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Biomedical subjects

K Kumon

Publications and source records attributed to K Kumon.

At least 19 recordsLinked to original sources
PubMed1999

Nitric oxide inhalation as a chemical assist for circulation in patients after cardiovascular surgery.

The objective of this study was to investigate whether nitric oxide (NO) inhalation might be an alternative strategy as a chemical assist for the circulation in patients showing a deterioration in oxygen delivery. Twelve adult patients whose oxygen delivery indices (DO2I) were less than 400 ml/min/m2 after cardiovascular surgery were included in this study. NO was administered via a premixing system or a side stream system at doses between 1 and 10 (5.1+/-2.4) ppm. Data obtained before and during a 120 min NO inhalation were compared using the paired Student's t-test. The increase in PaO2/FiO2 resulting from NO inhalation was significant (from 162 to 251 mm Hg). DO2I increased significantly from 326 to 417 ml/min/m2 concomitantly with significant increases in both arterial oxygen content (CaO2) and cardiac index (CI) (from 14.1 to 15.4 vol% and from 2.31 to 2.71 L/min/m2 , respectively). The increase in SvO2 during NO inhalation was significant (from 55.2 to 62.6%). Among the other hemodynamic parameters, both total pulmonary resistance and systolic pulmonary arterial pressure (SPAP) showed significant decreases during NO inhalation, but right atrial pressure did not change significantly. There was a close relationship between the baseline SPAP level (bSPAP) and the decrease in SPAP during NO inhalation (dSPAP) (r = -0.88). However, negative correlations were observed between bSPAP and percentage increase in CI (%CI) (r = -0.61) and between bSPAP and percentage increase in DO2I (%DO2I) (r = -0.48). Moreover, positive relationships were observed between dSPAP and %CI (r = 0.62) and between dSPAP and %DO2I (r = 0.45). Hemoglobin (Hb) increased significantly from 11.0 to 11.4 g/dl. There were no significant changes in Fio2, pH, PacO2, or base excess (BE) during NO inhalation. The level of methemoglobin measured during the study period remained within the normal range (0.86+/-0.23%). In conclusion, NO inhalation could be an efficient and alternative assist for the circulation in patients whose oxygen delivery deteriorates after cardiovascular surgery.

Administration, Inhalation↗
PubMed1998

[Early recovery after valvular heart surgery].

There have been published not a few reports concerning the early recovery from heart surgery. But most of them were restricted in CABG cases. We report our efforts and its results about the early recovery from valvular heart surgery. To make a contribution to the early recovery we have made some efforts since 1995, including normothermic perfusion, low-dose fentanyl and introduction of terminal warm blood cardioplegia. As the results, the tracheal intubation period was shortened from 12.6 +/- 5.3 (hour) to 6.7 +/- 4.1. The number of the cases who had tracheal extubation in the operative day increased from 27% to 84%. The postoperative cardiac function was satisfactory and there were no abdominal or neurologic disturbances among the patients those who were entered into the early recovery protocol. We obtained satisfied early recovery in safe after valvular heart surgery.

Aortic Valve↗
PubMed1998

Antiphospholipid antibody syndrome in a case with redo coronary artery bypass grafting under cardiopulmonary bypass.

A patient who underwent redo coronary artery bypass grafting developed severe thrombocytopenia. A platelet transfusion caused recurrent hypotension and hypoxia. The patient status was complicated by a systemic thrombosis including coronary graft occlusion and central vein thrombosis. We found that the lupus anticoagulant, as well as other autoimmune antibodies, was positive only after the thrombotic episode developed. Even though the lupus anticoagulant returned to negative about 2 months after the episode of graft occlusion, the patient eventually died of heart failure.

Aged↗
PubMed1998

Value of mild hypothermia in patients who have severe circulatory insufficiency even after intra-aortic balloon pump.

STUDY OBJECTIVE: To evaluate the effectiveness of mild hypothermia in postcardiac surgical patients with severe heart failure in spite of conventional medical therapy and the use of intra-aortic balloon pumping (IABP). DESIGN: Prospective, clinical study. SETTING: Teaching hospital. PATIENTS: 10 postcardiac surgical patients with severe heart failure despite the use of IABP with massive doses of catecholamine. INTERVENTIONS: Patients underwent mild hypothermia produced by surface cooling (to approximately 34.5 degrees C). Hemodynamic criteria for the induction of hypothermia included a cardiac index (CI) of less than 2.2 L/min/m2 with a pulmonary capillary wedge pressure (PCWP) of up to 18 mmHg despite the use of IABP with massive doses of catecholamine. MEASUREMENTS AND MAIN RESULTS: After control measurements had been taken at normal core body temperature (37 degrees C), patients were cooled to approximately 34.5 degrees C (using a cooling blanket and gastric lavage with cold water) to decrease tissue oxygen (O2) demand. Patients showed significant improvements in CI (1.9 +/- 0.3 to 2.2 +/- 0.3 L/min/m2), mixed venous O2 saturation, (SvO2; 55 +/- 7 to 64 +/- 6%), and urine output (2.1 +/- 1.1 to 3.4 +/- 2.2 ml/kg/hr). Patients were rewarmed while SvO2 was being monitored. The duration of the hypothermia was 38 +/- 41 hours. Oxygen delivery increased in 8 of the 10 patients, the mean value (+/- SD) for the group rising from 309 +/- 65 ml/min/m2 to 358 +/- 57 ml/min/m2 as temperature was reduced from 36.7 +/- 0.4 degrees C to 34.7 +/- 0.3 degrees C. All patients were successfully weaned from IABP at 140 +/- 107 hours after admission to the intensive care unit. CONCLUSIONS: Mild hypothermia is a simple and useful procedure for improving the circulation of postcardiac surgical patients with severe heart failure despite the use of IABP.

Aged↗
PubMed1998

Cardiac surgery and inhaled nitric oxide: indication and follow-up (2-4 years).

We studied the effect of inhaled nitric oxide (NO) on 80 patients who had undergone cardiac surgery in our center. The indications for receiving NO inhalation and the number of patients were as follows: Pp/Ps > 0.5 for pulmonary hypertension (PH) (n = 32; 21 children and 11 adults), severe PH crisis (n = 9), high pulmonary vascular tone (Glenn pressure more than 18 mm Hg after bidirectional Glenn operation) or arterial oxygen saturation (SaO2) less than 70% despite an FiO2 of 1.0 after Blalock-Taussig shunt (n = 6), mean pulmonary artery pressure (PAP) > 15 mm Hg and transpulmonary gradient (TPG) (mean PAP - left atrial pressure [LAP]) > 8 mm Hg after Fontan-type operation (n = 18), elevated pulmonary vascular tone (mean PAP > 30 mm Hg and left ventricular assist system [LVAS] flow rate < 2.5 L/min/m2) in patients with LVAS (n = 3), and impaired oxygenation (PaO2/FiO2 < 100 under positive end-expiratory pressure [PEEP] > 5 cm H2O) (n = 12). Low dose inhaled NO (10 ppm) had the following effects. In adult PH patients, it significantly reduced the mean PAP (from 37.3 to 27.0 mm Hg; average values are given) and increased the mean systemic arterial pressure (SAP) (64.7 to 75.3 mm Hg). In infant PH patients, it increased the mean SAP (51.8 to 56.1 mm Hg). In patients with a PH crisis, it significantly reduced the central venous pressure (CVP) (13.3 to 8.8 mm Hg) while increasing both the mean SAP (49.4 to 57.9 mm Hg) and PaO2/FiO2 (135 to 206). In patients after a Fontan-type operation, it significantly reduced the mean PAP (16.8 to 13.8 mm Hg) and TPG (9.5 to 5.8 mm Hg). In patients under LVAS, it reduced the CVP (11.7 to 8.0 mm Hg) and mean PAP (32.0 to 24.7 mm Hg). In impaired oxygenation patients, PaO2/FiO2 was increased (75 to 106). Sixty-five patients were all followed for 2.0-4.3 years (average, 3.1 years). All 65 patients remained free from oxygen requirement, and possible chronic adverse effects including the occurrence of malignant tumors or chronic inflammation in the respiratory tract were not observed.

Administration, Inhalation↗
PubMed1998

Blood volume measurement at the bedside using ICG pulse spectrophotometry.

BACKGROUND: In the treatment of critically ill patients, blood volume (BV) measurement requires injection of some tracer substance and subsequent blood sampling to analyze the tracer concentration. To obviate both the sampling and laboratory analysis, techniques of pulse oximetry have been adapted to the noninvasive optical measurement in the patient's nose or finger of the arterial concentration of an injectable dye. METHODS: The authors report the clinical accuracy of a new noninvasive bedside BV measurement test that uses pulse spectrophotometry (the pulse method). The device detects pulsatile changes of tissue optical density of a nostril or a finger spanned by a probe emitting two infrared wavelengths (805 and 890 nm). After a peripheral or central intravenous injection of indocyanine green, the arterial dye concentration is continuously computed by reference to the previously measured blood hemoglobin concentration. Three types of tests of its accuracy are described here. RESULTS: In 10 healthy volunteers, the authors compared BV determined by the pulse method with an (131)I-labeled human serum albumin method. Three subject data sets were excluded because of motion artifact, a low signal:noise ratio, or both. For the other seven volunteers, the bias+/-SD of pulse spectrophotometric BV values were 0.20+/-0.24 l (or 4.2+/-4.9%) for the nose probe and 0.34+/-0.31 l (or 7.3+/-6.9%) for the finger probe, with a mean BV of 5 l. In 30 patients who underwent cardiac surgery, the pulse method was compared with a standard indocyanine green method using intermittent blood sampling. In three patients, the BV could not be determined by the pulse method because of motion artifact, low signal:noise ratio, or both. In 27 patients, the bias+/-SD of the BV by the pulse method was -0.23+/-0.37 l (-5.3+/-8.7%) for the nose and -0.25+/-0.5 l (-4.2+/-8.4%) for the finger. Patient BV ranged from 2.51 to 7.13 l (mean, 4.48 l). In 10 additional patients before cardiac surgery, BV was measured by the pulse method before and shortly after removal of 400 ml blood. The pulse method recorded a decrease of BV of 480+/-114 mL Three days after venesection, the mean BV was 117+/-159 ml less than the predonation control. CONCLUSIONS: In most patients, the pulse method provides bedside measurement of BV without blood sampling (except for hemoglobin determination), with an estimated error less than 10%. In 10-30% of tests the method failed because of motion distortion of the record during the 10-min data collection period or because of insufficient pulse amplitude in the test tissue.

Adult↗
PubMed1998

[A case of central sleep-apnea syndrome accompanied by bilateral paralysis of the diaphragma after pediatric cardiac surgery].

Sleep-apnea syndrome is a serious problem in respiratory care. Considerable attention has been paid to it, because it sometimes produces severe hypoxia and hypercapnia, and can cause death. We present a case of a six-year-old girl who showed sleep-apnea syndrome. She suffered from bilateral paralysis of the diaphragm after cardiac surgery and had to be managed under mechanical ventilation for three months. When weaning was tried from mechanical ventilation, she frequently showed apnea lasting over 15 seconds at night, and she was diagnosed as having sleep apnea. She was medicated with theophylline to stimulate the so-called respiratory center. Next day she was successfully weaned from mechanical ventilation. After she had been weaned from mechanical ventilation, hypoxia, hypercapnia, and tachycardia were detected by respiratory monitor at night. The respiratory monitor enabled us to identify the clinical appearance of sleep-apnea, and theophylline may have contributed to its improvement.

Cardiac Surgical Procedures↗
PubMed1997

Effects of inhaled nitric oxide on postoperative pulmonary circulation in patients with congenital heart disease.

We studied 22 patients with residual pulmonary hypertension or symptoms of postoperative pulmonary hypertensive crisis. They received low-dose inhalation (10 ppm) of nitric oxide (NO), a selective pulmonary vasodilator, after total correction for congenital heart anomalies. Fifteen minutes of NO inhalation improved the pulmonary circulation and lessened the imbalance in the ventilation-perfusion ratio in both groups. Thus, NO inhalation is effective in the treatment of pulmonary hypertension and in the prevention of pulmonary hypertensive crises after total correction for congenital heart anomalies. All patients continued to receive NO therapeutically. The duration of such therapeutic NO inhalation was well correlated with postoperative Qp/Qs (p = 0.014) and Rp/Rs (p = 0.029).

Administration, Inhalation↗
PubMed1997

Long-term sedation with isoflurane in postoperative intensive care in cardiac surgery.

After cardiac surgery, patients often require prolonged mechanical ventilation. We studied the effectiveness and potential toxicity of isoflurane sedation in 40 patients undergoing mechanical ventilation after cardiovascular surgery. All patients who received isoflurane (0.5-1.0 minimum alveolar concentration [MAC] were well sedated by it without significant adverse effects, such as renal, hepatic, or cardiovascular dysfunction. The highest serum inorganic fluoride concentration recorded was 45 mumol/L after 98 MAC h. Patients on isoflurane recovered more rapidly and were weaned from mechanical ventilation sooner than those sedated with intravenous drugs including fentanyl/midazolam. Patients who received intravenous sedatives, but not those on isoflurane, often showed tachyphylaxis in the early stages, and some exhibited an abstinence syndrome involving nonpurposeful movements. Patients sedated with isoflurane did not show these two side effects. In conclusion, isoflurane can provide effective long-term sedation for patients after cardiovascular surgery without significant adverse effects.

Acute Kidney Injury↗
PubMed1997

Helium/oxygen breathing improves hypoxemia after cardiac surgery.

The effects of helium/oxygen (He/O2) on oxygenation (respiratory index [PaO2/FiO2] and intrapulmonary shunt [Qs/Qt]) and on lung parameters (dynamic compliance [Cdyn] and peak inspiratory pressure [PIP]) were studied in 12 patients. After cardiac surgery, they had impairment of oxygenation without physiological findings and with normal chest radiographs despite having a positive end expiratory pressure of up to 10 cm H2O. After 90 min of inhalation of He/O2, oxygenation had improved significantly; that is, PaO2/FidO2 increased significantly (from 113 to 174 mm Hg; mean values are given; p < 0.01), and there was a significant fall in Qs/Qt (from 29 to 19%; p < 0.001) together with an increase in Cdyn (from 60 ml/cm H2O to 64 ml/cm H2O; p < 0.05). These results suggest that He/O2 may have improved oxygenation by recruiting previously obstructed small airways and alveoli.

Administration, Inhalation↗
PubMed1997

Successful treatment of mediastinitis after cardiovascular surgery using electrolyzed strong acid aqueous solution.

Dilute povidone-iodine solution has been widely used as an irrigant for the treatment of mediastinitis. However, its use is not without adverse effects and often causes poor growth of granulation tissues. To avoid the problems seen with the use of povidone-iodine solution, we applied electrolyzed strong acid aqueous solution (ESAAS) to mediastinal irrigation in 4 patients (2 infants and 2 adults) who developed mediastinitis after cardiovascular surgery. According to the "open" method, the mediastinal wound was left open and irrigated with ESAAS 1 to 3 times a day until the infection was eradicated. Satisfactory growth of granulation tissues was observed in all patients treated with no evidence of adverse effects attributable to ESAAS. Delayed primary sternum closure was performed for 2 patients, and musculocutaneous transposition of rectus abdominis for 1. Our experience suggests that irrigation with ESAAS is a safe and effective method of therapy for mediastinitis.

Acids↗
PubMed1997

[Antithymocyte globulin as conditioning regimen for bone marrow transplantation].

Bone marrow transplantation was performed with a conditioning regimen including antithymocyte globulin (ATG) for 8 patients with HLA-compatible unrelated donors or HLA mismatched donor. Administration of ATG was halted due to side effects in only 1 case, but the other cases were had no adverse reaction. During administration of ATG, platelet counts did not decrease rapidly, but platelet infusion was not effective in some cases. As compared between patients with conventional allogeneic BMT, autologous BMT or peripheral blood stem cell transplantation and those with ATG administration, no obvious difference was seen between the two groups in lymphocyte counts, CD3, CD4, CD8 and CD20 positive cells. No patient with ATG saffered graft failure or acute GVHD. However, cytomegalovirus infection was observed more frequently than in patients without ATG. In hematological malignancy, relapse was more frequent than in patients without ATG.

Adolescent↗
PubMed1996

[Transesophageal echocardiography (Part 2): Basic concepts in Doppler techniques].

Cardiac Doppler techniques provide information on blood flow dynamics by applying Doppler frequency shift analysis to echo signals from moving red blood cells. Velocity and direction of blood flow can be determined and instantaneously displayed on a monitor screen. These techniques include pulsed-wave Doppler (PWD), continuous wave Doppler (CWD) and color Doppler imaging (CDI). In PWD, short bursts of ultrasound waves are emitted at a pulse-repetition frequency (PRF), and velocity and direction of blood flow can be measured at specific locations in the heart. This technique enables measurement with high spatial resolution. By its nature as a sampling system, however, PWD can not accurately measure Doppler shift frequency exceeding the Nyquist limit (PRF/2). In CWD, ultrasound pulses are continuously emitted and received by two separate transducers. Precise localization of a sampling volume is impossible in this technique, but CWD can determine higher flow velocity without ambiguity than that detected by PWD. CWD is useful to evaluate high-velocity blood flows such as those seen with valvular diseases or shunt lesions. CDI displays two-dimensional patterns of blood flow in colors, superimposed on the two-dimensional images of the heart structures. Thus, the velocity, direction and location of blood flows can be visualized in real-time. This technique facilitates detection of abnormal blood flows in the heart and major blood vessels, and it is also utilized to evaluate the severity of valvular regurgitation.

Blood Flow Velocity↗
PubMed1996

[Transesophageal echocardiography (Part 1): Basic concepts in two-dimensional imaging and M-mode].

Transesophageal echocardiography has features suitable for intraoperative use. It enables intraoperative evaluation of cardiac or thoracic aortic lesions before and after surgical intervention. It also provides real-time information on cardiac performance throughout the operation without interfering with surgical procedures. Anatomical relationship of the esophagus and the heart allows the use of high frequency ultrasound, which is advantageous to increase the resolution of echo images. An ultrasound beam emitted by a transducer is absorbed, reflected and scattered as it progresses in inhomogeneous living tissues. The reflected ultrasound waves reach the transducer, and their mechanical vibrations are converted to electronic signals. These signals are further processed by the ultrasound imaging system, and echo images are displayed on a video screen. Ultrasound imaging techniques include M-mode, two-dimensional imaging and Doppler techniques. M-mode is the most basic technique, which displays a scroll of the echo signals along a single ultrasound beam on a video screen. It has higher temporal resolution than other modes, and is therefore useful for precise timing of events and quantitative measurements of size or distance within the cardiac cycle. Two-dimensional mode produces a real-time cross-sectional view of cardiac structures, which can be easily interpreted. It is suited to visualization of anatomic structures.

Aorta, Thoracic↗