The effect of interscalene block (ISB) on pulmonary function of obese participants has not been investigated. The goal of this study is to assess the association of obesity (body mass index BMI >29 ...kg/m vs BMI <25 kg/m) and change in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) after ISB in participants undergoing outpatient shoulder surgery.
This prospective, observational cohort study compared obese (BMI >29 kg/m) and normal-weight (BMI <25 kg/m) groups undergoing ISB for ambulatory shoulder surgery, on preblock and postblock FVC and FEV1, at 30 minutes postblock and in the postanesthesia care unit (PACU). The primary outcome in this study was FVC% change (percentage change from preblock to postblock values of FVC) at 30 minutes postblock in the supine position. Secondary outcomes included FVC% change at PACU and in the sitting position, FEV1% change (percentage change from preblock to postblock values of FEV1), FVC, FEV1, incidence of diaphragmatic paresis, modified Borg scale for perceived dyspnea, Richmond Agitation-Sedation Scale scores for sedation, and intraoperative airway events.
Fourteen participants were recruited to each group. The mean (standard deviation) BMI in the normal-weight and obese groups was 23 (1.7) and 33 (3.1) kg/m, respectively. ISB success rate was 100%. All participants demonstrated hemidiaphragmatic paresis after ISB. Compared to the normal-weight group, in the sitting position, the obese group had a significant decrease in FVC% change at 30 minutes (-30 10.5 vs -23 7.2, P = .046) and an FEV1% change in the PACU (-40 12.6 vs -27 13.9, P = .02). No difference was found for measurements taken in the supine position. A repeated-measures analysis demonstrated that, adjusted for position, there is no significant group effect on FVC% change or FEV1% change from 30 minutes to PACU. The 2 groups were not different in terms of breathlessness and sedation at 30 minutes (P = .67, P = .48, respectively) and in the PACU (P = .69, P > .99, respectively) nor in the occurrence of intraoperative airway events (P > .99).
ISB is associated with greater FVC and FEV1 reductions in obese participants undergoing shoulder surgery compared to normal-weight participants. Neither time (30 minutes versus PACU) nor position (sitting versus supine) affected this relationship. Despite these changes, obesity was not associated with increased clinical respiratory symptoms or events.
Purpose
We estimated the rate of unplanned hospital and intensive care unit (ICU) admissions following ambulatory surgery centre (ASC) procedures, and identified factors associated with their ...occurrence.
Methods
This retrospective cohort included adult patients who underwent ASC procedures within a large community practice from January 2010 to December 2014. Patients were categorized into two groups: unplanned postoperative hospital/ICU admission within 24 hr of procedure or uneventful discharge. Demographics, comorbidities, anesthesia type, procedure type, procedure group, and ASC facility were assessed.
Results
Of the 211,389 patients included, there were 211,147 uneventful discharges (99.89%) and 242 unplanned hospital admissions (0.11%), of which 75 were ICU admissions (0.04%). The multivariable logistic regression model for hospital admission showed an increased risk associated with age > 50 yr (odds ratio OR, 1.53); American Society of Anesthesiologists (ASA) physical status (III
vs
II: OR, 1.45; IV
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II: OR, 1.88), comorbidity (chronic obstructive pulmonary disease: OR, 2.63; diabetes mellitus: OR, 1.62; transient ischemic attack: OR, 2.48) procedure (respiratory: OR, 2.92; digestive: OR, 2.66; musculoskeletal system: OR, 2.53), anesthetic management (general anesthesia GA and peripheral nerve block
vs
GA: OR, 1.79), and ASC facility (189BB: OR, 2.29; 30E9A: OR, 7.41; and BD21F: OR, 1.69). The multivariable logistic regression model for ICU admission showed increased risk of unplanned ICU admission associated with ASA physical status (ASA III
vs
II: OR, 3.0; ASA IV
vs
II: OR, 8.52), procedure (musculoskeletal system: OR, 2.45), and ASC facility (00E6C: OR, 3.14; 189BB: OR, 2.77; 30E9A: OR, 2.59; and BD21F: OR, 3.71).
Conclusion
While a small percentage of adult patients who underwent ASC procedures required unplanned hospital admission (0.07%), approximately one-third of these admissions were to the ICU (0.04%). Facility was at least as strong a predictor of hospital admission as the patient- and/or procedure-specific variables.
Limited information exists on the effects of temporary functional deafferentation (TFD) on brain activity after peripheral nerve block (PNB) in healthy humans. Increasingly, resting-state functional ...connectivity (RSFC) is being used to study brain activity and organization. The purpose of this study was to test the hypothesis that TFD through PNB will influence changes in RSFC plasticity in central sensorimotor functional brain networks in healthy human participants.
The authors achieved TFD using a supraclavicular PNB model with 10 healthy human participants undergoing functional connectivity magnetic resonance imaging before PNB, during active PNB, and during PNB recovery. RSFC differences among study conditions were determined by multiple-comparison-corrected (false discovery rate-corrected P value less than 0.05) random-effects, between-condition, and seed-to-voxel analyses using the left and right manual motor regions.
The results of this pilot study demonstrated disruption of interhemispheric left-to-right manual motor region RSFC (e.g., mean Fisher-transformed z effect size at pre-PNB 1.05 vs. 0.55 during PNB) but preservation of intrahemispheric RSFC of these regions during PNB. Additionally, there was increased RSFC between the left motor region of interest (PNB-affected area) and bilateral higher order visual cortex regions after clinical PNB resolution (e.g., Fisher z between left motor region of interest and right and left lingual gyrus regions during PNB, -0.1 and -0.6 vs. 0.22 and 0.18 after PNB resolution, respectively).
This pilot study provides evidence that PNB has features consistent with other models of deafferentation, making it a potentially useful approach to investigate brain plasticity. The findings provide insight into RSFC of sensorimotor functional brain networks during PNB and PNB recovery and support modulation of the sensory-motor integration feedback loop as a mechanism for explaining the behavioral correlates of peripherally induced TFD through PNB.
Despite surgical reconstruction and extensive rehabilitation, persistent quadriceps inhibition, gait asymmetry, and functional impairment remain prevalent in patients after anterior cruciate ligament ...(ACL) injury. A combination of reports have suggested underlying central nervous system adaptations in those after injury govern long-term neuromuscular impairments. The classic assumption has been to attribute neurophysiologic deficits to components of injury, but other factors across the continuum of care (e.g. surgery, perioperative analgesia, and rehabilitative strategies) have been largely overlooked.
This review provides a multidisciplinary perspective to 1) provide a narrative review of studies reporting neuroplasticity following ACL injury in order to inform clinicians of the current state of literature and 2) provide a mechanistic framework of neurophysiologic deficits with potential clinical implications across all phases of injury and recovery (injury, surgery, and rehabilitation)
Studies using a variety of neurophysiologic modalities have demonstrated peripheral and central nervous system adaptations in those with prior ACL injury. Longitudinal investigations suggest neurophysiologic changes at spinal-reflexive and corticospinal pathways follow a unique timecourse across injury, surgery, and rehabilitation.
Clinicians should consider the unique injury, surgery, anesthesia, and rehabilitation on central nervous system adaptations. Therapeutic strategies across the continuum of care may be beneficial to mitigate maladaptive neuroplasticity in those after ACL injury.
Novel anesthetic and analgesic agents are currently under development or investigation to improve anesthetic delivery and patient care. The pharmacokinetic and analgesic profiles of these agents are ...especially tailored to meet the challenges of rapid recovery and opioid minimization associated with ambulatory anesthesia practice.
Peripheral nerve stimulation has a long history in regional anesthesia. Despite the advent of ultrasound-guided peripheral nerve blockade, nerve stimulation remains a popular technique used alone or, ...now, in combination with ultrasound-guided techniques. In light of this evolving utility of nerve stimulation, this is an appropriate time to review the basic concepts and knowledge base of this historically important tool. Electrical nerve stimulation facilitates nerve localization, using threshold current as a surrogate for needle-to-nerve distance. Preferential activation of motor nerves is possible because motor nerve fibers are more readily activated with a shorter duration of current compared with sensory nerves. The association between current and needle-to-nerve distance predicts that less current is needed to evoke a motor response as the needle moves closer to the nerve. Thus, an elicited motor response at or below 0.5 mA is considered a common end point for successful neural blockade. However, current magnitude is neither 100% sensitive nor specific. Independent of technical ability, both the biological environment and the equipment used impact the current-distance relationship. Thus, successful electrical nerve stimulation is dependent on an anesthesiologist with a solid foundation in anatomy and a thorough understanding of electrophysiology.
Although there are extensive studies of postoperative and postdischarge nausea and vomiting (PONV/PDNV) up to 24 h, few investigate 'delayed PDNV'. With an increasing outpatient surgical population, ...specific 'delayed PDNV' risk identification and management is necessary for improving outcomes and helping patients after discharge. This review will discuss possible PDNV specific risk factors, successful prevention and management of PDNV following ambulatory anesthesia and the principles and pharmacology of these interventions.
Current research has demonstrated beneficial PDNV management up to 72 h with the long-acting 5-hydroxytryptamine-3 receptor antagonist palonosetron. Neurokinin-1 antagonists have demonstrated superior antiemesis, but not antinausea compared with more traditional and less expensive options. Dexamethasone provides improvements in quality of recovery associated with improved PDNV outcomes.
Further PDNV specific research is needed, including PDNV predictive models in directing antiemetic interventions. Long-acting antiemetics and postdischarge oral antiemetics are effective in PDNV pharmacologic management. Neurokinin-1 receptor antagonists are effective in reducing the incidence of vomiting, but not nausea. The addition of nonpharmacologic interventions such as acustimulation may reduce PDNV. Multimodal analgesia including nonopioid analgesics and ambulatory continuous peripheral nerve blocks are encouraged to achieve adequate postoperative analgesia and reduce opioid induced PDNV.
Transplantation of a donor hand has been successful as a surgical treatment following amputation, but little is known regarding the brain mechanisms contributing to the recovery of motor function. We ...report functional magnetic resonance imaging (fMRI) findings for neural activation related to actual and imagined movement, for a 54-year-old male patient, who had received a donor hand transplant 50 years following amputation. Two assessments, conducted 3 months and 6 months post-operatively, demonstrate engagement of motor-control related brain regions for the transplanted hand, during both actual and imagined movement of the fingers. The intact hand exhibited a more intense and focused pattern of activation for actual movement relative to imagined movement, whereas activation for the transplanted hand was more widely distributed and did not clearly differentiate actual and imagined movement. However, the spatial overlap of actual-movement and imagined-movement voxels, for the transplanted hand, did increase over time to a level comparable to that of the intact hand. At these relatively early post-operative assessments, brain regions outside of the canonical motor-control networks appear to be supporting movement of the transplanted hand.
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