Feasibility of adjunct facial motor evoked potential monitoring to reduce the number of false-positive results during cervical spine surgery

OBJECTIVE

False-positive intraoperative muscle motor evoked potential (mMEP) monitoring results due to systemic effects of anesthetics and physiological changes continue to be a challenging issue. Although control MEPs recorded from the unaffected side are useful for identifying a true-positive signal, there are no muscles on the upper or lower extremities to induce control MEPs in cervical spine surgery. Therefore, this study was conducted to clarify if additional MEPs derived from facial muscles can feasibly serve as controls to reduce false-positive mMEP monitoring results in cervical spine surgery.

METHODS

Patients who underwent cervical spine surgery at the authors' institution who did not experience postoperative neurological deterioration were retrospectively studied. mMEPs were induced with transcranial supramaximal stimulation. Facial MEPs (fMEPs) were subsequently induced with suprathreshold stimulation. The mMEP and subsequently recorded fMEP waveforms were paired during each moment during surgery. The initial pair was regarded as the baseline. A significant decline in mMEP and fMEP amplitude was defined as > 80% and > 50% decline compared with baseline, respectively. All mMEP alarms were considered false positives. Based on 2 different alarm criteria, either mMEP alone or both mMEP and fMEP, rates of false-positive mMEP monitoring results were calculated.

RESULTS

Twenty-three patients were included in this study, corresponding to 102 pairs of mMEPs and fMEPs. This included 23 initial and 79 subsequent pairs. Based on the alarm criterion of mMEP alone, 17 false-positive results (21.5%) were observed. Based on the alarm criterion of both mMEP and fMEP, 5 false-positive results (6.3%) were observed, which was significantly different compared to mMEP alone (difference 15.2%; 95% CI 7.2%-23.1%; p < 0.01).

CONCLUSIONS

fMEPs might be used as controls to reduce false-positive mMEP monitoring results in cervical spine surgery.

Neutrophil-to-lymphocyte ratio as indicator to severe complication after pancreaticoduodenectomy or distal pancreatectomy

BACKGROUND

Pancreaticoduodenectomy and distal pancreatectomy are complex procedures with high rates of post-operative complications. We evaluated the factors associated with post-operative complications, focusing on pre-operative hematologic markers such as the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and prognostic nutritional index.

METHODS

Data from patients (≥age 20) who underwent pancreaticoduodenectomy or distal pancreatectomy between January 2013 and December 2017 at a Japanese tertiary hospital were retrospectively reviewed. Patients who failed to complete the operation and those who underwent additional procedure were excluded. The primary outcome was reoperation and unplanned intensive care unit admission before first discharge, and secondary outcome was the length of hospital stay. Multivariate analysis was used to identify explanatory factors associated with post-operative complications. The differences in length of hospital stay were compared with the Mann-Whitney U test.

RESULTS

Of 238 eligible patients, 208 with a median age of 71 years were included in the analysis. The median values [1st interquartile range, 3rd interquartile range] of the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and prognostic nutritional index were 2.65 [1.69, 4.04], 247 [146, 407], and 46.0 [42.0, 49.7], respectively. Eleven patients (5.3%) experienced post-operative complications. The neutrophil-to-lymphocyte ratio (odds ratio, 1.13; 95% confidence interval, 1.02-1.26; P = 0.03) and blood loss volume (odds ratio per 100 mL, 1.11; 95% confidence interval, 1.00-1.22; P = 0.039) were independently associated with post-operative complications. Post-operative complications contributed to longer hospital stays (19 [15, 28] vs 33 [22, 65] days, P = 0.005).

CONCLUSION

The neutrophil-to-lymphocyte ratio and blood loss volume were significantly associated with post-operative complications, leading to prolonged hospitalization.

Transient Augmentation of Intraoperative Motor Evoked Potentials During Middle Cerebral Artery Aneurysm Surgery

OBJECTIVE

To study clinical significance of augmentation of intraoperative motor evoked potentials (MEPs) during direct open surgery for middle cerebral artery (MCA) aneurysms.

METHODS

Between 2009 and 2017, 134 MCA aneurysm surgeries were performed with intraoperative MEP monitoring. The frequency and cause of augmentation with >50% increase of MEP amplitude from baseline were studied. Factors associated with MEP augmentation were investigated.

RESULTS

MEP augmentation was demonstrated in 9 patients. All 9 events were observed just after application of the temporary clip to the parent artery. The ratio of the maximum amplitude to baseline was 2.6 ± 1.1 at an mean of 2.4 ± 1.1 minutes after parent artery occlusion. Ten patients who did not show MEP augmentation after parent artery occlusion were compared with the patients showing MEP augmentation. The distance of the temporary clip point from the midline was smaller in patients with MEP augmentation compared with patients without MEP augmentation (P = 0.033).

CONCLUSIONS

MEP augmentation was thought to be an early ischemic sign preceding a significant decrease in MEPs during MCA aneurysm surgery. Transient augmentation of MEPs was more frequently observed in cases with a temporary clip applied to the more proximal part of the MCA.

Morphine inhibits cell viability and growth via suppression of vascular endothelial growth factor in human oral cancer HSC-3 cells

PURPOSE

Although many oral cancer patients require opioids, the effects of morphine and related drugs on oral cancer progression have not been well established. Thus, we examined the effects of morphine exposure on the viability of human oral squamous carcinoma HSC-3 cells and aimed to identify the underlying mechanism.

METHODS

We exposed HSC-3 cells to the various concentrations of morphine (0, 0.1, 1, 10, 100, or 1000 μmol/L) for 48 h and, subsequently, evaluated cell viability using the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay and cytotoxicity using the lactate dehydrogenase (LDH) assay. To explore the effects of morphine on cell proliferation further, colony formation assay and cell cycle analysis were performed. Additionally, the intracellular expression of nuclear factor kappa B (NF-κB) was analyzed using flow cytometry, and vascular endothelial growth factor (VEGF)-A was evaluated using human VEGF assay.

RESULTS

Morphine exposure reduced cell viability and enhanced cytotoxicity in HSC-3 cells in a concentration-dependent manner. The number of colonies in the morphine-treated groups was significantly lower than that in the control group. Consistent with these results, morphine exposure significantly reduced the concentration of VEGF in the cell culture medium in a concentration-dependent manner. However, our data show that morphine at clinical concentrations (0.1-10 μmol/L) does not affect cell cycle and apoptosis.

CONCLUSIONS

Our results suggest that in human oral cancer HSC-3 cells, morphine exposure inhibits cell viability and growth via suppression of VEGF in clinical conditions.

Postoperative intensive care unit admission does not affect outcomes in elective surgical patients with severe comorbidity

OBJECTIVE

The impact of postoperative intensive care upon patient outcomes was evaluated by retrospectively investigating the rate of poor outcomes among miscellaneous elective surgical patients with severe comorbidities.

DESIGN

A retrospective cohort study was carried out.

SETTING

University hospital.

PATIENTS

Surgical patients with severe comorbidities.

INTERVENTION

The outcomes of 1218 surgical patients treated in intensive care units (ICUs) and postsurgical wards (ICU group vs. non-ICU group) were reviewed for poor outcomes (i.e., no discharge or death). A propensity score analysis was used to generate 248 matched pairs of ICU-admitted patients and controls.

VARIABLES OF INTEREST

Poor outcome rates on postoperative day 90 and mortality on postoperative days 30 and 90.

RESULTS

No significant between-group differences were observed in terms of poor outcomes on postoperative day 90 [ICU vs. non-ICU: 33/248 (13%) vs. 28/248 (11%), respectively; ICU odds ratio (OR): 1.19, 95% confidence interval (CI), 0.71-2.01, p=0.596] or in between-group differences in terms of mortality on postoperative days 30 and 90 [ICU vs. non-ICU: 4/248 (1.6%) vs. 2/248 (0.8%) on postoperative day 30 and 5/248 (2.0%) vs. 3/248 (1.2%) on day 90, respectively; ICU OR (95% CI), 2.00 (0.37-10.9) and 1.67 (0.40-6.97) for postoperative 30- and 90-day mortality, respectively (p=0.683 and 0.724)]. Low preoperative body weight was negatively correlated to patient outcomes [OR (95% CI): 0.82/10kg (0.70-0.97), p=0.019], whereas regional analgesia combined with general anesthesia was positively correlated to patient outcomes [OR (95% CI): 0.39 (0.69-0.96), p=0.006]. Extra ICU admission was correlated to poor patient outcomes [OR (95% CI): 4.18 (2.23-7.81), p < 0.0001].

CONCLUSIONS

Postoperative ICU admission failed to demonstrate any meaningful benefits in patients with severe comorbidities undergoing miscellaneous elective surgeries.

A case of thoracic pneumatosis due to severe coughs and tracheal tube displacement induced by tracheal tube size mismatch

Background

Thoracic pneumatosis during mechanical ventilation may be life-threatening. We encountered a patient with thoracic pneumatosis after frequent displacement of the tracheal tube with an overinflated cuff.

Case presentation

We admitted a 62-year-old man to the intensive care unit (ICU) due to respiratory failure. We secured his airway using a cuffed 8.5-mm tracheal tube. However, air leakage did not stop with the regular intracuff pressure (25 cm H₂O) because the diameter of his trachea was too large for the tracheal tube inserted. In addition, a chest X-ray examination revealed rostral tube displacement. Therefore, we applied a higher intracuff pressure (35 cm H₂O) to prevent air leakage and tracheal tube movement. However, severe coughing episodes developed, and 3 days after ICU admission, a chest X-ray and CT scan revealed pneumomediastinum and pneumothorax. We did not have larger tracheal tubes in stock. We decided to use a tracheostomy tube instead, which we expected to be placed securely and to prevent tube displacement. After tracheostomy, the severe coughing episodes became infrequent. Finally, we weaned the patient from mechanical ventilation 12 days after ICU admission.

Conclusions

The clinical signs and symptoms in our patient point to tracheal tube size mismatch as the cause of pneumothorax.

Clinical Utility of Intraoperative Motor-Evoked Potential Monitoring to Prevent Postoperative Spinal Cord Injury in Thoracic and Thoracoabdominal Aneurysm Repair: An Audit of the Japanese Association of Spinal Cord Protection in Aortic Surgery Database

BACKGROUND

Spinal cord ischemic injury is the most devastating sequela of descending and thoracoabdominal aortic surgery. Motor-evoked potentials (MEPs) have been used to intraoperatively assess motor tract function, but it remains unclear whether MEP monitoring can decrease the incidence of postoperative motor deficits. Therefore, we reviewed multicenter medical records of patients who had undergone descending and thoracoabdominal aortic repair (both open surgery and endovascular repair) to assess the association of MEP monitoring with postoperative motor deficits.

METHODS

Patients included in the study underwent descending or thoracoabdominal aortic repair at 12 hospitals belonging to the Japanese Association of Spinal Cord Protection in Aortic Surgery between 2000 and 2013. Using multivariable mixed-effects logistic regression analysis, we investigated whether intraoperative MEP monitoring was associated with postoperative motor deficits at discharge after open and endovascular aortic repair.

RESULTS

We reviewed data from 1214 patients (open surgery, 601 [49.5%]; endovascular repair, 613 [50.5%]). MEP monitoring was performed in 631 patients and not performed in the remaining 583 patients. Postoperative motor deficits were observed in 75 (6.2%) patients at discharge. Multivariable logistic regression analysis revealed that postoperative motor deficits at discharge did not have a significant association with MEP monitoring (adjusted odds ratio [OR], 1.13; 95% confidence interval [CI], 0.69-1.88; P = .624), but with other factors: history of neural deficits (adjusted OR, 6.08; 95% CI, 3.10-11.91; P < .001), spinal drainage (adjusted OR, 2.14; 95% CI, 1.32-3.47; P = .002), and endovascular procedure (adjusted OR, 0.45; 95% CI, 0.27-0.76; P = .003). The sensitivity and specificity of MEP <25% of control value for motor deficits at discharge were 37.8% (95% CI, 26.5%-49.5%) and 95.5% (95% CI, 94.7%-96.4%), respectively.

CONCLUSIONS

MEP monitoring was not significantly associated with motor deficits at discharge.

Association Between Motor-Evoked Potentials and Spinal Cord Damage Diagnosed With Magnetic Resonance Imaging After Thoracoabdominal and Descending Aortic Aneurysm Repair

OBJECTIVES

The authors investigated the association between intraoperative motor-evoked potential (MEP) changes and the severity of spinal cord infarction diagnosed with magnetic resonance imaging (MRI) to clarify the discrepancy between them, which was observed in patients with postoperative motor deficits after thoracic and thoracoabdominal aortic surgery.

DESIGN

A multicenter retrospective study.

SETTING

Motor-evoked potential <25% of control values was deemed positive for spinal cord ischemia. The severity of spinal cord infarction was categorized into grades A to D based on previous studies using the most severe axial MRI slices. The associations between MRI grade, MEP changes, and motor deficits were examined using logistic regression.

PARTICIPANTS

Twenty-three of 1,245 patients (from 1999 to 2013, at 12 hospitals in Japan) were extracted from medical records of patients who underwent thoracic and thoracoabdominal aortic repair, with intraoperative MEP examinations and postoperative spinal MRI.

INTERVENTIONS

No intervention (observational study).

MEASUREMENTS AND MAIN RESULTS

Motor-evoked potential <25% of control value was associated significantly with motor deficits at discharge (adjusted odds ratio [OR], 130.0; p = 0.041), but not with severity of spinal cord infarction (adjusted OR, 0.917; p = 0.931). Motor deficit at discharge was associated with severe spinal cord infarction (adjusted OR, 4.83; p = 0.043), MEP <25% (adjusted OR, 13.95; p = 0.031), and combined deficits (motor and sensory, motor and bowel or bladder, or sensory and bowel or bladder deficits; adjusted OR, 31.03; p = 0.072) in stepwise logistic regression analysis.

CONCLUSION

Motor-evoked potential <25% was associated significantly with motor deficits at discharge, but not with the severity of spinal cord infarction.

Bite injuries caused by transcranial electrical stimulation motor-evoked potentials' monitoring: incidence, associated factors, and clinical course

PURPOSE

The incidence of bite injuries associated with transcranial electrical stimulation motor-evoked potentials monitoring reportedly ranges from 0.13 to 0.19%. However, in clinical practice, bite injuries appear to occur more frequently than previously reported. Our aim was to identify the incidence of and perioperative risk factors associated with bite injuries caused by transcranial electrical stimulation motor-evoked potential monitoring.

METHODS

Patients who underwent elective surgery with transcranial electrical stimulation motor-evoked potential monitoring at a single tertiary hospital in Japan between June 2017 and December 2017 were included in this study. All patients were assessed by oral surgeons preoperatively and postoperatively. The associated factors with bite injuries were explored by the univariate analysis.

RESULTS

12 of 186 patients experienced 13 bite injuries, including three lip, six oral mucosa, and four tongue injuries. No patient required suture repair. 11 of 12 patients had uneventful postoperative courses and were cured within 12 postoperative days. One patient with a tongue ulcer and a hematoma had difficulty in oral intake and persistent dysgeusia. Patient severe movement during transcranial electrical stimulation motor-evoked potential monitoring was associated with bite injuries (p = 0.03).

CONCLUSIONS

The incidence of bite injuries assessed by oral surgeons was 6.5% in patients with transcranial electrical stimulation motor-evoked potential monitoring, and the patients with severe movement during the monitoring tended to incur bite injuries. In rare cases, transcranial electrical stimulation motor-evoked potential monitoring may cause difficulty in oral intake and dysgeusia.

Factors associated with anesthetic satisfaction after cesarean delivery under neuraxial anesthesia

Introduction

Evaluating patient satisfaction with anesthesia is critical for improving their experiences. We investigated perioperative anesthetic satisfaction and associated predictive factors in patients receiving cesarean delivery under neuraxial anesthesia (spinal anesthesia only or combined spinal-epidural anesthesia).

Methods

This was an institutionally approved retrospective chart review of patients who received cesarean delivery under spinal anesthesia and postoperative evaluation administered by anesthesiologists from January 2009 to December 2013. Multiple pregnancies and patients reporting headache prior to cesarean delivery were excluded. Patients were divided into satisfied and not satisfied groups according to their scores from the 4-point Likert scale. Multivariate analysis was used to identify explanatory factors associated with satisfaction.

Results

Of 813 patients enrolled, 425 (52.2%) were classified as satisfied. Combined spinal–epidural anesthesia (CSEA) (odds ratio, 3.3; 95% confidence interval, 1.08–10.1) was positively associated with satisfaction. Paresthesia during needle insertion (odds ratio, 0.56; 95% confidence interval, 0.42–0.76), lightning pain during neuraxial anesthesia (odds ratio 0.62; 95% confidence interval, 0.39–0.98), failed block (odds ratio 0.28; 95% confidence interval, 0.09–0.87), and intraoperative use of antiemetic (odds ratio 0.71; 95% confidence interval, 0.53–0.94) were negatively associated with satisfaction. In the 792 patients receiving spinal anesthesia only, the same factors except for CSEA were associated with satisfaction.

Conclusions

The addition of epidural to spinal anesthesia for cesarean delivery can increase patient satisfaction, whereas paresthesia during needle insertion, lightning pain, failed block, and the use of intraoperative antiemetic were major obstacles to patient satisfaction.

[A Case of Granulocyte-Colony Stimulating Factor Producing Esophageal Carcinoma]

The patient was a 42-year-old man who presented with dysphagia.Upper gastrointestinal endoscopy revealed a protruding lesion in the lower thoracic esophagus.Pathological analysis of the lesion showed squamous cell carcinoma.Laboratory data showed leukocytosis(21,200/mL)despite no evidence of infection, and the serum levels of granulocyte colony-stimu- lating factor(G-CSF)were elevated to 283 pg/mL.We diagnosed him with esophageal squamous cell carcinoma(Lt, type 1, cT4N4M0, cStage IV a).After administering 2 courses of docetaxel plus cisplatin plus S-1(DCS)as neoadjuvant chemotherapy, the patient underwent surgery.The pathological diagnosis was pType 2, T2, N4, M0, pStage IV a. G-CSF immunostaining was positive in tumor cells.After the surgery, the number of leukocytes and serum G-CSF levels decreased to within normal limits.Adjuvant chemotherapy was administered.

Amiodarone does not affect brain injury in a rat model of transient forebrain ischemia

OBJECTIVES

Although amiodarone may cause neurotoxicity that can affect patient outcomes when used during cardiopulmonary resuscitation (CPR), it has been commonly prescribed during CPR. This study investigated the possible neurotoxic effects of amiodarone in a rat model of transient forebrain ischemia.

DESIGN

A prospective laboratory animal study was carried out.

SETTING

Animal laboratory.

MATERIALS

Male Sprague-Dawley rats.

INTERVENTION

Eight minutes of forebrain ischemia was induced in rats by bilateral carotid occlusion and hypotension (mean arterial pressure=35mmHg) under isoflurane (1.5%) anesthesia. Amiodarone (0, 50, 100 and 150mg/kg) with saline was injected intraperitoneally 10min after ischemia. Rats given 0mg/kg of amiodarone were used as saline-treated controls. Sham operated rats received no treatment.

VARIABLES OF INTEREST

Animals were evaluated neurologically on postoperative days 4-7, and histologically after a one-week recovery period.

RESULTS

The greatest improvement in water maze test performance corresponded to the sham operated group (p=0.015 vs. saline-treated controls). No differences in performance were seen in amiodarone-treated rats compared with saline-treated controls. In the control group, 45% of the CA1 hippocampal neurons survived, compared with 78% in the sham operated group (p=0.009). Neuron survival after ischemia in the amiodarone treatment groups (50, 100 and 150mg/kg) (58%, 40% and 36%, respectively) and in the control rats did not differ significantly.

CONCLUSIONS

The administration of amiodarone immediately after transient forebrain ischemia did not worsen spatial cognitive function or neuronal survival in the hippocampal CA1 region in rats. The current results must be applied with caution in humans. However, they indicate that the potential neurotoxicity induced by amiodarone during resuscitation after cardiac arrest may be negligible.

The unnecessary application of central venous catheterization in surgical patients

Background and objectives

Methods

Results

Conclusions

Transforaminal vs Interlaminar Epidural Steroid Injection for Acute-Phase Shingles: A Randomized, Prospective Trial

BACKGROUND

The acute phase of shingles is characterized by severe pain, and one of the complications of shingles known as postherpetic neuralgia (PHN) is associated with prolonged pain. Although factors predicting the development of PHN, as well as its preventative measures, have been investigated, there is no single treatment effective for PHN. Some studies showed effectiveness of epidural injection to alleviate pain associated with acute-phase shingles. In these studies, epidural injection was performed by interlaminar (IL) approach. However, transforaminal (TF) approach may be more effective as it enables injection of steroids and local anesthetics closer to the dorsal root ganglion where inflammation primarily occurs. There have not been any studies comparing the analgesic effects of epidural injection approaches for pain associated with acute-phase shingles.

OBJECTIVE

We compared the analgesic effects of IL and TF epidural injection approaches for pain associated with acute-phase shingles.

STUDY DESIGN

We conducted a randomized prospective trial.

SETTING

Nara Medical University Hospital, Department of Anesthesiology.

METHODS

Forty patients with acute-phase shingles were randomly assigned to receive epidural steroid injections by TF or IL approaches. Patients were evaluated at the baseline, as well as at 1 month and 3 months after the treatment using the VAS and SF-36 scores. Patients with VAS score of over 40 at the 3-month follow-up were considered as having PHN, and the number of patients with PHN was compared between the IL and TF groups.

RESULTS

Except the mental component of the SF-36 score and severity of skin rash, patient characteristics were not significantly different between the groups. VAS scores at 1 and 3-month follow-up were significantly lower than those at the baseline, and there was no difference between the groups. All SF-36 scores were not significantly different between groups at 1- and 3-month. There was no significant difference in the occurrence of PHN between the groups.

LIMITATIONS

We had a small sample size that did not reach the number of patients needed by the power analysis in the study. Then, our follow-up period of 3 months was relatively short.

CONCLUSIONS

VAS scores, the SF-36 RCS and MCS scores improved in both groups, however, there was no difference in the analgesic effects of the IL and TF epidural steroid injections at 1 and 3 months for acute-phase shingles patients.

KEY WORDS

Shingles epidural steroid injection interlaminar approach; transforaminal approach, fluoroscopic, postherpetic neuralgia, VAS, SF-36.