Acidic FGF promotes neurite outgrowth of cortical neurons and improves neuroprotective effect in a cerebral ischemic rat model

Acidic fibroblast growth factor (aFGF) is a neurotrophic factor which is a powerful neuroprotective and neuroregenerative factor of the nervous system. Prior study had shown that levels of FGFs significantly increase following ischemic injury, reflecting a physiological protection mechanism. However, few reports demonstrated the efficacy of applying aFGF in cerebral ischemia. A recent report showed that the intranasal aFGF treatment improved neurological functional recovery; however, it did not significantly reduce the lesion size in ischemic rats. The present study examines the neuroprotective effect of aFGF on cortical neuron-glial cultures under oxygen glucose deprivation (OGD)-induced cell damage and investigates whether epidural application of slow-released aFGF could improve benefit on ischemic stroke injury in conscious rats. We used a topical application of aFGF mixed in fibrin glue, a slow-release carrier, over the peri-ischemic cortex and examined such treatment on cerebral infarction and behavioral impairments of rats subjected to focal cerebral ischemia (FCI). Results demonstrate that aFGF effectively protected cortical neuron-glial cultures from OGD-induced neuronal damage. Neurite extension from cortical neurons was significantly enhanced by aFGF, mediated through activation of AKT and ERK. In addition, topical application of fibrin glue-mixed aFGF dose-dependently reduced ischemia-induced brain infarction and improved functional restoration in ischemic stroke rats. Slow-released aFGF not only protected hippocampal and cortical cell loss but reduced microglial infiltration in FCI rats. Our results suggest that aFGF mixed in fibrin glue could prolong the protective/regenerative efficacy of aFGF to the damaged brain tissue and thus improve the functional restorative effect of aFGF.

Compact optical curvature sensor with a flexible microdisk laser on a polymer substrate

We demonstrate a chip-scale compact optical curvature sensor. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. A good agreement between experiment and three-dimensional finite-difference time-domain simulation was also obtained. The sensitivity of the compact device to the bending curvature is -23.7 nm/mm from the experiment.

Flexible compact microdisk lasers on a polydimethylsiloxane (PDMS) substrate

Compact microdisk cavities were fabricated on a polydimethylsiloxane substrate. The lasing of the flexible compact cavity was achieved with a low threshold power. The whispering-gallery mode of the microdisk was also characterized with three-dimensional finite-difference time-domain simulation. The curvature dependence in output power and threshold was also demonstrated by bending the microdisk cavity.

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.

Prediction of the distance from skin to epidural space for low-thoracic epidural catheter insertion by computed tomography

BACKGROUND

It may be clinically useful to predict the depth of the epidural space.

METHODS

To investigate the accuracy of preoperative abdominal computed tomography (CT) in prediction of the distance for low-thoracic epidural insertion, a single group observational study was conducted in 30 male patients undergoing elective major abdominal surgery requiring epidural analgesia for postoperative pain relief. Using the paramedian approach, low-thoracic epidural insertion at T10-11 interspace was performed with a standardized procedure to obtain an actual insertion length (AIL). According to the principles of trigonometry, an estimated insertion length (EIL) was calculated as 1.26 times the distance from skin to epidural space measured from the preoperative abdominal CT.

RESULTS

The mean (SD) EIL and AIL were 5.5 (0.7) and 5.1 (0.6) cm, respectively, with a significant correlation (r=0.899, P<0.01). The EIL tended to have a higher value than the AIL (0.4 (0.3) cm). There were significant correlations of both EIL and AIL with weight (P<0.01), BMI (P<0.01), and body fat percentage (P<0.01), but not with height (P>0.05).

CONCLUSIONS

We conclude that the preoperative abdominal CT is helpful in prediction of the distance for low-thoracic epidural insertion using the paramedian approach.

Welded tracheal stent removal in a child under cardiopulmonary bypass

Metallic tracheal stents have been used in the treatment of paediatric tracheomalacia for more than a decade. We describe a case in which critical airway obstruction occurred during removal of a welded tracheal stent using a rigid bronchoscope under general anaesthesia. Life-saving cardiopulmonary bypass was instituted urgently, and the welded stent was then removed successfully by directly opening the trachea.

Transoesophageal echocardiographic monitoring of pulmonary venous obstruction induced by sternotomy closure during infant heart transplantation

A case of an infant receiving orthotopic heart transplantation with over-sized donor heart was reported. Left lower pulmonary venous obstruction after sternotomy closure was detected by transoesophageal echocardiography (TOE) and the decision to delay sternal closure was made and the clinical outcome was very satisfactory. The usefulness of intraoperative TOE monitoring and postoperative TOE follow-up for infant heart transplantation, especially in those cases of size mismatch, was well demonstrated.

Neuromuscular pharmacology of TAAC3, a new nondepolarizing muscle relaxant with rapid onset and ultrashort duration of action

We selected bis [N-(3,4-diacetoxybenzyl) tropanium-3alpha-yl] glutarate dibromide (TAAC3) from many new tropinyl diester derivatives to evaluate its neuromuscular blocking (NMB) and autonomic side effects on anesthetized rats, rabbits, guinea pigs, cats, pigs, dogs, and monkeys. NMB potency, onset, recovery index, and duration of action were determined. Comparisons of these pharmacologic variables were made between TAAC3 and rocuronium. In the cat, the degrees of train-of-four and tetanic fade, posttetanic potentiation, and pharmacologic antagonism were evaluated. For determination of the NMB maintenance dose, TAAC3 was also given to rabbits and pigs in the initial dose/maintenance infusion mode. Cardiac vagal block was evaluated in the rat, pig, cat, and guinea pig on the basis of the inhibition of the bradycardia to stimulation of the vagus nerve. Sympathetic ganglion block was studied on the superior cervical ganglion-nictitating membrane preparation of the cat. TAAC3 produced nondepolarizing NMB. Its NMB 90% effective doses ranged from 90 to 425 microg/kg, depending on the species. TAAC3 had a faster onset (0.8-1.0 min), shorter recovery index (0.6-1.1 min), and shorter duration of action (1.8-3.5 min) than rocuronium. It produced a slight cumulative effect on infusion, but not on repeated single-dose administration. Cardiac vagal block was present at doses exceeding the NMB 90% effective dose. In the cat and pig at equipotent NMB doses, the degree of cardiac vagal block was similar to that of rocuronium. There was no demonstrable sympathetic ganglion block in the cat. In view of its favorable NMB characteristics, TAAC3 is now undergoing detailed preclinical studies.

IMPLICATIONS

We developed a new nondepolarizing muscle relaxant, TAAC3, and investigated it in several animal models. TAAC3 has shown a very rapid onset and an ultrashort duration of neuromuscular blocking action. A minor degree of cardiac vagal block was observed. TAAC3 is promising for further studies.

Reversal of mivacurium chloride: edrophonium of spontaneous recovery in microscopic laryngeal surgery

BACKGROUND

A double-blind, randomized study was designed to compare the recovery manner of mivacurium infusion with or without edrophonium reversal in microscopic laryngeal surgery. Neuromuscular blockade was quantified using the train-of-four stimuli to the ulnar nerve and quantification of the ratio of the fourth twitch to the first twitch.

METHODS

With the approval of the Human Studies Committee of the Taipei Veterans General Hospital and patient informed consent, 40 healthy (ASA I or II) patients with age from 24 to 54 years, undergoing microscopic laryngeal surgery were randomly selected for study. Mivacurium chloride 0.2 mg/kg was given intravenously, and then it was given in continuous infusion to maintain muscle relaxation at 90% twitch block during the procedure. At the end of operation, mivacurium infusion was terminated. In a double-blind manner, group I patients (n = 20) received intravenous edrophonium 1 mg/kg and atropine 0.01 mg/kg for reversal when T1 was at 10% recovery whereas patients in Group II (n = 20) received placebo in the same manner. Mean infusion rate, recovery index (RI50, time from T1 25% to T1 50%; RI75, time from T1 25% to T1 75%), extubation time, and discharge time between groups were compared. Nausea, vomiting, and dysrhythmias were also documented until the patient was discharged from hospital.

RESULTS

The demographic data between two groups were similar. The recovery index (RI75) for group I was shorter than that of placebo group (5.3 +/- 2.19 min vs. 7.3 +/- 0.9 min) and the difference was statistically significant (P = 0.017). There were no statistically significant differences in mean infusion rate, incidence of nausea and vomiting, and discharge time from the POR. The incidence of tachycardia or arrhythmia in group I was significantly greater than that in group placebo.

CONCLUSIONS

Mivacurium, a short-acting nondepolarizing agent, is a suitable muscle relaxant for patients receiving microscopic laryngeal surgery. Recovery time with the use of edrophonium as reversal agent was shorter than with placebo, but extubation and discharge time did not differ in two groups. The time which could be saved by the use of edrophonium for reversal of mivacurium to hasten the maximal recovery appears to be less than a few minutes. Therefore, clinically, the value of routine use of edrophonium to obtain a faster recovery does not outweigh its demerits of cost and risk and is not worthy of recommendation.

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.

Bedside pericardiocentesis under the guidance of transesophageal echocardiography in a 13-month-old boy

Pericardial effusion is a common sequel to cardiac surgery. Urgent pericardiocentesis is required in the case of cardiac tamponade. In adult patients, most pericardiocentesis is accomplished using transthoracic echocardiographic imaging. However, transthoracic echocardiographic imaging may interfere with the procedure field in children. We report the case of a 13-month-old boy who developed cardiac tamponade resulting in heart failure after surgical repair of tetralogy of Fallot. Urgent pericardiocentesis was safely performed at the bedside under transesophageal echocardiographic guidance. Transesophageal echocardiographic monitoring during pericardiocentesis in children has the advantages of better imaging of pericardial effusion without procedure-field interference.

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.

The assessment of the proximal left pulmonary artery by transesophageal echocardiography and computed tomography in neonates and infants: a case series

IMPLICATIONS

Transesophageal echocardiography (TEE) is often used during surgical repair of congenital heart disease. In our case series of 256 newborns and infants, we found that a left paracarinal view of TEE could visualize the proximal left pulmonary artery, a frequent blind spot for TEE, in most patients, except in a few cases with anatomic variations of the esophagus in the right lateral to the vertebra.

Resveratrol reduction of infarct size in Long-Evans rats subjected to focal cerebral ischemia

Resveratrol is found in a wide variety of plant species. It is present in the seeds and skin of grapes and constitutes one of the major components of red wine. This study was undertaken to evaluate whether resveratrol could effectively suppress infarct size from the damaging effects of focal cerebral ischemia. The middle cerebral artery was occluded for 1 hr and 24 hr reperfusion in anesthetized Long-Evans rats. In pretreatment or treatment groups, resveratrol, at dosages of 10(-6), 10(-7), 10(-8) and 10(-9) g/kg, was intravenous injected 15 minutes before middle cerebral artery (MCA) occlusion or when the common carotid arteries clips were removed respectively. Pretreatment or treatment of resveratrol (10(-6), 10(-7), 10(-8) and 10(-9) g/kg) did not produce any changes in pH, blood gases, heart rate or mean arterial blood pressure, but it significantly reduced the total volume of infarction at the doses 10(-6) and 10(-7) g/kg. Our study suggests resveratrol is a potent neuroprotective agent in focal cerebral ischemia. Its beneficial effects may be related to its anti-platelet aggregation activity, vasodilating effect, antioxidant property or by all mechanisms together.

Delayed airway obstruction secondary to inadvertent arterial puncture during percutaneous central venous cannulation

We report a case of fatal respiratory complication secondary to central venous cannulation in a 63-year-old male patient, which came up gradually and insidiously following an accidental puncture of carotid artery in an attempt to cannulate the right internal jugular vein. He died 14 h after the mishap due to severe upper airway obstruction. The nature of the vascular laceration was still obscure.

Neuroprotective effect of hexasulfobutylated C60 on rats subjected to focal cerebral ischemia

The effects of hexasulfobutylated C60 (FC4S), a free radical remover, on the total volume infarct size elicited by the damaging effects of focal cerebral ischemia were studied on Long-Evans rats in vivo. FC4S was administered intravenously either 15 min before middle cerebral artery (MCA) occlusion (pretreatment groups) or it was injected when the common carotid arteries clips were removed (treatment groups). FC4S did not alter the pH, blood gases, heart rate, or mean arterial blood pressure in either pretreatment or treatment groups of the rats. However, after administration of FC4S at dosages of 10 and 100 microg/kg, the total volume of infarction was significantly reduced in both pretreatment and treatment groups. In addition, after FC4S administration, the nitric oxide (NO) content in plasma was increased and the lactate dehydrogenase (LDH) levels was decreased. It is concluded that FC4S may be used as a neuroprotective agent on focal cerebral ischemia. The beneficial effects may be partly related to its antioxidant property and to the upregulation of NO production of the compound.

The addition of morphine prolongs fentanyl-bupivacaine spinal analgesia for the relief of labor pain

The combination intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) provides effective labor analgesia for approximately 90 minutes. The purpose of this prospective, randomized, double-blinded investigation was to determine if the addition of morphine (150 microg) to the intrathecal combination of fentanyl (25 microg) and bupivacaine (2.5 mg) would prolong labor analgesia. By using the combined spinal epidural technique, 95 healthy primiparous laboring women in early labor received 2 mL of one of the two intrathecal study solutions, either FB (n = 48): fentanyl (25 microg) and bupivacaine (2.5 mg); or FBM (n = 47): fentanyl (25 microg) and bupivacaine (2.5 mg) plus morphine (150 microg). The mean duration of labor analgesia was significantly longer in the FBM group than in the FB group (252 +/- 63 min vs 148 +/- 44 min, P < 0.01). There were no significant differences between the two groups regarding the sensory levels, the incidence of nausea, vomiting, pruritus, hypotension, or operative delivery. In conclusion, the addition of 150 microg of morphine to the intrathecal combination of fentanyl plus bupivacaine prolonged the duration of labor analgesia duration without increasing adverse effects.

IMPLICATIONS

The addition of morphine (150 microg) to intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) prolongs the duration of labor analgesia duration without increasing adverse effects.

Rapid recovery of spontaneous baroreflex after sevoflurane anesthesia in ambulatory surgery

BACKGROUND

Although sevoflurane seems to have fulfilled the criteria of ideal anesthetic agent for ambulatory surgery, its effects on intraoperative alteration and postoperative recovery of arterial baroreflex have not been well documented. This study assessed the time required for patients anesthetized with sevoflurane to regain their baseline baroreflex after ambulatory surgeries.

METHODS

Ten ASA class I female patients scheduled for minor gynecological operation (D&C) were enrolled in this study. Spontaneous baroreflex sensitivity (SBR) calculated by sequence analysis of beat-to-beat variations in systolic arterial pressure and R-R intervals was recorded before anesthesia (Baseline), during anesthesia (Anesthesia), five min after operation (Post-op 1) and ten min after operation (Post-op 2). Data obtained from Anesthesia, Post-op 1, and Post-op 2 was compared with the Baseline.

RESULTS

SBR value determined in Baseline group (28.6 +/- 4.9 ms/mmHg) was significantly different from Anesthesia group (12.2 +/- 2.1 ms/mmHg) and Post-op 1 group (15.8 +/- 1.8 ms/mmHg). Patients regained their conscious baseline baroreflex sensitivity within ten min after sevoflurane was switched off.

CONCLUSIONS

Sevoflurane anesthesia depresses SBR and provides a quick SBR recovery upon emergence.

Valveless outflow reconstruction using autologous tissue as a posterior wall for pulmonary atresia with ventricular septal defect

BACKGROUND AND PURPOSE

Reoperation is inevitable for some patients with pulmonary atresia who receive a heterograft or homograft in a primary Rastelli operation. Nonetheless, the need for reoperation in patients with classic Fallot's tetralogy who have undergone total correction with a transannular patch is unusual. We sought to change pulmonary atresia into Fallot's tetralogy and used a transannular patch instead of the conventional Rastelli operation.

PATIENTS AND METHODS

Valveless outflow direct reconstruction was performed on 10 consecutive patients with pulmonary atresia and ventricular septal defect between August 1997 and 1999. Patient ages ranged from 1.3 to 11.5 years. A Blalock-Taussig shunt was previously constructed in four of these patients and a central shunt was constructed in five. The major aortopulmonary collateral arteries were occluded in one patient by repeated coil embolization after the central shunt. The strategy was to connect the right ventriculotomy with the pulmonary arteries directly, even if there was a gap with a long atretic cord. In patients with a previous central shunt covered with a Gore-Tex membrane, the reactive visceral pericardium over the in situ tissue (the left atrium, right ventricle, or aorta) was used as the autologous posterior wall. Thus, only autologous, fresh pericardium without a valve was used to cover the anterior part of the right ventricular outflow tract, as in the repair of classic Fallot's tetralogy with a transannular patch.

RESULTS

There was no mortality, and the postoperative central venous pressure was low in all patients. No gradient was noted across the right ventricular outflow tract. Follow-up echocardiography revealed a competent tricuspid valve with mild pulmonary regurgitation in all patients.

CONCLUSIONS

The results of this study suggest that valveless outflow direct reconstruction provides adequate pulmonary circulation without hypertension in pulmonary atresia patients with a ventricular septal defect if the tricuspid valve is competent.

Pulmonary venous obstruction in patients with transposition of the great arteries

We report two cases of complete transposition of the great arteries with pulmonary venous obstruction which was diagnosed by intraoperative transesophageal echocardiography, but was not detected by transthoracic echocardiography and cardiac catheterization. The pulmonary venous obstruction was relieved simultaneously with arterial switch operation. The intraoperative transesophageal echocardiography has great contribution for thorough evaluation of the pulmonary venous return of the patients.

Graft failure caused by pulmonary venous obstruction diagnosed by intraoperative transesophageal echocardiography during lung transplantation

IMPLICATIONS

Intraoperative transesophageal echocardiography can be useful to diagnose pulmonary venous anastomotic stenoses during lung transplantation.