Sangmin M. Lee

Potentially modifiable risk factors for acute kidney injury after surgery on the thoracic aorta: a propensity score matched case-control study.

Abstract Perioperative risk factors were identified for acute kidney injury (AKI) defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage) after surgery on the thoracic aorta with cardiopulmonary bypass (CPB) in this case-control study. A retrospective review was completed for 702 patients who underwent surgery on the thoracic aorta with CPB. A total of 183 patients with AKI were matched 1:1 with patients without AKI by a propensity score. Matched variables included age, gender, body-mass index, preoperative creatinine levels, estimated glomerular filtration rate, a history of hypertension, diabetes mellitus, cerebrovascular accident, smoking history, or chronic obstructive pulmonary disease to exclude the influence of patient demographics, preoperative medical status, and baseline renal function. Multivariate logistic regression analysis was used to evaluate for independent risk factors in the matched sample of 366 patients. The incidence of AKI was 28.6% and 5.9% of patients from the entire sample required renal replacement therapy. AKI was associated with a prolonged postoperative hospital stay and a higher one-month and one-year mortality both in the entire and matched sample set. Independent risk factors for AKI were a left ventricular ejection fraction <55%, preoperative hemoglobin level <10 g/dL, albumin <4.0 g/dL, diagnosis of dissection, operation time >7 hours, deep hypothermic circulatory arrest (DHCA) time >30 min, pRBC transfusion >1000 mL, and FFP transfusion >500 mL. Although the incidence of poor glucose control (blood glucose >180 mg/dL) was higher in patients with AKI in matched sample, it was not an independent risk factor. AKI was still associated with a poor clinical outcome in the matched sample. Potentially modifiable risk factors included preoperative anemia and hypoalbuminemia. Efforts to minimize operation time and DHCA time along with transfusion amount may protect patients undergoing aortic surgery against AKI.

Simplified Clinical Risk Score to Predict Acute Kidney Injury After Aortic Surgery

OBJECTIVE The authors identified risk factors for acute kidney injury (AKI) defined by risk, injury, failure, loss, end-stage (RIFLE) criteria after aortic surgery with cardiopulmonary bypass and constructed a simplified risk score for the prediction of AKI. DESIGN Retrospective and observational. SETTING Single large university hospital. PARTICIPANTS Patients (737) who underwent aortic surgery with cardiopulmonary bypass between 1997 and 2010. MAIN RESULTS Multivariate logistic regression analysis was used to evaluate risk factors. A scoring model was developed in a randomly selected derivation cohort (n = 417), and was validated on the remaining patients. The scoring model was developed with a score based on regression β-coefficient, and was compared with previous indices as measured by the area under the receiver operating characteristic curve (AUC). The incidence of AKI was 29.0%, and 5.8% required renal replacement therapy. Independent risk factors for AKI were age older than 60 years, preoperative glomerular filtration rate <60 mL/min/1.73 m(2), left ventricular ejection fraction <55%, operation time >7 hours, intraoperative urine output <0.5 mL/kg/h, and intraoperative furosemide use. The authors made a score by weighting them at 1 point each. The risk score was valid in predicting AKI, and the AUC was 0.74 [95% confidence interval (CI): 0.69 to 0.79], which was similar to that in the validation cohort: 0.74 (95% CI: 0.69 to 0.80; p = 0.97). The risk-scoring model showed a better performance compared with previously reported indices. CONCLUSIONS The model would provide a simplified clinical score stratifying the risk of postoperative AKI in patients undergoing aortic surgery.

Fibrinogen recovery and changes in fibrin‐based clot firmness after cryoprecipitate administration in patients undergoing aortic surgery involving deep hypothermic circulatory arrest

Cryoprecipitate may be used to treat bleeding in cardiac surgery. Its effects on plasma fibrinogen and fibrin clotting in this setting are poorly defined.

Use of fibrin-based thromboelastometry for cryoprecipitate transfusion in cardiac surgery involving deep hypothermic circulatory arrest during cardiopulmonary bypass.

We aimed to assess the predictive value of fibrin-based thromboelastometry performed before weaning from cardiopulmonary bypass (CPB) for cryoprecipitate administered to correct the bleeding diathesis after CPB involving deep hypothermic circulatory arrest. Eleven patients undergoing aortic surgery were enrolled. The arterial blood was withdrawn before skin incision, 30 min before CPB weaning (Cweaning), 5 min after protamine reversal (Preversal) and at closure of the sternum to run intrinsically activated INTEM, heparinase-treated HEPTEM, extrinsically activated EXTEM and platelet-inhibited FIBTEM analysis, platelet count, fibrinogen, prothrombin time (international normalized ratio) and activated partial thromboplastin time. The predicted value of FIBTEM A10 obtained during CPB for cryoprecipitate transfusion at Preversal was calculated. The cut-off points for FIBTEM A10 to reflect fibrinogen of 200 mg/dl at Preversal were 5 mm (P = 0.15). FIBTEM A10 at Preversal and Cweaning showed correlations as follows: FIBTEM A10 at Preversal = 0.02 + 1.42 × FIBTEM A10 at Cweaning (r2 = 0.80). The cut-off value for FIBTEM A10 at Cweaning to determine whether to prepare cryoprecipitate in advance during CPB was calculated to be 3 mm, and the positive and negative predictability for FIBTEM A10 of 3 or less versus more than 3 at Cweaning for the necessity of cryoprecipitate transfusion at Preversal (A10 ≤ 5 versus > 5) were 100 and 80%, respectively. This study showed that fibrinogen reflected in FIBTEM during pump can be used to estimate FIBTEM after Preversal and the amount of cryoprecipitate needed for replacing mainly the fibrinogen could be predicted with high sensitivity and specificity.

Protective Effects of Gabapentin on Allodynia and α2δ1-Subunit of Voltage-dependent Calcium Channel in Spinal Nerve-Ligated Rats

This study was designed to determine whether early gabapentin treatment has a protective analgesic effect on neuropathic pain and compared its effect to the late treatment in a rat neuropathic model, and as the potential mechanism of protective action, the α2δ1-subunit of the voltage-dependent calcium channel (α2δ1-subunit) was evaluated in both sides of the L5 dorsal root ganglia (DRG). Neuropathic pain was induced in male Sprague-Dawley rats by a surgical ligation of left L5 nerve. For the early treatment group, rats were injected with gabapentin (100 mg/kg) intraperitoneally 15 min prior to surgery and then every 24 hr during postoperative day (POD) 1-4. For the late treatment group, the same dose of gabapentin was injected every 24 hr during POD 8-12. For the control group, L5 nerve was ligated but no gabapentin was administered. In the early treatment group, the development of allodynia was delayed up to POD 10, whereas allodynia was developed on POD 2 in the control and the late treatment group (p<0.05). The α2δ1-subunit was up-regulated in all groups, however, there was no difference in the level of the α2δ1-subunit among the three groups. These results suggest that early treatment with gabapentin offers some protection against neuropathic pain but it is unlikely that this action is mediated through modulation of the α2δ1-subunit in DRG.

Relationship between the bevel of the tuohy needle and catheter direction in thoracic epidural anesthesia

Background and Objectives: Directing an epidural catheter cephalad or caudad is usually attempted by orienting the beveled edge of the epidural needle. However, there have been few studies about the relationship between the direction of the bevel of epidural needle and the resulting position of the catheter. We studied this relationship in thoracic epidural catheter placement. Catheter position was confirmed by using picture archiving communication systems (PACS). PACS is a workstation that stores radiologic images, which can be manipulated to visualize the catheters. Methods: One hundred six patients receiving thoracic epidural anesthesia were enrolled. The cephalad and caudad groups (each with 53 patients) received epidural anesthesia at the T6-7 interspace with either a cephalad- or caudal-directed Tuohy needle. The final position of all of the catheters was confirmed by PACS. Results: In the cephalad group, 63.5% of the catheters were confirmed to travel in a cephalad direction. In the caudad group, 22.0% of the catheters advanced in a caudad direction. Curling of the catheters occurred in 17.6%. PACS showed the catheter positions with satisfactory quality. Conclusions: The correlation between bevel direction and location of the thoracic epidural catheter was relatively low. Practices such as threading an epidural catheter by manipulation of the Tuohy needle for the control of pain at a distant site may not yield good results.

Is Preoperative Biochemical Testing for Pheochromocytoma Necessary for All Adrenal Incidentalomas

AbstractThis study examined whether imaging phenotypes obtained from computed tomography (CT) can replace biochemical tests to exclude pheochromocytoma among adrenal incidentalomas (AIs) in the preoperative setting.We retrospectively reviewed the medical records of all patients (n = 251) who were admitted for operations and underwent adrenal-protocol CT for an incidentally discovered adrenal mass from January 2011 to December 2012. Various imaging phenotypes were assessed for their screening power for pheochromocytoma. Final diagnosis was confirmed by biopsy, biochemical tests, and follow-up CT.Pheochromocytomas showed similar imaging phenotypes as malignancies, but were significantly different from adenomas. Unenhanced attenuation values ⩽10 Hounsfield units (HU) showed the highest specificity (97%) for excluding pheochromocytoma as a single phenotype. A combination of size ⩽3 cm, unenhanced attenuation values ⩽ 10 HU, and absence of suspicious morphology showed 100% specificity for excluding pheochromocytoma.Routine noncontrast CT can be used as a screening tool for pheochromocytoma by combining 3 imaging phenotypes: size ⩽3 cm, unenhanced attenuation values ⩽10 HU, and absence of suspicious morphology, and may substitute for biochemical testing in the preoperative setting.

Stanford type A aortic dissection in a patient with Marfan syndrome during pregnancy: a case report

Aortic dissection during pregnancy is a devastating event for both the pregnant woman and the baby. We report a case of acute aortic dissection (Stanford type A) in a pregnant woman with Marfan syndrome at the 29th week of gestation. She underwent a cesarean section followed by an ascending aorta and total arch replacement with cardiopulmonary bypass, without a prior sternotomy. The hemodynamic parameters were kept stable during the cesarean section by using inotropes and vasopressors under transesophageal echocardiography monitoring. The newborn survived after endotracheal intubation and management in a neonatal intensive care unit.

Incidence and risk factors of postoperative sore throat after endotracheal intubation in Korean patients

Objective To investigate the incidence of postoperative sore throat (POST) in Korean patients undergoing general anaesthesia with endotracheal intubation and to assess potential risk factors. Methods This prospective study enrolled patients who underwent all types of elective surgical procedures with endotracheal intubation and general anaesthesia. The patients were categorized into group S (those with a POST) or group N (those without a POST). The demographic, clinical and anaesthetic characteristics of each group were compared. Results This study enrolled 207 patients and the overall incidence of POST was 57.5% (n = 119). Univariate analysis revealed that significantly more patients in group S had a cough at emergence and hoarseness in the postanaesthetic care unit compared with group N. Receiver operating characteristic curve analysis showed that an intracuff pressure ≥17 cmH2O was associated with POST. Multivariate analysis identified an intracuff pressure ≥17 cmH2O and cough at emergence as risk factors for POST. At emergence, as the intracuff pressure over ≥17 cmH2O increased, the incidence of hoarseness increased. Conclusions An intracuff pressure ≥17 cmH2O and a cough at emergence were risk factors for POST in Korean patients. Intracuff monitoring during anaesthesia and a smooth emergence are needed to prevent POST.

Preoperative depressed mood and perioperative heart rate variability in patients with hepatic cancer.

STUDY OBJECTIVE How perioperative heart rate variability (HRV) indices differ according to the anxiety or depressed mood of patients scheduled to undergo a major surgical procedure for cancer. DESIGN Prospective observational study. SETTING Operating room. PATIENTS Forty-one male patients between 40 and 70 years of age with hepatocellular carcinoma were included in the final analysis. INTERVENTIONS HRV was measured on the day before surgery (T1), impending anesthesia (T2), and after anesthetic induction (T3). Preoperative anxiety and depressed mood of all patients were evaluated using the State-Trait Anxiety Inventory and Self-Rating Depression Scale (SDS). MEASUREMENTS AND RESULTS HRV was significantly different among T1, T2, and T3. At T2, high frequency (HF) (normalized units of HF [nuHF]) was decreased and low frequency (LF) (normalized units of LF) and LF/HF were increased compared with those at T1 and T3. In the subgroup analysis between high and low SDS groups, high SDS group showed significantly decreased nuHF (P = .035), increased nuLF (P = .039), and increased LF/HF (P = .020) compared to low SDS group at T1. However, these values at T2 and T3 were not different between 2 groups. In analysis within the groups, low SDS group showed significant differences in nuHF, nuLF, and LF/HF among T1, T2, and T3 (P < .05, respectively), but no changes in these values were observed in high SDS group among the 3 different time points. CONCLUSIONS HRV decreased significantly immediately before anesthesia and recovered to baseline with anesthetic induction. Preoperative, more depressed patients showed increased sympathetic tone at baseline and blunted response to impending anesthesia on the HRV measurements.