BACKGROUND: Coronary perfusion pressure(CPP) is the most important factor for the success of cardiopulmonary resuscitation(CPR). Therefore, CPP must be optimized during the resuscitation. The purpose of this study is to investigate the effects of isosorbide dinitrate(Isoket(R)) on CPP during CPR. METHODS: 10 Korean dogs were divided into two groups: Group I(N=5) was resuscitated with infusion of isosorbide dinitrate(1 microgram /kg/min) and Group II(N=5) was resuscitated without using isosorbide dinitrate. Following CPR, the heart rate(HR), blood pressure(BP), pulmonary capillary wedge pressure, cardiac output(CO), CPP and endocardial viability ratio(EVR) were measured repeatedly. RESULTS: The changes in HR were not significantly different between the two groups but systolic and diastolic BP, CO, CPP and EVR were well maintained in group 1. CONCLUSIONS: These results suggest that the usual dosage of isosorbide dinitrate is effective in improving CPP and EVR on CPR after impending cardiac arrest.
Animals ; Cardiopulmonary Resuscitation* ; Dogs ; Heart ; Heart Arrest ; Isosorbide Dinitrate ; Isosorbide* ; Perfusion* ; Pulmonary Wedge Pressure ; Resuscitation

BACKGROUND: Acutely induced hypoxia causes an increase in the mean arterial pressure, cardiac output and oxygen consumption. However, comparisons of hemodynamic changes and oxygen consumption between subjects with and without anesthesia are rare. The purpose of this study was to examine and compare the hemodynamic changes and oxygen availability after acute apnea between the dogs with and without anesthesia. METHODS: Apnea was induced to 19 healthy mongrel dogs. Group 1 (N=10) constituted dogs with anesthesia and group 2 (N=9) constituted dogs without anesthesia. Hemodynamic data and oxygen levels were rapidly measured with 1 minute intervals. RESULTS: The survival time of group 1 was longer than that of group 2. The mean arterial pressure increased in group 1. Although the cardiac outputs in both groups increased at the same time course in early phase of apnea, the preload values increased more rapidly in group 1. Systemic vascular resistance decreased at 2 and 3 minutes of apnea in group 1 but not in group 2. The oxygen extraction ratio increased significantly at 4 and 5 minutes of apnea in group 2. CONCLUSION: In this study the dogs with anesthesia had a prolonged survival time compared to the dogs without anesthesia. Most hemodynamic values did not differ significantly between the two groups, except for an increased mean arterial pressure and decreased systemic vascular resistance in the dogs with anesthesia. It was suggested that the cause of early death in the dogs without anesthesia was decreased oxygen delivery.
Anesthesia* ; Animals ; Anoxia ; Apnea* ; Arterial Pressure ; Cardiac Output ; Dogs ; Hemodynamics* ; Oxygen Consumption ; Oxygen* ; Vascular Resistance

To evaluate the regulation of and in the CSF during respiratory acidosis, the changes in cisternal CSF and arterial plasma acid-base status were asaessed in anesthetized, paralyzed, mechanically ventilated dogs rendered hypercapneic (PaCO2 of 60~70 mmHg) by hypoventilation. The electrochemical potential difference (u) between the CSF and blood for H+ and HCO2- was calculated from values for and in CSF and arterial plasma, and CSF/plasma DC potential difference was calculated. Simultaneously arterial blood and the CSF samples were drawn at 0, 1, 2, 3, 4, 6, 8 hours after hypercapnia. After 8 hours of respiratory acidosis, the arterial pH declined 0.09 units to 7.26 whereas the CSF pH fell by 0.07 units to 7.29. The CSF rose to 34 mEq/L whereas arterial plasma increased to 29 mEq/L. Therefore, increase of the CSF was almost 11 mEq/L, while the arterial plasma HCO, had increased 7 mE/L. So, much increase in CSF bicarbonate maintained the spinal fluid significantly less acidic than the blood during sustained hypercapnia. CSF/plasma PD was not only increased during acute respiratory acidosis, but also remained high as long as the plasma pH was acid. Values of p for H+ and HCO at 8 hours had returned to +1.1 and -0.1 mV of the control value. The attainment of steady-state values for u close to the control value may be compatible with passive distribution of these ions between the CSF and blood. But active mechanism can not be ruled out, because CSF/plasma PD remained high during the study.
Acidosis, Respiratory ; Animals ; Dogs ; Hydrogen-Ion Concentration ; Hypercapnia ; Hypoventilation* ; Ions ; Plasma

The use of hyperventilation technique to reduce intracranial pressure for surgical intervention of cerebral aneurysm has been well documented and most common in general practice. The decrease of blood flow with hyperventilation may aggravate pre-existing ischemic region. On this occasion it was suggested that cerebral intracellular metabolic acidosis may be accentuated so that its metabolic status could be measured from the analysis of cerebrospinal fluid gases. Hyperventilation can cause an increase in PH of cerebrospinal fluid due to the decrease of PCO but if hyperventilation is induced chronically, an elevated PH returns gradually to its previous normal value by loss of HCO, from the cerebrospinal fluid. Anesthesia was maintained with hyperventilation throughout the cerebral aneurysm surgery then cerebrospinal fluid and arterial blood gases were measured at regular intervals. PH in cerebrospinal fluid at 1 hour after hyperventilation revealed severe metabolic acidosis and arterial blood gases showed respiratory alkalosis. At 6 hours after hyperventilation the PH in cerebrospinal fluid in-creased markedly but the changes of HCO2were not significant from its control value and accord-ingly metabolic acidosis in cerebrospinal fluid was improved. It was suggested that compensatory mechanism for PH of cerebrospinal fluid to return to its low value by decreasing HCO2was shown. If such mechaniwm does not exist cerebrospinal fluid HCO2must he increased theoretically.
Acidosis ; Alkalosis, Respiratory ; Anesthesia ; Cerebrospinal Fluid ; Gases ; General Practice ; Hydrogen-Ion Concentration ; Hyperventilation* ; Intracranial Aneurysm* ; Intracranial Pressure ; Reference Values

Preoxygenation is a standard anesthetic technique for preventing a significant hypoxemia during the induction of anesthesia. Complete denitrogenation is especially important in clinical situations of difficult intubation or in patients with decreased functional residual capacity, and in situations where oxygen saturation is critical. Oxygen consumption in pregnancy is markedly increased at term as compaired to the nonpregnant stage. It is important to evaluate how long parturient women can withstand apneic hypoxemia during induction of general anesthesia. This study was carried out to measure the duration of time required to decrease the SaO2 to 90% After written informed consent was obtained from six healthy parturients who were to under go elective Cesarean section and six healthy non-pregnant women who were to have total abdominal hysterectomies. All subjects had a tight fitting anesthesia mask applied and breathed 100% oxygen, and a single isolated apnea was carried out. Arterial oxygen saturation and gas tensions were measured at a time SaO2 decreased to 90%, also blood gas data of 4 minutes after apnea in the non-pregnant women were obtained. From these, arterial oxyhemoglobin content was calculated, and mean desaturation rate from denitrogenation to the time SaO2 decreased to 90% was calculated. The mean time to obtain 90% saturation was 7.5+/-0.9 minutes in the nonpregnant women and 3.6+/-0.8 minutes in the parturient group. The mean slope of desaturation was steeper in the paturient(-3.336) than the nonpregnant (-1.52). The PaO2 inereased over 400mmHg in both the groups after denitrogenatio. After 4 minutes of apnea, the mean PaO2 decreased to 200mmHg in the non-pregnant women. The rate of rise of alveolar PCO2 during apnea were alower in the non-pregnant women(2.8+/-1.2mmHg/minute) than in the parturient women(6.8+/-1.8mmHg/minute). This study demonstrates that the rate of oxygen desaturation is faster in the parturients than the nonpregnant women. It is suggested that those results came out because of pregnancy-in-duced increase of oxygen consumption rate and decrease in FRC. The results of this study show the induction for term parturients should be speeded up with caution after full oxygenation in comparison with non-pregnant patients.
Anesthesia ; Anesthesia, General ; Anoxia ; Apnea* ; Cesarean Section ; Female ; Functional Residual Capacity ; Humans ; Hysterectomy ; Informed Consent ; Intubation ; Masks ; Oxygen Consumption ; Oxygen* ; Oxyhemoglobins ; Pregnancy

Caudal anesthesia appears to be a safe and reliable techniuqe for surgical anesthesia as well as an alternative to narcotics for postoperative analgesia for procedures below the umbilicus. The caudal anesthesia might be particularly helpful in infants and children to avoid repetitive injections of narcotics to control postoperative pain. Advantages of caudal anesthesia for pediatric surgery i.e. clearly defined anatomic landmarks, a simplicity of the technique and high success rate have been reported. However, it has not been popular in clinical practice due to several reasons. First of all, small children do not cooperate with technical procedures. Therfore, an additional measure to provide a cooperative state is needed, such as pentothal or ketamine injection, or general anesthesia induced beforehand. Secondly, there is no clear determination or unanimity in anesthetic dosage according to the patient's age or body weight. Lastly, clinical experience and reports have not been enough for clinical practice. The aim of this study was to determine whether commonly accepted dosages used in infants produce blood levels within a safe range. This study was undertaken to measure changes of plasma concentration of lidocaine in patients with pediatric caudal anesthesia, and to check pain and motor scores and analgesic level at the recovery room. The time courses of the plasma concentration were observed in 29 healthty children(0.5-13 yr) to whom were caudally injected with 1% lidocaine mixed 1: 200,000 epinephrine(10 mg/kg). The plasma concentrations were measured by immunofluoresence assay at the intervals of l5, 30, 45, and 60 minutes. The values of plasma concnetration were 1.67+/-0.41, 1.85+/-0.61, 1.73+/-0.46, 1.75+/-0.29mcg/ml(MEAN+/-SD). The peak plasma concentration was 1.85+/-0.61mcg/ml at 30 minutes. However, there no significant differences during the first hour. No data exceeded 5 mcg/ml which is plasma toxic level of lidocaine, nor children had an experience of toxic complications. When the pain and motor scores were checked in the recovery room, most children had no pain and were not ahle to stand but movalble. Sensory levels were checked up to T9 which were suitable for lower abdominal and perineal surgery. These results indicate that the injection of l% lidocaine 10 mg/kg with epinephrine in children is considered to be safe because plasma concentration dose not exceed the toxic levels.
Analgesia ; Anatomic Landmarks ; Anesthesia ; Anesthesia, Caudal* ; Anesthesia, General ; Body Weight ; Child ; Epinephrine ; Humans ; Infant ; Ketamine ; Lidocaine* ; Narcotics ; Pain, Postoperative ; Plasma* ; Recovery Room ; Thiopental ; Umbilicus

T-cain has been used for spinal anesthesia as a substitute agent for tetracaine for many years in Korea. However, no clinical study has been made since its use was started in 1971. This study was primarily undertaken to assess the clinical effects of T-cain and to compare its effects with tetracaine and lidocaine. T-cain is directly derived from tetracaine by substituting a diethyl group for a dimethyl group in tetracaine and its clinical effects are known to be similar to the tetracaine except for the duration of action of the drug that is 1 and 1/2 times longer than tetracaine. We had 52 cases of spinal anesthesia using T-cain in various doses for various surgeries. The time from the injection of the drug to the complete motor recovery was measured by Bromage scale. The level of sensory blockade checked in the recovery room was variable and unpredictable, and the motor blockade was below the knee joint level in all the cases in spite of variable dosages. As larger doses were given, the longer the duration of the motor blockade was noticed. The use of T-cain for ordinary surgery seems to be inconvenient because of its longer duration of motor paralysis with patients discomfort in the recovery room.
Anesthesia, Spinal* ; Humans ; Knee Joint ; Korea ; Lidocaine ; Paralysis ; Recovery Room ; Tetracaine

BACKGROUND: Tuffier's line, which connect the two iliac crests, is the often used landmark in determining the level for the needle insertion into lumbar intervertebral space for the spinal and/or epidural blocks. However, the level of Tuffier's line varies depending on the observer. METHODS: Two methods were used to measure the level of Tuffier's line was measured on a simple abdominal X-ray taken in the supine position (study 1). Second, the level of Tuffier's line was also measured on fluroscopy of students in the sitting position (study 2). RESULTS: Overall, the level of Tuffier's line was most frequently observed along the L4-5 intervertebral space and second most frequently observed along the lower one-third of L4. In study 1 using abdominal X-ray, the level of Tuffiers line was most frequently observed along the L4-5 intervertebral space, however, the second most frequently observed level varied depending on the ages of the volunteers. In study 2 using fluoroscopy, the level of Tuffier's line was most frequently observed along the L4-5 intervertebral space and second most frequently observed along the upper one-third of L5. CONCLUSIONS: The level of Tuffier's line was most frequently observed along the L4-5 intervertebral space both in the supine and sitting positions. Further, the level of Tuffier's line went higher with age for women but stayed constant independent of age for men in the supine position.
Adult* ; Female ; Fluoroscopy ; Humans ; Male ; Needles ; Supine Position ; Volunteers

BACKGROUND: This study examined hemodynamic variables, oxygen delivery, extraction, and consumption in response to acute progressive hypoxia and hypercarbia in the setting of apnea. METHODS: Apnea was induced in 9 healthy mongrel dogs by disconnecting animals from mechanical ventilation of 30 minutes with pure oxygen. Hemodynamic variables, oxygen transport, extraction, and consumption were rapidly and repeatedly measured using pulmonary arterial and arterial catheters until cardiac output was undetectable. RESULTS: The baseline PaO2, PaCO2, pH, base excess were 318 +/- 137 mm Hg, 36 +/- 3.5 mm Hg, 7.30 +/- 0.06, 6.81 +/- 2.65 mmol/l respectively. Hypercarbia and hypoxemia (76 +/- 33 mm Hg) was first noted at 1 and 4 minute respectively. Base excess was not changed. Indices of preload (PCWP and CVP) were increased early in the time course (p<0.05). In contrast, indices of afterload (SVR) increased later, just before cardiac decompensation began (p<0.05). No significant reduction of cardiac output, oxygen delivery, extraction, and consumption was detected just until abrupt cardiac decompensation started, 5 minute. CONCLUSIONS: These data suggest that the early increase in preload was primarily due to hypercarbia whereas the late increase in afterload was due to hypoxemia, but the main cause of acute cardiac decompensation was a critical decrease in arterial oxygen tension with some contribution of increased preload and afterload.
Animals ; Anoxia ; Apnea* ; Cardiac Output ; Catheters ; Dogs* ; Hemodynamics* ; Hydrogen-Ion Concentration ; Oxygen* ; Respiration, Artificial

Spinal anesthesia has been virtually abandoned in general practice for lumbar laminectomy because of the fear of airway obstruction and the difficulty of sedation in the prone position. Nontheless, spinal anesthesia offers obvious benefits to the surgeon such as a clear surgical field with less bleeding. The objective of this study was to evaluate the effects of bupivacaine as a spinal anesthetic for lumbar laminectomy. Spinal anesthesia was induced to 25 random patients who were scheduled for lumbar laminectomy. This spinal anesthetic was isobaric 0.5% bupivacaine mixed with 1:300,000 epinephrine. A spinal tapping was made in a sitting position at the interspace above or below the surgical area depending on the patients height and then 3 ml of local anesthetic was injected. Next, each patient was laid down in a supine position for 3 minutes and then turned him around in a prone position. Each patient was then given a deep sedation using thiopental or nembutal until the operation was over. Arterial blood gases were analysed for the evaluation of ventilatory function. P.CO2 were 39.3+/-3.9mmHg preoperatively and 50.39+/-6.8 mmHg at 1 hour during operation. P.O2 were 94.4+/-11.2mmHg preoperatively and 83.57+/-14.4 mmHg at 1 hour during operation. PH were 7.40+/-0.02 preoperatively and 7.30+/-0.04 at 1 hour during operation. The duration of motor paralysis was 3-3.5 hours which waa suitable for the lumbar laminectomy. We observed no serious complications. This study showed that spinal anesthesia using bupivacaine with sedation in the prone position for laminectomy caused slight hypoventilation but it was a tolerable amount. Furthermore, the duration of anesthetic effect of bupivacaine was suitable for laminectomy. Consequently, we concluded that bupivacaine can be a good choice of spinal anesthetic agents for laminectomy.
Airway Obstruction ; Anesthesia, Spinal* ; Anesthetics ; Bupivacaine* ; Deep Sedation ; Epinephrine ; Gases ; General Practice ; Hemorrhage ; Humans ; Hydrogen-Ion Concentration ; Hypoventilation ; Laminectomy* ; Paralysis ; Pentobarbital ; Prone Position ; Spinal Puncture ; Supine Position ; Thiopental