Gabapentin and Rapidity of Recovery Among Patients Undergoing Minimally Invasive Ambulatory Uro-Oncologic Surgeries.

INTRODUCTION: Gabapentin has been used in enhanced recovery after surgery (ERAS) pathways for pain control for patients undergoing ambulatory uro-oncologic surgery; however, it may cause undesirable side effects. We studied the causal association between gabapentin and rapidity of recovery and perioperative pain management after minimally invasive uro-oncologic surgery. METHODS: We identified 2397 patients ≤ 65 years undergoing prostatectomies or nephrectomies between 2018 and 2022; 131 (5.5%) did not receive gabapentin. We tested the effect of gabapentin use on time of discharge and perioperative opioid consumption, respectively, using multivariable linear regression adjusting for potential confounders including age, gender, BMI, American Society of Anesthesiologists score, and surgery type. RESULTS: On adjusted analysis, we found no evidence of a difference in discharge time among those who did vs did not receive gabapentin (adjusted difference 0.07 hours shorter on gabapentin; 95% CI -0.17, 0.31; P = .6). There was no evidence of a difference in intraoperative opioid consumption by gabapentin receipt (adjusted difference -1.5 morphine milligram equivalents; 95% CI -4.2, 1.1; P = .3) or probability of being in the top quartile of postoperative opioid consumption within 24 hours (adjusted difference 4.2%; 95% CI -4.8%, 13%; P = .4). We saw no important differences in confounders by gabapentin receipt suggesting causal conclusions are justified. CONCLUSIONS: Our confidence intervals did not include clinically meaningful benefits from gabapentin, when used with an ERAS protocol, in terms of length of stay or perioperative opioid use. These results support the omission of gabapentin from ERAS protocols for minimally invasive uro-oncologic surgeries.

Transfers and anesthesia-related postoperative outcomes after 3361 same-day cancer surgeries at a freestanding surgery center: An observational retrospective study.

BACKGROUND AND OBJECTIVES: Expanding outpatient surgery to the increasing number of procedures and patient populations warrants continuous evaluation of postoperative outcomes to ensure the best care and safety. We describe adverse postoperative outcomes and transfer rates related to anesthesia in a large sample of patients who underwent same-day cancer surgery at a freestanding ambulatory surgery center. METHODS: Between January 2017 and June 2021, 3361 cancer surgeries, including breast and plastic, head and neck, gynecology, and urology, were performed. The surgeries were indicated for diagnosis, staging, and/or treatment. We report the incidence of transfers and adverse postoperative outcomes related to anesthesia. RESULTS: Breast and plastic surgeries were the most common (1771, 53%), followed by urology (1052, 31%), gynecology (410, 12%), and head and neck surgeries (128, 4%). Based on patients' first procedure, comorbidity levels were highest for urology (75% American Society of Anesthesiologists physical status score 3, 1.7% score 4) and lowest for breast surgeries (31% score 3, 0.2% score 4). Most gynecology surgeries used general anesthesia (97.6%), whereas breast surgeries used the least (38%). A total of seven patients (0.2%; 95% CI: 0.08%-0.4%) were immediately transferred to an outside hospital; four due to anesthesia-related reasons. Only 7 (0.2%) patients needed additional postoperative care related to anesthesia-related adverse events, specifically cardiac events (4), difficult intubations (2), desaturation (1), and agitation, nausea, and headache (1). CONCLUSIONS: The incidence of anesthesia-related adverse postoperative outcomes is low in cancer patients undergoing outpatient surgeries at our freestanding ambulatory surgery center. This suggests that carefully selected cancer patients, including patients with metastatic cancer, can undergo anesthesia for same-day surgery, making cancer care accessible locally and reducing stress associated with travel for treatment. More research investigating complication rates related to surgery and to cancer disease trajectory are needed to establish a complete evaluation of safety for outpatient cancer surgery.

Paravertebral and erector spinae plane blocks decrease length of stay compared with local infiltration analgesia in autologous breast reconstruction.

BACKGROUND: Autologous breast reconstruction is associated with significant pain impeding early recovery. Our objective was to evaluate the impact of replacing surgeon-administered local infiltration with preoperative paravertebral (PVB) and erector spinae plane (ESP) blocks for latissimus dorsi myocutaneous flap reconstruction. METHODS: Patients who underwent mastectomy with latissimus flap reconstruction from 2018 to 2022 were included in three groups: local infiltration, PVB, and ESP blocks. Block effect on postoperative length of stay (LOS) and the association between block status and pain, opioid consumption, time to first analgesic, and postoperative antiemetic administration were assessed. RESULTS: 122 patients met the inclusion criteria for this retrospective cohort study: no block (n=72), PVB (n=26), and ESP (n=24). On adjusted analysis, those who received a PVB block had a 20-hour shorter postoperative stay (95% CI 11 to 30; p<0.001); those who received ESP had a 24-hour (95% CI 15 to 34; p<0.001) shorter postoperative stay compared with the no block group, respectively. Using either block was associated with a reduction in intraoperative opioids (23 morphine milligram equivalents (MME)), 95% CI 14 to 31, p<0.001; ESP versus no block: 23 MME, 95% CI 14 to 32, p<0.001). CONCLUSIONS: Replacing surgical infiltration with PVB and ESP blocks for autologous breast reconstruction reduces LOS. The comparable reduction in LOS suggests that ESP may be a viable alternative to PVB in patients undergoing latissimus flap breast reconstruction following mastectomy. Further research should investigate whether ESP or PVB have better patient outcomes in complex breast reconstruction.

Institution of Monthly Anesthesia Quality Reports Does Not Reduce Postoperative Complications despite Improved Metric Compliance.

While quality programs have been shown to improve provider compliance, few have demonstrated conclusive improvements in patient outcomes. We hypothesized that there would be increased metric compliance and decreased postoperative complications after initiation of an anesthesiology quality improvement program at our institution. We performed a retrospective study of all adult inpatients having anesthesia for a twelve-month period that spanned six months before and after program implementation. The primary outcome was the rate of complications in the post-implementation period. Secondary outcomes included the change in proportion of complications and compliance with quality metrics. We studied a total of 9620 adult inpatient cases, subdivided into pre- and post-implementation groups (4832 vs 4788.) After multivariate model adjustment, the rate of any complication (our primary outcome) was not significantly changed (32% to 31%; adjusted P = 0.410.) Of the individual complications, only wound infection (2.0% to 1.5%; adjusted P = 0.020) showed a statistically significant decrease. Statistically and clinically significant increases in compliance were seen for the BP-02 Avoiding Monitoring Gaps metric (81% to 93%, P < 0.001), both neuromuscular blockade metrics (NMB-01 76% to 91%, P < 0.001; NMB-02 95% to 97%, P = 0.006), both tidal volume metrics (PUL-01 84% to 93%, P < 0.001; PUL-02 30% to 45%, P < 0.001), and the TEMP-02 Core Temperature Measurement metric (88% to 94%, P < 0.001). Implementation of a comprehensive quality feedback program improved metric compliance but was not associated with a change in postoperative complications.

The impact of real-time clinical alerts on the compliance of anesthesia documentation: A retrospective observational study.

INTRODUCTION: Clinical alert systems (CAS) have been used to analyze deviations from hospital standards in the electronic medical record to identify missing documentations and send alerts to the appropriate providers to increase adherence to required elements. To improve compliance, an alert system for documentation of the Immediate Preoperative Assessment (IPOA) was implemented at our institution in August 2018 with the goal of improving documentation compliance rates. We hypothesized that implementation of this alert system would increase the compliance of on-time documentation of the IPOA. METHODS: An initial data query in our institutional data warehouse was made for all patients who had a completed anesthetic during our study period. This date range corresponded to 6 months before and after August 2nd, 2018, the date when the IPOA alert was implemented and the anesthesiology department. The following analyses were performed: testing the proportion of cases compliant with on-time documentation of the IPOA pre- versus post-implementation for the full cohort and among subsets of interest, testing the time when the IPOA was completed relative to anesthesia end, and testing whether time of day of when surgery occurred had an impact on the time when the IPOA was completed relative to the drapes off/IPOA alert sent time. The proportion of compliance for pre- versus post-implementation was tested by Chi-square test. RESULTS: Through retrospective chart review of electronic patient records, 47,417 cases matched our inclusion criteria of patients that had a completed anesthetic between February 2nd, 2018 to February 2nd, 2019. In total, we excluded 5132 cases. The compliance rate of IPOA completion increased from 76% to 88% (P < 0.001) before and after the alert implementation date. In the initial month following alert implementation, the compliance rate immediately increased to 83% and stayed in the high 80's for the balance of the study period. CONCLUSION: In summary, we demonstrate that automated Clinical Alert Systems operating via a single page notification can improve the compliance rate for documentation of key anesthesia events and that this observation is sustained six months after the implementation date. Furthermore, improvement in compliance is highest shorter cases and cases that occur early in the day. This study shows promising results in the use of automatic CAS system alerts to help hospitals meet the Center for Medicare and Medicaid Services (CMS) and The Joint Commission (TJC) standards.

Improved Compliance With Anesthesia Quality Measures After Implementation of Automated Monthly Feedback.

PURPOSE: Minimization of postoperative complications is important in patients with cancer. We wished to improve compliance with anesthesiology quality measures through staff education reinforced with automated monthly feedback. METHODS: The anesthesiology department implemented a program to capture and report quality metrics. After staff education, monthly e-mail reports were sent to each anesthesiology physician and nurse anesthetist to detail individual compliance rates for a set of quality measures. For each measure, the proportion of patient cases that passed the measure before and after implementation of the program was compared using a two-sample proportion test. RESULTS: After exclusions, we analyzed 15 of 23 quality measures. Of the 15 measures, 11 were process measures, and four were outcome measures. Of the 11 process measures, seven demonstrated statistically significant improvements (P < .01). The most improved measure was TEMP-02 (core temperature measurement), which increased from 69.6% to 85.7% (16.1% difference; P < .001). Also improved were PUL-02 (low tidal volume, less than 8 mL/kg ideal body weight; 15.4% difference; P < .001) and NMB-01 (train of four taken; 12.2% difference; P < .001). The outcome measure TEMP-03 (perioperative temperature management) had a statistically significant increase of a small magnitude (0.2% difference; P < .001). No other outcome measures showed statistically significant improvement. CONCLUSION: After implementation of a comprehensive quality improvement program, our group observed significant improvements in anesthesia quality measure compliance for several process measures. Future work is needed to determine if this initial success can be preserved and associated with improved outcomes.

Propofol sedation in children: sleep trumps amnesia.

OBJECTIVE: Detailed assessments of the effects of propofol on memory in children are lacking. We assessed the feasibility of measuring memory during propofol infusion, as commonly performed in sedation for MRI scanning. In addition, we determined the onset of memory loss in relation to the onset of sedation measured by verbal responsiveness. MATERIALS AND METHODS: Children scheduled for sedation for MRI received a 10-min infusion of propofol (3 mg/kg) as they viewed and named 100 simple line drawings, one shown every five seconds, until they were no longer responsive (encoding). A control group receiving no sedation for MRI underwent similar tasks. Sedation was measured as any verbal response, regardless of correctness. After recovery from sedation, recognition memory was tested, with correct yes/no recognitions matched to sedation responses during encoding (subsequent memory paradigm). RESULTS: Of the 48 children who received propofol, 30 could complete all study tasks (6.2 ± 1.6 years, 16 males). Individual responses could be modeled in all 30 children. On average, there was a 50% probability of no verbal response 3.1 min after the start of infusion, with 50% memory loss at 2.7 min. Children receiving propofol recognized 65 ± 16% of the pictures seen, whereas the control group recognized 93 ± 5%. CONCLUSION: Measurement of memory and sedation is possible in verbal children receiving propofol by infusion in a clinical setting. Despite propofol being an amnestic agent, there was little or no amnestic effect of propofol while the child was verbally responsive. It is important for sedation providers to realize that propofol sedation does not always produce amnesia while the child is responsive. CLINICALTRIALS. GOV NUMBER: NCT02278003.

Visual P2-N2 complex and arousal at the time of encoding predict the time domain characteristics of amnesia for multiple intravenous anesthetic drugs in humans.

BACKGROUND: Intravenous anesthetics have marked effects on memory function, even at subclinical concentrations. Fundamental questions remain in characterizing anesthetic amnesia and identifying affected system-level processes. The authors applied a mathematical model to evaluate time-domain components of anesthetic amnesia in human subjects. METHODS: Sixty-one volunteers were randomized to receive propofol (n = 12), thiopental (n = 13), midazolam (n = 12), dexmedetomidine (n = 12), or placebo (n = 12). With drug present, subjects encoded pictures into memory using a 375-item continuous recognition task, with subsequent recognition later probed with drug absent. Memory function was sampled at up to 163 time points and modeled over the time domain using a two-parameter, first-order negative power function. The parietal event-related P2-N2 complex was derived from electroencephalography, and arousal was repeatedly sampled. Each drug was evaluated at two concentrations. RESULTS: The negative power function consistently described the course of amnesia (mean R = 0.854), but there were marked differences between drugs in the modulation of individual components (P < 0.0001). Initial memory strength was a function of arousal (P = 0.005), whereas subsequent decay was related to the reaction time (P < 0.0001) and the P2-N2 complex (P = 0.007/0.002 for discrete components). CONCLUSIONS: In humans, the amnesia caused by multiple intravenous anesthetic drugs is characterized by arousal-related effects on initial trace strength, and a subsequent decay predicted by attenuation of the P2-N2 complex at encoding. The authors propose that the failure of normal memory consolidation follows drug-induced disruption of interregional synchrony critical for neuronal plasticity and discuss their findings in the framework of memory systems theory.

Propofol and midazolam inhibit conscious memory processes very soon after encoding: an event-related potential study of familiarity and recollection in volunteers.

BACKGROUND: Intravenous drugs active via gamma-aminobutyric acid receptors to produce memory impairment during conscious sedation. Memory function was assessed using event-related potentials (ERPs) while drug was present. METHODS: The continuous recognition task measured recognition of photographs from working (6 s) and long-term (27 s) memory while ERPs were recorded from Cz (familiarity recognition) and Pz electrodes (recollection recognition). Volunteer participants received sequential doses of one of placebo (n = 11), 0.45 and 0.9 microg/ml propofol (n = 10), 20 and 40 ng/ml midazolam (n = 12), 1.5 and 3 microg/ml thiopental (n = 11), or 0.25 and 0.4 ng/ml dexmedetomidine (n = 11). End-of-day yes/no recognition 225 min after the end of drug infusion tested memory retention of pictures encoded on the continuous recognition tasks. RESULTS: Active drugs increased reaction times and impaired memory on the continuous recognition task equally, except for a greater effect of midazolam (P < 0.04). Forgetting from continuous recognition tasks to end of day was similar for all drugs (P = 0.40), greater than placebo (P < 0.001). Propofol and midazolam decreased the area between first presentation (new) and recognized (old, 27 s later) ERP waveforms from long-term memory for familiarity (P = 0.03) and possibly for recollection processes (P = 0.12). Propofol shifted ERP amplitudes to smaller voltages (P < 0.002). Dexmedetomidine may have impaired familiarity more than recollection processes (P = 0.10). Thiopental had no effect on ERPs. CONCLUSION: Propofol and midazolam impaired recognition ERPs from long-term memory but not working memory. ERP measures of memory revealed different pathways to end-of-day memory loss as early as 27 s after encoding.

Low-dose propofol-induced amnesia is not due to a failure of encoding: left inferior prefrontal cortex is still active.

BACKGROUND: Propofol may produce amnesia by affecting encoding. The hypothesis that propofol weakens encoding was tested by measuring regional cerebral blood flow during verbal encoding. METHODS: Seventeen volunteer participants (12 men; aged 30.4 +/- 6.5 yr) had regional cerebral blood flow measured using H2O positron emission tomography during complex and simple encoding tasks (deep vs. shallow level of processing) to identify a region of interest in the left inferior prefrontal cortex (LIPFC). The effect of either propofol (n = 6, 0.9 microg/ml target concentration), placebo with a divided attention task (n = 5), or thiopental at sedative doses (n = 6, 3 microg/ml) on regional cerebral blood flow activation in the LIPFC was tested. The divided attention task was expected to decrease activation in the LIPFC. RESULTS: Propofol did not impair encoding performance or reaction times, but impaired recognition memory of deeply encoded words 4 h later (median recognition of 35% [interquartile range, 17-54%] of words presented during propofol vs. 65% [38-91%] before drug; P < 0.05). Statistical parametric mapping analysis identified a region of interest of 6.6 cm in the LIPFC (T = 7.44, P = 0.014). Regional cerebral blood flow response to deep encoding was present in this region of interest in each group before drug (T > 4.41, P < 0.04). During drug infusion, only the propofol group continued to have borderline significant activation in this region (T = 4.00, P = 0.063). CONCLUSIONS: If the amnesic effect of propofol were solely due to effects on encoding, activation in the LIPFC should be minimal. Because LIPFC activation was not totally eliminated by propofol, the amnesic action of propofol must be present in other brain regions and/or affect other memory processes.

Unified approach for multiple sclerosis lesion segmentation on brain MRI.

The presence of large number of false lesion classification on segmented brain MR images is a major problem in the accurate determination of lesion volumes in multiple sclerosis (MS) brains. In order to minimize the false lesion classifications, a strategy that combines parametric and nonparametric techniques is developed and implemented. This approach uses the information from the proton density (PD)- and T2-weighted and fluid attenuation inversion recovery (FLAIR) images. This strategy involves CSF and lesion classification using the Parzen window classifier. Image processing, morphological operations, and ratio maps of PD- and T2-weighted images are used for minimizing false positives. Contextual information is exploited for minimizing the false negative lesion classifications using hidden Markov random field-expectation maximization (HMRF-EM) algorithm. Lesions are delineated using fuzzy connectivity. The performance of this algorithm is quantitatively evaluated on 23 MS patients. Similarity index, percentages of over, under, and correct estimations of lesions are computed by spatially comparing the results of present procedure with expert manual segmentation. The automated processing scheme detected 80% of the manually segmented lesions in the case of low lesion load and 93% of the lesions in those cases with high lesion load.

Multicentre proton magnetic resonance spectroscopy imaging of primary progressive multiple sclerosis.

Multicentre baseline proton magnetic resonance spectroscopic data on primary progressive multiple sclerosis (PPMS) patients are acquired and analysed, using automatic analysis software. The metabolite ratios did not differ from centre to centre. The average N-acetylaspartate/creatine (NAA/Cr) ratio in PPMS was significantly lower compared to normal controls. No significant differences were observed in this ratio between lesion-containing regions (LCR) and normal-appearing tissues (NAT). Strong lipid resonances, even in the absence of lesions, are observed in the both grey and white matter in these patients. These observations suggest extensive diffuse and/or microscopic pathology in PPMS. No significant correlation between any of the metabolite ratios and the Extended Disability Scale Score (EDSS) or with other MR measures such as lesion burden and enhancement volumes is observed.

Adaptive FCM with contextual constrains for segmentation of multi-spectral MRI.

An adaptive fuzzy c-means (FCM) clustering algorithm is explored for segmentation of three-dimensional (3D) multi-spectral MR images. This algorithm takes into consideration of both noise and 3D intensity non-uniformity. This algorithm models the intensity nonuniformity of MR images as a gain field or bias field that slowly varies in space, which is approximated by a linear combination of smooth basis functions made up of polynomials with different orders. The contextual constraints are included by introducing a regularization term into the cost function of FCM. The regularization term is a measure of aggregation of local voxels that tend to overcome the noise in voxel labeling. We present our scheme both for bias and gain fields, with special attention is paid to robust estimation of the bias field.

Color coding for visualization of the directional information of DTI.

A new color coding scheme which can fully retrieve the directional information of diffusion tensor image (DTI) with maximum use of the color space is proposed and implemented. This new scheme overcomes the loss of directional information in conventional schemes and easy to implement. Comparison between the new scheme and the conventional color coding method are presented using the DTI data of human brain.