Capnometer has been used in anesthesia for the evaluation of pulmonary ventilation because of its nonivasive and continuous monitoring advantges. We studied pulmonary ventilation effects with arterial blood gas parameter between normoventilation and hyperventilation with capnometric control during 1 hr duration. We devided two group. Control group was maintained PetCO2 38 mmHg and experimental group PetCO2 28 mmHg and four times arterial blood gas sample were done. The results were as follows. 1) Serum K+ concentration was decreased siginifcantly in hyperventilation group. 2) Arterial pH changes were observed respiratory alkalosis in experimental group and respiratory acidosis in control group. 3) (a-t)PCO2 differnce were increased in both group and especially control group with correlation of time duration. 4) No arrhythmia were detected in both group. We conclude that only capnometric control of pulmonary ventilation is not suffieient and it has to be combined periodic ABGS and resetting of ventilation mode.
Acidosis, Respiratory ; Alkalosis, Respiratory ; Anesthesia ; Arrhythmias, Cardiac ; Hydrogen-Ion Concentration* ; Hyperventilation* ; Pulmonary Ventilation ; Ventilation

This study was attempted to observe the possible effects of open chest and the decubitus position on blood gas values during controlled ventilation. We used a volume-type ventilator to maintain regular tidal volume throughout the operation. A total of 51 cases which underwent open chest surgery between 1979 and 1981 in Department of Anesthesiology in Kyungpook National University Hospital were selected. PaO2, PaCO2, pH and MAP were measured at ten minutes after induction (control group), decubitus position (ducubitus group) and chest was opened(open chest group). The PaCO2 value in open chest and decubitus group revealed a tendency of elevation compared with the control group. The PaCO2 value in open chest revealed no remarkable change compared with the control group. The pH in open chest and decubitus group showed a tendency to increase compared with the control group. The MAP showed a tendency to decrease in open chest & decubitus groups and decreased gradually. From the above results, MAP showed a gradual decrease but the increase of pH and PaO2 suggested the inclination of respiratory alkalosis due to hyperventilation during volume controlled ventilation anesthesia.
Alkalosis, Respiratory ; Anesthesia* ; Anesthesiology ; Gyeongsangbuk-do ; Hydrogen-Ion Concentration ; Hyperventilation ; Thorax* ; Tidal Volume ; Ventilation* ; Ventilators, Mechanical

Hyperventilation syndrome is primary hyperventilation producing respiratory alkalosis associated with highly variable and impressive array of signs and symptoms. Typical features are tachypnea, paresthesia, carpopedal spasm, tetany, chest pain and dizziness. Rebreathing into a paper or vinyl bag will reverse the alkalosis-induced symptoms and help the patient calm down. We report hyperventilation syndrome associated with extraction of mandibular third molar and describe the physiology and treatment. Accidental displacement of mandibular third molars is rarely reported complication. Most common anatomic structures of dislodgement are submandibular space, lateral pharyngeal space and pterygomandibular space. This report describe an unusual case of two roots of mandibular third molar that were displaced into submandibular space.]]>
Alkalosis, Respiratory ; Chest Pain ; Dizziness ; Humans ; Hyperventilation ; Molar, Third ; Paresthesia ; Physiology ; Spasm ; Tachypnea ; Tetany

For the purpose of recommending appropriate fraction of inspired oxygen(F1O2) for long term mechanical ventilation support by evaluating the effect of changes in F1O2 on pulmonary shunt ratio in respiratory intensive care, the effects of various F1O2 on pulmonary shunt ratio were investigated and analysed with 20 pediatric intensive care patients who had received open heart surgeries for their congenital heart diseases in the department of Pediatrics, Seoul National University Hospital. The results were as follows ; 1. Through the whole process of control of mechanical ventilation the arterial CO2 tension(PaCO2) showed hyperventilation with the average of 31-34mmHg and pH showed pure respiratory alkalosis with the average of 7.45-7.51. As the fraction of inspired oxygen decreased, the arterial oxygen tension decreased. 2. Inspite of the change of F1O2, analysis of central venous blood gas showed no significant change. 3. The alveolar-arterial oxygen tension difference(AaDO2) was positively related to F1O2. 4. The pulmonary shunt ratio(Q's/Q'T) showed no significant difference in the F1O2 range of 0.6 to 1.0. But the Q's/Q'T in the F1O2 range of 0.3 to 0.4 decreased significantly comparing to that of 0.6 to 1.0 F1O2 range. Linear regression analysis of Q's/Q'T showed that the Q's/Q'T was positively related to F1O2 and AaDO2, respectively.
Alkalosis, Respiratory ; Heart ; Heart Diseases ; Humans ; Hydrogen-Ion Concentration ; Hyperventilation ; Critical Care* ; Linear Models ; Oxygen ; Pediatrics ; Respiration, Artificial ; Seoul

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

An endoscopic third ventriculostomy was performed in a 55-year-old man with an obstructive hydrocephalus due to aqueductal stenosis. The vital signs and laboratory studies upon admission were within the normal limits. Anesthesia was maintained with nitrous oxide in oxygen and 6% desflurane. The patient received irrigation with approximately 3,000 ml normal saline during the procedure. Anesthesia and operation were uneventful. However, he developed postoperative hyperventilation in the recovery room, and arterial blood gas analysis revealed acute respiratory alkalosis. We report a rare respiratory alkalosis that occurred after an endoscopic third ventriculostomy.
Alkalosis, Respiratory ; Anesthesia ; Blood Gas Analysis ; Humans ; Hydrocephalus ; Hyperventilation ; Isoflurane ; Middle Aged ; Nitrous Oxide ; Oxygen ; Recovery Room ; Ventriculostomy ; Vital Signs

This study was aimed to comprehend the pattern of renal response in bicarbonate reabsorption during various alterations in acid-base equilibrium in twelve dogs. In metabolic acidosis induced by infusion of hydrochloric acid, as the plasma bicarbonate and filtered load of bicarbonate decreased eminently, urinary excretion of bicarbonate was found to be negligible. which was attributable to almost complete reabsorption via the hydration of CO2. In metabolic alkalosis induced by infusion of sodium bicarbonate, along with an increment of plasma concentration of bicarbonate, all filtered bicarbonate was reabsorbed, with negligible amount of excretion until the plasma level attains the renal bicarbonate threshold. During the respiratory acidosis and alkalosis with higher or lower arterial Pco2, the bicarbonate reabsorption varied linearly with plasma Pco2. The linear relationship indicated that the hydration of CO, was an important source of hydrogen ion for the reabsorption of bicarbonate. In this regards, however, in metabolic alkalosis the renal bicarbonate threshold was found to be much higher than that of respiratory acidosis. The characteristics of renal bicarbonate reabsorption, during the mixed acid-base disturbances of metabolic and respiratory origin with no considerable alteration of plasma pH, induced by hydrochloric acid infusion with hyperventilation or sodium bicarbonate infusion with CO2 inhalation, were quite similar to those in metabolic acidosis and alkalosis caused by simple hydrochloric acid or sodium bicarbonate infusion, respectively.
Acid-Base Equilibrium ; Acidosis ; Acidosis, Respiratory ; Alkalosis ; Animals ; Dogs* ; Hydrochloric Acid ; Hydrogen-Ion Concentration* ; Hyperventilation ; Inhalation ; Plasma* ; Protons ; Sodium Bicarbonate

Acid-base balances in the CSF have been reported by a number of groups during the past 20 years. The CSF contains only neligilbe concentrations of buffer anions other than HCO3(-). Acid-base balances in the CSF depend mainly on arterial PCO2 because arterial CO2 diffuses easily into the blood-brain barrier to form H2CO2 in the CSF. This study was primarily undertaken to observe the changes of pH, CO2 and HCO3(-) values in the CSF in the acute stage of hyperventilation. We have studied relatively healthy patients who were scheduled for surgery for cerebral aneuryams. Prior to induction of anesthesia, the radial artery was cannulated for and arterial line and blood samples taken and lumbar tapping was performed at the level of L3-4 using at 14 gause long needle, then a 18 gauze catheter was inserted through the needle. Pre-operative samples for gases were taken, then the patient was anesthetized and his repiration was controlled and maintained at the PaCO2 of 30 torr. The samples in both blood and CSF for gases were obtained at intervals of 15, 30, 45 and 60 minutes and observed and compared. The results were as follows: The PCO2 in CSF decreased as rapidly as the arterial PCO2 decreased by hyperventilation. The data obtained after hyperventilation of 45 minutes showed a significant decrease of CO2 value in the CSF as compared to the control group. The pH in the CSF increased as rapidly as the pH of the arterial blood. The arterial HCO3(-) decreased significantly in the groups of 15, 30 and 45 minutes and it was highly significant in the 60 minutes group, despite this the HCO3(-) in the CSF showed no significant changes in any of the groups. In conclusion as a result of this study, no visible metabolic compensation in the CSF for respiratory alkalosis was observed in an acute stage of hyperventilation.
Alkalosis, Respiratory ; Anesthesia ; Anions ; Blood-Brain Barrier ; Catheters ; Compensation and Redress ; Gases ; Humans ; Hydrogen-Ion Concentration ; Hyperventilation* ; Needles ; Radial Artery ; Vascular Access Devices

BACKGROUND: During general anesthesia the adult patient's tidal volume is determined by patient's weight. Therefore patients with severe ascites, huge abdominal mass or pregnancy have considerable ventilatory change during the operation because the great change in their body weight, that might cause unwanted respiratory alkalosis or acidosis. The purpose of this study is to identify the effects of such changes in ventilation between pre-delivery and post-delivery periods during the cesarean section. METHODS: Eighteen 36weeks or older pregnant patients (ASA 1), scheduled for elective cesarean section under general anesthesia, are selected for the study. PhysioFlex was used for ventilation. Pre-induction maternal gas analysis were performed in all cases. They were randomly divided into two groups according to the ventilator setting for minute ventilation, one set by pre-pregnant weight (Group 1) and the other by pregnant (term) weight (Group 2). Blood gas analysis were performed 5 minutes after induction and 20 minutes after delivery. End-tidal CO2 and inspiratory airway pressure were also measured. RESULTS: All patients show mild hyperventilation with normal acid-base status at pre-induction period. There were no significant differences in arterial PCO2 value between two groups. Group 1 shows mild metabolic acidosis compared with group 2 (by pH at 20 minutes after delivery). CONCLUSION: Term(just prior to operation) body weight rather than pre-pregnant weight is preferable for ventilator setting in the case of cesarean section under general anesthesia.
Acidosis ; Adult ; Alkalosis, Respiratory ; Anesthesia, General* ; Ascites ; Blood Gas Analysis ; Body Weight ; Cesarean Section* ; Female ; Humans ; Hydrogen-Ion Concentration ; Hyperventilation ; Pregnancy ; Pregnancy* ; Respiration, Artificial* ; Tidal Volume ; Ventilation ; Ventilators, Mechanical

If in the aneurysmal rupture patients the brain metabolic parameters obtained from blood chemistry were significant and useful in clinical practice, it cannot be overstimated. Hansdorfer er al.(1973) reported that lactate, pyruvate, uric acid and alpha-HBDH of central venous blood obtained form the patients with brain contusion in basal metabolic state were significantly increased and they were useful in evaluating the prognosis of the patients. Zooping(1970) and Broderson(1974) also had tried to evaluate the prognosis and brain metabolic status of the comatous patients with blood gas analysis and CSF biochemistry. They encouraged us to estimate lactate and lactate/pyruvate ratios of canine jugular venous blood combined with gas analysis. Complete cerebral bloody-ischemia similar with initial stage of aneurysmal rupture was induced by the instanteneous elevation of intracranial pressure 30 mmHg above systemic arterial pressure by infusion of blood and mock CSF mixture into the cisterna arrest or pulmonary hypertension were discarded. At the end of the 5 minutes ischemic period, the needle tip which was inserted in to cisterna magna was removed without decreasing intracranial pressure. At 3 hours, 24 hours, 48 hours and 72 hours after ischemic period jugular venous and arterial blood were sampled for determination of lactate and pyruvate, and blood gas analysis. The following results were obtained. ie ; 1. Both lactate and pyruvate of canine jugular venous blood were increased from 3 hours and reached peak level at 24 hours after insult. Standard value of lactate and pyruvate were 1.416mM and 0.075mM and peak values were 2.429 and 0.165mM(P<0.05). 2. The more severe the neurological deficits of the animals, the highest levels of lactate and pyruvate were observed. 3. The lactate concentrations in 48 hours and 72 hours sample slopped down from 24 hours peak level but were significantly higher than those of standard. 4. Pyruvate returned to the normal range within 48 hours after insult. 5. L/P ratios were not changed significantly until 48 hours after insult but steeply elevated in 72 hours sample. 6. In gas analysis all the animals show respiratory alkalosis after insult. 7. In arterial boundary zones multiple focal ischemia were found in necropsy which was thought as reflecting no-reflow phenomenon. We concluded that elevation of lactate and pyruvate in early stage must be due to the hyperventilation after insult and lactate of late stage reflected CSF lactic acidosis.
Acidosis, Lactic ; Alkalosis, Respiratory ; Aneurysm ; Animals ; Arterial Pressure ; Biochemistry ; Blood Gas Analysis ; Brain ; Brain Injuries ; Chemistry ; Cisterna Magna ; Humans ; Hypertension, Pulmonary ; Hyperventilation ; Intracranial Pressure ; Ischemia ; Lactic Acid* ; Needles ; No-Reflow Phenomenon ; Prognosis ; Pyruvic Acid ; Reference Values ; Rupture ; Uric Acid