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Biomedical subjects

Y Sakanashi

Publications and source records attributed to Y Sakanashi.

18 recordsLinked to original sources
PubMed2001

Experimental evaluation of the V-point heparin-bonding system applied to a dense-membrane artificial lung during 24-hour extracorporeal circulation in beagles.

Heparin was covalently bonded to a hollow-fiber dense-membrane artificial lung and circuit using a silane coupling agent and polyethyleneimine as a spacer. This study investigated whether the novel artificial lung could sustain prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in beagles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagulant nafamostat mesilate, and without any systemic anticoagulant. The results were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificial lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the artificial lung. Although several clots were observed in stagnant areas of the artificial lungs and circuits, there was no clot formation inside the artificial lung in any group. This highly biocompatible, heparin-bonded dense-membrane artificial lung performed well and safely during prolonged ECLA with blood clotting times less than 120 s.

Animals↗
PubMed2000

Jugular vein temperature reflects brain temperature during hypothermia.

PURPOSE: The neuroprotective properties of mild to moderate hypothermia are well recognized but may not be employed correctly because brain temperature cannot usually be measured directly. This study investigated the jugular vein as a more accessible site that accurately reflects the actual brain temperature during mild, induced hypothermia. METHODS: We selected ten mongrel dogs (mean weight 12 +/- 2 kg) and measured temperatures of the brain, jugular vein, cisterna magna, pulmonary artery and rectum during hypothermia, including cooling and rewarming. The brain temperature needle probe was inserted 2.0 cm into the parenchyma. A temperature probe was placed in the cisterna magna with an epidural needle. Swan-Ganz thermistor probes measured the jugular venous and pulmonary artery blood temperatures. RESULT: The brain temperature decreased from 37.5 +/- 0.3 to 33.0 +/- 0.3 degrees C over an average 150 +/- 45 min cooling period. Stable cool was maintained for 245 +/- 32 min, followed by 165 +/- 50 min for rewarming from 33.5 +/- 0.3 to 37.5 +/- 0.3 degrees C. Jugular, cisterna magna and pulmonary arterial blood (PAB), but not rectal temperature, were close to brain temperature during stable cool. The mean jugular and cisterna magna temperatures were near the brain temperature at 0.1 degrees C higher and 0.1 degrees C lower, respectively. No significant effects of hypothermia were noted on hemodynamics in any phase. CONCLUSION: Jugular vein temperature, along with cisterna magna and pulmonary artery blood and rectal temperature, reflected brain temperature during hypothermia. The jugular vein and cisterna magna sites more sensitively reflected brain temperature than other sites.

Animals↗
PubMed2000

Total and prolonged filling of the lungs with Ringer's solution under extracorporeal lung assist (ECLA) in dogs.

BACKGROUND: Massive alveolar lavage has been used clinically to remove materials accumulated in the alveoli. Recently, filling the lungs with oxygenated perfluorochemical (total liquid ventilation) has been investigated. However, effects of complete and prolonged filling of bilateral lungs with aqueous fluid, such as saline or Ringer's solution, has not been evaluated, although it is possible to sustain gas exchange without the natural lung by using extracorporeal circulation and an artificial lung (extracorporeal lung assist: ECLA). It is also not known whether the lung can recover gas exchange ability after prolonged fluid filling. METHODS: Normal mongrel dogs were endotracheally intubated under general anesthesia and mechanically ventilated. After initiation of venoarterial ECLA, warmed lactated Ringer's solution was instilled into the lungs through the endotracheal tube, and the lungs were completely filled at a hydrostatic pressure of 15 cmH2O (fluid-filled group: group F). After the lungs were filled for 4 h, the fluid was drained and ventilation was re-instituted. ECLA, then mechanical ventilation was gradually weaned within 24 h after fluid drainage. In control group (group C), dogs were kept apneic for 4 h with their lungs inflated at an airway pressure of 15 cmH2O with air. RESULTS: Transient hypoxemia occurred during fluid filling but every dog could be weaned from ECLA and mechanical ventilation to spontaneous respiration. The average rate of fluid absorption from the lung during fluid filling was 4.2+/-1.8 ml kg(-1) h(-1). After fluid drainage and restart of mechanical ventilation, bilateral lungs were expanded and well aerated. Total static respiratory system compliance (static compliance) remained unchanged even after fluid filling, and the weight of the lung water did not increase significantly compared to that in group C. Total urine volume was significantly increased in group E Histologically, alveolar structures were preserved and no interstitial edema or bleeding was seen in either group. CONCLUSION: Complete filling of the bilateral lungs for 4 h with lactated Ringer's solution under ECLA causes no deterioration in gas exchange or static compliance in normal dogs, although transient hypoxemia occurs during fluid filling.

Animals↗
PubMed1999

[Incidence of asthmatic attack during anesthesia in patients with a history of bronchial asthma].

We investigated retrospectively, the incidence of intraoperative asthmatic attack in patients with bronchial asthma, and compared the past 5-year period (Jan 1, 1979 to Dec 31, 1983) and the recent 5-year period (July 1, 1990 to June 30, 1994). The influence of anesthetic methods, induction agents, and intervals between the most recent attack and anesthesia were evaluated. The incidence of the attack during anesthesia in patients with asthma was similar in both period, 6.7% in the past and 7.8% in the recent period. Patients who had a history of recurrent attacks within 2 years prior to anesthesia tended to have higher incidence of intraoperative attack in both periods. Furthermore, the incidence of asthmatic attack was significantly greater in patients receiving inhalational anesthetics for induction of anesthesia than in those given intravenous anesthetics in the recent period. Although inhalational anesthetics are considered to be used safely for asthmatic patients, care should be taken when volatile anesthetics are administered to asthmatic patients during induction of anesthesia.

Anesthesia, Inhalation↗
PubMed1998

A new heparin-bonded dense membrane lung combined with minimal systemic heparinization prolonged extracorporeal lung assist in goats.

Heparin was covalently bonded to a new hollow-fiber dense membrane artificial lung and extracorporeal circuit using a silane coupling agent and polyethyleneimine. This study investigated whether prolonged, venoarterial bypass extracorporeal lung assist (V-A bypass ECLA) could be sustained in a goat by the combination of the new membrane lung and minimal systemic heparinization. We maintained ECLA with the hollow-fiber lungs (surface area, 0.8 m2) and circuits by titrating the activated clotting time (ACT) to below 150 s with minimal systemic heparinization in 5 goats. The outcome was assessed from the function of the artificial lung via macro and microscopic examinations after the experiments and the incidence of systemic complications. The 5 goats were maintained on ECLA for 6 to 27 days. The bypass flow rate, blood gases at the return and drainage sites, platelet counts, and platelet aggregation activity were well maintained. Although the hemoglobin concentration, hematocrit, and plasma protein at the start of the ECLA were significantly lower than the pre-ECLA values due to hemodilution, the values remained stable during ECLA. A cerebral infarction occurred in 1 goat. However, in the other 4 goats, no complications such as bleeding, thrombosis, or plasma leakage from the artificial lung were observed. Although several thrombi were observed in the stagnant area of the artificial lung, these local thrombi did not cause the function of the artificial lung to deteriorate. We found that this new type of highly biocompatible, dense membrane artificial lung, when combined with minimal systemic heparinization, prolonged ECLA without the deterioration of the artificial lung function and was suitable for prolonged ECLA.

Animals↗
PubMed1998

[Sudden ventricular tachyarrhythmia immediately following hepatectomy in a patient with hypomagnesemia].

A 57-year-old male without pre- or intraoperative arrhythmia developed ventricular tachyarrhythmia immediately following hepatectomy. Postoperative examination of plasma electrolytes revealed severe hypomagnesemia (0.16 mmol.l-1). The arrhythmia may have been caused by hypomagnesemia and an imbalance between supply and demand of oxygen in the myocardium, due to hypovolemia and severe anemia from massive hemorrhage. We recommend that measurement of plasma magnesium concentration be included in all perioperative laboratory examinations.

Carcinoma, Hepatocellular↗
PubMed1998

[A case of prolonged apnea probably caused by vecuronium potentiated with hypermagnesemia].

A 73-year-old female weighing 41 kg who had undergone ilecolostomy under general anesthesia showed extremely prolonged apnea. Despite only 7 mg of vecuronium, she needed postoperative mechanical ventilation for more than 24 hours. A postoperative examination revealed hypermagnesemia, which probably potentiated the effect of vecuronium. Her hypermagnesemia might be caused by chronic renal failure with hypocalcemia and administration of magnesium sulfate as a cathartic. Plasma magnesium concentration should be measured perioperatively in all surgical cases.

Aged↗
PubMed1994

Kinetics of macrophage subpopulations and expression of monocyte chemoattractant protein-1 (MCP-1) in bleomycin-induced lung injury of rats studied by a novel monoclonal antibody against rat MCP-1.

We investigated the kinetics of macrophage subpopulations and the expression of monocyte chemoattractant protein 1 (MCP-1) in a rat model of bleomycin-induced lung injury. Rat macrophage subpopulations were examined by immunohistochemistry using various anti-rat macrophage monoclonal antibodies (mAbs) and their proliferative capacity by [3H]thymidine (3HTdR) autoradiography. To detect the localization of expressed MCP-1, we generated an mAb against rat MCP-1 for immunohistochemical staining. Expression of MCP-1 messenger RNA (mRNA) was detected by Northern blot hybridization. Shortly after intratracheal instillation of bleomycin, the number of exudate macrophages recognized by mAb TRPM-3 increased in the injured lungs, peaked 3 days later, and decreased thereafter, whereas tissue macrophages identified by mAb ED2 increased slowly and peaked 2 weeks after instillation. Northern blot analysis disclosed that the expression of MCP-1 mRNA in the lung was most prominent 1 day after instillation and declined thereafter, preceding the numerical change of the TRPM-3-positive exudate macrophages. Immunohistochemistry with anti-rat MCP-1 revealed that the main sources of MCP-1 production were alveolar and interstitial macrophages and polymorphonuclear leukocytes. Based on these results, MCP-1 produced by polymorphonuclear leukocytes and by alveolar and interstitial macrophages is thought to induce the infiltration of blood monocytes, and infiltrated exudate macrophages produce MCP-1 to enhance subsequent accumulation of macrophages. In contrast, the expression of MCP-1 did not correlate with the numerical changes of the ED2-positive macrophages.

Animals↗
PubMed1993

Newborn extracorporeal lung assist using a novel double lumen catheter and a heparin-bonded membrane lung.

We report the clinical application of a novel double lumen catheter for veno-venous extracorporeal lung assist (ECLA) and the use of a heparin-bonded hollow fiber membrane lung, in the treatment of newborn respiratory failure. The outer lumen of the double lumen catheter was 14 Fr and was used for blood drainage; while the inner 8 Fr catheter was used for blood return. The double lumen catheter was made of spiral wire reinforced polyurethane, with a wall thickness of 0.25 mm. The hollow fiber membrane was made of non-microporous polyolefin, and was not permeable to water or plasma. We used this system to treat a newborn patient with meconium aspiration syndrome. Heparin was infused continuously at a rate of 18-25 units/kg/h, equal to 1/3 of the usual amount when a non-heparin bonded ECLA system was used and maintaining the activated clotting time near 120 s. Bleeding from cutdown sites was negligible. Only the right internal jugular vein was sacrificed. The patient was successfully weaned from ECLA and appears normal one year following discharge.

Blood Gas Analysis↗
PubMed1992

[A patient with severe ventricular tachycardia who was saved by prolonged extracorporeal lung and heart assist].

A 47-y-o man had been suffering from cardiac failure due to refractory ventricular tachycardia (VT) after myocardial infarction. He underwent resection of the left ventricular aneurysm and cryocoagulation of the arrhythmogenic foci. On the 2nd post-operative day, VT often recurred in spite of repeated cardioversion and drug therapy, and threatened his life, even under IABP. Therefore, a veno-arterial bypass route was made and extracorporeal lung and heart assist, ECLHA, was started with a heparin bonded Maxima lung on the following day. Even under ECLHA, VT continued to recur. Cryocoagulation of the VT foci was tried again, without immediate success. A record high dose of beta-blockers, given under the circulatory support by ECLHA, stopped VT on the following day. The patient was weaned from the ECLHA circuit 12 days after the first operation, then from IABP on the 14th day. During the 10 day course of surgeries and ECLHA, the patient had almost 100 defibrillations. But for ECLHA, we may say that the patient couldn't have survived two open heart surgeries, administration of a great amount of beta-blockers, and repeated cardiac arrest without neurological sequelae.

Adult↗
PubMed1989

Simple and noninvasive indicator of pulmonary gas exchange impairment using pulse oximetry.

We postulated that the fractional inspired oxygen concentration (FIO2) required to achieve a certain value of arterial oxygen saturation (SaO2) can be used as an indicator of pulmonary gas exchange impairment in patients during mechanical ventilation. We tested this hypothesis in 20 patients. By reducing FIO2 in increments of 10 vol% of capacity while monitoring SaO2 with pulse oximetry, we could determine FI98, FI97, FI96, and FI95; that is, the FIO2 that yields 98, 97, 96, and 95% SaO2, respectively. On the basis of our data, we chose FI98 as the most appropriate index, as an SaO2 of 97% or below could not be achieved even with a low FIO2 in some of the patients. To test the significance of the newly proposed index, we compared FI98 with the alveolar-arterial oxygen tension difference, P(A - a)O2, and with the respiratory index, which are routinely used elsewhere. The correlation between FI98 and P(A - a)O2 was excellent: P(A - a)O2 = 490.5 * FI98 + 117.2 with a correlation coefficient of 0.906 (P less than 0.01). FI98 also correlated significantly with the respiratory index: respiratory index = 4.354 * FI98 - 0.776 (r = 0.889, P less than 0.01). We conclude that FI98 may be used as a simple index for the rough estimation of pulmonary gas exchange impairment without the need for invasive procedures. However, further studies are needed to confirm the validity of our method in hemodynamically unstable patients or when other brands of pulse oximeters are used.

Adolescent↗
PubMed1988

Acute respiratory failure induced by mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH2O.

The effects of high pressure mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH(2)O were studied on the lungs of healthy newborn pigs (14-21 days after birth). Forty percent oxygen in nitrogen was used for ventilation to prevent oxygen intoxication. The control group (6 pigs) was ventilated for 48 hours at a peak inspiratory pressure less than 18 cmH(2)O and a PEEP of 3-5 cmH(2)O with a normal tidal volume, and a respiratory rate of 20 times/min. The control group showed few deleterious changes in the lungs for 48 hours. Eleven newborn pigs were ventilated at a peak inspiratory pressure of 40 cmH(2)O with a PEEP of 3-5 cmH(2)O and a respiratory rate of 20 times/min. To avoid respiratory alkalosis, a dead space was placed in the respiratory circuit, and normocarbia was maintained by adjusting dead space volume. In all cases in the latter group, severe pulmonary impairments, such as abnormal chest roentgenograms, hypoxemia, decreased total static lung compliance, high incidence of pneumothorax, congestive atelectasis, and increased lung weight were found within 48 hours of ventilation. When the pulmonary impairments became manifest, 6 of the 11 newborn pigs were switched to the conventional medical and ventilatory therapies for 3-6 days. However, all of them became ventilator dependent, and severe lung pathology was found at autopsy. These pulmonary insults by high pressure mechanical pulmonary ventilation could be occurring not infrequently in the respiratory management of patients with respiratory failure.

Journal Article↗
PubMedDate not supplied

Heparin bonding of the extracorporeal circuit reduces thrombosis during prolonged lung assist in goats.

This study investigated whether an artificial membrane lung of nonmicroporous polyolefin hollow fibers bonded with heparin could prolong venoarterial extracorporeal lung assist (ECLA) with low dose systemic heparin in goats. We compared heparin bonded circuits (Carmeda Bioactive Surface, "HB" group, n = 5) with non heparin bonded circuits ("NHB" group, n = 5) in venoarterial ECLA (V-A ECLA) for 7 days. Activated coagulation time (ACT) was maintained at approximately 130 sec by systemic infusion of small doses of heparin in the HB group, and at 200-230 sec in the NHB group. Thrombus formation was assessed by visual examination of the circuit, and possible cerebral embolization of thrombi was observed from behavioral abnormalities of the animals. The mean heparin dose given during ECLA was 20.4 +/- 3.6 U/kg per hr in HB, and 50.9 +/- 14.2 U/kg per hr in NHB, significantly less in HB than NHB (p < 0.01). Blood gas changes across the oxygenator, bypass flow rate, platelet aggregation activity, platelet counts, fibrin monomer (FM) test, and antithrombin-III (AT-III) activity did not differ between the two groups. In HB, thrombi were fewer and no abnormal neurologic symptoms were observed during ECLA. Numerous thrombi were observed in all oxygenators with NHB. One NHB goat developed convulsions and cerebral hemorrhage on the 6th day of ECLA. Nonmicroporous polyolefin hollow fibers can be bonded with heparin. An artificial membrane lung constructed of these fibers showed good anticoagulation by decreased thrombus formation with a small dose of infused heparin.

Animals↗