Diagnostic Role of Conventional Ultrasonography and Shearwave Elastography in Asymptomatic Patients with Diffuse Thyroid Disease: Initial Experience with 57 Patients

Purpose

Thyroid ultrasonography (US) is a useful diagnostic tool in the evaluation of diffuse thyroid disease (DTD), whereas shearwave elastography is a dynamic technique that can provide information about tissue hardness by using acoustic shearwaves remotely induced by a focused ultrasonic beam. This study aims at investigating the role of conventional US and shearwave elastography in the diagnosis of asymptomatic patients with DTD.

Materials and Methods

Fifty-seven patients who underwent both conventional US and shearwave elastography were included in this study. Interobserver variability of the three radiologists in assessment of underlying thyroid echogenicity on conventional US was analyzed. Diagnostic performances for diagnosing DTD on conventional US and shearwave elastography were calculated and compared.

Results

Fair agreement was observed in the identification of DTD with conventional US (kappa value=0.27). The area under the receiver operating characteristic curve (A_z) were 0.52-0.585 on conventional US by three radiologists. The A_z values when using the mean and maximum elasticity values as a diagnostic criteria for DTD were 0.619 and 0.59 on shearwave elastography. Patients with DTD showed higher mean [24.1±10 kilo-Pascals (kPa)] and maximum (36.4±13.3 kPa) elasticity values on shearwave elastography when compared to the normal group (23.4±10.8 kPa and 33.7±12.4 kPa, respectively), although without statistical significance (p=0.802 and p=0.452, respectively).

Conclusion

Conventional US did not show reliable interobserver agreement in the diagnosis of DTD. Although not statistically significant, shearwave elastography may provide additional information in the diagnosis of DTD. Therefore, larger prospective studies are needed to define the values of shearwave elastography for diagnosing DTD.     

The Influence of Hypothermia on Transfusion Requirement in Patients Who Received Clopidogrel in Proximity to Off-Pump Coronary Bypass Surgery

Purpose

Hypothermia adversely affects the coagulation that could be of clinical significance in patients receiving clopidogrel. We evaluated the influence of hypothermia on transfusion requirements in patients undergoing isolated off-pump coronary artery bypass surgery (OPCAB) who continued clopidogrel use within 5 days of surgery.

Materials and Methods

Protocol-based, prospectively entered data of 369 patients were retrospectively reviewed. The time-weighted average of intraoperative temperatures and the temperature upon ICU admission (TWA-temp) was assessed. Patients were divided into normothermia (≥36℃, n=224) and hypothermia (<36℃, n=145) group. The transfusion requirement for perioperative blood loss was assessed and compared.

Results

Patients with hypothermia were older and had lower body surface area (BSA) than patients with normothermia. Age and BSA adjusted transfusion requirement was significantly larger in the hypothermia group [patients requiring transfusion: 64% versus 48%, p=0.003; number of units: 0 (0-2) units versus 2 (0-3) units, p=0.002]. In multivariate analysis of predictors of perioperative multiple transfusion requirements, hypothermia was identified as an independent risk factor along with age, female gender, BSA, chronic kidney disease, and congestive heart failure.

Conclusion

Hypothermia was associated with increased transfusion requirement in patients undergoing OPCAB who received clopidogrel in proximity to surgery. Considering the high prevalence and the possibility of hypothermia being a modifiable risk factor, aggressive measures should be undertaken to maintain normothermia in those patients.     

Thyroid Nodules with Macrocalcification: Sonographic Findings Predictive of Malignancy

Purpose

To analyze which sonographic features of thyroid nodules with macrocalcifications were predictable of thyroid malignancy.

Materials and Methods

We reviewed sonographic findings of 854 macrocalcified thyroid nodules in patients who underwent fine needle aspiration biopsy between December 2009 and January 2011. There were 171 non-diagnostic aspirations, 34 nodules with category 3, 4, 5 based on Bethesda system, which were not confirmed by surgery, and these nodules were excluded from the analysis. Sonographic characteristics of the macrocalcifications including its thickness, interruption, and existence of soft tissue rim outside the macrocalcification were analyzed. Other sonographic characteristics of nodules such as shape, margin, composition, echo pattern, vascularity, and underlying parenchymal echogenicity were also evaluated. The correlation of sonographic features with cytopathologic results and the diagnostic performance of sonographic features for the prediction of malignancy were analyzed.

Results

Among 649 nodules, 179 (27.6%) nodules were malignant and 470 (72.4%) nodules were benign. Among the features of the macrocalcification, interruption, irregular thickness, or the presence of soft tissue outside calcification rim were associated with malignancy (p<0.001). A high sensitivity and negative predictive values for the prediction of malignancy was found in sonographic characteristics of irregular thickness (92.2% and 91.0%, respectively) and the presence of soft tissue (88.5% and 88.8%, respectively).

Conclusion

Sonographic characteristics of macrocalcification such as interruption, irregular thickness and the presence of soft tissue rim were associated with malignancy in thyroid nodules with macrocalcifications.     

Can Ultrasound Be as a Surrogate Marker for Diagnosing a Papillary Thyroid Cancer? Comparison with BRAF Mutation Analysis

Purpose

We investigated the merit of ultrasound (US) features and BRAF^V600E mutation as an additional study of cytology and compared the diagnostic performances of cytology alone, cytology with US correlation, cytology with BRAF^V600E mutation, and a combination of cytology, US, and BRAF^V600E mutation all together.

Materials and Methods

This study included 185 patients (mean age, 48.4 years; range 20-77 years) with 191 thyroid nodules who underwent US-guided fine-needle aspiration (FNA) with an additional BRAF^V600E mutation test. Three radiologists highly experienced in thyroid imaging retrospectively reviewed US images and classified each nodule into two categories (positive for malignancy or negative for malignancy). Interobserver variability (IOV) of US assessment between the three readers was estimated using the generalized kappa statistic of Landis and Koch. We also calculated the diagnostic performances of these studies.

Results

There were 131 cases of malignancy (131/191, 68.6%) and 60 cases of benign nodules (60/191, 31.4%). In terms of IOV of US assessment, the generalized kappa value was 0.242, indicating fair agreement was reached. The combination of cytology with BRAF^V600E showed higher specificity (100%) and positive predictive value (PPV) (100%) compared to the combination of cytology, BRAF^V600E, and US (specificity 28.3%, 66.7%, 68.3%; PPV 74.6%, 86.6%, 86.8%, respectively; p<0.001). However, cytology with BRAF^V600E showed lower sensitivity (84.7%) than cytology with BRAF^V600E and US (96.2%, 98.5%, 95.4%, respectively; p<0.001).

Conclusion

Considering the diagnostic performance and low reproducibility of US, the combination of FNA with BRAF^V600E is the most reliable and objective method for diagnosing thyroid malignancy.     

Spatial control of adult stem cell fate using nanotopographic cues

Adult stem cells hold great promise as a source of diverse terminally differentiated cell types for tissue engineering applications. However, due to the complexity of chemical and mechanical cues specifying differentiation outcomes, development of arbitrarily complex geometric and structural arrangements of cells, adopting multiple fates from the same initial stem cell population, has been difficult. Here, we show that the topography of the cell adhesion substratum can be an instructive cue to adult stem cells and topographical variations can strongly bias the differentiation outcome of the cells towards adipocyte or osteocyte fates. Switches in cell fate decision from adipogenic to osteogenic lineages were accompanied by changes in cytoskeletal stiffness, spanning a considerable range in the cell softness/rigidity spectrum. Our findings suggest that human mesenchymal stem cells (hMSC) can respond to the varying density of nanotopographical cues by regulating their internal cytoskeletal network and use these mechanical changes to guide them toward making cell fate decisions. We used this finding to design a complex two-dimensional pattern of co-localized cells preferentially adopting two alternative fates, thus paving the road for designing and building more complex tissue constructs with diverse biomedical applications.     

Improvement of burn pain management through routine pain monitoring and pain management protocol

Introduction

Pain management is an important aspect of burn management. We developed a routine pain monitoring system and pain management protocol for burn patients. The purpose of this study is to evaluate the effectiveness of our new pain management system.

Methods

From May 2011 to November 2011, the prospective study was performed with 107 burn patients. We performed control group (n = 58) data analysis and then developed the pain management protocol and monitoring system. Next, we applied our protocol to patients and performed protocol group (n = 49) data analysis, and compared this to control group data. Data analysis was performed using the Numeric Rating Scale (NRS) of background pain and procedural pain, Clinician-Administered PTSD Scale (CAPS), Hamilton Depression Rating Scale (HDRS), State-Trait Anxiety Inventory Scale (STAIS), and Holmes and Rahe Stress Scale (HRSS).

Results

The NRS of background pain for the protocol group was significantly decreased compared to the control group (2.8 ± 2.0 versus 3.9 ± 1.9), and the NRS of procedural pain of the protocol group was significantly decreased compared to the control group (4.8 ± 2.8 versus 3.7 ± 2.5). CAPS and HDRS were decreased in the protocol group, but did not have statistical significance. STAIS and HRSS were decreased in the protocol group, but only the STAIS had statistical significance.

Conclusion

Our new pain management system was effective in burn pain management. However, adequate pain management can only be accomplished by a continuous and thorough effort. Therefore, pain control protocol and pain monitoring systems need to be under constant revision and improvement using creative ideas and approaches.     

The effect of alfentanil versus ketamine on the intubation condition and hemodynamics with low-dose rocuronium in children

Purpose

We investigated the effect of alfentanil and ketamine on the intubation condition and hemodynamic parameters during propofol anesthesia with low-dose rocuronium in children.

Methods

Fifty-four children, aged 3–9 years undergoing tonsillectomy, were randomly allocated to receive either alfentanil 20 μg/kg (alfentanil group, n = 27) or ketamine 0.5 mg/kg (ketamine group, n = 27) 1 min before anesthesia induction. Anesthesia was induced with propofol 2.5 mg/kg and rocuronium 0.3 mg/kg and maintained with propofol infusion (6 mg/kg/h). The neuromuscular relaxation was monitored, and intubation conditions, hemodynamic changes, and recovery time were assessed.

Results

All patients were successfully intubated and there were no significant differences in the intubation conditions between alfentanil and ketamine groups. At the time of tracheal intubation, the median [inter-quartile range] twitch height was similar between two groups (37 [4–48] % in the alfentanil group vs. 29 [4–43.5] % in the ketamine group, p = 0.326).

Conclusions

This study showed that both ketamine 0.5 mg/kg and alfentanil 20 μg/kg provided adequate intubation condition during propofol induction with low-dose rocuronium in children. The mean arterial pressure and heart rate were higher in the ketamine group after propofol injection but they remained within the normal limit in both groups throughout the study period.     

The safety of a “fast-track” program after laparoscopic colorectal surgery is comparable in older patients as in younger patients

Introduction

Fast-track protocols, introduced in the late 1990s, have been applied in several surgical fields, particularly for colorectal surgery. However, currently many surgical patients are elderly, and discussion about the application of such programs for elderly patients is lacking. The present study was designed to assess the safety of application of a fast-track program after laparoscopic colorectal surgery in elderly patients.

Methods

From August 2009 to January 2011, we prospectively collected data from patients who underwent laparoscopic colorectal surgery with a perioperative fast-track program. The data of patients older and younger than 70 years were compared.

Results

Of a total of 337 patients, the group of patients older than 70 years (OG) totaled 87 (25.8 %) and the younger group (YG) totaled 250 (74.2 %). Ten patients (11.5 %) were excluded in the OG and 24 (9.6 %) in the YG. There were no differences in gender, history of previous surgeries, body mass index, type of operation, operative time, or blood loss between groups. Age (74.8 vs. 56.7 years, p < 0.001), presence of comorbidities (70.1 vs. 44.7 %, p < 0.001), and ASA score (I:II:III, 33.8:57.1:9.1 vs. 60.6:33.2:6.2 %, p < 0.001) were significantly different between the two groups. Postoperative course did not show differences, including return of flatus, stool passage, advancement of diet, removal of urinary catheter, length of usage of IV antibiotics, complications, and length of postoperative stay. Emergency department visits or readmission within a month after discharge were more frequent in the OG (11.7 %) than the YG (4 %; p = 0.013).

Conclusions

Fast-track after laparoscopic colorectal surgery can be safely applied in carefully selected elderly patients older than age 70 years. Physicians should keep in mind complications that may present after discharge and should actively educate patients about them.     

Epidemiology and Molecular Characterization of Bacteremia Due to Carbapenem‐Resistant Klebsiella pneumoniae in Transplant Recipients

We conducted a retrospective study of 17 transplant recipients with carbapenem‐resistant Klebsiella pneumoniae bacteremia, and described epidemiology, clinical characteristics and strain genotypes. Eighty‐eight percent (15/17) of patients were liver or intestinal transplant recipients. Outcomes were death due to septic shock (18%), cure (24%) and persistent (>7 days) or recurrent bacteremia (29% each). Thirty‐ and 90‐day mortality was 18% and 47%, respectively. Patients who were cured received at least one active antimicrobial agent and underwent source control interventions. Forty‐one percent (7/17) of patients had intra‐abdominal infections; all except one developed persistent/recurrent bacteremia despite drainage. Two patients tolerated persistent bacteremia for >300 days. All patients except one were infected with sequence type 258 (ST258), K. pneumoniae carbapenemase (KPC)‐2‐producing strains harboring a mutant ompK35 porin gene; the exception was infected with an ST37, KPC‐3‐producing strain. Seventy‐one percent (12/17) of patients were infected with ST258 ompK36 mutant strains. In two patients, persistent bacteremia was caused by two strains with different ompK36 genotypes. Three ompK36 mutations were associated with significantly higher carbapenem minimum inhibitory concentrations than wild‐type ompK36. Pulse‐field gel electrophoresis identified a single ST258 lineage; serial strains from individual patients were indistinguishable. In conclusion, KPC‐K. pneumoniae bacteremia exhibited highly diverse clinical courses following transplantation, and was caused by clonal ST258 strains with different ompK36 genotypes.