Bispectral Index Can Reliably Detect Deep Sedation in Mechanically Ventilated Patients: A Prospective Multicenter Validation Study.

BACKGROUND: Excessively deep sedation is prevalent in mechanically ventilated patients and often considered suboptimal. We hypothesized that the bispectral index (BIS), a quantified electroencephalogram instrument, would accurately detect deep levels of sedation. METHODS: We prospectively enrolled 90 critically ill mechanically ventilated patients who were receiving sedation. The BIS was monitored for 24 hours and compared with the Richmond Agitation Sedation Scale (RASS) evaluated every 4 hours. Deep sedation was defined as a RASS of -3 to -5. Threshold values of baseline BIS (the lowest value before RASS assessment) and stimulated BIS (the highest value after standardized assessment) for detecting deep sedation were determined in a training set (45 patients, 262 RASS assessments). Diagnostic accuracy was then analyzed in a validation set (45 patients, 264 RASS assessments). RESULTS: Deep sedation was only prescribed in 6 (6.7%) patients, but 76 patients (84.4%) had at least 1 episode of deep sedation. Thresholds for detecting deep sedation of 50 for baseline and 80 for stimulated BIS were identified, with respective areas under the receiver-operating characteristic curve of 0.771 (95% confidence interval, 0.714-0.828) and 0.805 (0.752-0.857). The sensitivity and specificity of baseline BIS were 94.0% and 66.5% and of stimulated BIS were 91.0% and 66.5%. When baseline and stimulated BIS were combined, the sensitivity, specificity, and clinical utility index were 85.0% (76.1%-91.1%), 85.9% (79.5%-90.7%), and 66.9% (57.8%-76.0%), respectively. CONCLUSIONS: Combining baseline and stimulated BIS may help detect deep sedation in mechanically ventilated patients.

Effect of pulmonary autograft transplantation in the surgical treatment of aortic valve disease.

BACKGROUND: Aortic root replacement with pulmonary autograft (Ross procedure) has the advantages of good haemodynamics and growth potential without the need for anticoagulation. In this study, we reviewed our experience of the Ross procedure for patients with aortic valve disease. METHODS: From October 1994 to January 2005, 42 Ross procedures were performed in our centre. There were 30 males and 12 females. The mean age was 28 +/- 15 years (range, 5-56 years). Congenital heart disease (CHD) with aortic valve stenosis (AS) and/or aortic valve insufficiency (AI) in 40 cases including one associated with ventricular septal defect (VSD), degenerated aortic valve disease with AS in 1 and subacutive bacterial endocarditis (SBE) with AI in 1 were studied. The diagnosis was made by ultracardiography (UCG) in all patients. The mean aortic valve annulus diameter (AVD) was (2.45 +/- 0.31) cm and pulmonary valve annulus diameter (MPVD) was (2.34 +/- 0.21) cm. All patients had normal pulmonary valves. The New York Heart Association (NYHA) function class was II in 36 cases and III in 6 cases. The operation was performed under moderate hypothermic cardiopulmonary bypass (CPB) with aortic root replacement using pulmonary autograft and pulmonary valve replacement with a homograft. RESULTS: There was no early hospital mortality. Postoperative UCG showed normal aortic valve function in all our patients. The mean gradient across the aortic valve was (6.11 +/- 0.12) mmHg. The left ventricular diastole diameter (LVDD) decreased significantly from (62 +/- 5) mm to (56 +/- 3) mm (P < 0.001). The mean postoperative left ventricular ejective fraction (LVEF) was 0.49 +/- 0.23. All patients were in NYHA class I-II. Follow-up was completed in 38 cases for a mean period of 3.2 years (range 1-10 years). All survivors were in NYHA class I with normal neo-aortic and pulmonary valve function. One patient died after secondary operation due to homograft fungal endocarditis 1 year after the Ross procedure. The cause of death was uncontrolled bleeding. Another patient suffered from cardiogenic shock and was on extracorporeal membrane oxygenation (ECMO) for 10 days postoperatively. This patient was subsequently self-discharged from hospital due to financial issues and he was excluded from follow-up. CONCLUSION: The Ross procedure is an excellent technique to treat aortic valve disease. Our data show that it can be performed safely with good early and mid-term clinical outcomes.

Emergence agitation during recovery from intracranial surgery under general anaesthesia: a protocol and statistical analysis plan for a prospective multicentre cohort study.

INTRODUCTION: Emergence agitation after intracranial surgery is an important clinical issue during anaesthesia recovery. The aim of this multicentre cohort study is to investigate the incidence of emergence agitation, identify the risk factors and determine clinical outcomes in adult patients after intracranial surgery under general anaesthesia. Additionally, we will deliberately clarify the relationship between postoperative pneumocephalus and agitation. METHODS AND ANALYSIS: The present study is a prospective multicentre cohort study. Five intensive care units (ICUs) in China will participate in the study. Consecutive adult patients admitted to the ICUs after intracranial surgery will be enrolled. Sedation-Agitation Scale (SAS) or Richmond Agitation-Sedation Scale (RASS) will be used to evaluate the patients 12 h after the enrolment. Agitation is defined as an SAS score of 5-7, or an RASS score of +2 to +4. According to the maximal SAS and RASS score, patients will be divided into two cohorts: the agitation group and the non-agitation group. Factors potentially related to emergence agitation will be collected at study entry, during anaesthesia and operation, during postoperative care. Univariate analyses between the agitation and the non-agitation groups will be performed. The stepwise backward logistic regression will be carried out to identify the independent predictors of agitation. Patients will be followed up for 72 h after the operation. Accidental self-extubation of the endotracheal tube and removal of other catheters will be documented. The use of sedatives and analgesics will be collected. ETHICS AND DISSEMINATION: Ethics approval has been obtained from each of five participating hospitals. Study findings will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT02318199.

A novel surgical procedure: scaffold-pulmonary autograft transplantation.

Mitral valve-related operations are easy to perform and show good results, but to prevent severe thromboembolism or a high ratio of prosthetic valve destruction by tissue, lifetime anticoagulant therapy is essential after the operation. Thus, identifying a new type of surgical procedure and prosthetic valve to cure mitral valve diseases is necessary. Pulmonary valve autograft transplantation (Ross II) with the "top hat" transplantation technique was first reported by Ross DN to cure mitral disease. Because the "top hat" procedure has some shortcomings, we designed the scaffold-pulmonary autograft transplantation procedure and performed animal experiments to confirm the feasibility and effectiveness of the procedure. A total of 13 minipigs, weighing 20-25 kg, were employed as experimental animals to undergo scaffold-pulmonary autograft valve transplantation in our surgical animal lab. The surgical procedure was performed under hypothermic general anaesthesia and extracorporeal circulation (or cardiopulmonary bypass, CPB). Briefly, the chest cave was opened through the left intercostal, the pulmonary valve autograft was harvested during on-pump beating heart, and the pulmonary valve autograft was mounted in a self-made pulmonary valve scaffold and transferred to the mitral valve annulus without removing the mitral instruments. Finally, the outflow tract of the right ventricle was re-established with a pig pulmonary homograft. After finishing data collection, all animals were executed 1 hour after removal from the CPB. For the 13 minipigs that underwent the operation, the CPB time was 182.4 ± 23.4 min. Two of the thirteen cases died of bleeding during the operation and of a post-operative pulmonary embolism, and the remaining eleven survived for one hour. The pressure of the left atrium did not increase significantly (P = 1.00), and the ultrasonic cardiograph (UCG) showed good function of the new mitral valves, with mean ejection fraction (EF) values of 63.6%. The mitral valve orifice areas were 1.10 ± 0.13 cm(2) (pre-operation) and 1.01 ± 0.08 cm(2) (post-operation) (P = 0.013). The function and structure of the new mitral valves were normal. We preliminarily consider scaffold-pulmonary autograft valve transplantation to be a new alternative to cure mitral valve disease, but advanced chronic animal experiments will be needed to confirm the long-term results of the operation. The results showed it could be a new alternative to cure mitral valve disease.