• Neonatal Medicine
• /
• v.18 no.2
• /
• pp.320-327
• /
• 2011

Purpose: To determine the effect of changing practice guidelines designed to avoid hyperoxia or hypoxia in very low birth weight or very preterm infants. Methods: We analyzed a database of <1,500 g birth weight or <32 weeks of gestation infants who were born and admitted to the neonatal intensive care unit of Chungnam National University Hospital from January 2007 to July 2010. First, we defined the relationship between arterial partial pressure of oxygen ($PaO_2$) and pulse oxygen saturation ($SpO_2$). When we evaluated 96 pairs of $PaO_2$ and $SpO_2$ measurements, oxygen saturation was 90-94% at a $PaO_2$ of 43-79 mmHg on the oxyhemoglobin dissociation curve, according to pulse oximetry. Based on this observation, a change in practice was instituted in August 2008 with the objective of avoiding hypoxia and hyperoxia in preterm infants with targeting a $SpO_2$ 90-94% (period II). Before the change in practice, high alarms for $SpO_2$ were set at 100% and low alarms at 95% (period I). Results: Sixty-eight infants the met enrollment criteria and 38 (56%) were born during period II, after the change in $SpO_2$ targets. Demographic characteristics, except gender, were similar between the infants born in both periods. After correcting for the effect of confounding factors, the rates for mortality, severe retinopathy of prematurity, and IVH attended to be lower than those for infants in period II. No difference in the rate of patent ductus arteriosus needed to treat was observed. Conclusion: A change in the practice guidelines aimed at avoiding low oxygen saturation and hyperoxia did not increase neonatal complication rates and showed promising results, suggesting decreased mortality and improvements in short term morbidity. It is still unclear what range of oxygen saturation is appropriate for very preterm infants but the more careful saturation targeting guideline should be considered to prevent hypoxemic events and hyperoxia.

• Journal of Veterinary Clinics
• /
• v.26 no.4
• /
• pp.317-323
• /
• 2009

This study was performed to evaluate the effect of intravenous administration of glycopyrrolate on cardiovascular and respiratory system in dogs given intravenous medetomidine (20 ${\mu}g$/kg) and intramuscular midazolam (0.3 mg/kg) (MM). Prior to administration of MM, glycopyrrolate was administered intravenously at doses of 5 ${\mu}g$/kg (Gly-5), 10 ${\mu}g$/kg (Gly-10) or 20 ${\mu}g$/kg (Gly-20), respectively. For the control group saline was administered intravenously. In the cardiovascular system, HR, BP, RAP, PAWP, CI, SI, SVR, and PVR were measured. RR, $V_T$, $P_{ETCO2}$, and arterial blood gas analysis were measured for respiratory system. Although rapid and satisfied depth of sedation was obtained by MM, life-threatening bradycardia, the outstanding side-effect on cardiovascular system in dogs were observed. This combination also decreased CO and increased SVR, RAP, and PAWP significantly. The bradycardia could be prevented in all the glycopyrrolate treated groups, but tachycardia was observed in Gly-10 and Gly-20 groups. Significant increases in blood pressure were shown in glycopyrrolate treated groups. Also, tachycardia depends on dose of glycopyrrolate, compensating the CO. However, these were not fully reserved. In conclusion, MM combination could induce rapid and satisfied depth of sedation but was not the suitable method for the deep sedation of dogs with cardiovascular or circulatory problems.

• Clinical and Experimental Pediatrics
• /
• v.51 no.7
• /
• pp.747-753
• /
• 2008

Purpose : Diabetes mellitus is a major risk factor for the development of cardiovascular disease. Early atherosclerotic changes in the arterial walls begin in adolescence and the risk factors are associated with its development. To assess the usefulness of carotid artery intima-media thickness (IMT), as a marker of early atherosclerosis, we evaluated the structural and functional characteristics of the carotid artery and investigated their relationshop with the metabolic and anthropometric parameters in children and adolescents with type 1 diabetes. Methods : For this study, we enrolled 23 children with type 1 diabet and 19 age and sex-equivalent healthy children as the control group. Metabolic and anthropometric parameters such as serum lipid levels, plasma glycated hemoglobin (HbA1c), and body mass index were measured after a 12-h fasting period. The carotid artery IMT was measured by a high-quality ultrasound system, and compliance, and distensibility were calculated by an equation. Results : There were no significant differences between the 2 groups with regard to the sex ratio, age, blood pressure and serum cholesterol levels' however, HbA1c levels were significantly higher in the diabetic children ($8.5{\pm}1.8$ vs. $5.0{\pm}0.2$, P=0.001). Ultrasonographic findings showed that compared with the control group, the diabetic group had higher IMT ($0.45{\pm}0.06mm$ vs. $0.41{\pm}0.04mm$, P=0.04), but there were no significant differences in compliance and distensibility. The HbA1c (P=0.002) and high-density lipoprotein cholesterol (P=0.026) levels were independent IMT predictors in the diabetic group. Conclusion : Here, the carotid artery IMT was higher in the diabetic group, and it is correlated with atherosclerotic risk factor. Thus, carotid IMT could be evaluated as a marker of early atherosclerosis in diabetic children.

• The Korean Journal of Pharmacology
• /
• v.24 no.2
• /
• pp.221-232
• /
• 1988

Studies were conducted to determine whether reduced renal blood flow (RBF) exhibited by rats with uncontrolled, streptozotocin (STZ)-induced diabetes is attributable to diabetes-associated, enhanced renal vasoconstrictor influence of endogenous thromboxane $(TX)A_2$. Rats which were injected with STZ after pretreatment with 3-O-methyl glucose (3OMG), an agent which prevents STZ-induced hyperglycemia, were also studied. Basal values of total RBF (RBF; ml $min^{-1}$ $gKw^{-1}$; electromagnetic flow probe), systemic arterial pressure (BP; mm Hg) and renal vascular resistance (RVR;BP $RBF^{-1})$in pentobarbital-anesthetized rats during a control period were $5.9{\pm}0.3$(P<0.1_{VS}. CR), $115{\pm}3$ and $20.3{\pm}1.0$(P<0.1_{VS}. CR) for STZR (n=15), and $8.4{\pm}0.4$, $123{\pm}3$ and $15.1{\pm}0.8$ for age-matched control rats (CR; n= 15), respectively. Basal values of RBF, BP and RVR in 3OMG pretreated STZR were identical to CR. In preparations shown capable of renal vasodilatation, OKY 1581 (1 mg/kg, i.v. followed by 0.4 mg/kg min infusion) abolished arachidonate-induced $(TX)A_2$ synthesis, but did not alter basal BP, RBF or RVR in either STZR or CR (n=4/group). Similarly, i.r.a. infusion of SQ29548 (100 ng/ml RBF) abolished renal vasoconstriction induced by a TX/prostaglandin endoperoxide mimic, U46619, but had no discern able affect on RVR in either STZR (n=8) or CR (n=8). The data indicates that $TXA_2$ does not participate in the elevated basal RVR of STZR which are associated with the diabetic state.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.5
• /
• pp.645-653
• /
• 1999

Introduction : Although myocardial ischemia tends to occur more frequently than can he documented in ventilated patients, it has not been well studied on the factors related to the occurrence of the ischemia. Methods : To investigate the related factors to ischemia development, a prospective study was done in 95 cases with consecutive 73 patients who had received mechanical ventilation(MV) in MICU. In addition to 24 h holter monitoring, echocardiogram, electrolytes, cardiac enzymes, hemodynamic, and gas exchange measurements were done within 24 h after initiation of MV in 69 cases. The measurements were repeated at weaning period in 26 cases. The ischemia was defined by the ST segment changes; up-sloping depression more than 1.5 mm or down-sloping or horizontal depression more than 1.0 mm from isoelectric baseline for 80 ms following J point. Results : Twelve patients(12.6% in 95 cases) developed ischemia in total. The incidence of ischemia development showed an increased tendency in the initial 24 hr after MV (15.9%) and in patients with left-sided heart failure found by echocardiogram (18.2%) compared with that of the weaning period (3.8%) and patients without heart failure (10.9%) (P=0.12, P=0.09, in each). There were no differences in APACHE III score, baseline ECG findings, electrolytes abnormalities, use of inotropics or bronchodilators, presence of sepsis or shock, mode of ventilation, and survival rate according to the development of ischemia. Maximal heart rates and mean arterial pressure also were not different between patients with ($137.2{\pm}30.9/min$, $82.5{\pm}15.9$ mm Hg) and without ischemia ($l29.5{\pm}29.7/min$, $83.8{\pm}17.6$ mm Hg). Conclusion : Although the incidence of myocardial ischemia was 12.6% in total, there were no clinically predictable factors to the development of ischemia during mechanical ventilation.

• Clinical and Experimental Pediatrics
• /
• v.53 no.2
• /
• pp.195-202
• /
• 2010

Purpose : Despite recent advances in pulmonary hypertension management and surgery, appropriate guidelines remain to be developed for operability in congenital heart disease with pulmonary artery hypertension (PAH). Our aim was to evaluate clinical outcomes of patients with severe PAH who underwent surgical closure of left-to-right shunt lesions (LRSL) on the basis of pulmonary reactivity. Methods : We retrospectively reviewed 21 patients who underwent surgical closure of LRSL with severe PAH (${\geq}8$ Wood unit) from January 1995 to April 2009. The median age at operation was 26 years. Atrial septal defect, ventricular septal defect (VSD), VSD and patent ductus arteriosus (PDA), and PDA was present in 11, 4, 4, and 2 patients, respectively. Results : Operability was based on vasoreactivity of PAH. Of the 21 patients, 5 showed response to pulmonary vasodilator therapy and 8 showed vasoreactivity after balloon occlusion of defects. The remaining 8 patients were considered operable because of significant left-to-right shunt (Qp/Qs ${\geq}1.5$). Five patients underwent total closure of defects and 16 were left with small residual shunts. The median follow-up duration was 32 months. There was no significant postoperative mortality or morbidity. Systolic pulmonary artery pressure (PAP) decreased in all but 2 patients. All patients except 1 showed improvement of New York Heart Association functional class. Conclusion : Closure of LRSL in patients with severe PAH on the basis of pulmonary vasoreactivity seems reasonable. PAP and clinical symptoms improved in most patients. Further research is needed for the evaluation of long-term results.

• The Korean Journal of Pharmacology
• /
• v.32 no.1
• /
• pp.51-56
• /
• 1996

The objectives of this study is to find out mechanism of vasodilating effects of ANP in 2K-1C renovascular hypertensive rat aorta and to compare with those of normotensive rat aorta. In 2K-1C renovascular hypertensive rat, average arterial blood pressure and plasma renin activity were higher than in normotensive rat. In 2K-1C renovascular hypertensive rat aorta, NE sensitivity was more increased and maximal contraction of aorta by NE was higher than those of normotensive rat aorta. ANP inhibited NE-induced contraction in both 2K-1C renovascular hypertensive and normotensive rat aorta, concentration-dependently. However, ANP was less effective for relaxing NE-induced contraction in 2K-1C renovascular hypertensive rat aorta than in normotensive rat aorta. ANP inhibited $^{45}Ca^{2+}$ uptake induced by NE in both 2K-1C renovascular hypertensive and normotensive rat aorta. From these results. inhibition of $Ca^{2+}$ influx may be one of the vasodilating mechanism of ANP in 2K-1C renovascular hypertensive rat aorta. Although the potency of ANP in relaxing NE-induced contractions was attenuated, the efficacy of ANP was not changed in 2K-1C renovascular hypertensive rat aorta compared with that of ANP in normotensive rat aorta. Abbreviations: ANP, Atrial natriuretic peptide; 2K-1C, 2-kidney 1 clip; NE, norepinephrine; SHR, Spontaneously hypertensive rat; DOC, Deoxycorticosterone; EDTA, Ethylenediaminetetra-acetic acid; PSS, Physiological salt solution; TRIS, tris(hydroxymethyl) aminomethane

• Tuberculosis and Respiratory Diseases
• /
• v.55 no.5
• /
• pp.506-515
• /
• 2003

Background : A decreased level of serum arginine vasopressin(AVP) and an increased sensitivity to an exogenous AVP is expected in patients with septic shock who often require a high infusion rate of catecholamines. The goal of the study was to determine whether an exogenous AVP infusion to the patients with septic shock would achieve a significant decrement in infusion rate of catecholamine vasopressors while maintaining hemodynamic stability and adequate urine output. Method : Eight patients with septic shock who require a high infusion rate of norepinephrine had received a trial of 4-hour AVP infusion with simultaneous titration of norepinephrine. Hemodynamic parameters and urine output were monitored during the AVP infusion and the monitoring continued up to 4 hours after the AVP infusion had stopped. Results : Mean arterial pressure showed no significant changes during the study period(p=0.197). Norepinephrine infusion rate significantly decreased with concurrent AVP administration(p=0.001). However, beneficial effects had disappeared after the AVP infusion was stopped. In addition, hourly urine output showed no significant changes throughout the trials(p=0.093). Conclusion : Concurrent AVP infusion achieved the catecholamine vasopressor sparing effect in the septic shock patients, but there was no evidence of the improvement of renal function. Further study may be indicated to determine whether AVP infusion would provide an organ-protective effect to the septic shock patients.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.6
• /
• pp.1326-1331
• /
• 1997

Background : Weaning is the process of switching a patient from mechanical ventilator to spontaneous breathing. A number of different weaning techniques can be employed. At recent study, conventional spontaneous breathing trial was superior to other techniques, such as intermittent mandatory ventilation(IMV) or pressure support ventilation(PSV). But adequate observation time of the spontaneous breathing trial was not determined. We reported the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotrachial tube. In this study, we tried to shorten the spontaneous breathing time from 60 minutes to 30 minutes. If weaning success was predicted after 30 minutes spontaneous breathing, extubation was done without reconnection with ventilator. Methodes : Subjects consisted of 42 mechanically ventilated patients from August 1994 to July 1995. The weaning trial was done when the patients recovered sufficiently from respiratory failure that originally required ventilatory assistance, the patients became alert and showed stable vital sign, and arterial $O_2$ tension was adequated($PaO_2$ > 55 mmHg) with less than 40% of inspired oxygen fraction. We conducted a careful physical examination when the patients was breathing spontaneously through the endobronchial tube for 30 minutes. We terminated the trial if a patients was any of following signs of distress; cyanosis, diaphoresis, tachypnea(above 30 breaths per minute), and extreme tachycardia. Patients who had none of this features during spontaneous breathing for 30 minutes were extubated promptly. Result : 17 weaning trials of 15 patients were done in 42 mechanically ventilated patients. Successful weaning and extubation was possible in 14 trials of total 17 trials. In this 14 patients, 8 patients were extubated after 30 minutes spontaneous breathing, 3 patients were extubated after 60 minutes spontaneous breathing, and 3 patients needed over 3 hours for extubation from weaning. We found similar overall success rate compared with weaning following a 60 minutes spontaneous breathing trial. Conclusion : From the result of present study, we believe that weaning and extubation from mechanical ventilation following a 30 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method.

• Tuberculosis and Respiratory Diseases
• /
• v.50 no.1
• /
• pp.106-116
• /
• 2001

Background : Pulmonary thromboembolism is relatively frequent and potentially fatal. However, it is commonly misdiagnosed. The incidence of pulmonary thromboembolism is not decreasing despite advances in diagnosis and effective prophylatic measures. Its potential for significant sequela necessitates a prompt diagnosis and treatment. Unfortunately, there are many difficulties and problems regarding accurate diagnosis. There is a low prevalence of deep vein thrombosis and pulmonary thromboembolism in Korea and only few reports on this subject are available. Method : The clinical features of 36 patients, who were diagnosed with pulmonary thromboembolism at the Korea University medical center, were reviewed. Results : 1) There was no significant difference in prevalence between men an women, and the mean age was 50.9 years in men 59.2 years in women. 2) The frequent causes of pulmonary thromboembolism were malignancies (22.2%), surgery (22.2%), and heart disease(8.2%). Specific causes were not identified in 33.3%. 3) The most common symptom was dyspnea(72.2%), and the most common sign was tachypnea(61.1%). 4) The EKG findings were normal in 28.6%, an S1Q3T3 pulmonale pattern in 25.7%, ST or QRS changes in others. 5) The chest X-ray findings indicated pulmonary infiltration in 37.5%, cardiomegaly in 15.6%, pleural effusion in 12.5%, and normal in 27.8%. The perfusion lung scan showed a high probability in 66.7%, and intermediate or low probability in 33.3%. 6) The pulmonary arterial pressure(PAP) in the high probability groups was 57.9mmHg with a higher mortality rate(35%). Conclusion : Pulmonary thromboembolism is not uncommon in Korea and its clinical features do not differ greatly from thase reported in the literature. When pulmonary thromboemblism of unknown causes are diagnosed, a search for an occult malignancy is recommended. Rapid diagnosis and treatment are achieved when thromboemblism is suspected.