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.

Gastric rupture after awake fibreoptic intubation in a patient with laryngeal carcinoma.

An 86-yr-old man with recurrent laryngeal carcinoma developed gastric rupture after awake fibreoptic intubation before induction of general anaesthesia. Early clinical signs included a distended, tense and tympanic abdomen with pain and massive pneumoperitoneum (chest radiograph). Laparotomy revealed a 4-cm longitudinal perforation along the lesser curvature of the stomach. This case represents a rare but severe complication that may occur during fibreoptic intubation in the awake patient.

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.

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.

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.

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.

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.

Comparison of invasive and non-invasive measurement of spontaneous baroreflex during anesthesia.

BACKGROUND: Many works have shown that beat-to-beat variations in systolic arterial pressure (SAP) could be used for the assessment of cardiac baroreflex function. The purpose of this study was to evaluate whether Finapres, a non-invasive device to measure systolic arterial pressure, could serve as an acceptable alternative to intra-arterial catheterization for assessing the spontaneous baroreflex during anesthesia. METHODS: Thirty ASA class I patients scheduled for surgical hepatic and gastric tumor excisions were enrolled in this study. Spontaneous baroreflex sensitivity (SBR) during anesthesia was calculated by sequence analysis of beat-to-beat variations in systolic arterial pressure and R-R intervals. Data obtained from Finapres were compared with those from standard intra-arterial catheterization technique. RESULTS: SBR values determined by non-invasive and invasive blood pressure measurement technique were precisely correlated (r = 0.96) and the mean difference was about 0.22 ms/mmHg (12.5%). However, the individual data might differ by -0.52 to +0.96 ms/mmHg (-35% to +60%). CONCLUSIONS: Finapres may trace the changes of SBR during anesthesia and provides similar results as does invasive method but individual variation exists.

Spinal anesthesia in MELAS syndrome: a case with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes.

MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) is one of the classic mitochondrial encephalomyopathies with variable clinical presentation and multisystem involvement. Enhanced sensitivity to neuromuscular blockade or anesthetic agents and susceptibility to malignant hyperthermia in these patients have ever been reported, all of which complicate the management of general anesthesia. To avoid these appalling troubles in general anesthesia, we chose spinal anesthesia for a patient with MELAS syndrome receiving appendectomy. The patient obtained adequate anesthesia and good recovery without neurologic sequelae. Although there is little information about the application of regional anesthesia in MELAS patients, we demonstrate that it may be a satisfactory choice. However, it is suggested that regional anesthesia is performed only when neurological abnormalities of spinal cord or peripheral nerves are definitely ruled out.

First successful ventricular septation of double inlet left ventricle in Taiwan.

Patients with a double inlet ventricle may undergo surgery using a modified Fontan procedure, in which the pulmonary ventricle is not utilized, or a procedure in which a pulmonary ventricle is created through ventricular septation. Ventricular septation is preferred to the Fontan procedure because there is better cardiorespiratory response to exercise after surgery. A 4-year-old girl with Holmes heart underwent ventricular septation on 12 May 1998. Pulmonary artery banding had been performed at 3 months of age and rebanding 16 days later. She was well and continued to grow. Ultrafast computed tomography and cardiac catheterization prior to surgery showed a double inlet left ventricle (LV) connected to a right posterior aorta with a right-sided rudimentary right ventricle that drained to the left anterior pulmonary trunk. Left ventricular end diastolic volume was 218% of normal and the ejection fraction was 79%. After debanding and enlargement of the bulboventricular foramen, a 3 x 4-cm composite patch of equine pericardium and Dacron velour was used to septate the ventricle, with transmural stitching at the apical portion. The patient survived the operation with complete atrioventricular block, and was extubated 6 days later. A permanent pacemaker was implanted 1 month later. One year after surgery, she was doing well. Echocardiography revealed paradoxical septal motion with good ventricular function. This is the first report of successful ventricular septation of a double inlet left ventricle performed in Taiwan.

Comparison of recovery characteristics of sevoflurane and halothane for outpatient surgery in infants.

BACKGROUND: Sevoflurane, a newly approved potent inhaled anesthetic in Taiwan, provides rapid emergence from anesthesia in adults and children. Clinically, it is difficult to accurately assess the rate of recovery from anesthesia in infants. This study was designed to compare the emergence characteristics of halothane with those of sevoflurane having recourse to a respiratory agent monitor in infants undergoing outpatient surgery. METHODS: Forty infants of ASA class I, scheduled for day-case urologic surgery were studied. Patients were randomly allocated to two groups of 20. Sevoflurane or halothane was used as the inhaled anesthetic. Toward the end of surgery, sevoflurane or halothane was turned off. The concentrations of exhaled sevoflurane or halothane were read every minute after its discontinuation until extubation. The decay curve of the exhaled concentration of either agent was recorded minute by minute for 10 minutes. The time intervals from discontinuation of the inhalation agent to spontaneous movement and tracheal extubation were recorded. Untoward side-effects during emergence were also compared. RESULTS: Sevoflurane was eliminated faster than halothane. Based on the decay curves of the exhaled concentrations of the two agents, the time constant for halothane was 2.59 minutes and that for sevoflurane was only 1.43 minutes. The time from discontinuation of agent to extubation was also shorter for sevoflurane. Postoperative restlessness or agitation occurred more frequently in infants who received sevoflurane, although the difference was of no statistical significance. CONCLUSIONS: Sevoflurane is superior to halothane for rapid elimination in infant outpatient surgery as gauged by observation of end-tidal concentration elimination curves recorded with a respiratory agent monitor. No other postoperative side-effect was evident in sevoflurane anesthesia.

Effects of estrogen on autotomy in normal and ovariectomized rats.

Gonadal hormones may modulate analgesia responses induced by acute stress in humans and rats. To evaluate the effects of gonadal hormones in modifying neuropathic pain, we measured autotomy changes following sciatic nerve resection in ovariectomized rats and in the presence of estrogen replacement. Two groups of female rats were subjected to ovariectomy and sham surgery. Each group was then divided into two subgroups receiving subcutaneously sesame oil with or without estradiol benzoate (5 microg/day/rat). All rats then underwent sciatic nerve resection in one hindlimb. Degree of self-mutilation was measured daily for 8 weeks. Estradiol treatment resulted in significantly lower autotomy scores in ovariectomized rats (3.6 +/- 0.6 vs. 5.5 +/- 0.3, p < 0.01) and in sham-operated rats (3.4 +/- 0.7 vs. 5.1 +/- 0.4, p < 0.05). The results of this study indicate that estrogen can modify the autotomy behavior, an indicator of neuropathic pain, in rats after nerve injury.

Airway management and transesophageal echocardiographic monitoring for pulmonary artery sling.

Pulmonary artery sling is an uncommon vascular anomaly and can be life threatening when it causes tracheal compression. We report on a 14-day-old boy who presented with respiratory distress soon after birth. A series of examinations showed tracheal stenosis due to a pulmonary artery sling. Surgery was performed with the aid of cardiopulmonary bypass. The external compression and intrisic stenosis could not be resolved by vascular surgery because of tracheal malacia and a complete tracheal ring. We recommend cutting extra holes 1 to 2 cm from the distal end of the endotracheal tube for endobronchial intubation. The airway obstruction was resolved successfully with a custom-made endobronchial tube. However, the patient died of pneumomediastinum and pneumothorax induced by barotrauma, on the fourth postoperative day.

The neuromuscular effects of mivacurium in adults with priming technique during nitrous oxide-fentanyl anesthesia: a randomized comparative study with succinylcholine.

BACKGROUND: We investigated the neuromuscular effects of equipotent dose (3 x ED90) of mivacurium either given as a single bolus or under the influence of priming technique, comparing with that of succinylcholine in adults undergoing elective surgery during nitrous oxide-narcotic anesthesia. METHODS: Sixty ASA class I patients of either sex with age between 16 to 49 years were randomly assigned to 3 groups for a trial of mivacurium under nitrous oxide-narcotic anesthesia. Group I (non-priming group, n = 20) received mivacurium 0.25 mg/kg straight as a single intubating dose; Group II (priming group, n = 20) received an intubating dose of 0.225 mg/kg mivacurium which was preceded by 0.025 mg/kg 3 min earlier; and Group III received an intubating bolus of succinylcholine 1 mg/kg. Thenar electromyogram response to supramaximal train-of-four stimulation of the ulnar nerve at 12-s intervals was used to determine neuromuscular blockade. Blood pressure and heart rate were recorded before and at 1-min interval for 3 min after injection of drugs. Data were presented as mean +/- standard deviation. P value < 0.05 was considered statistically significant. RESULTS: The onset time of mivacurium was accelerated by priming procedure in comparison with the nonpriming technique (2.0 min vs. 2.7 min), but it was much slower than that of succinylcholine (0.8 min). The priming procedure did not influence the duration of action or recovery. Side effects of mivacurium, such as cutaneous flushing and hypotension, were minimal at this dose in our patients. CONCLUSIONS: Priming technique (with 10% of the total dose as the priming dose, and 3 min as the priming interval) can hasten the onset of mivacurium in adults during nitrous oxide-narcotic anesthesia without influencing the duration of action and recovery time.

Effect of BL-10 (tianzhu), BL-11 (dazhu) and GB-34 (yanglinquan) acuplaster for prevention of vomiting after strabismus surgery in children.

BACKGROUND: Stimulation of P6 (Neiguan) acupoint can prevent nausea and vomiting in adults. However, there is no antiemetic effect in children undergoing strabismus surgery. The effect of P6 may act only on hollow organs; in contrast, BL-10 (Tianzhu), BL-11 (Dazhu) and GB-34 (Yanglinquan) are more related to the meridians of the eye. Therefore these three more relevant acupoints, BL-10, BL-11 and GB-34 were stimulated to evaluate the antiemetic effect in children undergoing strabismus surgery. METHODS: Sixty-five children, ASA physical status I, between 3 and 14 years of age, were randomly divided into two groups as follows: placebo group (n = 31) and acuplaster group (n = 34). Bilateral acupressure using the Vital Point Needleless Acuplaster (Koa, Japan) was applied to BL-10, BL-11 and GB-34 points the night before surgery. Anesthesia was induced and maintained with halothane and nitrous oxide in oxygen. Postoperative emesis was assessed at early (at PACU) and late (at ward) phases, and was recorded by an investigator blind to the treatment characteristics. RESULTS: In the early emesis phase, the incidence of vomiting was 35.5% for placebo group, compared with 14.7% for acuplaster group. In the late emesis phase, acuplaster patients had a significantly lower incidence of vomiting (23.5% vs. 58.1% in placebo patients, p < 0.05). The overall postoperative vomiting incidence in the acuplaster patients in a 24 h period which was significantly decreased was 29.4% as opposed 64.5% in the placebo group (p < 0.05). CONCLUSIONS: The results demonstrated that prophylactic use of bilateral noninvasive acuplaster on the BL-10, BL-11, and GB-34 acupoints significantly reduces vomiting after strabismus correction. The mechanism may be dispersal of these three acupoints, thus diminishing the parasympathetic stimulation resulting from surgical traction of eye muscles.

Preoperative evaluation and postoperative prediction of hemostatic function with thromboelastography in patients undergoing redo cardiac surgery.

BACKGROUND: Patients who receive cardiac procedures, in particular "redo" ones, often suffer complications from massive bleeding, largely due to bypass-induced coagulopathies. Cardiopulmonary bypass (CPB) may cause damage of the blood components, both in terms of quality and quantity. In order to investigate the qualitative changes of blood constituents with special regard to coagulation resulting from the complex insult of previous cardiac surgery, thromboelastography (TEG) was used to analyze the whole clotting process. METHODS: Seventy-four patients who underwent cardiac surgery with CPB were prospectively studied. Of them, 32 patients received "redo" cardiac surgery. Blood samples for routine laboratory coagulation tests (RCT) and TEG examination were drawn before and after cardiopulmonary bypass. Clinically significant bleeding was defined if the chest tube drainage was greater than 100 ml/h for 3 consecutive h or greater than 300 ml in 1 h during the first 8 h after surgery. Prebypass and postbypass coagulation parameters were compared and the percentage of accuracy, false positive and false negative rate were deduced from calculation. RESULTS: In the TEG tracings, preoperative alpha angle and maximum amplitude were significantly decreased in the "redo" group when compared with primary group, indicating less competent platelet function and platelet-fibrin interaction. Lower platelet count was also found by conventional coagulation tests in "redo" patients. Postoperatively, higher percentage of excessive hemorrhage was also noted in the "redo" group (42.8% vs. 27.5% in primary group). However, a much lower predictive accuracy was found in "redo" patients in comparison with primary cardiac patients (53.5% vs. 90%). CONCLUSIONS: We concluded that thromboelastography failed to predict postoperative hemorrhage in "redo" cardiac patients and the graphic recordings derived could not be treated as a guide of transfusion therapy. We thought that inferior preoperative hemostatic status and severer coagulopathy might be responsible for the differences between "redo" and primary cardiac patients.

Priming technique accelerates the onset time of mivacurium in children during halothane anesthesia.

BACKGROUND: Mivacurium is considered a relaxant suitable for tracheal intubation in children due to its rapid onset. We compared the neuromuscular effects of mivacurium, with and without priming, in children undergoing elective surgery during halothane anesthesia. METHODS: Forty pediatric patients (2-10 yr, ASA class I) were randomly into 2 groups and studied under halothane anesthesia. The non-priming group (n = 20) received mivacurium 0.25 mg/kg, and the priming group (n = 20) received a priming dose of mivacurium 0.025 mg/kg, followed by an intubating dose of 0.225 mg/kg 3 min later. Thenar Electromyogram responsive to supramaximal train-of-four stimulation of the ulnar nerve at 12 s intervals was used as neuromuscular monitoring. RESULTS: The onset time in the priming group was significantly faster than in the non-priming group (1.04 min vs. 1.7 min). The mean time from injection of intubating dose to spontaneous recovery to 25%, 50% and 75% twitch were not influenced by priming technique. Side effects, such as cutaneous flushing and hypotension, were unremarkable at this dose in children. CONCLUSIONS: Priming technique can significantly accelerates the onset of mivacurium in the pediatric patients under halothane anesthesia.

Anesthetic management in a parturient with progressive systemic sclerosis during cesarean section--a case report.

This case report concerns a successful Cesarean section (C/S) delivery in an expectant woman affected with progressive systemic sclerosis (PSS) with clinical manifestations of severe pulmonary hypertension (PH), cor pulmonale, severely restrictive ventilatory impairment, pregnancy-induced hypertension (PIH), and esophageal dysfunction under general anesthesia (GA). This is an extremely rare condition in obstetrics and the victim is usually in a great peril of conception, delivery, surgery and anesthesia because of poor pulmonary and cardiac reserves. We herewith reported our experience in two GAs given uniquely to the same patient who was affected with the disorder and discuss the problem.

The physiological effect of CO2 pneumoperitoneum in pediatric laparoscopy.

BACKGROUND: The physiological effect of CO2 pneumoperitoneum during laparoscopy is a great concern of the anesthesiologists. Its effect in pediatric laparoscopy has not been previously reported. The purpose of this study was to examine the physiological alteration of pediatric patients during CO2 pneumoperitoneum. METHODS: One hundred and twenty six children aged from 11 mon to 13 yr undergoing laparoscopic inguinal exploration were divided into three groups based on age orientation: group I comprising 40 children with age from 11 mon to 2 yr; group II 46 children with age between 2 to 5 yr; and group III 40 children aged from 5 to 13 yr. All patients received endotracheal anesthesia with halothane-N2O in 50% O2 and atracurium for muscle relaxation. Respiration was controlled by an Ohmeda 7000 ventilator with constant minute ventilation to maintain baseline end-tidal CO2 tension (PETCO2) between 32-33 mmHg. After anesthesia, CO2 was insufflated into the peritoneal cavity via the opened hernia sac. The intraabdominal pressure exerted by CO2 was 10 mmHg and the duration of pneumoperitoneum and laparoscopy was 15 min. We recorded airway pressure, PETCO2, body temperature, blood pressure, heart rate, heart rhythm, and oxygen saturation simultaneously at 1 min interval before, during, and after laparoscopy. RESULTS: The airway pressure and PETCO2 showed significant increases during laparoscopy (15-18% and 18-20% respectively) in all cases, but the percentage of increases were not significantly different among groups. However, the PETCO2 change in terms of time lag were different between groups: (1) the time lag from CO2 insufflation to the emergence of PETCO2 change (latent period) was respectively 0.7 +/- 0.1 (mean +/- SD) min in group I, 0.9 +/- 0.2 min in group II and 1.5 +/- 0.2 min in group III (p < 0.05); (2) the PETCO2 change from baseline to a plateau (ascending period) was respectively 4.2 +/- 0.6 min in group I, 6.3 +/- 1.0 min in group II and 9.1 +/- 1.1 min in group III (p < 0.05); (3) the PETCO2 decline from plateau to baseline after CO2 deflation (descending period) was respectively 6.2 +/- 0.5 min in group I, 8.3 +/- 0.8 min in group II and 12.0 +/- 1.3 min in group III (p < 0.05). The body temperature and hemodynamics including blood pressure, heart rate, heart rhythm, oxygen saturation were not significantly changed during laparoscopy in all groups. CONCLUSIONS: The changes of PETCO2 during laparoscopy did not influence the hemodynamic stability in our study. The younger children give a faster reaction time of PETCO2 change after CO2 insufflation than do the older children which may be related to the variation of physiological exhibition at different state of development.

Transesophageal indirect atrial pacing for open-heart surgery in children.

BACKGROUND: Transesophageal atrial pacing (TAP) has been successfully applied for clinical use for more than 30 years. Not only for cardiac pacing, or diagnosis and treatment of rhythmic disturbance but also for assessing the presence and severity of coronary artery disease and maintaining adequate heart rate can TAP provide satisfactory effect. In this study we applied TAP on children undergoing the cardiac surgery to evaluate its efficacy and side effects during such major surgery. METHODS: Twenty-four children (15 M and 9 F) undergoing open-heart surgery with informed consents were included in this study. After induction of anesthesia the bipolar pacing electrode (Tapcath, Arzco Medical Electronics) was inserted into esophagus through the nose until the ideal site for atrial pacing was found by monitoring the esophageal ECG lead (lead I), and then initiation of atrial pacing was performed by applying the transesophageal cardiac stimulator (Arzco Medical Electronics). Continuous ECG, arterial blood pressure and central venous pressure (CVP) were simultaneously monitored and recorded. Patient's height, inserted length of the pacing electrode, current and pulse duration for effective atrial pacing were also recorded. RESULTS: The effective rate for initiating sinus tachycardia (atrial capture) by applying TAP was 79.2% (19/24) in our study. For effective atrial pacing the average current was 11.6 +/- 2.4 mA, the average stimulus pulse duration was 4.8 +/- 1.0 ms, and the average inserted length of bipolar electrode was 19.1 +/- 2.2 cm. CONCLUSIONS: TAP method can be applied satisfactorily in children undergoing cardiac surgery. If urgent cardiac pacing must be applied in these patients TAP would be a choice.