• Tuberculosis and Respiratory Diseases
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• v.57 no.5
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• pp.434-438
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• 2004

Background : An excessive endotracheal cuff pressure can cause tracheal injury, and insufficient cuff pressure may not generate an effective cuff seal. The peak inspiratory pressure influences the minimal occlusion pressure of the endotracheal tube cuff. However, the relationship between the minimal occlusion pressure and the tidal volume has not been investigated. This study was conducted to estimate the relationship between the tidal volume and the minimal occlusion pressure of the cuff. Methods : Ten mechanically ventilated patients were included. The minimal occlusion pressure of the cuff was measured using a pressure gauge. The basal tidal volume was increased and decreased as much as 10% whilst maintaining the same peak inspiratory pressure. The, minimal occlusion pressures were then measured in the high and low tidal volume state, respectively. Results : The peak inspiratory pressure was $32.6{\pm}4.72cmH_2O$ and the minimal occlusion pressure was $19.0{\pm}2.26$ mmHg in the basal ventilator setting. There was a significant relationship between the peak inspiratory pressure and the minimal occlusion pressure(r=0.77, p<0.01). The minimal occlusion pressure of the cuff was increased to $20.3{\pm}2.4$ mmHg in the high tidal volume state(p<0.05), and decreased to $16.8{\pm}3.01$ mmHg in the low tidal volume state (p<0.001). Conclusion : The minimal occlusion pressure of the cuff can be influenced by changes in the tidal volume as well as by the peak inspiratory pressure.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.402-410
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• 2001

This study was performed to investigate the hemodynamic changes which occur after occlusion of coronary artery and relation to reperfusion arrhythmias(RA) which occur when occlusion materials were removed form coronary artery in dogs. The occlusion of coronary artery was designed by temporary ligation of left circumflex branch of coronary artery during 30 minutes in 16 dogs. During occlusion of coronary artery, cardiac output(CO), mean aortic pressure (mAP), aortic systolic pressure(ASP), aortic diastolic pressure(ADP). left ventricular systolic pressure(LVSP), left ventricular maximum dp/dt (LV max. dp/dt) and left ventricular end-diastolic pressure (LVEDP) were measured. The occurrence of RA were observed for 5 minute after reperfusion by explained of ligation. As a results, cardiac arrest occurred in 4 dogs during occlusion of coronary artery, and RA was not observed in 5 dogs while it was seen in 5 dogs when explained ligation(reperfusion) after 30 minutes, the rest 2 dogs occurred temporary tachycardia. In hemodynamics changes, LVSP decreased by 10.9% and LV max. dp/dt by 5.4 % in comparison to control value which not ligated coronary artery, and LVEDP increased by 73.3%. The CO/min and mAP also decreased by 10.7% and by 11.3% expectedly. In the relationship to occurrence RA and hemodynamics changes, the LVSP and LV max. dp/dt at the time of occlusion in the RA group decreased by 11.9% and 0.8% in comarison to the control value while the decrease was 7.7% and 10% in the non-RA group. But the LVEDP in creased by 109.1% in the RA group while the decreased was 44.6% in the non-RA group. Referring CO/min, the drop was 8.8% in the RA occurrence group and 12.9% in the non-occurence group. These parameters of LVEDP, LV max. dp/dt, and CO were significant difference(p<0.05). The mAP also decreased by 11.9 in the RA group and by 9.8% in the non-RA group, but these defference were not the significant difference.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.126-132
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• 2007

Pressure-induced decubitus is a serious disease among the elderly people. Interface pressure occluding vascular perfusion is known to be a cause of decubitus. Therefore, it is essential to quantify the relationship between vascular perfusion and interface pressure among the elderly people to understand more about decubitus. Nine healthy elderly people (57.8$\pm$ 5.6 years, 63.3$\pm$ 7.0kg, 1.68$\pm$ 0.05m) were participated. Three healthy young people (31.7$\pm$ 3.2 years, 74.7$\pm$ 8.4kg, 1.75$\pm$ 0.04m) were also examined to be compared with the elderly group. Capillary vascular perfusion on the ischial tuberosity was recorded in the sitting posture as pressures were applied from 15mmHg to 135mmHg. The average interface pressure to occlude vascular perfusion (the average occlusion pressure) under the ischial tuberosity was 115.7mmHg in the elderly group. This value was not significantly different from the average occlusion pressure of the young group. Obesity effect on the occlusion pressure was investigated among the elderly group. The result was not significantly different between the obesity and the normal group in this study. This is a preliminary study to unveil the complicated cause of pressure-induced decubitus associated with occlusion of vascular perfusion. More subjects are required for the future study.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.109-120
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• 1989

We tend to consider only static occlusion such as molar relationship, canine key, and interdigitation at finishing stage. Of course, this static occlusion is important for post-orthodontic stability. But we should remember that mandible is always on the move during its various functions. If no pressure or too much pressure is put on during its functions, untoward tooth movement could occur. And tooth mobility, periodontitis, wear facet, bruxism, and far worse temporomandibular disorder could occur. After many studies have been done on what is a desirable occlusal scheme to strengthen post-orthodontic stability, today, "mutually protective occlusion" is recommended. If an orthodontist does not have understanding about this occlusal scheme during orthodontic treatment, the following conditions will be resulted after orthodontic treatment. I. Centric discrepancy 1. centric prematurity 2. sunday bite 3. molar fulcrum II. Eccentric discrepancy 1. posterior interference 2. anterior interference If we have deep understanding about these discrepancies that can happen after orthodontic treatment and their causes, corrections, and especially preventions against them, post-orthodontic stability could be strengthened and further temporomandibular disorder could be prevented.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.547-554
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• 2010

Purpose: The purpose of this study is to delineate the optimal time of venous revascularization for preventing the flap necrosis due to venous occlusion, and to clarify the usefulness of tissue oxygen pressure ($TcpO_2$) in the determination of the point of time for venous revascularization. Methods: Thirty-six, $3{\times}3\;cm$ sized epigastric island flap was elevated in left abdomen of male Sprague-Dawley rat weighing 250 gram. Flaps were randomly assigned to six groups of six flaps according to the duration of venous occlusion with microvascular clamp; 10 minutes in the group I as the control, 60 minutes in the group II, 2 hours in the group III, 3 hours in the group IV, 4 hours in the group V, and 6 hours in the group VI, respectively. Just before removal of clamp after flap was reposed in situ, the ratio of $TcpO_2$ (tissue oxygen pressure) of the island flap to that of right abdomen was calculated in each group, and tissue specimen was harvested from the distal area of the flap for histological evaluation of vascular change. Five days later, survival area of the flap was estimated, and evaluated the correlation between the tissue oxygen pressure and the rate of flap survival. Results: The $TcpO_2$ and the survival rate of flap were decreased proportionally with the duration of venous occlusion. The ratio of the $TcpO_2$ of the flap is decreased abruptly to below sixty percentile compared to the $TcpO_2$ of normal tissue, and the survived area of the flap is decreased to nine-tenth of the designed size after three hours of total venous occlusion. Histologically, the number of congested vessels was increased according to venous occluded time, and proportionally increased after 3-hours of occlusion significantly. Conclusion: There is a close correlation between the $TcpO_2$ and the survival rate of flaps according to the duration of venous occlusion. Therefore, the $TcpO_2$ represents the hemodynamic changes within the flap, and thought to be an alternative effective tool in the flap monitoring for venous revascularization.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.51-54
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• 2017

A 9-month-old intact male Maltese dog (1.52 kg) was diagnosed with a patent ductus arteriosus (PDA). Transcatheter occlusion of the PDA was performed by using the Amplatz canine duct occluder (ACDO). After occlusion, reflex bradycardia occurred and lasted for at least 15 h with normal systolic arterial pressure and slightly increased diastolic arterial pressure. The bradycardia slowly resolved, and the heart rate was normal in re-examinations after 7 and 30 days. This is the first case of reflex bradycardia after ACDO implantation, in which the bradycardia continued for a long time, even after recovery from anesthesia.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.449-454
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• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• The Korean Journal of Pharmacology
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• v.1 no.1 s.1
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• pp.63-65
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• 1965

Rabbit blood pressure showed gradual fall by intraventricular guanethidine (5mg). The pressure rise by carotid occlusion was markedly inhibited or abolished by the guanethidine, while it was enhanced by small dose (2mg). The intraventricular guanethidine did not affect norepinephrine pressor effect, but caused marked inhibition or abolishment of depressor action of serotonin.

• Journal of Chest Surgery
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• v.25 no.2
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• pp.200-204
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• 1992

A 63 year old male had suffered from hypertension and angina pectoris for 4 years, On physical examination, blood pressure was 150/110 mmHg with medication of antihypertensive drugs. Aortogram showed the stenosis of the left renal artery, the complete occlusion of the right renal artery, and atherosclerotic change of abdominal aorta. Blood urea nitrogen was 25 mg/dl, serum creatinine was 1.2 mg/dl, and renin activity in peripheral blood was 8.7 ng /ml /hour, The stenosis of left renal artery and the complete occlusion of right renal artery should have produced the renovascular hypertension Bilateral aorto-renal bypasses with saphenous grafts were done for treatment of ren-ovascular hypertension Postoperatively, blood pressure was normalized with only small dosage of antihypertensive drugs.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.108-116
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• 2023

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has recently gained popularity as an adjunct to resuscitation of patients with traumatic shock. However, the effectiveness of REBOA is still debated because of inconsistent indications across centers and the lack of medical records. The purpose of this study was to investigate the effectiveness and feasibility of REBOA by analyzing clinical results from a single center. Methods: This study included 96 patients who underwent REBOA between August 2016 and September 2021 at a regional trauma center according to the center's treatment algorithm for traumatic shock. Medical records, including the time of the decision to conduct the REBOA procedure, time of operation, type of aortic occlusion, and clinical outcomes, were collected prospectively and analyzed retrospectively. Patients were classified by REBOA protocol (group 1, 2, or 3) and survival status (survivor or non-survivor) for analysis. Results: The overall success rate of the procedure was 97.9%, and the survival rate was 32.6%. In survivors, blood pressure was higher than in non-survivors both before the REBOA procedure (p=0.002) and after aortic occlusion (p=0.03). The total aortic occlusion time was significantly shorter (p=0.001) and the proportion of partial aortic occlusion was significantly higher (p=0.014) among the survivors. The non-survivors had more acidosis (p<0.001) and higher lactate concentrations (p<0.001) than the survivors. Conclusion: REBOA may be a feasible bridge therapy for resuscitation of patients with traumatic shock. Prompt and accurate decision-making to perform REBOA followed by damage control surgery could improve survival rates and clinical outcomes.