Albumin Use in Brain-injured and Neurosurgical Patients: Concepts, Indications, and Controversies.

Human albumin has been used extensively for decades as a nonwhole blood plasma replacement fluid in the perioperative and critical care setting. Its potential advantages as a highly effective volume expander must be weighed, however, against its potential harm for patients in the context of various neurological states and for various neurosurgical interventions. This narrative review explores the physiological considerations of intravenous human albumin as a replacement fluid and examines the extant clinical evidence for and against its use within the various facets of modern neuroanesthesia and neurocritical care practice.

Normal Brain Response to Propofol in Advance of Recovery from Unresponsive Wakefulness Syndrome.

Up to 40% of individuals with unresponsive wakefulness syndrome (UWS) actually might be conscious. Recent attempts to detect covert consciousness in behaviorally unresponsive patients via neurophysiological patterns are limited by the need to compare data from brain-injured patients to healthy controls. In this report, we pilot an alternative within-subject approach by using propofol to perturb the brain state of a patient diagnosed with UWS. An auditory stimulation series was presented to the patient before, during, and after exposure to propofol while high-density electroencephalograph (EEG) was recorded. Baseline analysis revealed residual markers in the continuous EEG and event-related potentials (ERPs) that have been associated with conscious processing. However, these markers were significantly distorted by the patient's pathology, challenging the interpretation of their functional significance. Upon exposure to propofol, changes in EEG characteristics were similar to what is seen in healthy individuals and ERPs associated with conscious processing disappeared. At the 1-month follow up, the patient had regained consciousness. We offer three alternative explanations for these results: (1) the patient was covertly consciousness, and was anesthetized by propofol administration; (2) the patient was unconscious, and the observed EEG changes were a propofol-specific phenomenon; and (3) the patient was unconscious, but his brain networks responded normally in a way that heralded the possibility of recovery. These alternatives will be tested in a larger study, and raise the intriguing possibility of using a general anesthetic as a probe of brain states in behaviorally unresponsive patients.

Predictors of unanticipated admission following ambulatory surgery: a retrospective case-control study.

PURPOSE: The primary objectives of this historical case-control study were to evaluate the incidence of and reasons and risk factors for adult unanticipated admissions in three tertiary care Canadian hospitals following ambulatory surgery. METHODS: A random sample of 200 patients requiring admission (cases) and 200 patients not requiring admission (controls) was taken from 20,657 ambulatory procedures was identified and compared. The following variables were included: demographics, reason for admission, type of anesthesia, surgical procedure, length of procedure, American Society of Anesthesiologists' (ASA) classification, surgical completion time, pre-anesthesia clinic, medical history, medications (classes), and perioperative complications. Multiple logistic regression analysis was used to assess factors associated with unanticipated admissions. RESULTS: The incidence of unanticipated admission following ambulatory surgery was 2.67%. The most common reasons for admission were surgical (40%), anesthetic (20%), and medical (19%). The following factors were found to be associated with an increased risk of unanticipated admission: length of surgery of one to three hours (odds ratio [OR] 16.70; 95% confidence interval [CI] 4.10 to 67.99) and length of surgery more than three hours (OR 4.26; 95% CI 2.40 to 7.55); ASA class III (OR 4.60; 95% CI 1.81 to 11.68); ASA class IV (OR 6.51; 95% CI 1.66 to 25.59); advanced age (> 80 yr) (OR 5.41; 95% CI 1.54 to 19.01); and body mass index (BMI) of 30-35 (OR 2.81; 95% CI 1.31 to 6.04). Current smoking status was found to be associated with a decreased likelihood of unanticipated admission (OR 0.44; 95% CI 0.23 to 0.83), as was monitored anesthesia care when compared with general anesthesia (OR 0.17; 95% CI 0.04 to 0.68) and plastic (OR 0.18; 95% CI 0.07 to 0.50), orthopedic (OR 0.16; 95% CI 0.08 to 0.33), and dental/ear-nose-throat surgery (OR 0.32; 95% CI 0.13 to 0.83) when compared with general surgery. Other comorbid conditions did not impact unanticipated admission. CONCLUSION: Unanticipated admission after ambulatory surgery occurs mainly due to surgical, anesthetic, and medical complications. Length of surgery more than one hour, high ASA class, advanced age, and increased BMI were all predictors. No specific comorbid illness was associated with an increased likelihood of unanticipated admission. These findings support continued use of the ASA classification as a marker of patient perioperative risk rather than attributing risk to a specific disease process.

How good is good? Students and assessors' perceptions of qualitative markers of performance.

BACKGROUND: Qualitative markers of performance are routinely used for medical student assessment, though the extent to which such markers can be readily translated to actionable pieces of information remains uncertain. PURPOSE: To explore (a) the perceived value to be indicated by descriptor phrases commonly used for describing student performance, (b) the perceived weight of the different performance domains (e.g. communication skills, work ethic, knowledge base, etc), and (c) whether or not the perceived value of the descriptors changes as a function of the performance domains. METHODS: Five domains of performance were identified from the thematic coding of past medical student transcripts (N = 156). From the transcripts, 91 distinct descriptors indicating the language commonly used by assessors were also identified. From the list of 91 descriptors, Thurstone's method of equal-appearing intervals was used to extract 10 descriptors that were representative of the continuum of student performance. A modified paired comparisons method was then used to enable the relative ranking of each of 10 descriptors combined with each of 5 different domains of performance. A web-based survey was used to collect responses from participants (N = 209), which consisted of medical students and faculty members who were previously involved in student assessment. RESULTS: Results demonstrated that respondents did not simply sum positive and negative descriptors in a uniform manner. Rather, comments on some domains (e.g., "ability to apply patient centred medicine") were seen as particularly positive when associated with positive descriptors but not particularly negative when associated with negative descriptors. For others (e.g., "receptivity and responsiveness to feedback") the reverse was true. Comments on "knowledge-base" elicited a relatively muted perception at both ends of the scale. Finally, the results also revealed moderate misalignment in the perceptions of assessors and students. CONCLUSIONS: The findings from this study suggest that the use of any given descriptor conveys slightly different meaning dependent on the context in which it is used. This helps to address some key issues surrounding the application of qualitative markers to performance assessment in medical education.