Practical strategies for the prevention and management of chronic postsurgical pain

Chronic postsurgical pain (CPSP) is a multifactorial condition that affects a significant proportion of patients undergoing surgery. The prevention and management of CPSP require the identification of preoperative risk factors to screen high-risk patients and establish appropriate perioperative pain management plans to prevent its development. Active postoperative pain management should be provided to prevent CPSP in patients with severe pain following surgery. These tasks have become important for perioperative team members in the management of CPSP. This review article provides a comprehensive overview of the latest research on the role of perioperative team members in preventing and managing CPSP. Additionally, it highlights practical strategies that can be employed in clinical practice, covering the definition and risk factors for CPSP, including preoperative, intraoperative, and postoperative factors, as well as a risk prediction model. The article also explores various treatments for CPSP, as well as preventive measures, including preemptive analgesia, regional anesthesia, pharmacological interventions, psychoeducational support, and surgical technique modification. This article emphasizes the importance of a comprehensive perioperative pain management plan that includes multidisciplinary interventions, using the transitional pain service as an example. By adopting a multidisciplinary and collaborative approach, perioperative team members can improve patient outcomes, enhance patient satisfaction, and reduce healthcare costs. However, further research is necessary to establish targeted interventions to effectively prevent and manage CPSP.

Retrospective analysis of the incidence and predictors of postoperative nausea and vomiting after orthopedic surgery under spinal anesthesia / 대한마취과학회지

Background@#Postoperative nausea and vomiting (PONV) commonly occurs after spinal anesthesia; however, its incidence rate and predictors have been scarcely studied. Therefore, we aimed to investigate its incidence rate and potential predictors. @*Methods@#The electronic medical records of 6,610 consecutive patients undergoing orthopedic surgery under spinal anesthesia were reviewed between January 2016 and December 2020. The primary outcome was PONV incidence within 24 h after spinal anesthesia. Along with its incidence rate, we investigated its predictors using multivariable logistic regression analysis. @*Results@#Among the 5,691 patients included in the analysis, 1,298 (22.8%) experienced PONV within 24 h after spinal anesthesia. Female sex (odds ratio [OR]: 3.23, 95% CI [2.72, 3.83], P < 0.001), nonsmoker (OR: 2.12, 95% CI [1.46, 3.07], P < 0.001), history of PONV (OR: 1.52, 95% CI [1.26, 1.82], P < 0.001), prophylactic 5-hydroxytryptamine receptor antagonist use (OR: 0.35, 95% CI [0.24, 0.50], P < 0.001), prophylactic steroid use (OR: 0.53, 95% CI [0.44, 0.62], P < 0.001), baseline heart rate ≥ 60 beats/min (OR: 1.38, 95% CI [1.10, 1.72], P = 0.005), and postoperative opioid use (OR: 2.57, 95% CI [1.80, 3.67], P < 0.001), were significant predictors of the primary outcome. @*Conclusions@#Our study showed the common incidence of PONV after spinal anesthesia and its significant predictors. A better understanding of its predictors may provide important information for its management.

Retrospective analysis of the feasibility and safety of external jugular vein cannulation in surgical patients

Establishing intravenous (IV) access is an essential procedure in surgical patients. External jugular vein (EJV) cannulation can be a good alternative for patients forwhom it is difficult to establish peripheral IV access. We aimed to investigate the feasibilityand safety of EJV cannulation in surgical patients.Methods: We performed a retrospective review of EJV cannulation in patients who underwent anesthesia for surgery at a tertiary hospital between 2010 and 2021. We collectedclinical characteristics, including EJV cannulation-related variables, from the anesthetic records. We also investigated the EJV cannulation-related complications, which included anyEJV cannulation-related complications (insertion site swelling, infection, thrombophlebitis,pneumothorax, and arterial cannulation) within 7 days after surgery, from the electronicmedical records during the hospitalization period for surgery.Results: We analyzed 9,482 cases of 9,062 patients for whom EJV cannulation was performed during anesthesia. The most commonly performed surgery was general surgery(49.6%), followed by urologic surgery (17.5%) and obstetric and gynecologic surgery (15.7%).Unplanned EJV cannulation was performed emergently during surgery for 878 (9.3%) cases.The only EJV cannulation-related complication was swelling at the EJV-cannula insertion site(65 cases, 0.7%). There was only one case of unplanned intensive care unit admission dueto swelling related to EJV cannulation.Conclusions: Our study showed the feasibility and safety of EJV cannulation for surgical patients with difficult IV access or those who need additional large-bore IV access during surgery. EJV cannulation can provide safe and reliable IV access with a low risk of major complications in a surgical patient.

Effect of postoperative non-steroidal anti-inflammatory drugs on anastomotic leakage after pancreaticoduodenectomy / 대한마취과학회지

Background@#Although the association between an increase in anastomotic leakage (AL) and non-steroidal anti-inflammatory drugs (NSAIDs) has been reported in gastrointestinal surgeries, this issue has rarely been addressed for pancreaticoduodenectomy (PD). We aimed to investigate the association between postoperative NSAIDs administration and clinically relevant AL (CR-AL) following PD. @*Methods@#We retrospectively evaluated 2,163 consecutive patients who underwent PD between 2007 and 2019. The patients were divided into two groups; patients who received and did not receive NSAIDs by postoperative day (POD) 5. We conducted a propensity score analysis using inverse probability of treatment weighting (IPTW) to adjust the baseline differences between both groups. We compared the occurrence of CR-AL and other postoperative outcomes before and after IPTW. Further, we used the multivariable binary logistic regression method for a sensitivity analysis for CR-AL. @*Results@#A total of 2,136 patients were included in the analysis. Of these, 222 (10.4%) received NSAIDs by POD 5. The overall occurrence rate of CR-AL was 14.9%. After IPTW, postoperative NSAIDs were significantly associated with CR-AL (odds ratio [OR]: 1.24, 95% CI [1.05, 1.47], P = 0.012), prolonged postoperative hospitalization (OR: 1.31, 95% CI [1.14, 1.50], P < 0.001), and unplanned readmission within 30 days postoperatively (OR 1.48: 95% CI [1.15, 1.91], P = 0.002). However, this association was not consistent in the sensitivity analysis. @*Conclusions@#Postoperative NSAIDs use was significantly associated with an increase in CR-AL incidence following PD. However, sensitivity analysis failed to show its association, which precludes a firm conclusion of its detrimental effect.

Analysis of endotracheal intubation-related judicial precedents in South Korea / 대한마취과학회지

Background@#Medical malpractice during endotracheal intubation can result in catastrophic complications. However, there are no reports on these severe complications in South Korea. We aimed to investigate the severe complications associated with endotracheal intubation occurring in South Korea, via medicolegal analysis. @*Methods@#We retrospectively analyzed the closed judicial precedents regarding complications related to endotracheal intubation lodged between January 1994 and June 2020, using the database of the Supreme Court of Korea. We collected clinical and judicial characteristics from the judgments and analyzed the medical malpractices related to endotracheal intubation. @*Results@#Of 220 potential cases, 63 were included in the final analysis. The most common event location was the operating room (n = 20, 31.7%). All but 3 cases were associated with significant permanent or more severe injury, including 31 deaths. The most common problems were failed or delayed intubation (n = 56, 88.9%). Supraglottic airway device was used in 5.2% (n = 3) cases of delayed or failed intubation. Fifty-one (81%) cases were ruled in favor of the plaintiff in the claims for damages, with a median payment of Korean Won 133,897,845 (38,000,000, 308,538,274). The most common malpractice recognized by the court was that of not attempting an alternative airway technique (n = 32, 50.8%), followed by violation of the duty of explanation (n = 10, 15.9%). @*Conclusion@#Our results could increase physicians’ awareness of the major complications related to endotracheal intubation and help ensure patient safety.

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery

Objective@#: Accurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. @*Methods@#: We enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. @*Results@#: The mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88–0.96|). @*Conclusion@#: C2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.

Effect of epidural polydeoxyribonucleotide in a rat model of lumbar foraminal stenosis

Background@#We aimed to investigate the effect of epidural polydeoxyribonucleotide (PDRN) on mechanical allodynia and motor dysfunction in a rat model of lumbar foraminal stenosis (LFS). @*Methods@#This study was conducted in two stages, using male Sprague-Dawley rats. The rats were randomly divided into eight groups. In the first stage, the groups were as follows: vehicle (V), sham (S), and epidural PDRN at 5 (P5), 8 (P8), and 10 (P10) mg/kg; and in the second stage, they were as follows: intraperitoneal PDRN 8 mg/kg, epidural 3,7-dimethyl-1-propargilxanthine (DMPX) (0.1 mg/kg), and DMPX (0.1 mg/kg). The LFS model was established, except for the S group. After an epidural injection of the test solutions, von Frey and treadmill tests were conducted for 3 weeks. Subsequently, histopathologic examinations were conducted in the V, S, P5, and P10 groups. @*Results@#A total of 65 rats were included. The P8 and P10 groups showed significant recovery from mechanical allodynia and motor dysfunction at all time points after drug administration compared to the V group. These effects were abolished by concomitant administration of DMPX. On histopathological examination, no epineurial inflammation or fibrosis was observed in the epidural PDRN groups. @*Conclusions@#Epidural injection of PDRN significantly improves mechanical allodynia and motor dysfunction in a rat model of LFS, which is mediated by the spinal adenosine A2A receptor. The present data support the need for further research to determine the role of epidural PDRN in spinal stenosis treatment.

Physiologic Cervical Alignment Change between Cervical Spine X-ray and Computed Tomography

Objective@#: The purpose of this study was to investigate the correlations among various radiological parameters used to determine cervical alignment from cervical spine radiographs (X-CS) and cervical spine computed tomography (CT-CS), both within and between modalities. @*Methods@#: This study included 168 patients (≤60 years old) without a definite whole spine deformity who underwent CT-CS and X-CS. We measured occipital slope (O-s), C1 slope, C2 slope, C7 slope, sella turcica - C7 sagittal vertical axis (StC7-SVA), spinocranial angle, T1 slope, and C27-SVA. We calculated the O-C2 angle, O-C7 angle, and C2-7 angle from the measured parameters and conducted correlation analyses among multiple parameters. @*Results@#: The intrinsic correlation features among multiple cervical parameters were very similar for both X-CS and CT-CS. The two SVA parameters (C27-SVA and StC7-SVA) were mainly influenced by the upper cervical slope parameters (r=|0.13–0.74|) rather than the lower slope cervical parameters (r=|0.08–0.13|). The correlation between X-CS and CT-CS for each radiological parameter was statistically significant (r=0.26–0.44) except for O-s (r=0.10) and StC7-SVA (r=0.11). @*Conclusion@#: The correlation patterns within X-CS and CT-CS were very similar in this study. The correlation between X-ray and CT was statistically significant for most radiological parameters, and the correlation score increased when the horizontal gaze was consistently maintained. The lower cervical parameters were not statistically associated with translation-related parameters (C2-7 SVA and StC7-SVA). Therefore, the upper cervical segment may be a better predictor for determining head and neck translation.

Physiologic Cervical Alignment Change between Cervical Spine X-ray and Computed Tomography

Objective@#: The purpose of this study was to investigate the correlations among various radiological parameters used to determine cervical alignment from cervical spine radiographs (X-CS) and cervical spine computed tomography (CT-CS), both within and between modalities. @*Methods@#: This study included 168 patients (≤60 years old) without a definite whole spine deformity who underwent CT-CS and X-CS. We measured occipital slope (O-s), C1 slope, C2 slope, C7 slope, sella turcica - C7 sagittal vertical axis (StC7-SVA), spinocranial angle, T1 slope, and C27-SVA. We calculated the O-C2 angle, O-C7 angle, and C2-7 angle from the measured parameters and conducted correlation analyses among multiple parameters. @*Results@#: The intrinsic correlation features among multiple cervical parameters were very similar for both X-CS and CT-CS. The two SVA parameters (C27-SVA and StC7-SVA) were mainly influenced by the upper cervical slope parameters (r=|0.13–0.74|) rather than the lower slope cervical parameters (r=|0.08–0.13|). The correlation between X-CS and CT-CS for each radiological parameter was statistically significant (r=0.26–0.44) except for O-s (r=0.10) and StC7-SVA (r=0.11). @*Conclusion@#: The correlation patterns within X-CS and CT-CS were very similar in this study. The correlation between X-ray and CT was statistically significant for most radiological parameters, and the correlation score increased when the horizontal gaze was consistently maintained. The lower cervical parameters were not statistically associated with translation-related parameters (C2-7 SVA and StC7-SVA). Therefore, the upper cervical segment may be a better predictor for determining head and neck translation.

Arthroscopic Procedure in the Treatment of Chronic Lateral Ankle Instability / 대한족부족관절학회지

The open Broström procedure is considered the surgery of choice for treating chronic lateral ankle instability. The role of arthroscopy has gained popularity in the surgical treatment of chronic lateral ankle instability, partly for the ability to manage the intra-articular pathology combined with ankle instability. Arthroscopic techniques can be divided broadly into the arthroscopic-assisted Broström technique and arthroscopic all-inside ligament repair. The clinical results of these arthroscopic techniques are similar to open procedures. The arthroscopic technique may be an excellent alternative to the open Broström procedure in treating chronic lateral ankle instability when applying the appropriate indications.

Effect of epidural polydeoxyribonucleotide in a rat model of lumbar foraminal stenosis

Background@#We aimed to investigate the effect of epidural polydeoxyribonucleotide (PDRN) on mechanical allodynia and motor dysfunction in a rat model of lumbar foraminal stenosis (LFS). @*Methods@#This study was conducted in two stages, using male Sprague-Dawley rats. The rats were randomly divided into eight groups. In the first stage, the groups were as follows: vehicle (V), sham (S), and epidural PDRN at 5 (P5), 8 (P8), and 10 (P10) mg/kg; and in the second stage, they were as follows: intraperitoneal PDRN 8 mg/kg, epidural 3,7-dimethyl-1-propargilxanthine (DMPX) (0.1 mg/kg), and DMPX (0.1 mg/kg). The LFS model was established, except for the S group. After an epidural injection of the test solutions, von Frey and treadmill tests were conducted for 3 weeks. Subsequently, histopathologic examinations were conducted in the V, S, P5, and P10 groups. @*Results@#A total of 65 rats were included. The P8 and P10 groups showed significant recovery from mechanical allodynia and motor dysfunction at all time points after drug administration compared to the V group. These effects were abolished by concomitant administration of DMPX. On histopathological examination, no epineurial inflammation or fibrosis was observed in the epidural PDRN groups. @*Conclusions@#Epidural injection of PDRN significantly improves mechanical allodynia and motor dysfunction in a rat model of LFS, which is mediated by the spinal adenosine A2A receptor. The present data support the need for further research to determine the role of epidural PDRN in spinal stenosis treatment.

Experience of essay during the clinical clerkship in emergency medicine and inter-rater reliability on essay

Objective@#An essay test is difficult to carry out because of the effort for hand scoring and the concerns about inter-rater reliability, even though the use of a rubric can increase inter-rater reliability. This study examined the feasibility of an essay test in medical school students and whether the use of a rubric increases inter-rater reliability. @*Methods@#An essay test was given to 51 undergraduate students in the third grade of emergency medicine clinical clerkship. Three raters assessed the essay test independently with a prepared rubric immediately after the test. They then did the same essay test without a rubric three months later. The researchers compared the Pearson’s correlation coefficients between raters. The researchers analyzed the validity comparing the correlation coefficient between the essay test and previous multiple-choice questions (MCQ) and feasibility by acceptance. @*Results@#Fifty-one students took the essay test. The Pearson’s correlation coefficient using rubric between raters 1 and 2, 1 and 3, and 2 and 3 were 0.898 (P<0.001), 0.896 (P<0.001), and 0.856 (P<0.001), respectively. Without a rubric, the correlation coefficients were 0.838 (P<0.001), 0.888 (P<0.001), and 0.824 (P<0.001), respectively. The new essay test showed a positive correlation (0.367) with the previous MCQ, and the evidence for validity and feasibility was acceptable. @*Conclusion@#In this study, the rubric did not increase the inter-rater reliability of the essay test. On the other hand, the inter-rater reliability was higher than 0.8, even without a rubric. In addition, the essay test showed evidence of validity and feasibility.

Complex regional pain syndrome in the young male population: a retrospective study of 200 Korean young male patients / 대한통증학회지

BACKGROUND: The aim of this study was to investigate the clinical characteristics of complex regional pain syndrome (CRPS) in young male patients in South Korea, especially focusing on the association with military service. METHODS: From January 2007 to May 2017, we investigated the electronic medical records of 430 consecutive patients, aged 18 to 30 years, who visited Seoul National University Hospital Pain Center, with a suspected diagnosis of CRPS at the initial visit. The following patient details were available for analysis: demographic and disease-related variables, relevance to military service, medications, and the treatment modalities received. RESULTS: Out of 430 patients, 245 (57.0%) were diagnosed with CRPS, of which, 200 were male patients and 45 were female patients. Of the male patients, 95 (47.5%) developed CRPS during military service. CRPS during military service was more likely to result from sprain/strain, and the incidence of CRPS was significantly higher in the lower extremities in patients from the military service group than in those from the non-military service group. During the follow-up period, 37.9% of male CRPS patients (n = 61/161) were treated successfully. Patients with moderate to severe initial pain intensity, and diagnosed during their military service, showed better outcomes. CONCLUSIONS: Our results demonstrated that manifestation of CRPS in the young Korean population was more common in male and among those male CRPS patients, about half the cases developed during the military service period.

Effectiveness of continuous hypertonic saline infusion with an automated infusion pump for decompressive neuroplasty: a randomized clinical trial / 대한통증학회지

BACKGROUND: Hypertonic saline (HS) injections for decompressive neuroplasty (DN) can cause pain. We assessed whether a continuous infusion of HS through an infusion pump would reduce injection-related pain compared with repeated bolus administrations. METHODS: Fifty patients scheduled for DN were randomized to either the bolus injection or the continuous infusion group. After appropriately placing the epidural catheter, 4 mL of 5% NaCl was injected as four boluses of 1 mL each at 15-minute intervals or infused over 1 hour using an infusion pump. The severity of pain induced by HS injection, as measured by the 11-point numerical rating scale (NRS), was the primary outcome. The severity of low back or lower extremity pain, as measured by the 11-point NRS and Oswestry Disability Index (ODI), 3 months following the procedure, was the secondary outcome. RESULTS: Data from 21 patients in the bolus group and 23 in the continuous infusion group were analyzed. No statistically significant difference in injection-related pain was identified between the two groups during the initial HS administration (P = 0.846). However, there was a statistically significant reduction in injection-related pain in the continuous infusion group compared to the bolus injection group from the second assessment onwards (P = 0.001, < 0.001, and < 0.001, respectively). No significant between-group differences in the NRS and ODI scores 3 months post-procedure were noted (P = 0.614 and 0.949, respectively). CONCLUSIONS: Our study suggests that administering HS through a continuous infusion is a useful modality for reducing HS injection-related pain during DN.

Long-Term Survival Analysis of Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: This study evaluated the long term clinical and radiographic results and the survival rates of unicompartmental knee arthroplasty (UKA). In addition, the factors affecting the survival of the procedure were analyzed and the survival curve was compared according to the affecting factors. MATERIALS AND METHODS: Ninety-nine cases of UKA performed between December 1982 and January 1996 were involved: 10 cases with Modular II, 44 cases with Microloc, and 45 cases with Allegretto prostheses. The mean follow-up period was 16.5 years. Clinically, the hospital for special surgery (HSS) scoring system and the range of motion (ROM) were evaluated. Radiographically, the femorotibial angle (FTA) was measured. The survival rate was analyzed using the Kaplan–Meier method. Cox regression analysis was used to identify the factors affecting the survival according to age, sex, body mass index, preoperative diagnosis, and type of implant. The Kaplan–Meier survival curves were compared according to the factors affecting the survival of UKA. RESULTS: The overall average HSS score and ROM was 57.7 and 134.3° preoperatively, 92.7 and 138.4° at 1 year postoperatively, and 79.1 and 138.4° at the last follow-up (p<0.001, respectively). The overall average FTA was varus 0.8° preoperatively, valgus 4.1° at postoperative 2 weeks, and valgus 3.0° at the last follow-up. The overall 5-, 10-, 15- and 20-year survival rates were 91.8%, 82.9%, 71.0%, and 67.0%, respectively. The factors affecting the survival were the age and type of implant. The risk of the failure decreased with age (hazard ratio=0.933). The Microloc group was more hazardous than the other prostheses (hazard ratio=0.202, 0.430, respectively). The survival curve in the patients below 60 years of age was significantly lower than those of the patients over 60 years of age (p=0.003); the survival curve of the Microloc group was lower compared to the Modular II and Allegretto groups (p=0.025). CONCLUSION: The long-term clinical and radiographic results and survival of UKA using old fixed bearing prostheses were satisfactory. The selection of appropriate patient and prosthesis will be important for the long term survival of the UKA procedure.

Biportal Endoscopic Spinal Surgery for Lumbar Intervertebral Disc Herniation / 대한정형외과학회잡지

Herniation of the intervertebral disc is a medical disease manifesting as a bulging out of the nucleus pulposus or annulus fibrosis beyond the normal position. Most lumbar disc herniation cases have a favorable natural course. On the other hand, surgical intervention is reserved for patients with severe neurological symptoms or signs, progressive neurological symptoms, cauda equina syndrome, and those who are non-responsive to conservative treatment. Numerous surgical methods have been introduced, ranging from conventional open, microscope assisted, tubular retractor assisted, and endoscopic surgery. Among them, microscopic discectomy is currently the standard method. Biportal endoscopic spinal surgery (BESS) has several merits over other surgical techniques, including separate and free handling of endoscopy and surgical instruments, wide view of the surgical field with small skin incisions, absence of the procedure of removing fog from the endoscope, and lower infection rate by continuous saline irrigation. In addition, existing arthroscopic instruments for the extremities and conventional spinal instruments can be used for this technique and surgery for recurred disc herniation is applicable because delicate surgical procedures are performed under a brightness of 2,700 to 6,700 lux and a magnification of 28 to 35 times. Therefore, due to such advantages, BESS is a novel technique for the surgical treatment of lumbar disc herniation.

Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis

Biportal endoscopic spinal surgery (BESS) is a minimally invasive spinal surgery, which is basically similar to microscopic spinal surgery in terms of the use of floating technique and technically similar to conventional percutaneous endoscopic spinal surgery in terms of the use of endoscopic or arthroscopic instruments. Using two independent portals (viewing and working) and maintaining a certain distance from the bony and neural structures allow closer access to the target lesion through a panoramic view by free handling of the scope and instruments rather than through a fixed view by docking into the Kambin's triangle. Minimally invasive surgery allows for reduced dissection and inevitable muscle injury, preserving stability and reducing risks of restabilization. The purpose of fusion surgery is the same as that of the three surgical techniques stated above. Its wider range of view helps to overcome limitations of conventional endoscopic spinal surgery and to supplement the weak points of microscopic spinal surgery, such as limited working space in a tubular retractor and difficulty in accessing the contralateral area. This technique provides an alternative to unilateral or bilateral decompression of lumbar central spinal stenosis, foraminal stenosis, low-grade spondylolisthesis, and adjacent segment degeneration. Early clinical outcomes are promising despite potential for complications, such as dural tearing and postoperative epidural hematoma, similar to other procedures. Merits of BESS include decreased postoperative infection rate due to continuous irrigation throughout the procedure and decreased need for fusion surgery for one- or two-level lumbar stenosis by wide sublaminar and foraminal decompression with minimal sacrifice of stabilizing structures.

Bacteremia caused by Leuconostoc species : 6-case series / 고신대학교의과대학학술지

Leuconostoc species are Gram-positive coccobacilli and are used in dairy products and are intrinsically resistant to vancomycin. Leuconostoc infections are rare in humans, usually occurring in immune-compromised patients. We describe 6 patients with Leuconostoc bacteremia at Dong-A university hospital between 1990 and 2015. One isolate (L. lactis) was identified to species level using 16S rRNA gene sequencing analysis. All patients had underlying diseases and 5 patients underwent procedures that interrupted the normal integumentary defense. Four patients died within 30 days after being identified as carrying Leuconostoc species.

Prevalence of unrecognized depression in patients with chronic pain without a history of psychiatric diseases

BACKGROUND: We aimed to investigate the prevalence of unrecognized depression in patients with chronic pain, but with no history of psychiatric diseases. METHODS: Patients with chronic pain who did not have a history of psychiatric disease were selected for this study. The Beck Depression Index (BDI) was used to evaluate depression. Participants' socio-demographic characteristics and pain-related characteristics were also recorded. RESULTS: The study included 94 consecutive patients with chronic pain (28 men and 66 women). Based on the BDI scores, 33/94 (35.1%) patients with chronic pain had comorbid depression. The prevalence of depression was significantly higher in our cohort than it was in the general population (P < 0.001). The standardized incidence ratio, adjusted for age and sex, was 2.77 in men and 2.60 in women. Patients who were unmarried (odds ratio [OR] = 3.714, P = 0.044), and who had subjective sleep disturbance (OR = 8.885, P < 0.001), were more likely to have moderate to severe depression. Patients with high education levels (OR = 0.244, P = 0.016), and who were economically active (OR = 0.284, P = 0.023), were less likely to have moderate to severe depression. CONCLUSIONS: Our results indicate that unrecognized depression in patients with chronic pain is common. Therefore, pain physicians should actively seek to identify these problems rather than relying on the patient to volunteer such information.

Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model / 대한구급학회지

BACKGROUND: Unilateral lung hyperinflation develops in lungs with asymmetric compliance, which can lead to vital instability. The aim of this study was to investigate the respiratory dynamics and the effect of airway diameter on the distribution of tidal volume during mechanical ventilation in a lung model with asymmetric compliance. METHODS: Three groups of lung models were designed to simulate lungs with a symmetric and asymmetric compliance. The lung model was composed of two test lungs, lung1 and lung2. The static compliance of lung1 in C15, C60, and C120 groups was manipulated to be 15, 60, and 120 ml/cmH₂O, respectively. Meanwhile, the static compliance of lung2 was fixed at 60 ml/cmH₂O. Respiratory variables were measured above (proximal measurement) and below (distal measurement) the model trachea. The lung model was mechanically ventilated, and the airway internal diameter (ID) was changed from 3 to 8 mm in 1-mm increments. RESULTS: The mean ± standard deviation ratio of volumes distributed to each lung (VL1/VL2) in airway ID 3, 4, 5, 6, 7, and 8 were in order, 0.10 ± 0.05, 0.11 ± 0.03, 0.12 ± 0.02, 0.12 ± 0.02, 0.12 ± 0.02, and 0.12 ± 0.02 in the C15 group; 1.05 ± 0.16, 1.01 ± 0.09, 1.00 ± 0.07, 0.97 ± 0.09, 0.96 ± 0.06, and 0.97 ± 0.08 in the C60 group; and 1.46 ± 0.18, 3.06 ± 0.41, 3.72 ± 0.37, 3.78 ± 0.47, 3.77 ± 0.45, and 3.78 ± 0.60 in the C120 group. The positive end-expiratory pressure (PEEP) of lung1 was significantly increased at airway ID 3 mm (1.65 cmH₂O) in the C15 group; at ID 3, 4, and 5 mm (2.21, 1.06, and 0.95 cmH₂O) in the C60 group; and ID 3, 4, and 5 mm (2.92, 1.84, and 1.41 cmH₂O) in the C120 group, compared to ID 8 mm (P < 0.05). CONCLUSIONS: In the C15 and C120 groups, the tidal volume was unevenly distributed to both lungs in a positive relationship with lung compliance. In the C120 group, the uneven distribution of tidal volume was improved when the airway ID was equal to or less than 4 mm, but a significant increase of PEEP was observed.