The association of allogeneic blood transfusion and the recurrence of hepatic cancer after surgical resection.

There is conflicting evidence whether allogeneic blood transfusion influences survival or cancer recurrence after resection of hepatocellular cancer. We followed up 1469 patients who had undergone hepatocellular resection for a median (IQR [range]) of 45 (21-78 [0-162]) months, of whom 626 (43%) had had blood transfusion within 7 days of surgery. Both disease-free survival and patient survival were measured using a proportional hazards regression model and inverse probability of treatment weighting. We used restricted cubic splines for the association of the number of packed red blood cell units transfused with cancer recurrence and survival. We found that peri-operative blood transfusion was independently associated with survival and cancer recurrence after resection of hepatocellular carcinoma. Adjusted hazard ratios (95%CI) for the association of blood transfusion with cancer recurrence and all-cause mortality were 1.3 (1.1-1.4) and 1.9 (1.6-2.3), p < 0.001 for both. With more units transfused cancer recurrence was more likely and survival was shorter. The association of the number of transfused units was non-linear for cancer recurrence and linear response for all-cause mortality.

Adaptation of non-linear mixed amount with zero amount response surface model for analysis of concentration-dependent synergism and safety with midazolam, alfentanil, and propofol sedation.

BACKGROUND: The non-linear mixed amount with zero amounts response surface model can be used to describe drug interactions and predict loss of response to noxious stimuli and respiratory depression. We aimed to determine whether this response surface model could be used to model sedation with the triple drug combination of midazolam, alfentanil and propofol. METHODS: Sedation was monitored in 56 patients undergoing gastrointestinal endoscopy (modelling group) using modified alertness/sedation scores. A total of 227 combinations of effect-site concentrations were derived from pharmacokinetic models. Accuracy and the area under the receiver operating characteristic curve were calculated. Accuracy was defined as an absolute difference <0.5 between the binary patient responses and the predicted probability of loss of responsiveness. Validation was performed with a separate group (validation group) of 47 patients. RESULTS: Effect-site concentration ranged from 0 to 108 ng ml-1 for midazolam, 0-156 ng ml-1 for alfentanil, and 0-2.6 µg ml-1 for propofol in both groups. Synergy was strongest with midazolam and alfentanil (24.3% decrease in U50, concentration for half maximal drug effect). Adding propofol, a third drug, offered little additional synergy (25.8% decrease in U50). Two patients (3%) experienced respiratory depression. Model accuracy was 83% and 76%, area under the curve was 0.87 and 0.80 for the modelling and validation group, respectively. CONCLUSION: The non-linear mixed amount with zero amounts triple interaction response surface model predicts patient sedation responses during endoscopy with combinations of midazolam, alfentanil, or propofol that fall within clinical use. Our model also suggests a safety margin of alfentanil fraction <0.12 that avoids respiratory depression after loss of responsiveness.

Discriminant analysis for anaesthetic decision-making: an intelligent recognition system for epidural needle insertion.

BACKGROUND: Incorrect placement of epidural catheters causes medical complications. We used linear discriminant analysis (LDA) to develop an intelligent recognition system (i-RS) in order to guide epidural placement and reduce physician error. METHODS: We analysed real-time dual-wavelength fibreoptic data recorded from the end of an epidural needle in a live porcine model. Two categories of tissue layers were necessary for correct placement of catheter: epidural space and ligamentum flavum. The data were tested using linear, quadratic and logistic parametric analysis to identify which method could distinguish the two anatomical structures. RESULTS: LDA was the best fit for our model. There was ∼80% sensitivity and specificity for correct anatomical identification. Error rates based on cross-validation were 17.0% for the epidural space and 18.6% for ligamentum flavum. Error rates were greater with the 532 nm compared with 650 nm wavelength. CONCLUSIONS: The sensitivity and specificity of LDA for identifying the correct anatomical structure was similar to a physician who is an expert in epidural placement. Overall performance of an i-RS could be improved by expanding the database for decision-making and adding a category of uncertainty. This would reduce complications caused by incorrect epidural placement.

Thromboelastography-guided transfusion decreases intraoperative blood transfusion during orthotopic liver transplantation: randomized clinical trial.

OBJECTIVE: To test in a prospective randomized study the hypothesis that use of thromboelastography (TEG) decreases blood transfusion during major surgery. MATERIAL AND METHODS: Twenty-eight patients undergoing orthotopic liver transplantation were recruited over 2 years. Patients were randomized into 2 groups: those monitored during surgery using point-of-care TEG analysis, and those monitored using standard laboratory measures of blood coagulation. Specific trigger points for transfusion were established in each group. RESULTS: In patients monitored via TEG, significantly less fresh-frozen plasma was used (mean [SD], 12.8 [7.0] units vs 21.5 [12.7] units). There was a trend toward less blood loss in the TEG-monitored patients; however, the difference was not significant. There were no differences in total fluid administration and 3-year survival. CONCLUSION: Thromboelastography-guided transfusion decreases transfusion of fresh- frozen plasma in patients undergoing orthotopic liver transplantation, but does not affect 3-year survival.

Item analysis for the written test of Taiwanese board certification examination in anaesthesiology using the Rasch model.

BACKGROUND: On the written test of board certification examination for anaesthesiology, the probability of a question being answered correctly is subject to two main factors, item difficulty and examinee ability. Thus, item analysis can provide insight into the appropriateness of a particular test, given the ability of examinees. METHODS: Study subjects were 36 Taiwanese examinees tested with 100 questions related to anaesthesiology. We used the Rasch model to perform item analysis of questions answered by each examinee to assess the effects of question difficulty and examinee ability using a common logit scale. Additionally, we evaluated test reliability and virtual failure rates under different criteria. RESULTS: The mean examinee ability was higher than the mean item difficulty in this written test by 1.28 (sd=0.57) logit units, which means that the examinees, on average, were able to correctly answer 78% of items. The difficulty of items decreased from 4.25 to -2.43 on the logit scale, corresponding to the probability of having a correct answer from 5% to 98%. There were 60 items with difficulty lower than the least able examinee and seven difficult items beyond the most able one. The agreement of item difficulty between test developers and our Rasch model was poor (weighted kappa=0.23). CONCLUSIONS: We demonstrated how to assess the construct validity and reliability of the written examination in order to provide useful information for future board certification examinations. The study was approved by the institutional review board with the following trial registered number: VGHIRB No. 97-08-14A.

Performance of AEP Monitor/2-derived composite index as an indicator for depth of sedation with midazolam and alfentanil during gastrointestinal endoscopy.

BACKGROUND AND OBJECTIVE: The A-Line auditory evoked potential index (AAI) (AEP Monitor/2, Danmeter A/S, Odense, Denmark) is a newly developed composite parameter representing the degree of hypnosis. We conducted a prospective, observational study to explore the performance and validity of the AAI during conventional sedation for gastrointestinal (GI) endoscopy. METHODS: Thirty adults of either sex, age <65, scheduled for combined oesophagogastroduodenoscopy (OGD) and colonoscopy under sedation with intravenous (i.v.) midazolam and alfentanil were enrolled. The sedative end-point was set at the Observer's Assessment of Alertness/Sedation (OAA/S) score less than 4. An AEP Monitor/2 was used in all patients. AAI, sedation scores, heart rate (HR), blood pressure (BP) and SPO2 were recorded every 2 min up to the end of the procedure. Receiver operator characteristic analysis was used to test validity and to select optimal sedation. RESULTS: There was a significantly positive correlation between AAI and OAA/S scores (rho = 0.886; P < 0.001). The AAI also showed significant differences between subsequent levels of sedation scores (P < 0.001). AAI greater than 54 indicated fully awake or minimal sedation and values between 54 and 42 were suggestive of moderate sedation. Values between 42 and 34 were associated with moderate to deep sedation and readings below 34 were associated with deep sedation. The relative risk of SPO2 < 95% for OAA/S = 2 compared with 3 was 15.98 (95% confidence interval (CI): 3.94-64.81). CONCLUSIONS: AAI is an effective tool for monitoring sedation during GI endoscopy induced by i.v. midazolam and alfentanil.

A paraspinal abscess following spinal anaesthesia for caesarean section and patient-controlled epidural analgesia for postoperative pain.

We present a rare case in which a healthy parturient developed a paraspinal abscess after spinal anaesthesia for caesarean section and epidural analgesia for postoperative pain management. The catheter was in situ for 58 h. Backache was the initial and major symptom. A concealed course with no neurological deficit resulted in a delayed diagnosis and treatment in this case. The infection was not diagnosed until 20 days after the removal of the epidural catheter when there was a purulent discharge from the epidural puncture site. Surgical drainage was required. Anaesthesiologists should be aware that serious epidural analgesia-related infections can happen in extra spinal-epidural spaces. Vigilance for these infections, especially in postpartum patients with backache, is needed.

Epidural analgesia associated with a fatal outcome in a patient with an unrecognized brain tumour.

A fatality associated with epidural analgesia in a patient with an unsuspected brain tumour has not been reported in the literature. We describe a case of postoperative lumbar epidural analgesia in a 54-year-old female patient who had an undiagnosed brain tumour and a fatal outcome postoperatively. The factors that potentially contributed to this mishap and the possible alternative management of this patient are discussed.

Anesthetic management of parturients with Eisenmenger's syndrome--report of two cases.

Pregnancy is badly tolerated in patients with Eisenmenger's syndrome; maternal mortality with coherent fetal morbidity is high. Even with the advancement of both obstetric and anesthetic managements, the maternal mortality still exceeds 25%. Once conception occurs in patients of Eisenmenger's syndrome with severe pulmonary hypertension, interruption of pregnancy is still the best manipulation to be recommended. We report two cases of parturients with Eisenmenger's syndrome, who underwent termination of pregnancy. In this report, the obstetric and anesthetic management of this kind of parturients with Eisenmenger's syndrome has been thoroughly discussed.

Prostaglandins may participate in opioidergic and cholinergic control of the diurnal changes of tuberoinfundibular dopaminergic neuronal activity and serum prolactin level in ovariectomized, estrogen-treated rats.

The roles of prostaglandins (PGs) involved in opioidergic, cholinergic, and serotonergic regulation of the diurnal changes of tuberoinfundibular dopaminergic (TIDA) neuronal activities were investigated in ovariectomized, estrogen-treated rats. Treatment with naloxone [10 mg/kg, intraperitoneal (i.p.)], atropine (5 mg/kg, i.p.), or ketanserin (10 mg/kg, i.p.) at either 1200 or 1400 h prevented the afternoon decrease of TIDA neuronal activity and the prolactin (PRL) surge. Intracerebroventricular (i.c.v.) injection of PGE(1) (5 microg/3 microl/rat) at 1500 h significantly reversed the effects of naloxone and atropine, but not that of ketanserin. In ovariectomized, estrogen-primed rats pretreated with indomethacin, i.c.v. injection of either nicotine (10 ng/rat) or fentanyl (10 ng/rat) failed to suppress the TIDA neuronal activity and to stimulate the PRL secretion. These data suggest that PG may be involved in opioidergic and cholinergic control of the diurnal changes of TIDA neuronal activity and the PRL secretion in ovariectomized (OVX) + E(2) rats.

Prostaglandins play an important role in diurnal changes of tuberoinfundibular dopaminergic neuronal activity and prolactin secretion in ovariectomized, estrogen-treated rats.

Intracerebroventricular injection of prostaglandins (PGs) has long been shown to stimulate the secretion of prolactin (PRL). The action of specific PG and the underlying mechanism, however, remain inconclusive. In this study, we evaluated the involvement of PGs in the diurnal changes of the tuberoinfundibular dopaminergic (TIDA) neurons and PRL secretion in ovariectomized (OVX) rats treated with estrogen (E2). Prior treatment of indomethacin (50 mg/kg, subcutaneous) for 24 h significantly prevented the afternoon decrease of TIDA neuronal activity and blocked the PRL surge. Intracerebroventricular injection of PGE(1) (5 microg/3 microl/rat) at 1000 h significantly lowered the activity of TIDA neurons, while similar treatment of PGE2 was without effect. In OVX + E(2) rats pretreated with indomethacin, PGE(1) given at 15, but not 30 or 180 min before decapitation at 1500 h significantly reversed the effects of indomethacin on TIDA neuronal activity, while the blocked PRL surge was not reversed. The PGs also exhibited a stimulatory effect on nigrostriatal dopamine (DA) neurons with PGE2 being the most effective agent. These results indicate that endogenous PGs play a significant role in the control of central DA neurons, especially the diurnal changes of TIDA neuronal activity and PRL secretion in OVX + E2 rats.

Repeated attacks of venous air embolism during craniotomy--a case report.

Venous air embolism (VAE) is not uncommon during craniotomy, but repeated attacks of VAE during a single surgical procedure is rarely seen. We report a successful intraoperative management of repeated attacks of air embolism in a patient who sustained craniotomy for intracranial hemorrhage (ICH) in prone position. A 70-year-old male suffering from hemorrhage in the right cerebellar hemisphere with impending brainstem herniation was scheduled for craniotomy. He had history of hypertension but it was not well controlled with medical treatment. Emergent craniotomy for removal of blood clot resulting from ICH was performed. During the operation, sudden decrease of end-tidal CO2 (EtCO2) level, fall of blood pressure and increase of central venous pressure (CVP) were noted. Since air bubbles were retrieved from CVP catheter venous air embolism was highly suspected. With prompt diagnosis and proper management, we successfully improved the patient's hemodynamic status and he was discharged without any sequelae. Early detection together with aggressive treatment is the only way in the management of intraoperative venous air embolism.

Inadvertent knotting of a thoracic epidural catheter.

We report a case of corrosive injury of upper gastrointestinal and respiratory tracts scheduled for feeding jejunostomy under thoracic epidural anesthesia. An epidural catheter was inserted at the T8-T9 intervertebral space and threaded 7 cm beyond the tip of the Tuohy needle in a rostral direction. Resistance was noticed during attempts to inject the local anesthetic. As resistance could not be relieved by changing the position of the patient, kinking of the epidural catheter was suspected. Following informing the patient of the associated risks, the catheter was retrieved successfully by gentle and steady pulling. A tight double-knot of catheter was found. No neurological sequelae to the procedure were noticed.

Bilateral pulmonary edema after endoscopic sympathectomy in a patient with glucose-6-phosphate dehydrogenase deficiency.

Transaxillary endoscopic sympathectomy of thoracic ganglia (T2-T3) has recently gained wider acceptance as the treatment of choice for palmar hyperhidrosis. It requires one-lung ventilation to facilitate the surgery. One-lung ventilation, however, is not without complications, among which acute pulmonary edema has been reported. In this case report, we present a patient with palmar hyperhidrosis complicated by glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, who received bilateral endoscopic sympathectomy under alternate one-lung anesthesia, and developed acute pulmonary edema immediately after recruitment of the successive collapsed lung. The effects of hypoxemia, G-6-PD deficiency and sympathectomy might all add to the development of acute pulmonary edema secondary to reexpansion of each individual lung after alternate one-lung ventilation. The possibilities of the inferred causes are herein discussed.

A modified method for intubation of a patient with ankylosing spondylitis using intubating laryngeal mask airway (LMA-Fastrach)--a case report.

We present an instance of successful use of an intubating laryngeal mask airway (LMA-Fastrach) and a Cook airway exchanger (CAE) for ventilation and intubation in a patient with severe ankylosing spondilitis (AS) receiving total hip arthroplasty. This measure may serve as an effective alternative for airway management in patients with difficult airway. A 61-year-old male was scheduled for right total hip arthroplasty because of degenerative osteoarthritis. He had been suffering from extensive ankylosing spondylitis, with the cervical spine markedly fixed in anterior flexion. Besides he could not open his mouth widely (35 mm when fully open) also because of ankylosis of jaw. Although we advised an awake fiberoptic tracheal intubation for anesthesia but he refused owing to a previous painful experience. After induction of anesthesia with glycopyrrolate, fentanyl, thiamylal sodium and succinylcholine, we inserted a # 5 Fastrach ILMA for primary airway maintenance. Then through the lumen of the ILMA we introduced the CAE as a guide for endotracheal tube (ETT) intubation. After applying the RAPI-FIT adapter to the CAE, we connected it to the capnography monitor for the confirmation of airway. We finally inserted an endotracheal tube into the trachea using the CAE as a guide. The whole procedure was uneventful and smooth. In sum, the modified Fastrach intubation method may facilitate tracheal intubation in patients with severe ankylosing spondilitis. It may be an alternative way for successful airway management in patients with difficult airway.

Detection of iatrogenic cardiac tamponade by transesophageal echocardiography during vena cava filter procedure.

PURPOSE: To present a patient who developed cardiac tamponade during insertion of an inferior vena cava (IVC) filter. Intraoperative transesophageal echocardiography (TEE) was used as a means to diagnose the cardiac tamponade and to facilitate guiding of pericardiocentesis. CLINICAL FEATURES: A 45-yr-old man with protein S deficiency complicated by repeated attacks of deep vein thrombosis and pulmonary thromboembolism was scheduled for insertion of an IVC filter. He had history of chronic renal insufficiency, heart failure, and cerebral infarction with mild left hemiparesis. Current medication included diltiazem (30 mg, I tab tid ), prednisolone (5 mg, 2 tabs qd ), and warfarin (2.5 mg daily). Preoperative transthoracic echocardiography demonstrated bilateral pleural effusions, moderate mitral regurgitation and tricuspid regurgitation, left atrial appendage thrombus and severe generalized hypokinesia of left ventricle. Nuclear medicine examination by (99)Tc showed ejection fractions of left ventricle and right ventricle as 20% and 22%, respectively. Under the impression of protein S deficiency with multiple attacks of thromboembolism and failure of anticoagulant therapy, he was arranged for the procedure of vena caval filter insertion. Unfortunately, iatrogenic cardiac tamponade occurred during the course of the procedure with rapid hemodynamic deterioration. Because of the expedient of routine monitoring of cardiac condition with TEE, a prompt diagnosis was made. We successfully improved the patient's hemodynamic status after transthoracic echo-guided pericardiocentesis. CONCLUSION: Intraoperative TEE is recommended to be used routinely in patients undergoing vena cava filter procedures. The availability of echocardiographic monitoring in the operation room allows the confirmation of the diagnosis and facilitation pericardiocentesis.

Effect of milrinone on postbypass pulmonary hypertension in children after tetralogy of Fallot repair.

BACKGROUND: Postbypass pulmonary hypertension in surgical correction of tetralogy of Fallot (TOF) is a risk for right ventricular failure. Effective management remains a major challenge. Milrinone is a new drug with a unique mechanism of "inodilation", which offers both inotropic and vasodilatory effects. We attempted to determine if application of milrinone could improve cardiopulmonary dysfunction in children after TOF repair. METHODS: We studied 10 children with postbypass pulmonary hypertension after TOF repair within six months. Heart rate, systolic pulmonary arterial pressure (PAP), systolic arterial blood pressure (SBP), pulmonary capillary wedge pressure and PAP/SBP ratio were recorded. Standard cardiopulmonary bypass (CPB) was performed. After CPB, if PAP/SBP was more than 0.5, pulmonary hypertension was suspected and milrinone was administered with a loading dose of 20 micrograms/kg followed by continuous infusion of 0.2 microgram/kg/minute. Hemodynamics were compared before and after administration of milrinone to evaluate its effect. RESULTS: significant reduction in PAP/SBP ratio within 15 minutes was found after administration of milrinone. The effect persisted for 24 hours during continuous infusion of milrinone. No remarkable adverse effect was noted in the study. CONCLUSIONS: We conclude that milrinone is effective in the management of pulmonary hypertension following CPB in children who underwent TOF repair.

Combined spinal-epidural anesthesia for cesarean section in a patient with Takayasu's disease.

We describe a successful episode of anesthesia management in a parturient affected with Takayasu's disease who underwent elective cesarean section under combined spinal-epidural anesthesia. Takayasu's disease is characterized by chronic occlusive inflammation of the arteries (panarteritis) of unknown origin that usually involves the aorta and its main branches. Progression of the disease may be marked by aneurysmal dilation of the affected arteries and may lead to a fatal outcome, usually from cerebral ischemia or heart failure. The impact of pregnancy on Takayasu's disease is unclear, but worsening of ischemic symptoms, cardiac failure, aggravation of hypertension and cerebral hemorrhage have been reported in sufferers who are in the later stages of pregnancy. Nonetheless, anesthesia management of a parturient with advanced Takayasu's disease presents a challenge to anesthetists.