Accuracy of Visually Estimated Blood Loss in Surgical Sponges by Members of the Surgical Team.

It is important that operating room personnel monitor the correct amount of blood loss during surgery in order to properly replace lost volume. The aim of this study was to investigate the accuracy of operating room personnel in visually estimating blood loss in surgical sponges. We performed an observational study with comparative descriptive design at a university hospital including all members of the surgical team. In total, 163 observations were completed. The participants estimated the amount of blood in surgical sponges in 4 stations with varying amounts of blood and/or numbers of sponges. Data were analyzed using the Wilcoxon signed rank, Kruskal-Wallis, and Mann-Whit-ney tests. Both overestimations and underestimations occurred. Underestimations dominated and tended to increase with major amounts of blood. Operating room personnel miscalculated the amount of blood by a median value of 30% regardless of profession, years of experience, and self-assessed ability about visual estimation. This study highlights that assessments of patients' conditions can be partially based on methods often demonstrated to be inaccurate. Inaccurate visual estimation of blood loss might endanger patient safety.

Disturbances in Oxygen Balance During Cardiopulmonary Bypass: A Risk Factor for Postoperative Delirium.

OBJECTIVE: The aim of this study was to determine risk factors for postoperative delirium after cardiac surgery, specifically associated with the conduct of cardiopulmonary bypass (CPB). DESIGN: Prospective observational study. SETTING: Heart Centre, University Hospital. PARTICIPANTS: The study included 142 patients aged 70 years and older scheduled for elective cardiac surgery with CPB. INTERVENTIONS: Risk factor analysis comprised information collected from the hospital clinical and CPB dedicated databases in addition to the medical chart. Delirium was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criterion using the Mini Mental State Examination and the Organic Brain Syndrome scale. MEASUREMENTS AND MAIN RESULTS: Assessments of delirium diagnosis were executed preoperatively and on the following first and fourth postoperative days. Delirium occurred in 55% (78/142) of the patients. Patients with delirium were identified with significantly higher body weight and body surface area preoperatively, accompanied with longer CPB time, higher positive fluid balance per CPB, and lower systemic pump flow related to body surface area. Furthermore, the duration of the mixed venous oxygen saturation (SvO2) below 75% was significantly longer during CPB. The result from the multivariable logistic regression analysis included the duration of SvO2 below 75%, fluid balance per CPB and patient age as independent risk factors for postoperative delirium. CONCLUSIONS: The influence of the SvO2 level during CPB, fluid balance, and patient age should be recognized as risk factors for postoperative delirium after cardiac surgery in patients 70 years and older.

Preoperative Cognitive Performance and Postoperative Delirium Are Independently Associated With Future Dementia in Older People Who Have Undergone Cardiac Surgery: A Longitudinal Cohort Study.

OBJECTIVE: To investigate if postoperative delirium was associated with the development of dementia within 5 years after cardiac surgery. DESIGN: Longitudinal cohort study. SETTING: Cardiothoracic Division, Umeå University Hospital, Sweden. PATIENTS: Patients aged 70 years old or older (n = 114) scheduled for routine cardiac procedures with cardiopulmonary bypass without documented dementia were enrolled in 2009. INTERVENTION: Structured assessments were performed preoperatively, 1 and 4 days after extubation, and 1, 3, and 5 years postoperatively. MEASUREMENTS AND MAIN RESULTS: Patients were assessed comprehensively, including cognitive and physical function, coexisting medical conditions, demographic characteristics, and medications. Diagnoses of delirium, depression, and dementia were made according to Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criteria. During the 5-year period, 30 of 114 participants (26.3%) developed dementia. Postoperative delirium had occurred in 87% of those who later developed dementia. A multivariable logistic regression model showed a lower preoperative Mini-Mental State Examination score (p < 0.001; odds ratio, 0.68; 95% CI, 0.54-0.84) and the occurrence of postoperative delirium (p = 0.002; odds ratio, 7.57; 95% CI, 2.15-26.65) were associated with dementia occurrence. CONCLUSIONS: Our findings suggest that older patients with reduced preoperative cognitive functions or who develop postoperative delirium are at risk of developing dementia within 5 years after cardiac surgery. Cognitive functions should be screened for preoperatively, those who develop postoperative delirium should be followed up to enable early detection of dementia symptoms, and management should be implemented.

Validation of the confusion assessment method in detecting postoperative delirium in cardiac surgery patients.

BACKGROUND: Early detection, prevention, and treatment of delirium after cardiac surgery are important for quick postoperative recovery. The Confusion Assessment Method (CAM) may be an easy-to-use instrument for detecting delirium in clinical practice. OBJECTIVES: To compare the congruent validity of the CAM with the results from repeated assessments by using a combination of the Organic Brain Syndrome Scale and the Mini-Mental State Examination according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria for delirium. METHODS: Patients aged 70 years or older undergoing cardiac surgery were assessed on postoperative days 1 and 4, and the 2 diagnostic methods were compared. The sensitivity and specificity of the CAM were examined. The reference method allowed categorization of delirium into subgroups of psychomotor activities and psychiatric symptom profiles, which were compared with the CAM results. RESULTS: Postoperative delirium was diagnosed in 78 of 141 patients (55.3%). According to the CAM, 59 patients (41.8%) were categorized as delirious, 53 correctly. Thus, the sensitivity was 68% and the specificity was 90%, indicating false-negative rather than false-positive observations. CONCLUSION: Patients with psychomotor hyperactivity and mixed psychotic-emotional symptoms were more likely to have delirium detected via the CAM than were patients with less obvious clinical manifestations of delirium. Repetitive cognitive testing and psychogeriatric experience are probably necessary to improve the results obtained with the CAM.

Validation of the Swedish version of the Nursing Delirium Screening Scale used in patients 70 years and older undergoing cardiac surgery.

AIMS AND OBJECTIVES: Validation of the Swedish version of the Nursing Delirium Screening Scale as a screening tool for nurses to use to detect postoperative delirium in patients 70 years and older undergoing cardiac surgery. BACKGROUND: Delirium is common among old patients after cardiac surgery. Underdiagnosis and poor documentation of postoperative delirium is problematic, and nurses often misread the signs. DESIGN: A prospective observational study. METHODS: Patients (n = 142) scheduled for cardiac surgery were assessed three times daily by the nursing staff using the Nursing Delirium Screening Scale. Nursing Delirium Screening Scale was compared with the Mini Mental State Examination and the Organic Brains Syndrome Scale, evaluated day one and day four postoperatively. Delirium was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders - DSM-IV-TR criteria. RESULTS: A larger proportion of patients were diagnosed with delirium according to the Mini Mental State Examination and Organic Brains Syndrome Scale compared with the Nursing Delirium Screening Scale, both on day one and day four. The Nursing Delirium Screening Scale protocol identified the majority of hyperactive and mixed delirium patients, whereas several with hypoactive delirium were unrecognised. CONCLUSIONS: The Swedish version of the Nursing Delirium Screening Scale was easily incorporated into clinical care and showed high sensitivity in detecting hyperactive symptoms of delirium. However, in the routine use by nurses, the Nursing Delirium Screening Scale had low sensitivity in detecting hypoactive delirium, the most prevalent form of delirium after cardiac surgery. Nursing Delirium Screening Scale probably has to be combined with cognitive testing to detect hypoactive delirium. RELEVANCE TO CLINICAL PRACTICE: Nurses play a key role in detecting delirium. The Nursing Delirium Screening Scale was easy incorporated instrument for clinical practice and identified the majority of hyperactive and mixed delirium, but several of the patients with hypoactive delirium were unrecognised. Training of assessment and cognitive testing seems to be necessary to detect hypoactive delirium.

Delirium after cardiac surgery: incidence and risk factors.

OBJECTIVES: Delirium after cardiac surgery is a problem with consequences for patients and healthcare. Preventive strategies from known risk factors may reduce the incidence and severity of delirium. The present aim was to explore risk factors behind delirium in older patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Patients (≥70 years) scheduled for routine cardiac surgery were included (n = 142). The patients were assessed and monitored pre-/postoperatively, and delirium was diagnosed from repeated assessments with the Mini-Mental State Examination and the Organic Brain Syndrome Scale, using the DSM-IV-TR criteria. Variables were analysed by uni-/multivariable logistic regression, including both preoperative variables (predisposing) and those extracted during surgery and in the early postoperative period (precipitating). RESULTS: Delirium was diagnosed in 78 patients (54.9%). Delirium was independently associated with both predisposing and precipitating factors (P-value, odds ratio, upper/lower confidence interval): age (0.036, 1.1, 1.0/1.2), diabetes (0.032, 3.5, 1.1/11.0), gastritis/ulcer problems (0.050, 4.0, 1.0/16.1), volume load during operation (0.001, 2.8, 1.5/5.1), ventilator time in ICU (0.042, 1.2, 1.0/1.4), highest temperature recorded in ICU (0.044, 2.2, 1.0/4.8) and sodium concentration in ICU (0.038, 1.2, 1.0/1.4). CONCLUSIONS: Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to delirium. When combined, the predictive strength of the model improved. Preventive strategies may be considered, in particular among the precipitating factors. Of interest, delirium was strongly associated with an increased volume load during surgery.