Recovery of cardiac electrophysiological alterations by heart rate complexity based on multiscale entropy following liver transplantation.

Autonomic nervous dysfunction is a known cardiac sequalae in patients with end-stage liver disease and is associated with a poor prognosis. Heart rate analysis using nonlinear models such as multiscale entropy (MSE) or complexity may identify marked changes in these patients where conventional heart rate variability (HRV) measurements do not. To investigate the application of heart rate complexity (HRC) based on MSE in liver transplantation settings. Thirty adult recipients of elective living donor liver transplantation were enrolled. HRV parameters using conventional HRV analysis and HRC analysis were obtained at the following time points: (1) 1 day before surgery, (2) postoperative day (POD) 7, (3) POD 14, (4) POD 90, and (5) POD 180. Preoperatively, patients with MELD score ≥ 25 had significantly lower HRC compared to patients with lower MELD scores. This difference in HRC disappeared by POD 7 following liver transplantation and subsequent analyses at POD 90 and 180 continued to show no significant difference. Our results indicated a significant negative correlation between HRC based on MSE analysis and liver disease severity preoperatively, which may be more sensitive than conventional linear HRV analysis. HRC in patients with MELD score ≧ 25 improved over time and became comparable to those with MELD < 25 as early as in 7 days.

Efficacy and safety of remifentanil for endoscopic ultrasound-guided tissue acquisition: a single center retrospective study.

BACKGROUND: Remifentanil is a rapid onset and rapid recovery opioid. The combination of remifentanil and propofol for deep sedation decreases the incidents of movement, cough, and hiccup. We evaluated the efficacy and safety of remifentanil during endoscopic ultrasound-guided tissue acquisition. METHODS: We retrospectively reviewed patients in whom endoscopic ultrasound-guided tissue acquisition was performed for solid mass lesions of the upper gastrointestinal tract and adjacent organs. All patients were premedicated with midazolam (2 mg), and target-controlled infusion of propofol, opioid, and Bispectral Index (BIS) monitoring were administered as necessary to maintain moderate-to-deep sedation. The opioids used were a bolus of alfentanil or remifentanil infusion. The discharge time, consumption of propofol and opioid, adverse events, diagnostic accuracy, and sensitivity and specificity for malignancy, were compared. RESULTS: Tissue acquisition was achieved in 123 patients (alfentanil group, n = 64; remifentanil group, n = 59). The discharge time of the remifentanil group (16.5 ± 3.2 min) was significantly shorter than that of the alfentanil group (19.0 ± 4.9 min, P = 0.001). The consumption of propofol, adverse events, diagnostic accuracy, sensitivity, and specificity for malignancy in the alfentanil group were not significantly different from those in the remifentanil group. CONCLUSIONS: Use of alfentanil or remifentanil for target-controlled infusion of propofol-BIS monitoring can provide good sedative and diagnostic quality for endoscopic ultrasound-guided tissue acquisition. However, remifentanil resulted in faster recovery than alfentanil.

Long-term outcomes after nonintubated versus intubated thoracoscopic lobectomy for clinical stage I non-small cell lung cancer: A propensity-matched analysis.

BACKGROUND: Nonintubated thoracoscopic lobectomy has been described as a feasible surgical treatment for early-stage lung cancer since 2011. Despite promising perioperative results, studies on tumor recurrence and long-term survival are very limited. This study was aimed to compare outcomes after thoracoscopic lobectomy with versus without intubation for stage I non-small cell lung cancer. METHODS: A retrospective data set including 115 and 155 patients who underwent nonintubated and intubated thoracoscopic lobectomy, respectively, between January 2011 and December 2013 was used to identify matched nonintubated and intubated cohorts (n = 97 per group) using a propensity score matching algorithm that accounted for confounding effects of preoperative patient variables. Primary outcome variables included freedom from recurrence and overall survival. Factors affecting survival were assessed using Cox regression analysis and Kaplan-Meier survival estimates. RESULTS: No perioperative mortality occurred in both groups. At an average follow-up of 74 months, comparing nonintubated thoracoscopic lobectomy with intubated procedure, no differences were observed in recurrence rates (14.4% vs. 25.8%, respectively; p = .057). Furthermore, no significant differences were noted in overall survival (97.9% vs. 93.8%, respectively; p = .144). Nonintubated thoracoscopic lobectomy was not found to be an independent predictor of recurrence (hazard ratio, .53; 95% confidence interval [CI], .28-1.02) or overall survival (hazard ratio, .33; 95% CI, .07-1.61). CONCLUSION: In this propensity-matched comparison, nonintubated thoracoscopic lobectomy was not associated with an increased risk for recurrence and overall survival during the 5-year follow-up. However, more randomized trials should be conducted for further validation of these results.

Target-controlled propofol infusion with or without bispectral index monitoring of sedation during advanced gastrointestinal endoscopy.

BACKGROUND AND AIM: Target-controlled infusion (TCI) uses averaged pharmacokinetic datasets derived from population samples to automatically control the infusion rate. Bispectral index (BIS) technology non-invasively measures levels of consciousness during surgical procedures. We compared the efficacy and safety of propofol TCI with or without BIS monitoring for sedation during advanced gastrointestinal endoscopy. METHODS: This prospective study enrolled 200 patients who were premedicated with midazolam 2 mg and alfentanil 0.4 mg before undergoing advanced gastrointestinal endoscopy. The initial target blood concentration of propofol was set at 1.0 µg/mL, and adjustments of 0.2 µg/mL were made as necessary to maintain moderate-to-deep sedation. Patients were randomized to either the BIS-blind group and evaluated for depth of anesthesia by monitoring scores of 1-2 on the Modified Observer's Assessment of Alertness/Sedation scale (n = 100) or to the BIS-open group and monitored by BIS scores of 60-80 (n = 100). The primary outcome was the total amount of propofol required to maintain anesthesia. Secondary outcomes were sedation-induced adverse events, recovery, and quality of sedation (endoscopist and patient satisfaction). RESULTS: The mean propofol infusion rate was significantly higher in patients not monitored by BIS scores than in those who were (5.44 ± 2.12 vs 4.76 ± 1.84 mg/kg/h; P = 0.016). Levels of satisfaction were higher for endoscopists who used BIS monitoring than in those who did not. CONCLUSIONS: Mean infusion rates were higher in propofol TCI without BIS monitoring compared with propofol TCI with BIS during advanced gastrointestinal endoscopy. Endoscopists expressed satisfaction with BIS monitoring.

Decreased Parasympathetic Activity of Heart Rate Variability During Anticipation of Night Duty in Anesthesiology Residents.

BACKGROUND: In residency programs, it is well known that autonomic regulation is influenced by night duty due to workload stress and sleep deprivation. A less investigated question is the impact on the autonomic nervous system of residents before or when anticipating a night duty shift. In this study, heart rate variability (HRV) was evaluated as a measure of autonomic nervous system regulation. METHODS: Eight residents in the Department of Anesthesiology were recruited, and 5 minutes of electrocardiography were recorded under 3 different conditions: (1) the morning of a regular work day (baseline); (2) the morning before a night duty shift (anticipating the night duty); and (3) the morning after a night duty shift. HRV parameters in the time and frequency domains were calculated. Repeated measures analysis of variance was performed to compare the HRV parameters among the 3 conditions. RESULTS: There was a significant decrease of parasympathetic-related HRV measurements (high-frequency power and root mean square of the standard deviation of R-R intervals) in the morning before night duty compared with the regular work day. The mean difference of high-frequency power between the 2 groups was 80.2 ms (95% confidence interval, 14.5-146) and that of root mean square of the standard deviation of R-R intervals was 26 milliseconds (95% confidence interval, 7.2-44.8), with P = .016 and .007, respectively. These results suggest that the decrease of parasympathetic activity is associated with stress related to the condition of anticipating the night duty work. On the other hand, the HRV parameters in the morning after duty were not different from the regular workday. CONCLUSIONS: The stress of anticipating the night duty work may affect regulation of the autonomic nervous system, mainly manifested as a decrease in parasympathetic activity. The effect of this change on the health of medical personnel deserves our concern.

Sample entropy analysis of EEG signals via artificial neural networks to model patients' consciousness level based on anesthesiologists experience.

Electroencephalogram (EEG) signals, as it can express the human brain's activities and reflect awareness, have been widely used in many research and medical equipment to build a noninvasive monitoring index to the depth of anesthesia (DOA). Bispectral (BIS) index monitor is one of the famous and important indicators for anesthesiologists primarily using EEG signals when assessing the DOA. In this study, an attempt is made to build a new indicator using EEG signals to provide a more valuable reference to the DOA for clinical researchers. The EEG signals are collected from patients under anesthetic surgery which are filtered using multivariate empirical mode decomposition (MEMD) method and analyzed using sample entropy (SampEn) analysis. The calculated signals from SampEn are utilized to train an artificial neural network (ANN) model through using expert assessment of consciousness level (EACL) which is assessed by experienced anesthesiologists as the target to train, validate, and test the ANN. The results that are achieved using the proposed system are compared to BIS index. The proposed system results show that it is not only having similar characteristic to BIS index but also more close to experienced anesthesiologists which illustrates the consciousness level and reflects the DOA successfully.

Relationship of abdominal circumference and trunk length with spinal anesthesia level in the term parturient.

BACKGROUND: We hypothesized that body shape metrics influence the anatomy of spinal canal and intraabdominal pressure in three dimensions. We explored the effects of abdominal circumference, trunk length, and their combination on the level of spinal anesthesia in the term parturient in this study. METHODS: Thirty term parturients, ASA class I-II, from 20 to 41 years of age, scheduled for cesarean section were enrolled in this observational study. Abdominal circumference (AC) and trunk length (TL) were recorded preoperatively. Spinal anesthesia was performed with 10 mg 0.5% hyperbaric bupivacaine at the L4-L5 intervertebral space in all parturients. Correlation between maximal sensory spinal anesthesia level and physical parameters was analyzed with Spearman rank correlation coefficients. The calculated r value was compared with r = 0 with p < 0.05 as the significant level. The prediction power of these physical parameters for spinal level was evaluated by prediction probability. RESULTS: The parameter TL/AC2 was statistically correlated with maximal sensory level (Spearman correlation coefficient, -0.45 with p < 0.02). The prediction probability of TL/AC2 for the dermatomal level was P K = 0.685. If the dermatomal levels were lumped as higher (above T2) and lower (below T3) levels, the prediction probability of TL/AC2 was as high as P K = 0.856. CONCLUSIONS: TL/AC2, which simulated the ratio of the long axis and transection area of the abdomen, was correlated with maximal spinal level, and parturients with low TL/AC2 values tended to have higher dermatomal levels during spinal anesthesia.

Surveillance and vaccine effectiveness of an influenza epidemic predominated by vaccine-mismatched influenza B/Yamagata-lineage viruses in Taiwan, 2011-12 season.

INTRODUCTION: The 2011-12 trivalent influenza vaccine contains a strain of influenza B/Victoria-lineage viruses. Despite free provision of influenza vaccine among target populations, an epidemic predominated by influenza B/Yamagata-lineage viruses occurred during the 2011-12 season in Taiwan. We characterized this vaccine-mismatched epidemic and estimated influenza vaccine effectiveness (VE). METHODS: Influenza activity was monitored through sentinel viral surveillance, emergency department (ED) and outpatient influenza-like illness (ILI) syndromic surveillance, and case-based surveillance of influenza with complications and deaths. VE against laboratory-confirmed influenza was evaluated through a case-control study on ILI patients enrolled into sentinel viral surveillance. Logistic regression was used to estimate VE adjusted for confounding factors. RESULTS: During July 2011-June 2012, influenza B accounted for 2,382 (72.5%) of 3,285 influenza-positive respiratory specimens. Of 329 influenza B viral isolates with antigen characterization, 287 (87.2%) were B/Yamagata-lineage viruses. Proportions of ED and outpatient visits being ILI-related increased from November 2011 to January 2012. Of 1,704 confirmed cases of influenza with complications, including 154 (9.0%) deaths, influenza B accounted for 1,034 (60.7%) of the confirmed cases and 103 (66.9%) of the deaths. Reporting rates of confirmed influenza with complications and deaths were 73.5 and 6.6 per 1,000,000, respectively, highest among those aged ≥65 years, 50-64 years, 3-6 years, and 0-2 years. Adjusted VE was -31% (95% CI: -80, 4) against all influenza, 54% (95% CI: 3, 78) against influenza A, and -66% (95% CI: -132, -18) against influenza B. CONCLUSIONS: This influenza epidemic in Taiwan was predominated by B/Yamagata-lineage viruses unprotected by the 2011-12 trivalent vaccine. The morbidity and mortality of this vaccine-mismatched epidemic warrants careful consideration of introducing a quadrivalent influenza vaccine that includes strains of both B lineages.

Coronary artery dissection in a patient with traumatic femoral shaft fracture.

We report a 24-year-old man who developed postoperative pulmonary edema and desaturation, after open reduction with internal fixation for left femoral shaft fracture sustained in a motorcycle accident. Cardiac catheterization revealed a left anterior descending coronary artery dissection. Review of his present history, showed that he neither had chest discomfort nor suffered from hemodynamic decompensation preoperatively. Only the abnormal 12-lead ECG with moderate tachycardia was suggestive of myocardial ischemia. Coronary artery dissection, although uncommon, is a disastrous complication following blunt chest trauma, and needs thorough preoperative evaluation to exclude its occurrence.

Upper airway obstruction after cervical spine fusion surgery: role of cervical fixation angle.

Upper airway obstruction is one of the life-threatening events in cervical spine surgery. The risk is particularly great during the period immediately after operation. We present the case of a 56-year-old female with breast cancer and metastasis to the cervical spine. The surgical procedure involved C2-C3 laminectomy, posterior fixation (C0-C5), and C2 neurectomy. Tracheal extubation was carried out in the intensive care unit, and upper airway obstruction immediately followed. Emergency cricothyrotomy was performed under well-managed ventilation with a laryngeal mask after several failed intubation attempts. Over-flexion of the cervical spine fixation and severe prevertebral soft tissue swelling were the most probable causes of upper airway obstruction. With a well-adjusted angle for fixation of the cervical spine under fluoroscopic guidance before the procedure, such a surgical mishap could be avoided. Reintubation with a fiberscope might be considered first, and sustaining intubation for 2-3 days postoperatively could be safer in such high risk patients.

Analgesic effect of lidocaine patch 5% in the treatment of acute herpes zoster: a double-blind and vehicle-controlled study.

BACKGROUND AND OBJECTIVES: Although lidocaine patch 5% has been widely used for postherpetic neuralgia, its analgesic effect on the intense pain associated with acute herpes zoster has not been investigated because of its potential hazard to damaged skin. METHODS: Forty-six patients suffering from moderate to severe pain caused by acute herpes zoster infection (within 4 weeks of onset) were enrolled in a randomized, double-blind, vehicle-controlled, parallel study. Lidocaine patch 5% or vehicle patch were applied to the intact portion of the painful skin area without blisters at 12-hour intervals twice a day for 2 consecutive days. Analgesic efficacy and side effect profiles were assessed before and 48 hours after patch application. RESULTS: We found that both groups of patients experienced significant pain relief during rest and movement. Differences of mean reduction of pain intensity between the two groups were 14.7 (4.7-24.8, P = 0.005) during rest and 10.4 (1.6-19.3, P = 0.007) during movement, favoring the lidocaine patch. The lidocaine patch produced a greater percentage change in a patient's global impression than the vehicle patch. The incidence and severity of adverse events were low with both treatments. CONCLUSIONS: This study demonstrates that lidocaine patch 5%, applied twice a day, could serve as a well tolerated and effective modality to relieve moderate to severe pain associated with acute herpes zoster presumably through its pharmacological action and physical barrier effect on sensitized skin.

Using a short-term parameter of heart rate variability to distinguish awake from isoflurane anesthetic states.

The measurement of anesthetic depth is important in anesthesiology. Although heart rate variability (HRV) is profoundly affected by general anesthesia, it has not yet been commonly used in this field. One of the reasons is the lack of suitable parameters of HRV for short-term observations. In this study, we designed a time domain parameter of HRV named the similarity index. It was based on observing the trend of the distribution of instantaneous heart rates as time moved. Taking epochs of ECG data as short as 64 s can derive the index. We observed the values of this index of 30 patients when they were awake and under isoflurane anesthesia. The values had very little overlapping between the two states and the prediction probability to distinguish the two states was 0.91. We suggest that HRV, if suitably treated, can play more roles in the monitoring of anesthetic depth.

Heart rate variability characterization in daily physical activities using wavelet analysis and multilayer fuzzy activity clustering.

A portable data recorder was developed to parallel measure the electrocardiogram and body accelerations. A multilayer fuzzy clustering algorithm was proposed to classify the physical activity based on body accelerations. Discrete wavelet transform was incorporated to retrieve time-varying characteristics of heart rate variability under different physical activities. Nine healthy subjects were included to investigate activity-related heart rate variability during 24 h. The results showed that the heartbeat fluctuations in high frequencies were the greatest during lying and the smallest during standing. Moreover, very-low-frequency heartbeat fluctuations during low activity level (lying) were greater than during high activity level (nonlying).

Acute cardiovascular collapse after pericardial drainage in a patient with aortic dissection.

Proximal aortic dissection is frequently associated with cardiac tamponade. The treatment sometimes is difficult. We present a 69-year-old female patient who after repeated episodes of syncope received an open drainage of pericardial effusion that ended in a fatal outcome. She was also known to have mural thrombi in the aorta. However, preanesthetic trransesophageal echocardiography revealed besides pericardial effusion, also dilatation of aortic root which compressed both atria. She developed sudden cardiovascular collapse following drainage of pericardial effusion to which she succumbed in spite of vigorous resuscitation. We suggest that the patients with cardiac tamponade complicated by aortic dissection must receive direct aortic repair together with intraoperative pericardial drainage. Selective or single pericardiocentesis should better be avoided.

Successful living-related renal transplantation in a 2-year-old girl weighing less than 10 kilograms.

The success of renal transplantation for infants weighing less than 10 kg is very limited because of graft thrombosis. We report a successful living-related renal transplant in a 2-year-old girl weighing 9.5 kg. Chronic renal failure was diagnosed 1 month before the transplantation. Laparoscopic donor nephrectomy was performed to retrieve the left kidney of her father, a 36-year-old man weighing 70 kg, and the recipient operation was conducted via a right retroperitoneal approach. The right native kidney of the recipient was removed to accommodate the graft kidney during the transplant surgery. The graft renal artery, renal vein, and ureter were anastomosed to the recipient abdominal aorta, inferior vena cava, and bladder, respectively. The abdominal fascial defect was closed with absorbable mesh grafting, and the skin was closed primarily. With intensive fluid therapy and monitoring after reperfusion of the graft kidney, the patient recovered uneventfully and was discharged with an FK506-based immunosuppressive regimen 2 weeks after the operation. Renal function was good, and serum creatinine was 0.5 mg/dL 6 months after the operation.