Acute Risk Change: An Innovative Measure of Operative Adverse Events and Perioperative Team Performance.

OBJECTIVES: Cardiac surgical risk models predict mortality preoperatively, whereas intensive care unit (ICU) models predict mortality postoperatively. Finding a large difference between the 2 (an acute risk change [ARC]) may reflect an alteration in the status of the patient related to the surgery. An adverse ARC was associated with morbidity and mortality in an Australian population. The aims of this study were to validate ARC in a UK population and to investigate the possible mechanisms behind ARC. DESIGN: This was a retrospective case-control study. SETTING: Single, high-volume cardiothoracic hospital. PARTICIPANTS: Data from 4,842 cardiac surgical patients were collected between 2013 and 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: EuroSCORE was recalibrated to each preceding year's data. ARC was defined as postoperative minus preoperative percentage mortality risk. Association among ARC, morbidity, and mortality was tested. Cases with large adverse ARC (greater than +15%) were compared with cases with large favorable ARC (less than -10%) with regard to intraoperative adverse events, unmeasured patient risk factors, and postoperative events. Adverse ARC was associated with hospital mortality, ICU stay, ICU readmission, renal support, prolonged intubation and return to the operating room (p < 0.001). Intraoperative adverse events occurred in 23 of 33 patients with adverse ARC; however, only 2 of 17 patients with favorable ARC reported adverse events (p < 0.001). Unmeasured risk factors were present in 48% of patients in the adverse ARC group. CONCLUSION: ARC is a readily available and sensitive marker that correlates strongly with morbidity and mortality. The use of ARC in local and national quality monitoring could identify areas for improvement of the quality of cardiac surgical care.

Positive role of continuous positive airway pressure for intensive care unit patients with severe hypoxaemic respiratory failure due to COVID-19 pneumonia: A single centre experience.

OBJECTIVES: Continuous positive airway pressure (CPAP) may be a useful treatment strategy for patients with severe COVID-19 pneumonia but its effectiveness in preventing mechanical ventilation is unknown. We aimed to evaluate the outcomes of COVID-19 patients treated with CPAP and determine predictors of CPAP response. DESIGN: This was a retrospective observational cohort study. SETTING: The study took place in the intensive care unit (ICU) at Royal Papworth Hospital (RPH) in Cambridge, UK. PATIENTS: We included all consecutive patients with confirmed COVID-19 pneumonia who were transferred from neighbouring hospitals between 14th March and 6th May, 2020 for consideration of ventilatory support. INTERVENTION: We instituted the use of CPAP for all patients who arrived in RPH not intubated and were not making satisfactory progress on supplemental oxygen alone. MEASUREMENTS AND MAIN RESULTS: Of 33 self-ventilating patients included in this study, 22 (66.7%) were male and the mean age was 54 ± 13.23 patients received CPAP. They were more hypoxaemic than those treated with oxygen alone (PaO2/FiO2 ratio; 84.3 ± 19.0 vs 170.0 ± 46.0 mmHg, p = 0.001). There was a significant improvement in PaO2/FiO2 ratio 1-2 hours after CPAP initiation (167.4 ± 49.0 from 84.3 ± 19.0 mmHg, p = 0.001). 14 (61%) patients responded to CPAP and 9 required intubation. There was no difference between these two groups in terms of the severity of baseline hypoxaemia (PaO2/FiO2 ratio; 84.5 ± 16.0 vs 83.9 ± 23.0 mmHg, p = 0.94) but CPAP responders had significantly lower C-reactive protein (CRP) (176 ± 83 vs 274 ± 63 mg/L, p = 0.007), interleukin-6 (IL-6) (30 ± 47 vs 139 ± 148 pg/mL, p = 0.037), and D-dimer (321 ± 267 vs 941 + 1990 ng/mL, p = 0.003). CT pulmonary angiogram was performed in 6 out of 9 intubated patients and demonstrated pulmonary emboli in 5 of them. All patients were discharged from ICU and there were no fatalities. CONCLUSIONS: In this cohort, CPAP was an effective treatment modality to improve hypoxaemia and prevent invasive ventilation in a substantial proportion of patients with severe respiratory failure. Accepting the small sample size, we also found raised biomarkers of inflammation (CRP and IL-6) and coagulopathy (D-Dimer) to be more useful predictors of CPAP responsiveness than the severity of hypoxaemia, and could help to guide intubation decisions in this clinical setting.

Perioperative transoesophageal echocardiography.

New technologies are being introduced every day in the perioperative setting and perioperative practitioners will need to become increasingly familiar with transoesophageal echocardiography (TOE). TOE is used as a diagnostic tool during cardiac surgery in the operating theatre to direct the surgical procedure and to detect acute complications. TOE is also used to monitor cardiac function in patients undergoing non-cardiac surgery and in the intensive care unit (ICU) (Figure 1). The use of TOE is increasing in the cardiac catheterisation laboratory for percutaneous transcatheter procedures such as patent foramen ovale (PFO) closure, atrial septal defect (ASD) closure, aortic and mitral valvuloplasty, aortic valve implantation and mitral valve repair. Since the oesophagus is located directly behind the heart, TOE provides better image quality than transthoracic imaging for the assessment of posterior cardiac structures such as the mitral valve, left atrium and pulmonary veins.

Is brain natriuretic peptide a marker for adverse postoperative outcomes in patients undergoing cardiac surgery?

A best evidence topic (BET) was constructed according to a structured protocol. The question addressed was 'Is brain natriuretic peptide (BNP) a marker for adverse postoperative outcomes in patients undergoing cardiac surgery?' Nearly 200 papers were found using the reported search, of which 17 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. BNP levels have been shown by several prospective observational cohort studies to be a marker for cardiac dysfunction and adverse outcome in patients undergoing cardiac surgery. BNP levels can be used to guide the therapy of patients with heart failure which may reduce adverse cardiac events. Whether BNP-guided therapy can be applied to patients undergoing cardiac surgery is unknown. We conclude that preoperative and postoperative measurement of natriuretic peptides could help predict postoperative cardiac dysfunction and adverse outcome in patients undergoing cardiac surgery. Furthermore, they may improve the ability of commonly used risk assessment tools to predict outcome.

Does the prophylactic administration of N-acetylcysteine prevent acute kidney injury following cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'does prophylactic administration of N-acetylcysteine (NAC) prevent acute kidney injury (AKI) following cardiac surgery?' More than 60 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The administration of NAC prior intravenous radioactive contrast has been shown to reduce the incidence of contrast-induced nephropathy. There have been two recent meta-analyses and several randomised controlled trials (RCTs) and investigating the effectiveness of prophylactic administration of NAC in the prevention of AKI following cardiac surgery. The RCTs have investigated the use of NAC to prevent AKI in low-risk patients, high-risk patients and high-risk patients with pre-existing chronic kidney disease. The meta-analyses and RCTs demonstrated that the prophylactic administration of NAC did not reduced the incidence of AKI, postoperative complications, postoperative interventions, mortality or length of ICU stay. We conclude that prophylactic administration of NAC does not prevent AKI or reduce mortality following cardiac surgery.

Anaesthesia for serial whole-lung lavage in a patient with severe pulmonary alveolar proteinosis: a case report.

INTRODUCTION: Pulmonary alveolar proteinosis is a rare condition that requires treatment by whole-lung lavage. We report a case of severe pulmonary alveolar proteinosis and discuss a safe and effective strategy for the anaesthetic management of patients undergoing this complex procedure. CASE PRESENTATION: A 34-year-old Caucasian man was diagnosed with severe pulmonary alveolar proteinosis. He developed severe respiratory failure and subsequently underwent serial whole-lung lavage. Our anaesthetic technique included the use of pre-oxygenation, complete lung separation with a left-sided double-lumen endotracheal tube, one-lung ventilation with positive end-expiratory pressure, appropriate ventilatory monitoring, cautious use of positional manoeuvres and single-lumen endotracheal tube exchange for short-term postoperative ventilation. CONCLUSION: Patients with pulmonary alveolar proteinosis may present with severe respiratory failure and require urgent whole-lung lavage. We have described a safe and effective strategy for anaesthesia for whole-lung lavage. We recommend our anaesthetic technique for patients undergoing this complex and uncommon procedure.

Acute leukaemoid reaction following cardiac surgery.

Chronic myelomonocytic leukaemia is an atypical myeloproliferative disorder with a natural history of progression to acute myeloid leukaemia, a complex and poorly understood response by the bone marrow to stress. Cardiac surgery activates many inflammatory cascades and may precipitate a systemic inflammatory response syndrome. We present a case of undiagnosed chronic myelomonocytic leukaemia who developed rapidly fatal multi-organ dysfunction following cardiac surgery due to an acute leukaemoid reaction.