Short- and longer-term learning effects from virtual scale endoscopy videos: a useful tool for colorectal lesion size estimation (with video).

BACKGROUND AND AIMS: Accurate assessment of colorectal polyp size is crucial for determining treatment and surveillance policies. However, visual estimation of lesion diameter is often inaccurate, making simple and effective educational tools essential. We aimed to evaluate the learning effects of virtual scale endoscopy (VSE). METHODS: Thirty-three endoscopists first watched pre-learning videos for SET1. They then estimated the diameters of 20 lesions and referred to instructional videos with VSE for self-study. Subsequently, they watched the post-learning videos for SET2 and estimated the lesion diameters. The error between the estimated and correct lesion sizes of both sets was compared. To evaluate longer-term learning effects, participants answered SET3 and SET4, which consisted of the same questions as SET2 and SET1, respectively, 2-3 months later without watching the instructional video for SET2. RESULTS: The error in the participants' estimation of the correct lesion diameter improved from SET1 to SET2 (34.7 mm ± 6.6 vs. 30.7 mm ± 7.7; p = 0.048), with a significant learning effect and error improvement specifically among non-experts (35.2 mm ± 5.3 vs. 30 mm ± 6.8; p = 0.028). In the SET3 and SET4, participants' errors indicated that the learning effect was well maintained (SET2 vs. SET3; 30.7 mm ± 7.7 vs. 28.6 mm ± 7.2; p = 0.1, and SET1 and SET4: 34.7 mm ± 6.6 vs. 31.7 mm ± 7.1; p = 0.025). CONCLUSIONS: VSE videos are a valuable learning tool for estimating lesion diameter, particularly for novice endoscopists, both in the short- and longer-term.

Padding the seat of a wheelchair reduces ischial pressure and improves sitting comfort.

In this study, we aimed to examine whether a wheelchair cushion placed directly atop a sling seat or deflection of the sling seat compensated by a pad along with the placement of a wheelchair cushion changed sitting pressure. Additionally, we examined whether these additions changed sitting comfort. For twenty healthy adults who consented to participate, measurements were taken for three types of cushions, each with and without padding, under six conditions. The cushion types tested included air (cushion A), urethane foam (cushion U), and three-dimensional thermoplastic elastomer (cushion T). A pressure distribution measurement equipment was used for the measurements. Following the measurement, the comfort of the wheelchair cushion was measured. The ischial area pressure of the cushion A pad was significantly lower than that without the pad. Cushions U and T were for ischial area pressure with a pad, resulting in a decreasing trend in ischial area pressure with a pad compared to that without a pad; however, the difference was insignificant. For all cushions, sitting comfort was significantly better in all groups with padding than in those without. In conclusion, ischial pressure can be dispersed by placing a pad on the seat surface of a wheelchair cushion, and pads were suggested to improve sitting comfort for all cushions.

Adverse Events after Different Endoscopic Resection Procedures for Small and Intermediate-Sized Colorectal Polyps.

INTRODUCTION: Cold snare polypectomy (CSP) and underwater endoscopic mucosal resection (UEMR) have been developed recently, in addition to conventional methods, but adverse events of each method have not been fully clarified. We compared the outcomes of each method for the appropriate choice. METHODS: Patients who underwent CSP, endoscopic mucosal resection (EMR)/hot snare polypectomy (HSP), or UEMR for small and intermediate-sized colorectal polyps between April 2017 and June 2020 were retrospectively examined. The rate of adverse events and recurrences due to each method were determined as the main outcomes. Clinical factors related to adverse events were examined. RESULTS: A total of 1,025 patients with 3,163 polyps underwent polypectomy using any of the methods. CSP, EMR/HSP, and UEMR were performed for 704 (22.2%), 2,145 (67.8%), and 314 polyps (9.9%), and the median size for each method was 4, 6, and 7 mm, respectively. Delayed bleeding for CSP, EMR/HSP, and UEMR was 0%, 0.2%, and 0.6% (p = 0.15), and perforation was 0%, 0.1%, and 0%, respectively (p = 0.62). Recurrence after CSP, EMR/HSP, and UEMR was 0.3%, 0.09%, and 1.3%, respectively (p < 0.01). Recurrence for UEMR was significantly higher in the early stage of procedure introduction (p = 0.015). Oral anticoagulants were the risk factor for delayed bleeding (p < 0.01, respectively). CONCLUSION: There was no significant difference regarding adverse events among each method for small and intermediate-sized polyps, although the recurrence rate after UEMR was higher than other methods.

Stability of ischial pressure with 3D thermoplastic elastomer cushion and the characteristics of four types of cushions in pressure redistribution.

Wheelchair cushions are recommended to be used with wheelchair and can protect the buttocks from pain and injury by relieving interface pressure for wheelchair users. However, further investigations are required for proper use in response to the development of new types of wheelchair cushions. The objective of this study was to evaluate physical characteristics of wheelchair cushions by comparing pressure redistributing effects of four types of cushions. The participants were 16 healthy adults who consented to participate in this study. A pressure mapping system (CONFORMat, Nitta Corp.) was used for the measurements. Pressure at ischium was measured immediately after the stabilization of the sitting posture and 10 minutes after. The pressure at ischium significantly decreased with any wheelchair cushions (P < 0.01). A significant negative correlation between body mass index and pressure at ischium was observed without a wheelchair cushion (r = - 0.70), however, the correlation disappeared upon use of a wheelchair cushion. The pressure at ischium increased over time with cushions of urethane, air, and urethane-air hybrid while that with the 3D thermoplastic elastomer cushion did not, and the change in the pressure was statistically less than that in other cushions (P < 0.01). Use of wheelchair cushions was effective in redistribution of the pressure at ischium, and the overtime change in the pressure depends on the type of used cushions.

Utility of Combined Use of Transabdominal Ultrasonography and Fecal Immunochemical Test Examinations in Ulcerative Colitis.

This study examined the utility of the combined use of transabdominal ultrasonography (TUS) and fecal immunochemical testing (FIT) to detect mucosal inflammation, vis-a-vis the Mayo endoscopic subscore (MES), in ulcerative colitis (UC). Sixty-three UC patients who underwent TUS and FIT were retrospectively enrolled. For TUS, the colon was divided into five segments, and the bowel wall thickness was measured and evaluated. The accuracy of FIT (> 100 ng/ml) in detecting mucosal inflammation (MES>0) was 0.93, whereas that of TUS (BWT>2 mm) in each segment was 0.84-0.97. The combined use of TUS and FIT may be helpful in noninvasive treatment strategies.

Regulation of lipid synthesis in myelin modulates neural activity and is required for motor learning.

Brain function relies on both rapid electrical communication in neural circuitry and appropriate patterns or synchrony of neural activity. Rapid communication between neurons is facilitated by wrapping nerve axons with insulation by a myelin sheath composed largely of different lipids. Recent evidence has indicated that the extent of myelination of nerve axons can adapt based on neural activity levels and this adaptive myelination is associated with improved learning of motor tasks, suggesting such plasticity may enhance effective learning. In this study, we examined whether another aspect of myelin plasticity-changes in myelin lipid synthesis and composition-may also be associated with motor learning. We combined a motor learning task in mice with in vivo two-photon imaging of neural activity in the primary motor cortex (M1) to distinguish early and late stages of learning and then probed levels of some key myelin lipids using mass spectrometry analysis. Sphingomyelin levels were elevated in the early stage of motor learning while galactosylceramide levels were elevated in the middle and late stages of motor learning, and these changes were correlated across individual mice with both learning performance and neural activity changes. Targeted inhibition of oligodendrocyte-specific galactosyltransferase expression, the enzyme that synthesizes myelin galactosylceramide, impaired motor learning. Our results suggest regulation of myelin lipid composition could be a novel facet of myelin adaptations associated with learning.

Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study.

BACKGROUND: Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy. METHODS: We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens. RESULTS: Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD. CONCLUSIONS: Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Microglia enable cross-modal plasticity by removing inhibitory synapses.

Cross-modal plasticity is the repurposing of brain regions associated with deprived sensory inputs to improve the capacity of other sensory modalities. The functional mechanisms of cross-modal plasticity can indicate how the brain recovers from various forms of injury and how different sensory modalities are integrated. Here, we demonstrate that rewiring of the microglia-mediated local circuit synapse is crucial for cross-modal plasticity induced by visual deprivation (monocular deprivation [MD]). MD relieves the usual inhibition of functional connectivity between the somatosensory cortex and secondary lateral visual cortex (V2L). This results in enhanced excitatory responses in V2L neurons during whisker stimulation and a greater capacity for vibrissae sensory discrimination. The enhanced cross-modal response is mediated by selective removal of inhibitory synapse terminals on pyramidal neurons by the microglia in the V2L via matrix metalloproteinase 9 signaling. Our results provide insights into how cortical circuits integrate different inputs to functionally compensate for neuronal damage.

Effects of the addition of dexamethasone on postoperative analgesia after anterior cruciate ligament reconstruction surgery under quadruple nerve blocks.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction is an invasive surgical procedure for the knee. Quadruple nerve blocks including continuous femoral nerve block and single-injection sciatic, obturator, and lateral femoral cutaneous nerve blocks can provide effective intraoperative anesthesia and analgesia in the early postoperative period. However, severe pain often appears after the effect of single-injection nerve blocks resolves and that is why we conducted two studies. The first study was to determine whether dexamethasone administered along with local anesthetic for sciatic nerve block could prolong the duration of analgesia in patients given quadruple nerve blocks, including continuous femoral nerve block, for ACL reconstruction using a hamstring tendon autograft. The second study was designed to evaluate any difference in effects from dexamethasone administered perineurally versus intravenously. METHODS: Patients undergoing unilateral arthroscopic ACL reconstruction using a hamstring tendon autograft were enrolled into two studies. The first study was prospectively conducted to see if dexamethasone 4 mg could prolong the duration of analgesia when administered perineurally to the subgluteal sciatic nerve with 0.5% ropivacaine. In the second study, we retrospectively evaluated the effects of intravenous dexamethasone 4 mg as compared with those of perineural dexamethasone to the sciatic nerve block and effects with no dexamethasone. RESULTS: In the first study, perineural dexamethasone prolonged the duration of analgesia by 9.5 h (median duration: 22.5 and 13.0 h with and without perineural dexamethasone, respectively, P = 0.011). In the second study, the duration of analgesia was similarly prolonged for intravenous and perineural dexamethasone compared with no dexamethasone. CONCLUSION: Perineural dexamethasone administered along with local anesthetic for single sciatic nerve block prolonged the duration of analgesia of quadruple nerve blocks for ACL reconstruction, however the effects were not different from those of intravenous dexamethasone. TRIAL REGISTRATION: The protocols of both studies were approved by the Institutional Review Board of Shimane University Hospital, Japan (study number 2821 and 3390 for study 1 and study 2, respectively). Study 1 was registered in University Hospital Medical Information Network Clinical Trials Registry ( UMIN000028930 ). Study 2, which was a retrospective study, was not registered.

Anti-proteinase 3 antineutrophil cytoplasmic antibody reflects disease activity and predicts the response to steroid therapy in ulcerative colitis.

BACKGROUND: Serum anti-proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) is a disease-specific antibody against granulomatosis with polyangiitis. PR3-ANCA is a useful serological marker for disease severity in ulcerative colitis (UC). The purpose of this study was to investigate whether PR3-ANCA levels could also predict the success of induction therapy and to compare its performance against other markers, including serum CRP and fecal hemoglobin. METHODS: This was a multicenter retrospective study. In total, 159 patients with active-phase UC underwent colonoscopy. Disease activity was measured using the Mayo endoscopic subscore (MES). PR3-ANCA positivity and the response to induction therapy, either 5-aminosalicylic acid or steroid, were assessed. PR3-ANCA, CRP, and fecal hemoglobin were measured during the active phase, and during clinical remission. RESULTS: Eighty-five (53.5%) of 159 patients with active UC were positive for PR3-ANCA. PR3-ANCA titers were significantly higher in the group of patients with MES 3 compared to patients with MES 1 (P = 0.002) or MES 2 (P = 0.035). Steroid therapy was administered to 56 patients with a median partial Mayo score of 7 (5-9), which is equivalent to moderate-to-severe disease activity. PR3-ANCA positivity of non-responders to steroid therapy was significantly higher than that of responders (71.9% vs, 41.7%, P = 0.030), whereas CRP and fecal hemoglobin were not predictive of steroid response. Multivariate analysis demonstrated that PR3-ANCA positivity was associated with non-response to steroid therapy (odds ratio 5.19; 95% confidence interval, 1.54-17.5; P = 0.008). Of the 37 patients treated to clinical remission who were also positive for PR3-ANCA during the active phase, 27 had an MES of ≥ 1, and 10 patients had an MES of 0. In clinical remission, the proportion of patients with MES 0 in 17 patients whose PR3-ANCA became negative was significantly higher than that in 20 patients whose PR3-ANCA remained positive (47.1% vs. 10.0%, P = 0.023). CONCLUSIONS: PR3-ANCA not only serves as a marker of disease activity, but also predicts the failure of steroid therapy in moderate-to-severe UC. TRIAL REGISTRATION: This study was retrospectively registered in the UMIN Clinical Trials Registry System (000039174) on January 16, 2020.

An α-synuclein decoy peptide prevents cytotoxic α-synuclein aggregation caused by fatty acid binding protein 3.

α-synuclein (αSyn) is a protein known to form intracellular aggregates during the manifestation of Parkinson's disease. Previously, it was shown that αSyn aggregation was strongly suppressed in the midbrain region of mice that did not possess the gene encoding the lipid transport protein fatty acid binding protein 3 (FABP3). An interaction between these two proteins was detected in vitro, suggesting that FABP3 may play a role in the aggregation and deposition of αSyn in neurons. To characterize the molecular mechanisms that underlie the interactions between FABP3 and αSyn that modulate the cellular accumulation of the latter, in this report, we used in vitro fluorescence assays combined with fluorescence microscopy, transmission electron microscopy, and quartz crystal microbalance assays to characterize in detail the process and consequences of FABP3-αSyn interaction. We demonstrated that binding of FABP3 to αSyn results in changes in the aggregation mechanism of the latter; specifically, a suppression of fibrillar forms of αSyn and also the production of aggregates with an enhanced cytotoxicity toward mice neuro2A cells. Because this interaction involved the C-terminal sequence region of αSyn, we tested a peptide derived from this region of αSyn (αSynP130-140) as a decoy to prevent the FABP3-αSyn interaction. We observed that the peptide competitively inhibited binding of αSyn to FABP3 in vitro and in cultured cells. We propose that administration of αSynP130-140 might be used to prevent the accumulation of toxic FABP3-αSyn oligomers in cells, thereby preventing the progression of Parkinson's disease.

Pain induces stable, active microcircuits in the somatosensory cortex that provide a therapeutic target.

Sustained neuropathic pain from injury or inflammation remains a major burden for society. Rodent pain models have informed some cellular mechanisms increasing neuronal excitability within the spinal cord and primary somatosensory cortex (S1), but how activity patterns within these circuits change during pain remains unclear. We have applied multiphoton in vivo imaging and holographic stimulation to examine single S1 neuron activity patterns and connectivity during sustained pain. Following pain induction, there is an increase in synchronized neuronal activity and connectivity within S1, indicating the formation of pain circuits. Artificially increasing neuronal activity and synchrony using DREADDs reduced pain thresholds. The expression of N-type voltage-dependent Ca2+ channel subunits in S1 was increased after pain induction, and locally blocking these channels reduced both the synchrony and allodynia associated with inflammatory pain. Targeting these S1 pain circuits, via inhibiting N-type Ca2+ channels or other approaches, may provide ways to reduce inflammatory pain.

Incidence and effects of postoperative migration of interscalene catheter tips placed using ultrasound-guided anterior and posterior approaches.

BACKGROUND: Continuous interscalene brachial plexus block (CISB) provides analgesia after shoulder surgery. However, even a catheter securely fixed at the insertion site may be susceptible to migration, precluding the block from working consistently. We examined to see if catheter tip migration would occur with no catheter-at-skin change after anterior and posterior approaches to CISB in patients undergoing shoulder surgery, and compared the incidence rate and pain scores between approaches and between catheters with and without tip migration, respectively. METHODS: Patients were randomly assigned to receive CISB using either anterior or posterior approach. Catheter tip was observed using a cross-sectional view. The rates of catheter tip migration with no catheter-at-skin change at 24 h after the two approaches were calculated and compared, and pain scores were compared between catheters with and without tip migration after each approach. RESULTS: Fifty-four patients were analyzed. Catheter tip migration occurred at 24 h at a similar rate after both approaches (anterior approach 40.7% versus posterior approach 33.3%, p = 0.78). Worst pain score was significantly higher for 24 h in patients whose catheter tip had migrated as compared with those whose catheter had not migrated after anterior (median [IQR] 53 [42-73] versus 18 [0-50], p = 0.003) and posterior approaches (median [IQR] 63 [57-81] versus 29 [3-47], p < 0.0001). CONCLUSION: In patients undergoing shoulder surgery, an interscalene catheter tip can migrate after both anterior and posterior approaches at a similar rate, even if the catheter insertion length is not changed. The tip migration does decrease the analgesic effect of CISB.

Association between cognitive quotient test score and hippocampal volume: a novel, rapid application-based screening tool.

We aimed to develop a brief, preclinical test to screen the reduced hippocampal volume that is a marker of early dementia [Cognitive Quotient (CQ) test]. We performed an observational study of adult subjects who underwent brain MRI in seven institutions from February 2018 to May 2019. The CQ test consists of five components: (1) digits forward, (2) digits backward, (3) Stroop test, (4) simple calculation, and (5) mental rotation. The primary outcome measure was hippocampal volume. We separated the data into derivation (n = 322) and validation cohorts (n = 96). In the derivation cohort, we built two scoring systems using the results of CQ test (model 1 and 2). In the validation cohort, we validated the correlation of the scoring systems with hippocampal volume. In the derivation cohort, there was a moderate correlation between the scoring systems and hippocampal volume [e.g., correlation coefficient = 0.62 in model 1 (95% CI 0.44-0.75)]. Likewise, in the validation cohort, there was a moderate correlation between the scoring systems and hippocampal volume [e.g., correlation coefficient = 0.54 in model 2 (95% CI 0.38-0.67)]. In this analysis of 418 participants, the score of newly developed CQ test was correlated with hippocampal volume.

Erector Spinae Plane Block and Paravertebral Block for Breast Surgery: A Retrospective Propensity-Matched Noninferiority Trial.

PURPOSE: Thoracic paravertebral block (TPVB) is an established analgesic technique for breast surgery although it is technically challenging. Erector spinae plane block (ESPB) requires less technical expertise and may be an alternative to TPVB. However, whether ESPB has similar analgesic effects to TPVB for breast surgery is still inconclusive. Moreover, information on sensory blockade of ESPB is scarce. Accordingly, we conducted this retrospective propensity-matched study to see if ESPB could provide comparable analgesic effects to TPVB in patients undergoing breast surgery. We also compared cutaneous sensory block levels after the two techniques. PATIENTS AND METHODS: In this retrospective cohort study, we analyzed data saved in our database and compared the two techniques using a propensity matching method. The data of patients who underwent unilateral breast surgery under general anesthesia with the addition of either TPVB or ESPB were identified. We considered that the analgesic efficacy of ESPB was noninferior to TPVB if both postoperative fentanyl consumption and area under the curve (AUC) for pain scores within 24 h were within 50 µg and 240 mmï½¥h margins, respectively. Cutaneous sensory block levels, additional analgesic requirements, and complications were also compared between the two groups. RESULTS: Among 93 patients, 30 patients for each group were matched. Both postoperative fentanyl consumption and AUC for pain scores after ESPB were noninferior to those after TPVB. ESPB did not produce sensory blockade consistently, and the number of dermatomes was smaller after ESPB [1 (0-3)] [median (interquartile range)] than after TPVB [4 (2-5)] (P=0.002). No serious complications related to blocks were observed. CONCLUSION: ESPB and TPVB provided comparable postoperative analgesia for 24 h in patients undergoing breast surgery. Dermatomal sensory blockade was, however, less apparent and narrower after ESPB than after TPVB.

Distribution of injectate administered through a catheter inserted by three different approaches to ultrasound-guided thoracic paravertebral block: a prospective observational study.

BACKGROUND: Despite the popularity of continuous thoracic paravertebral block (TPVB), there is a paucity of information on catheter tip position and distribution of injectate through the catheter. We observed, in real time, the spread of dye, the catheter tip position and sensory block levels produced with three different (intercostal (IC), transverse process sagittal (TS) and paralaminar (PL)) approaches to ultrasound-guided TPVB in patients undergoing video-assisted thoracoscopic surgery. METHODS: After the induction of general anesthesia, ultrasound-guided TPVB was conducted with a patient in the lateral decubitus position. During surgery, 10 mL of dye was injected through a catheter to observe the catheter tip and the dye distribution under thoracoscopy. Dermatomal sensory block levels were measured postoperatively. RESULTS: Ten patients for each of three different approaches completed the study. There were a variety of dye spreading patterns. The median (range) number of segmental levels stained with dye was 1.5 (1-4), 3 (1-4) and 3 (1-5) with the IC, TS and PL approaches, respectively. We observed that a catheter tip was present at the same segmental paravertebral space as intended in 50%-90% of patients using these approaches. The median (range) number of dermatomes with sensory blockade at 6 hours after block was 2.5 (1-4), 3 (2-8) and 3 (1-8) with the IC, TS and PL approaches, respectively. CONCLUSIONS: Although a bolus injection through a catheter for ultrasound-guided TPVB produced multiple levels of spread and sensory blockade in more than half the patients, considerable differences existed in the spread regardless of approach.

Empathetic listening boosts nostalgia levels and positive emotions in autobiographical narrators.

Nostalgic memories serve to increase human resilience. Here, we hypothesized that emotional impressions on a narrator's nostalgic memory change depending on the level of empathy in the listener's response. This independent-measures study was conducted in 120 healthy Japanese undergraduates (66 women, 54 men, M age 20.3 ± 1.9 years). Nostalgia was induced using a medley of Japanese pop songs from the years 2006-2010. Thirty minutes later each participant was randomly allocated to be interviewed by an experimenter who applied one of three listening conditions: empathy, non-empathy, or non-response. Output measures were participant's talking time, nostalgia ratings, and positive and negative emotion ratings. Data were analyzed by analysis of variance followed by a multiple comparisons test. Empathy group participants had a significantly longer talking time than non-empathy or non-response participants, higher nostalgia scores than non-response participants, and higher positive emotion scores than non-empathy and non-response participants, but lower negative emotion scores than non-reponse participants. Participants were then divided into a less nostalgia-prone and a more nostalgia-prone group using the Southampton Nostalgia Rating Scale and the data were reanalyzed for each experimental condition. The results showed that a person more prone to nostalgia felt more nostalgic and more positive toward their autobiographical memory than those who are less nostalgia-prone. The present findings have implications for human interaction in everyday life and in therapeutic settings.

Continuous basal infusion versus programmed intermittent bolus for quadratus lumborum block after laparoscopic colorectal surgery: a randomized-controlled, double-blind study.

BACKGROUND: Quadratus lumborum block (QLB) has recently attracted attention as a part of multimodal analgesia after abdominal surgery. It has been shown that programmed intermittent boluses of local anesthetic can produce better analgesia and wider sensory blockade compared with continuous basal infusion with some peripheral nerve blocks. The present study was conducted to see if this theory holds true for QLB in patients undergoing laparoscopic colorectal surgery. METHODS: Fifty patients undergoing laparoscopic colorectal surgery were divided into 2 groups to receive continuous basal infusion (group C) or programmed intermittent boluses (group PIB) of local anesthetic. After surgery, patients received the posterior approach to QLB and a catheter was introduced bilaterally. Patients in group C received a continuous infusion of 0.15% levobupivacaine at 3 ml/h, and those in group PIB received a bolus of 12 ml every 4 h. All patients received intravenous patient-controlled analgesia using fentanyl. Measurements were taken for cumulative fentanyl consumption, pain scores, cutaneous sensory blockade, analgesic requirements, and adverse events for 46 h. RESULTS: The primary outcome of cumulative fentanyl consumption at 22 h showed no significant difference between the groups [group C: 11.9 (11.2-15.5) µg/kg (median (interquartile range)) and group PIB: 12.3 (11.6-15.3), p = 0.473]. Pain scores, demands for rescue analgesics, and spread of cutaneous sensory blockade were similar for the two groups. CONCLUSION: Programmed intermittent boluses of local anesthetic for continuous QLB did not produce better analgesia or wider sensory blockade compared with continuous basal infusion in patients undergoing laparoscopic colorectal surgery.