Paradoxical facilitation alongside interhemispheric inhibition

Neurophysiological experiments using transcranial magnetic stimulation (TMS) have sought to probe the function of the motor division of the corpus callosum. Primary motor cortex sends projections via the corpus callosum with a net inhibitory influence on the homologous region of the opposite hemisphere. Interhemispheric inhibition (IHI) experiments probe this inhibitory pathway. A test stimulus (TS) delivered to the motor cortex in one hemisphere elicits motor evoked potentials (MEPs) in a target muscle, while a conditioning stimulus (CS) applied to the homologous region of the opposite hemisphere modulates the effect of the TS. We predicted that large CS MEPs would be associated with increased IHI since they should be a reliable index of how effectively contralateral motor cortex was stimulated and therefore of the magnitude of interhemispheric inhibition. However, we observed a strong tendency for larger CS MEPs to be associated with reduced interhemispheric inhibition which in the extreme lead to a net effect of facilitation. This surprising effect was large, systematic, and observed in nearly all participants. We outline several hypotheses for mechanisms which may underlie this phenomenon to guide future research. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00221-021-06183-9

Evaluation of the utilization of the preanaesthetic clinics in a University teaching hospital

BACKGROUND: Dedicated out-patient preanaesthetic clinics are relatively recent phenomenon and information is sparse from developing world. This study attempted to evaluate the utilization of adult and paediatric preanaesthetic clinics and its impact on the cancellations of surgery in Trinidad. METHODS: All patients scheduled to have elective surgery during the period of twelve weeks were enrolled for prospective collection of data including demographics, the admitting diagnoses, surgical procedure, category of surgery and specialty, and the patients' attendance to preanaesthetic clinics. Cancellations on the day of surgery along with reasons were recorded. The difference between patients who attended and did not attend the clinic was analysed. RESULTS: Of 424 patients scheduled for procedures during the study period, 213 were adults and 211 were children. Overall 39% of adults and 46% of the children scheduled for surgery had previously attended the preanaesthetic clinic. Among adults, general surgery patients were the largest majority to attend the preanaesthetic clinic. The paediatric preanaesthetic clinic was mostly utilized by paediatric general surgery. Overall 30% of procedures in adults and 26% of those in children were cancelled. There was a statistically significant difference in cancellations between patients who attended and did not attend the preanaesthetic clinic (p = 0.004). There was a 52% more chance of the procedure getting cancelled if the patient did not attend the clinic. CONCLUSION: The study highlights the inadequate use of the preanaesthetic clinics and the impact of the clinics on last-minute cancellations

Efficacy of a separate informed consent for anesthesia services: A prospective study from the Caribbean

Background and Aims: This study aimed to determine whether a separate written consent form improved the efficacy of the informed consent process for anesthesia in adult patients undergoing elective surgery at a tertiary care teaching hospital. Material and Methods: We randomized patients into two groups prospectively. The first group (Group A) signed the hospital′s standard "Consent for Operation" form only while the second group (Group B) signed a separate "Consent for Anesthesia" form additionally. Patients were interviewed postoperatively with an eight-item questionnaire with responses in a 5-point Likert scale. A composite "adequacy of consent index" was generated from the responses and analyzed. Results: Two hundred patients (100 in each group) were studied. All patients indicated that the anesthesiologist(s) had their permission to proceed with their anesthesia care. The mean "adequacy of consent index score" in Group B was higher than that of Group A (30.6 ± 4.6 [standard deviation (SD)] vs. 27.9 ± 5.2 [SD]) (P < 0.001). The separate written consent had a positive impact on the patients′ understanding of the nature and purpose of the intended anesthesia procedures (P = 0.04), satisfaction with the adequacy of information provided about common side effects (P < 0.001) and rare but serious complications (P = 0.008). Conclusions: A separate written consent for anesthesia improved the efficacy of the informed consent process with respect to better information about the nature and purpose of anesthesia, common side effects, and rare but serious complications

Application of analytic hierarchy process for measuring and comparing the global performance of intensive care units

Purpose: To develop a model for the global performance measurement of intensive care units (ICUs) and to apply that model to compare the services for quality improvement. Materials and Methods: Analytic hierarchy process, a multiple-attribute decision-making technique, is used in this study to evolve such a model. The steps consisted of identifying the critical success factors for the best performance of an ICU, identifying subfactors that influence the critical factors, comparing them pairwise, deriving their relative importance and ratings, and calculating the cumulative performance according to the attributes of a given ICU. Every step in the model was derived by group discussions, brainstorming, and consensus among intensivists. Results: The model was applied to 3 ICUs, 1 each in Barbados, Trinidad, and India in tertiary care teaching hospitals of similar setting. The cumulative performance rating of the Barbados ICU was 1.17 when compared with that of Trinidad and Indian ICU, which were 0.82 and 0.75, respectively, showing that the Trinidad and Indian ICUs performed 70% and 64% with respect to Barbados ICU. The model also enabled identifying specific areas where the ICUs did not perform well, which helped to improvise those areas. Conclusions: Analytic hierarchy process is a very useful model to measure the global performance of an ICU. © 2005 Elsevier Inc. All rights reserved

The utilities of the therapeutic intervention scoring system (TISS-28)

Background and Aims: The study evaluates the utility of therapeutic intervention scoring system (TISS-28) in quantifying the resource utilization, costs and predicting outcome of critically ill patients. Materials and Methods: TISS-28 was prospectively applied to patients consecutively admitted to the intensive care units (ICU) of three public teaching hospitals and two private hospitals in Trinidad on a daily basis for a period of eight weeks. Demographic data, diagnoses on admission, nurse-patient ratio, ICU length of stay and hospital outcomes were recorded. Simplified acute physiology score (SAPS)-II was applied for all adult patients. Costs were calculated from data collected from the public hospitals in relation to TISS-28 score. Results : TISS-28 scores of five hundred and ninety-five patient-days were analyzed. The median daily TISS-28 per patient was 27 [24.5, 30.6 quartiles (IQR)]; the median day-1 TISS-28 score was 29 (25, 33 IQR) and the median last day TISS-28 score was 25 (21, 30 IQR). The overall average TISS per nurse was 26.2 per day. The mean cost per patient per day was 414 US dollars. The discriminatory function of day-1 TISS-28 as a prognostic scoring system was less compared to SAPS II as shown by the area under the receiver operating characteristic curve (0.65 compared to 0.71). Conclusions: TISS-28 is useful for evaluating the resource utilization and costs and may not be useful as a prognostic scoring syste