Transesophageal echocardiography for intraoperative management of the fenestrated Fontan procedure.
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Echocardiography, Transesophageal↗
Biomedical subjects
S Kawahito
Publications and source records attributed to S Kawahito.
Intraoperative evaluation of pulmonary artery flow during the Fontan procedure by transesophageal Doppler echocardiography.
After the Fontan procedure, pulmonary artery (PA) flow is maintained without right ventricular pump function. We evaluated intraoperative PA flow velocity patterns using transesophageal Doppler echocardiography (TEE) immediately after cardiopulmonary bypass (CPB) in patients during Fontan or hemi-Fontan procedures. We studied 10 patients with single-ventricle physiology (age range, 5 mo to 3 yr 1 mo). Anesthesia was induced and maintained with fentanyl. After induction of anesthesia, a pediatric TEE probe was inserted into the esophagus. All patients had surgical repair involving direct anastomosis of the right atrium to the PA. Immediately after completion of CPB, adequacy of the atriopulmonary anastomosis was assessed and PA flow velocity was recorded. In all patients, the atriopulmonary anastomosis was clearly defined using a single-plane TEE probe, and PA flow recording was completed successfully. Intraoperative PA flow velocities showed two distinct patterns. Biphasic forward flows with peak velocities during systole and diastole were observed in six patients. The remaining four patients showed forward flows with flow reversals. The four patients demonstrating flow reversals showed significantly reduced fractional shortening (26.5+/-2.1% vs. 35.5+/-6.3%) and larger pressure gradient between the right atrium and left atrium (10.8+/-1.3 mm Hg vs 8.0+/-0.9 mm Hg) when compared to those without reverse flow. Two patients with reverse flow required reoperation because of hypotension. Because PA flow is influenced by pulmonary vascular resistance and left ventricular function, TEE assessed intraoperative PA flow should be further evaluated as a useful predictor of surgical outcome after a Fontan procedure.
Blood Pressure↗
Development of a new silicone membrane oxygenator for ECMO.
Two types small and efficient ECMO oxygenators were developed utilizing the most up to date hollow fiber technology. Newly silicone hollow fibers possess sufficient mechanical strength while maintaining ultra thin walls of 50 micro meter. Two types of oxygenators were made with this fiber. The fiber length for the type 1 module is 150mm with a priming volume 194 cc (surface area 1.3 m(2)) and type 2 has a fiber length of 100 mm with a 144 cc priming volume (the surface area 0.8 m(2)). The studies were performed at 0.5, 1.0 and 2.0 L/min of blood flow and these oxygenators demonstrated. O(2) gas transfer rate of 69+/-4 ml/min/L for type 1 and 68+/-6 ml/min/L for type 2. The CO(2) gas transfer rate was 25+/-2 ml/min/L for type 1 and 32+/-2 ml/min/L for type 2. These results demonstrate type 2 oxygenator has similar gas exchange capabilities to those of Kolobows' oxygenator which has about 2.0 times larger surface area. Additionally, comparative hemolysis tests were preformed with this new oxygenator and the Kolbow. The NIH value was 0.006 (g/100 L) for the type 1 oxygenator and 0.01 (g/100 L) for the Kolbow oxygenator. These results suggested that this ECMO oxygenator had sufficient gas exchange performance in spite of being smaller and induced minimal blood damage.
Equipment Design↗
Recurrent laryngeal nerve palsy after cardiovascular surgery: relationship to the placement of a transesophageal echocardiographic probe.
OBJECTIVE: To examine the relationship between the incidence of recurrent laryngeal nerve palsy after cardiovascular surgery and the placement of a transesophageal echocardiographic probe. DESIGN: A prospective clinical study. SETTING: A single-institutional study in a university hospital. PARTICIPANTS: One hundred sixteen patients undergoing cardiovascular surgery. INTERVENTIONS: All patients were assigned into one of two groups: 64 patients in whom transesophageal echocardiography (TEE) was performed and 52 patients in whom TEE was not performed during surgery. The incidence of recurrent laryngeal nerve palsy was examined and compared between the two groups. MEASUREMENTS AND MAIN RESULTS: Five of 64 patients (7.8%) in whom TEE was monitored and 3 of 52 patients (5.8%) in whom TEE was not monitored were diagnosed with recurrent laryngeal nerve palsy postoperatively. There was no statistically significant difference between the incidence of recurrent laryngeal nerve palsy in patients with intraoperative TEE monitoring, and patients without it. The durations of surgery, anesthesia, and cardiopulmonary bypass were significantly longer in patients with nerve palsy than those without it. CONCLUSION: These results suggest that placement of the transesophageal echocardiographic probe is not responsible for postoperative recurrent laryngeal nerve palsy. It seems likely that surgical manipulation itself and the durations of surgery, cardiopulmonary bypass, and tracheal intubation are related to the incidence of laryngeal nerve palsy.
Cardiopulmonary Bypass↗
Autotransfusion performed on a patient with cis AB blood group.
Cis AB blood group is a rare variant of the AB blood group resulting from inheritance of both A and B genes on one chromosome. It may lead to misclassification in ABO grouping and clinical misdiagnosis as a result of its divergence from the laws of Landsteiner and Mendel. We encountered a case of cis AB blood group, and we found that autotransfusion was useful during surgery in this patient with a rare blood group.
ABO Blood-Group System↗
Intraoperative management of a pediatric patient undergoing cardiac tumor resection with the aid of transesophageal and epicardial echocardiography.
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Child↗
The feasibility of gastrothoracic ventricular pacing during transesophageal echocardiography.
UNLABELLED: We evaluated whether ventricular pacing is possible using pacing electrodes attached to a transesophageal echocardiography (TEE) probe in 20 patients undergoing elective cardiovascular surgery. A bipolar pacing lead was fixed with silicone adhesive anteriorly to the TEE probe with the distal electrode 25 mm from the TEE probe tip. The TEE probe was positioned to obtain a transgastric short-axis view of the left ventricle. The distal or proximal electrode on the TEE probe was the cathode; the chest electrode placed at the V5 lead position was the anode. Gastrothoracic ventricular pacing (GVP) was performed at 100 bpm at 30- or 50-ms pulse duration. Transgastric ventricular pacing (TVP) was also attempted using both TEE probe electrodes alternately as cathode/anode. Maximal generator output was 32 mA. GVP with the distal electrode as cathode was successful in 75% and 80% of patients at 30- and 50-ms pulse durations and 23.3+/-5.8 mA and 22.6+/-5.8 mA threshold currents, respectively. However, success rates (20% and 25%, respectively) were significantly lower with the proximal electrode as cathode using the same pulse durations and 14.4+/-5.3 mA and 16.7+/-6.8 mA threshold currents. The TVP success rate was significantly lower than that for GVP. With optimization, this system could become an available technique for intraoperative emergency ventricular pacing. IMPLICATIONS: Using an endocardial pacing lead attached to a transesophageal echocardiography probe, gastrothoracic ventricular pacing can be performed successfully without complications in 75%-80% of patients undergoing cardiovascular surgery.
Adult↗
Simultaneous transesophageal echocardiography and atrial pacing for intraoperative management of mitral regurgitation.
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Bradycardia↗
Effects of sevoflurane on regional myocardial blood flow distribution: quantification with myocardial contrast echocardiography.
BACKGROUND: Using myocardial contrast echocardiography, the authors tried to determine whether sevoflurane causes myocardial blood maldistribution in humans and dogs. METHODS: In animal experiments, 15 mongrel dogs were organized into dipyridamole (n = 6) and sevoflurane (n = 9) groups. Sonicated albumin was infused into the left main coronary artery. The peak gray level corrected for background was analyzed at the following intervals: (1) at baseline, (2) after stenosis of the left circumflex coronary artery (blood flow reduced by 40%), (3) after administration of dipyridamole (1 mg/kg given intravenously) or sevoflurane (1 minimum alveolar concentration) during stenosis, and (4) after phenylephrine during stenosis and administration of dipyridamole or sevoflurane. In human studies, nine patients undergoing coronary artery bypass grafting were studied. During partial extracorporeal circulation, the peak gray level was analyzed before and 20 min after sevoflurane (1 minimum alveolar concentration). RESULTS: In animal experiments, dipyridamole decreased significantly the inner:outer ratio of the peak gray level in the ischemic area and the ischemic:normal ratio of the peak gray level. After arterial pressure was restored with phenylephrine, neither the inner:outer ratio nor the ischemic:normal ratio improved. In contrast, after sevoflurane administration, the inner:outer ratio and the ischemic:normal ratio remained unchanged, but these increased with phenylephrine. In human studies, sevoflurane did not change the inner:outer ratio in the area supplied by the most stenotic coronary artery. CONCLUSION: These results suggest that dipyridamole, a potent coronary vasodilator, produces maldistribution of coronary blood flow in our dog models, whereas sevoflurane does not do this in animal or human studies.
Aged↗
Anaesthetic management of a patient with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis.
PURPOSE: A case of a patient associated with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis is presented. CLINICAL FEATURES: Williams syndrome is a rare disease associated with a characteristic facies, supravalvular aortic stenosis, and mental retardation. A 15-yr-old girl with Williams syndrome underwent aortoplasty for supravalvular aortic stenosis. Anaesthesia was induced with fentanyl and thiamylal, and maintained with nitrous oxide, oxygen, sevoflurane, and continuous intravenous infusion of fentanyl. Supravalvular aortic stenosis was evaluated using a multiplane transesophageal echocardiography (TEE) probe before and after repair. CONCLUSION: Multiplane TEE was found to be very useful for anaesthetic management in a patient with Williams syndrome undergoing aortoplasty for supravalvular aortic stenosis.
Adolescent↗
Effects of nicardipine on ventriculo-arterial coupling in humans.
The ratio of effective arterial elastance (Ea) to left ventricular elastance (Ees) is an indicator of the coupling between ventricular properties and arterial load properties. Another criterion for the coupling between an energy source and its load is the principle of economical fuel consumption, or mechanical efficiency, which is defined as the ratio of stroke work (SW) to myocardial oxygen consumption per beat (MVO2). It has been revealed that SW of ventricular contraction is maximized when Ea/Ees = 1, while mechanical efficiency is maximized when Ea/Ees = 0.5. The purpose of the present study was to investigate the ventriculo-arterial coupling during hypertension, and the effects of nicardipine on this relationship in surgical patients using Ea/Ees and SW/MVO2 as indicators. Anaesthesia was maintained with isoflurane, nitrous oxide, and fentanyl. Radial artery pressure was displayed on a polygraph, and left ventricular end-systolic and end-diastolic volumes were determined by use of transoesophageal echocardiography. Ees was calculated as MAP/(ESVI-4), where MAP is mean arterial pressure and ESVI is end-systolic volume index. Ea was calculated as the ratio of MAP to stroke volume index (SVI). Stroke work index (SWI) was calculated as the product of MAP and SVI. MVO2 was assessed by estimating the ventricular pressure-volume area index (PVAI), which is expressed as the sum of SWI and the end-systolic potential energy index. Before (baseline), and 3, 10, 20, and 30 min after i.v. nicardipine (30 micrograms kg-1), Ea/Ees and SWI/PVAI were determined in 14 surgical patients with intraoperative hypertension. Before nicardipine (during hypertension), Ea was almost equal to Ees, whereas Ea/Ees was significantly reduced to about 0.5-0.6 at 3, 10, and 20 min after nicardipine. SWI/PVAI was maximized and significantly greater than the baseline value at 3 min after nicardipine. These results suggest that, during hypertension, ventricular and arterial properties were so matched as to maximize SW at the expense of the work efficiency, whereas mechanical efficiency of ventricular contraction was maximized after nicardipine.
Adult↗
[Hypoxemia during cesarean section--evaluation of venous air embolism by transesophageal echocardiography].
We studied the incidence and cause of hypoxemia during Cesarean section under general anesthesia. Arterial oxygen desaturation (< or = 95%) occurred in 6 of 28 patients (21%). Venous air embolism (VAE) was detected in 7 of 28 subjects (25%), but the severity of which was mild and was not associated with oxygen desaturation. While, there were significant differences in obesity index, preoperative respiratory function, and PaO2 after the induction of anesthesia between the patients with and without oxygen desaturation. Our results suggest that hypoxemia may occur frequently during Cesarean section under general anesthesia, but is not caused by VAE, and is related with the physiological changes associated with pregnancy.
Adult↗
[Effects of PGE1 on pulmonary arterial and venous flow in elderly patients--evaluation by transesophageal Doppler echocardiography].
Effects of PGE1 on pulmonary arterial and venous flow were evaluated noninvasively with transesophageal Doppler echocardiography in 13 elderly patients (70-79 years old), and the results were compared with those in control group of 13 patients (20-48 years old). In control group, infusion of PGE1 at a rate of 20 ng.kg-1.min-1 decreased pulmonary arterial pressure significantly, but not in elderly patients even at a rate of 50 ng.kg-1.min-1. In elderly patients, effects of PGE1 were more remarkable for afterload reduction than preload, so that cardiac output was maintained without change in stroke volume and heart rate, but with increase of heart rate in control patients. From our results, it is concluded that PGE1 may have less effect on pulmonary hemodynamics in elderly patients.
Adult↗
[Bronchospasm during anesthesia in a patient with Prader-Willi syndrome].
A patient with Prader-Willi syndrome developed bronchospasm during anesthesia. The patient was a 9-year-old boy and was scheduled for orchiopexy. His psychomotor development was delayed, and at 12 months of age he was diagnosed as Prader-Willi syndrome by chromosomal examination. The patient weighed 17 kg, was 111 cm tall, and had no symptom of upper respiratory infection preoperatively. Preoperative examinations were normal except supraventricular extrasystole in electrocardiogram. Following administration of scopolamine 0.15 mg intramuscularly as preanesthetic medication, anesthesia was induced smoothly by slow induction using N2O-O2-sevoflurane. However, right after endotracheal intubation with vecuronium 2 mg, remarkable stridor was noticed. Despite hyperventilation, the patient exhibited hypercapnia, and the diagnosis of bronchospasm was made. Aminophylline and steroid were administered intravenously and halothane was inhaled instead of sevoflurane. The bronchospasm was improved gradually and surgery was finished. Prader-Willi syndrome is an uncommon disease first reported by Prader in 1956 and characterized by hypotonia, hypomentia, hypogonadism and obesity. In the perioperative management for a patient with Prader-Willi syndrome, special attention must be paid to the abnormalities in the upper and lower respiratory systems.
Adrenergic beta-Agonists↗
A CMOS integrated circuit for multichannel multiple-subject biotelemetry using bidirectional optical transmissions.
A CMOS integrated circuit for a noninvasive biological-signal telemetry system specified for use in medical and physiological studies of the influence of weightlessness in space is presented. The system can monitor multichannel (4 channels maximum) biological signals from multiple subjects (4 subjects maximum) in real time by using time multiplexing. A key technique, so-called synchronized multiple-subject telemetry, to achieve multiple-subject telemetry has been proposed. This technique utilizes bidirectional optical transmissions with direct and scattered infrared lights between an observer and each of the subjects. An experimental CMOS IC to give a small light-weight low-power, and smart telemetry instrument for use on animals has been developed. This IC is for evaluating circuit blocks of the implantable monolithic telemetry instrument. The major circuit blocks include CMOS digital circuits for synchronization, subject selection and time multiplexing, analog circuits for pulse interval modulation (PIM), and other blocks such as a CMOS optical pulse receiver and an LED driver. A preliminary experimental multichannel telemetry from two subjects has been performed with the implemented IC chips, and the principal operation of the multiple-subject optical biotelemetry has been demonstrated.
Aerospace Medicine↗
[Effects of diltiazem hydrochloride on blood gases].
The effects of diltiazem, Ca ion channel blocker, on arterial blood gases were evaluated in 50 patients (G-I: 24 patients undergoing abdominal surgery, G-II: 26 patients undergoing non-abdominal surgery). Diltiazem hydrochloride was administered to prevent intraoperative hypertension as a bolus (5 mg) followed by a continuous infusion (5-10 micrograms.kg-1.min-1). Arterial blood gases were analyzed just before, as well as 5 and 15 min after the administration of diltiazem. In G-I, arterial blood oxygen tension decreased significantly (P < 0.001) from 210.8 +/- 42.4 to 197.7 +/- 50.2 mmHg 5 min after infusion, and to 193.2 +/- 53.4 mmHg 15 min after; while there was no significant difference in G-II. Diltiazem infusion may deteriorate oxygenation in patients undergoing abdominal surgery, and therefore oxygenation should be carefully monitored.
Abdomen↗
[Severe hypoxemia during cesarean section].
We describe three cases in which severe hypoxemia occurred during cesarean section. The first and second patients showed low oxygen saturation (91, 90%, respectively) on their arrival at the operation room, and hypoxemia deteriorated rapidly after the induction of anesthesia. During surgery low oxygen saturation, ranging from 90 to 95%, persisted until the beginning of spontaneous respiration. In the third patient, oxygen saturation fell suddenly to 93% after the delivery of a neonate, and the arterial blood gas analysis revealed Pao2 68.5 mmHg with 38% oxygen. Hypoxemia was transient and resolved at the end of operation. Parturients have been reported to be likely to develop hypoxemia physiologically. Apnea for a short interval during tracheal intubation may cause severe hypoxemia in parturients compared with normal subjects. Ritodrine, a beta 2 stimulator, which was administered in the first and second patients just prior to operation, may be one of the factors leading to hypoxemia because of its inhibition of hypoxic pulmonary vasoconstriction. Venous air embolism (VAE) may occur frequently during cesarean section, especially during repair of the uterus. VAE may have caused hypoxemia in the third patient. In conclusion, parturients should be monitored carefully with pulse oximetry during cesarean section.
Adult↗
[Effects of sevoflurane on regional myocardial oxygen balance in the canine heart with coronary artery stenosis].
The effects of increasing inspired sevoflurane (Sev) concentrations (0.5, 1.0, 1.5, 2.0 MAC) on regional myocardial oxygen balance and metabolism were studied in 10 open-chest dogs with coronary artery stenosis. Regional myocardial oxygen balance was assessed by continuous recording of subendocardial and subepicardial oxygen tensions. After the basal measurement, the left circumflex coronary artery blood flow (CBFLCX) was reduced by 20% with a screw flow regulator. The institution of stenosis caused a slight but significant decline in subendocardial oxygen tension. Otherwise, there were no significant differences between basal values and those after the stenosis. During the subsequent inhalation of Sev at 0.5, 1.0 and 1.5 MAC, endocardial oxygen tension was maintained at the level of control value. Sev 2.0 MAC caused a severe reduction in systemic arterial pressure and resulted in a marked and significant decline of endocardial oxygen tension compared with control value. On the other hand, subepicardial oxygen tension remained unchanged during each Sev inhalation. The ratio of epicardial/endocardial oxygen tension did not show a significant decline with increasing Sev concentration. It seems that Sev may not possess sufficient potency to cause myocardial ischemia by redistribution of coronary blood flow.
Anesthesia, Inhalation↗