ABSTRACT
Intravenous patient-controlled analgesia (PCA) is valuable for delivering opioids in a flexible and timely manner. Although it is designed to offer personalized analgesia driven by the patients themselves, users often report insufficient pain relief, which can be addressed by optimizing its settings and multimodal analgesia. We adopted a systematic approach to modify PCA protocols by utilizing a serial audit process based on institutional PCA data. This review retrospectively examined the process, encompassing data from 13,230 patients who had used PCA devices. The two modifications to the fentanyl-based PCA protocols resulted in three distinct phases. In the first phase, high opioid consumption and unintended PCA withdrawal were the common issues. These were addressed in the second phase by omitting the routine use of basal infusion. However, this led to increased delivery-to-demand ratios, mitigated in the third phase by increasing the bolus dose from 15 µg to 20 µg. These serial protocol changes have produced varied outcomes across different surgical departments, underscoring the need for careful and gradual adjustments and thorough impact assessments. Drawing insights from this audit process, we incorporated findings from the literature on PCA settings and multimodal analgesic approaches. This review underscores the significance of iterative feedback and refinement of analgesic protocols to achieve optimal postoperative pain management. Additionally, it discusses critical considerations regarding the postoperative audit processes.
ABSTRACT
BACKGROUND: Inter-scalene block (ISB) is associated with an inevitable risk of hemi-diaphragmatic paresis (HDP). To reduce the risk of HDP, an upper trunk block (UTB) has been proposed at the brachial plexus division level. OBJECTIVE: We hypothesised that UTB would be associated with a lower incidence of HDP than ISB while providing sufficient analgesia following arthroscopic shoulder surgery. DESIGN: Randomised controlled trial. SETTING: A tertiary teaching hospital. PATIENTS: Seventy patients aged 20 to 80âyears undergoing arthroscopic rotator cuff repair. INTERVENTION: Ultrasound-guided ISB or UTB was performed with 5âml 0.75% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the incidence of complete HDP, assessed by diaphragm excursion using ultrasound, defined as a decrease to 25% or less of baseline or occurrence of paradoxical movement. Postoperative pulmonary function change, pain scores, opioid consumption and pain-related outcomes were the secondary outcomes. RESULTS: The UTB group had a significantly lower incidence of complete HDP than the ISB group [5.9% (2/34) vs. 41.7% (15/36); absolute difference, 35.8%; 95% confidence interval (CI), 17.8 to 53.7%; Pâ<â0.001]. The postblockade decline in pulmonary function was more pronounced in the ISB group than that in the UTB group. The pain score at 1âh postoperatively was not significantly different between the groups (ISB vs. UTB group: median 0 vs. 1; median difference, -1; 95% CI, -2 to 0.5). No significant difference was observed in any other secondary outcomes. CONCLUSION: UTB was associated with a lower incidence of HDP compared with ISB while providing excellent analgesia in arthroscopic shoulder surgery. TRIAL REGISTRATION: Clinical Trial Registry of Korea (https://cris.nih.go.kr) identifier: KCT0007002. IRB NUMBER: Chungnam National University Hospital Institutional Review Board No. 2021-12-069.
ABSTRACT
Acute cognitive impairments termed delirium often occur after inflammatory insults in elderly patients. While previous preclinical studies suggest mitochondria as a target for reducing neuroinflammation and cognitive impairments after LPS injection, fewer studies have evaluated the effects of a low-grade systemic inflammation in the aged brain. Thus, to identify the significance of mitochondrial dysfunction after a clinically relevant systemic inflammatory stimulus, we injected old-aged mice (18-20 months) with low-dose lipopolysaccharide (LPS, 0.04 mg/kg). LPS injection reduced mitochondrial respiration in the hippocampus 24 h after injection (respiratory control ratio [RCR], state3u/state4o; control = 2.82 ± 0.19, LPS = 2.57 ± 0.08). However, gene expression of the pro-inflammatory cytokine IL-1ß was increased (RT-PCR, control = 1.00 ± 0.30; LPS = 2.01 ± 0.67) at a more delayed time point, 48 h after LPS injection. Such changes were associated with cognitive impairments in the Barnes maze and fear chamber tests. Notably, young mice were unaffected by low-dose LPS, suggesting that mitochondrial dysfunction precedes neuroinflammation and cognitive decline in elderly patients following a low-grade systemic insult. Our findings highlight mitochondria as a potential therapeutic target for reducing delirium in elderly patients.
ABSTRACT
BACKGROUND: Among the various diaphragm-sparing alternatives to interscalene block, costoclavicular block (CCB) demonstrated a low hemidiaphragmatic paresis (HDP) occurrence but an inconsistent analgesic effect in arthroscopic shoulder surgery. We hypothesized that a larger volume of local anesthetic for CCB could provide sufficient analgesia by achieving sufficient supraclavicular spreading. METHODS: Sixty patients scheduled for arthroscopic rotator cuff repair were randomly assigned to receive CCB using one of two volumes of local anesthetic (CCB20, 0.75% ropivacaine 20 ml; CCB40, 0.375% ropivacaine 40 ml). The primary outcome was the rate of complete analgesia (0 on the numeric rating scale of pain) at 1 h postoperatively. The secondary outcomes included a sonographic assessment of local anesthetic spread, diaphragmatic function, pulmonary function, postoperative opioid use, and other pain-related experiences within 24 h postoperatively. RESULTS: The rates of complete analgesia were not significantly different (23.3% [7/30] and 33.3% [10/30] in the CCB20 and CCB40 groups, respectively; risk difference 10%, 95% CI [-13, 32], P = 0.567). There were no significant differences in other pain-related outcomes. Among the clinical factors considered, the only factor significantly associated with postoperative pain was the sonographic observation of supraclavicular spreading. There were no significant differences in the incidence of HDP and the change in pulmonary function between the two groups. CONCLUSIONS: Using 40 ml of local anesthetic does not guarantee supraclavicular spread during CCB. Moreover, it does not result in a higher rate of complete analgesia compared to using 20 ml of local anesthetic in arthroscopic shoulder surgery.
Subject(s)
Anesthetics, Local , Shoulder , Humans , Shoulder/surgery , Ropivacaine , Analgesics , Pain, Postoperative/etiology , Pain, Postoperative/prevention & controlABSTRACT
TOPIC: The placebo effect and its potential determinants in ocular hypotensive therapy. CLINICAL RELEVANCE: The placebo effect has been studied and documented within a wide clinical context. It remains unclear whether placebo is effective in glaucoma treatment or, if so, which factors are determinative of effect size (ES). METHODS: Randomized controlled trials (RCTs) of topical ocular hypotensive therapy for patients with open-angle glaucoma or ocular hypertension, conducted through June 2, 2022, were included. First, a perceived placebo effect was measured as the overall intraocular pressure (IOP) change from the baseline. It was evaluated in terms of the ES (mean difference between the baseline and the end point) and then was compared with the ES, as obtained from the untreated control participant to obtain a true placebo effect. The primary outcome was ES based on 4 weeks of treatment. Meta-analysis-based statistical pooling was performed where appropriate, and 95% confidence intervals (CIs) were used for comparison. Potential placebo effect determinants were scrutinized using a multiple meta-regression model (PROSPERO identifier, CRD42022348098). RESULTS: A total of 40 RCTs (7829 eyes) with 33 placebo groups (2055 eyes) along with 7 untreated groups (1184 eyes) were included. Among placebo-controlled trials, placebo was determined to be effective in lowering IOP (ES, -1.30 mmHg; 95% CI, -1.75 to -0.84 mmHg). Using NMA, the ES for placebo was -2.27 mmHg (95% CI, -3.52 to -1.01 mmHg) greater than ES for untreated control participants.. According to the multiple meta-regression model, the active treatment ES was a significant factor to predict the amount of placebo effect. Placebo additionally lowered IOP by -0.45 mmHg per -1 mmHg of active treatment effect. Add-on study design and larger sample size also were associated with greater amount of placebo effect. No publication bias was evident in either a funnel plot or the Begg and Mazumdar adjusted rank correlation test results (P = 0.24). DISCUSSION: This meta-analysis indicated that placebo is effective in lowering IOP and is superior to the effect observed for the untreated control participants. However, caution is required in interpreting the results because of the small number of untreated controlled trials and potential bias from the lack of direct comparison between the placebo and untreated arms. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
ABSTRACT
The highly dynamic changes in microglia necessary to achieve a rapid neuroinflammatory response require a supply of energy from mitochondrial respiration, which leads to the accumulation of unfolded mitochondrial proteins. We previously reported that microglial activation is correlated with the mitochondrial unfolded protein response (UPRmt) in a kaolin-induced hydrocephalus model, but we still do not know the extent to which these changes in microglia are involved in cytokine release. Here, we investigated the activation of BV-2 cells and found that treatment with lipopolysaccharide (LPS) for 48 h increased the secretion of pro-inflammatory cytokines. This increase was accompanied by a concurrent decrease in oxygen consumption rate (OCR) and mitochondrial membrane potential (MMP), in association with the up-regulation of the UPRmt. Inhibition of the UPRmt by knockdown of ATF5, a key upstream regulator of the UPRmt, using small-interfering RNA against ATF5 (siATF5) not only increased production of the pro-inflammatory cytokines, interleukin-6 (IL-6), IL-1ß and tumor necrosis factor-α (TNF-α), but also decreased MMP. Our results suggest that ATF5-dependent induction of the UPRmt in microglia acts as a protective mechanism during neuroinflammation and may be a potential therapeutic target for reducing neuroinflammation.
Subject(s)
Cytokines , Microglia , Activating Transcription Factors/metabolism , Cytokines/metabolism , Inflammation/metabolism , Lipopolysaccharides/pharmacology , Microglia/metabolism , Neuroinflammatory Diseases , Tumor Necrosis Factor-alpha/metabolismABSTRACT
BACKGROUND: Blood pressure measurement is an essential element during intraoperative patient management. However, errors caused by changes in transducer levels can occur during surgery. METHODS: This single center, prospective, observational study enrolled 25 consecutive patients scheduled for elective cardiac surgery with invasive arterial and central venous pressure (CVP) monitoring. Hydrostatic pressures caused by level differences (leveling pressure) between a reference point (on the center of the left biceps brachii muscle) and the transducers (fixed on the right side of the operating table) for arterial and central lines were continuously measured using a leveling transducer. Adjusted pressures were calculated as measured pressure - leveling pressure. Hypotension (mean arterial pressure < 80, <70, and < 60 mmHg), and CVP (< 6, ≥6 and < 15, or ≥ 15 mmHg) and pulmonary artery pressure (PAP, mean > 20 mmHg) levels were determined using unadjusted and adjusted pressures. RESULTS: Twenty-two patients were included in the analysis. Leveling pressure ≥ 3 mmHg and ≥ 5 mmHg observed at 46.0 and 18.7% of pooled data points, respectively. Determinations of hypotension using unadjusted and adjusted pressures showed disagreements ranging from 3.3 to 9.4% depending on the cutoffs. Disagreements in defined levels of CVP and PAP were observed at 23.0 and 17.2% of the data points, respectively. CONCLUSIONS: The errors in pressure measurement due to changes in transducer level were not trivial and caused variable disagreements in the determination of MAP, CVP, and PAP levels. To prevent distortions in intraoperative hemodynamic management, strategies should be sought to minimize or adjust for these errors in clinical practice. TRIAL REGISTRATION: cris.nih.go.kr (KCT0006510).
Subject(s)
Cardiac Surgical Procedures , Hypotension , Humans , Adult , Central Venous Pressure/physiology , Transducers, Pressure , Prospective Studies , Cardiac Surgical Procedures/adverse effects , Hypotension/diagnosisABSTRACT
(1) Background: Previous studies reported limited performance of arterial pressure waveform-based cardiac output (CO) estimation (FloTrac/Vigileo system; CO-FloTrac) compared with the intermittent thermodilution technique (COint). However, errors due to bolus maneuver and intermittent measurements of COint could limit its use as a reference. The continuous thermodilution technique (COcont) may relieve such limitations. (2) Methods: The performance of CO-FloTrac was retrospectively assessed using continuous recordings of intraoperative physiological data acquired from patients who underwent off-pump coronary artery bypass graft (OPCAB) surgery with CO monitoring using both CO-FloTrac and COcont. Optimal time adjustments between the two measurements were determined based on R-squared values. (3) Results: A total of 134.2 h of data from 30 patients was included in the final analysis. The mean bias was -0.94 (95% CI, -1.35 to -0.52) L/min and the limits of agreements were -3.64 (95% CI, -4.44 to -3.08) L/min and 1.77 (95% CI, 1.21 to 2.57) L/min. The percentage error was 66.1% (95% CI, 52.4 to 85.8%). Depending on the time scale and the size of the exclusion zone, concordance rates ranged from 61.0% to 75.0%. (4) Conclusion: Despite the time adjustments, CO-FloTrac showed non-negligible overestimation, clinically unacceptable precision, and poor trending ability during OPCAB surgery.
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BACKGROUND: Endothelial cells (ECs) in cerebral vessels are considered the primary targets in acute hemorrhagic brain injuries. EC dysfunction can aggravate neuronal injuries by causing secondary inflammatory responses and blood-brain barrier (BBB) disruption. Previous studies have reported that enhancement of mitochondrial function within ECs may reduce BBB disruption and decrease the severity of acute brain injuries. However, the molecular signaling pathways through which enhanced EC mitochondrial function is enhanced to exert this BBB protective effect have not been fully elucidated. METHODS: To identify signaling pathways involved in linking EC-specific mitochondrial dysfunction and BBB disruption, we first performed RNA sequencing using isolated cerebral vessels from TEKCRIF1 KO mice, a mouse strain that displays EC-specific mitochondrial dysfunction. After identification, we assessed the significance of candidate signaling pathways using an intracerebral hemorrhage (ICH) mouse model. BBB integrity was assessed using an IgG leakage assay, and symptomatic changes were evaluated using behavioral assays. RESULTS: Transcriptome analyses of the TEKCRIF1 KO mouse revealed significant changes in Notch1 signaling, a pathway intimately involved in BBB maintenance. We also observed a decrease in Notch1 signaling and expression of the mitochondrial oxidative phosphorylation (OxPhos) complex in the ICH mouse model, which also exhibits BBB disruption. To further assess the function of Notch1 signaling in relation to BBB disruption, we injected ICH model mice with adropin, a protein that interacts with the Notch1 ligand NB-3 and activates Notch1 signaling. We found that adropin prevented BBB disruption and reduced the extent (area) of the injury compared with that in vehicle controls, in association with alteration of mitochondrial function. CONCLUSION: These results suggest that the Notch1 signaling pathway acts as an upstream regulator of DEGs and can be a target to regulate the changes involved with endothelial mitochondrial dysfunction-dependent BBB disruption. Thus, treatment methods that activate Notch1 may be beneficial in acute brain injuries by protecting BBB integrity.
Subject(s)
Blood-Brain Barrier , Brain Injuries , Animals , Cerebral Hemorrhage , Disease Models, Animal , Endothelial Cells , Gene Expression Profiling , Mice , Microvessels , Mitochondria , Signal Transduction , TranscriptomeABSTRACT
BACKGROUND: Superior trunk block (STB) provides noninferior analgesia to the interscalene block and reduces the risk of hemidiaphragmatic paralysis (HDP). Recently, supraclavicular spreading has also been shown to occur during costoclavicular block (CCB), presenting as an alternative analgesic technique for shoulder surgery. OBJECTIVE: The aim of this study was to determine whether there is a difference in postoperative pain scores and HDP incidence between STB and CCB. DESIGN: Prospective randomised controlled trial. SETTING: Chungnam National University Hospital in Daejeon from January to July 2021. PATIENTS: Seventy patients, aged 20 to 70âyears with ASA Physical Status classifications I to III and scheduled for elective arthroscopic rotator cuff repair were recruited. INTERVENTION: Ultrasound-guided STB or CCB was performed with 20âml 0.5% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the pain score (numeric rating scale, NRS) at 1âh postsurgery. A 1.4 (NRS) noninferiority margin was set a priori . The incidence of HDP, postoperative change of pulmonary function and postoperative opioid use were included as secondary outcomes. RESULTS: The pain score was higher in the CCB group compared with the STB group at 1âh postoperatively (median difference, 2; 95% confidence interval (CI), 1 to 3; noninferiority was not demonstrated). Two patients in the CCB group received a rescue interscalene block due to severe postoperative pain. The incidence of complete HDP was lower in the CCB group (risk difference, -26%; 95% CI, -6 to -45%; P â<â0.001). The median reduction in forced vital capacity and forced expiratory volume in 1âs were also significantly lower in the CCB group. CONCLUSION: Although the incidence of HDP was lower, CCB did not show noninferiority in immediate postoperative analgesia compared with STB in arthroscopic shoulder surgery. CLINICAL TRIAL REGISTRATION: Clinical Trial Registry of Korea (KCT0005822, principal investigator: Boohwi Hong) on 25 January 2021 ( https://cris.nih.go.kr ).
Subject(s)
Brachial Plexus Block , Shoulder , Adult , Aged , Anesthetics, Local , Arthroscopy/adverse effects , Arthroscopy/methods , Brachial Plexus Block/methods , Humans , Middle Aged , Pain, Postoperative/diagnosis , Pain, Postoperative/epidemiology , Pain, Postoperative/etiology , Prospective Studies , Shoulder/surgery , Ultrasonography, Interventional/methods , Young AdultABSTRACT
Early exposures to anesthetics can cause long-lasting changes in excitatory/inhibitory synaptic transmission (E/I imbalance), an important mechanism for neurodevelopmental disorders. Since E/I imbalance is also involved with addiction, we further investigated possible changes in addiction-related behaviors after multiple ketamine anesthesia in late postnatal mice. Postnatal day (PND) 16 mice received multiple ketamine anesthesia (35 mg kg-1, 5 days), and behavioral changes were evaluated at PND28 and PND56. Although mice exposed to early anesthesia displayed normal behavioral sensitization, we found significant increases in conditioned place preference to both low-dose ketamine (20 mg kg-1) and nicotine (0.5 mg kg-1). By performing transcriptome analysis and whole-cell recordings in the hippocampus, a brain region involved with CPP, we also discovered enhanced neuronal excitability and E/I imbalance in CA1 pyramidal neurons. Interestingly, these changes were not found in female mice. Our results suggest that repeated ketamine anesthesia during neurodevelopment may influence drug reward behavior later in life.
Subject(s)
Anesthesia , Anesthetics, Dissociative , Ketamine , Anesthetics, Dissociative/pharmacology , Animals , Female , Hippocampus , Ketamine/pharmacology , Ketamine/toxicity , Male , Mice , Reward , Synaptic TransmissionABSTRACT
Ventriculomegaly induced by the abnormal accumulation of cerebrospinal fluid (CSF) leads to hydrocephalus, which is accompanied by neuroinflammation and mitochondrial oxidative stress. The mitochondrial stress activates mitochondrial unfolded protein response (UPRmt), which is essential for mitochondrial protein homeostasis. However, the association of inflammatory response and UPRmt in the pathogenesis of hydrocephalus is still unclear. To assess their relevance in the pathogenesis of hydrocephalus, we established a kaolin-induced hydrocephalus model in 8-week-old male C57BL/6J mice and evaluated it over time. We found that kaolin-injected mice showed prominent ventricular dilation, motor behavior defects at the 3-day, followed by the activation of microglia and UPRmt in the motor cortex at the 5-day. In addition, PARP-1/NF-κB signaling and apoptotic cell death appeared at the 5-day. Taken together, our findings demonstrate that activation of microglia and UPRmt occurs after hydrocephalic ventricular expansion and behavioral abnormalities which could be lead to apoptotic neuronal cell death, providing a new perspective on the pathogenic mechanism of hydrocephalus. [BMB Reports 2022; 55(4): 181-186].
Subject(s)
Hydrocephalus , Kaolin , Animals , Disease Models, Animal , Hydrocephalus/chemically induced , Hydrocephalus/pathology , Kaolin/adverse effects , Male , Mice , Mice, Inbred C57BL , Microglia/pathology , Unfolded Protein ResponseABSTRACT
BACKGROUND: Various regional analgesia techniques are used to reduce postoperative pain in patients undergoing video-assisted thoracic surgery (VATS). This study aimed to determine the relative efficacy of regional analgesic interventions for VATS using a network meta-analysis (NMA). METHODS: We searched the Medline, EMBASE, Cochrane Controlled Trial Register, Web of Science, and Google Scholar databases to identify all randomized controlled trials (RCTs) that compared the analgesic effects of the following interventions: control, thoracic paravertebral block (TPVB), erector spinae plane block (ESPB), serratus plane block (SPB), and intercostal nerve block (INB). The primary outcome was opioid consumption during the first 24-h postoperative period. Pain scores were also collected during three different postoperative periods: the early (0-6 h), middle (6-18 h), and late (18-24 h) periods. RESULTS: A total of 21 RCTs (1391 patients) were included. TPVB showed the greatest effect on opioid consumption compared with the control (mean difference [MD] = -13.2 mg; 95% CI [-16.2, -10.1]). In terms of pain scores in the early period, ESPB had the greatest effect compared to control (MD = -1.6; 95% CI [-2.3, -0.9]). In the middle and late periods, pain scores showed that TPVB, ESPB and INB had superior analgesic effects compared to controls, while SPB did not. CONCLUSIONS: TPVB had the best analgesic efficacy following VATS, though the analgesic efficacy of ESPBs was comparable. However, further studies are needed to determine the optimal regional analgesia technique to improve postoperative pain control following VATS.
Subject(s)
Analgesia , Thoracic Surgery, Video-Assisted , Analgesics, Opioid , Humans , Network Meta-Analysis , Pain, Postoperative/prevention & controlABSTRACT
Intravenous dexamethasone and dexmedetomidine, in conjunction with peripheral nerve blockade, have each been reported to prolong the duration of analgesia. This study tested whether combined use further prolongs analgesia duration after supraclavicular brachial plexus block (BPB) in patients undergoing orthopedic upper extremity surgery. One hundred twenty patients were randomized 1:1:1:1 to Control (saline bolus and midazolam infusion [0.05 mg/kg loading, 20 µg/kg/h thereafter]); DMED (saline bolus and dexmedetomidine infusion [1 µg/kg loading, 0.4 µg/kg/h thereafter]); DEXA (dexamethasone [10 mg] bolus and midazolam infusion); and DMED-DEXA (dexmedetomidine infusion and dexamethasone bolus) groups. The primary outcome was the duration of postoperative analgesia, defined as the time from the end of the BPB to the first dose of analgesia via a patient-controlled device. Median (interquartile range) times to first dose of analgesia in the Control, DMED, DEXA, and DMED-DEXA groups were 8.1 (6.2-11.6), 9.0 (8.1-11.3), 10.7 (8.1-20.5), and 13.2 (11.5-19.1) hours, respectively (p < 0.001). Pairwise comparisons showed significant prolongation of analgesia in the DEXA included groups compared with the non-DEXA included groups (DEXA vs. control, p = 0.045; DEXA vs. DMED, p = 0.045; DMED-DEXA vs. control, p < 0.001; DMED-DEXA vs. DMED, p < 0.001). A mixed effect model showed that dexamethasone was the only significant factor for the prolongation of analgesia (p < 0.001). Intravenous dexamethasone prolonged the analgesia duration of supraclavicular BPB after orthopedic upper extremity surgery. The concurrent use of mild to moderate sedation dose of intravenous dexmedetomidine in addition to intravenous dexamethasone showed no additional benefit to the prolongation of analgesia.
ABSTRACT
Preclinical studies suggest that repeated exposure to anesthetics during a critical period of neurodevelopment induces long-term changes in synaptic transmission, plasticity, and behavior. Such changes are of great concern, as similar changes have also been identified in animal models of neurodevelopmental disorders (NDDs) such as autism. Because of overlapping synaptic changes, it is also possible that anesthetic exposures have a more significant effect in individuals diagnosed with NDDs. Thus, we evaluated the effects of early, multiple anesthetic exposures in BTBR mice, an inbred strain that displays autistic behavior. We discovered that three cycles of sevoflurane anesthesia (2.5%, 1 h) with 2-h intervals between each exposure in late postnatal BTBR mice did not aggravate, but instead improved pathophysiological mechanisms involved with autistic behavior. Sevoflurane exposures restored E/I balance (by increasing inhibitory synaptic transmission), and increased mitochondrial respiration and BDNF signaling in BTBR mice. Most importantly, such changes were associated with reduced autistic behavior in BTBR mice, as sociability was increased in the three-chamber test and repetitive behavior was reduced in the self-grooming test. Our results suggest that anesthetic exposures during neurodevelopment may affect individuals diagnosed with NDDs differently.
ABSTRACT
Costoclavicular brachial plexus block is emerging as a promising infraclavicular approach performed just below the clavicle. However, there are relatively little data regarding the hemidiaphragmatic paralysis (HDP) compared to the commonly performed supraclavicular block. We hypothesized that the incidence of HDP in costoclavicular block is lower than supraclavicular block like classical infraclavicular approach. Eighty patients were randomly assigned to ultrasound-guided supraclavicular (group S) or costoclavicular (group C) block with 25 mL of local anesthetics (1:1 mixture of 1% lidocaine and 0.75% ropivacaine). The primary outcome was the incidence of HDP, defined as less than 20% of fractional change in the diaphragm thickness on ultrasound M-mode. Also, pulmonary function test and chest radiograph were assessed before and after the surgery. The incidence of HDP was 4/35 (11.4%) in the group C and 19/40 (47.5%) in the group S (risk difference, - 36%; 95% CI - 54 to - 17%; P = 0.002). The mean (SD) change of DTF values were 30.3% (44.0) and 56.9% (39.3) in the group C and S, respectively (difference in means, - 26.6%; 95% CI - 45.8 to - 7.4%; P = 0.007). The pulmonary function was more preserved in group C than in group S. The determined diagnostic cut off value of the diaphragm elevation on chest radiograph was 29 mm. Despite the very contiguous location of the two approaches around the clavicle, costoclavicular block can significantly reduce the risk of HDP compared with supraclavicular block.
Subject(s)
Brachial Plexus Block/methods , Diaphragm/pathology , Clavicle/diagnostic imaging , Diaphragm/diagnostic imaging , Humans , Single-Blind Method , Spirometry , UltrasonographyABSTRACT
BACKGROUND: The optimal insertion length for right subclavian vein catheterization in infants has not been determined. This study retrospectively compared landmark-based and linear regression model-based estimation of optimal insertion length for right subclavian vein catheterization in pediatric patients of corrected age < 1 year. METHODS: Fifty catheterizations of the right subclavian vein were analyzed. The landmark related distances were: from the needle insertion point (I) to the tip of the sternal head of the right clavicle (A) and from A to the midpoint (B) of the perpendicular line drawn from the sternal head of the right clavicle to the line connecting the nipples. The optimal length of insertion was retrospectively determined by reviewing post-procedural chest radiographs. Estimates using a landmark-based equation (IA + AB - intercept) and a linear regression model were compared with the optimal length of insertion. RESULTS: A landmark-based equation was determined as IA + AB - 5. The mean difference between the landmark-based estimate and the optimal insertion length was 1.0 mm (95% limits of agreement -18.2 to 20.3 mm). The mean difference between the linear regression model (26.681 - 4.014 × weight + 0.576 × IA + 0.537 × AB - 0.482 × postmenstrual age) and the optimal insertion length was 0 mm (95% limits of agreement -16.7 to 16.7 mm). The difference between the estimates using these two methods was not significant. CONCLUSION: A simple landmark-based equation may be useful for estimating optimal insertion length in pediatric patients of corrected age < 1 year undergoing right subclavian vein catheterization.