This leads to a bioenergetic crisis, with decreased intramuscular adenosine triphosphate content and a reduction in the highly energy-dependent process of protein synthesis. Numerous methods have been studied to try and reduce these effects, with only limited success. Trials investigating the use of increased energy and protein administration have instead found a decrease in relative lean body mass and a potential increase in morbidity and mortality. Ketone bodies have been proposed as alternative substrates for metabolism in critical illness, with promising results seen in animal models. They are currently being investigated in critical care patients in the Alternative Substrates in the Critically Ill Subjects trial (ASICS). The evidence to date suggests that individualized feeding regimens may be key in the nutrition approach to critical illness. Consideration of individual patient factors will need to be combined with personalized protein content, total energy load received, and the timing of such feeds. This review covers mitochondrial dysfunction in critical illness, how it contributes to muscle wasting and the resultant morbidity and mortality, and the scientific basis of why current nutrition approaches to date have not been successful in negating this effect. These two factors underpin the need for consideration of alternative nutrition strategies in the critically ill patient.

Novel methods to identify and measure catabolism.

PURPOSE OF REVIEW: Assess current potential catabolism-biomarkers to characterize patients developing prolonged critical illness. RECENT FINDINGS: A raised urea-to-creatinine ratio (UCR) during critical illness is negatively associated with muscle mass with greater increases in UCR seen patients developing persistent critical illness. Similarly, sarcopenia index (a ratio of creatinine to cystatin-c concentrations) correlates well to muscle mass in intensive care populations. Elevated growth/differentiation factor-15 (GDF-15) has been inconsistently associated with muscle loss. Although GDF-15 was a poor marker of feeding tolerance, it has been associated with worse prognosis in intensive care. SUMMARY: UCR is an available and clinically applicable biomarker of catabolism. Similarly, sarcopenia index can be used to assess muscle mass and indirectly measure catabolism based on readily available biochemical measurements. The utility of novel biomarkers, such as GDF-15 is less established.

Training and Accreditation Pathways in Critical Care and Perioperative Echocardiography.

In recent years, there has been a dramatic rise in the use of echocardiography in perioperative and critical care medicine. It is now recommended widely as a first-line diagnostic tool when approaching patients in shock, due to its ability to identify shock etiology and response to treatment noninvasively. To match the increasing training demand, and to ensure maintenance of high-quality and reproducible scanning, several accreditation pathways have been developed worldwide. Critical care echocardiography training pathways can include both transthoracic and transesophageal scanning and range from basic focused protocols to advanced comprehensive scans. The complexity of each individual training program is reflected in its accreditation process. While basic accreditations may require only course attendance and a relatively brief logbook, comprehensive accreditations often require extensive logbooks and written and practical examinations. Currently, the use of transoesophageal echocardiography remains restricted largely to cardiothoracic anesthesia and critical care; however, its use in the general intensive care setting is growing. This narrative review summarizes the most common training pathways, their curricula, and accreditation requirements. The authors initially focus on echocardiography training in the United Kingdom, and then go on to describe similar international accreditations available in Europe, North America, and Australasia.

Tension pneumothorax in a patient with COVID-19.

A 36-year-old man was brought to the emergency department with suspected COVID-19, following a 3-week history of cough, fevers and shortness of breath, worsening suddenly in the preceding 4 hours. On presentation he was hypoxaemic, with an SpO2 of 88% on 15 L/min oxygen, tachycardic and had no audible breath sounds on auscultation of the left hemithorax. Local guidelines recommended that the patient should be initiated on continuous positive airway pressure while investigations were awaited, however given the examination findings an emergency portable chest radiograph was performed. The chest radiograph demonstrated a left-sided tension pneumothorax. This was treated with emergency needle decompression, with good effect, followed by chest drain insertion. A repeat chest radiograph demonstrated lung re-expansion, and the patient was admitted to a COVID-19 specific ward for further observation. This case demonstrates tension pneumothorax as a possible complication of suspected COVID-19 and emphasises the importance of thorough history-taking and clinical examination.

Muscle wasting in the critically ill patient: how to minimise subsequent disability.

Muscle wasting in critically ill patients is the most common complication associated with critical care. It has significant effects on physical and psychological health, mortality and quality of life. It is most severe in the first few days of illness and in the most critically unwell patients, with muscle loss estimated to occur at 2-3% per day. This muscle loss is likely a result of a reduction in protein synthesis relative to muscle breakdown, resulting in altered protein homeostasis. The associated weakness is associated with in an increase in both short- and long-term mortality and morbidity, with these detrimental effects demonstrated up to 5 years post discharge. This article highlights the significant impact that muscle wasting has on critically ill patients' outcomes, how this can be reduced, and how this might change in the future.