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

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

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

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

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

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

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

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

The sudden onset of respiratory acidosis or alkalosis due to inadequate ventilation during general inhalation anesthesia may influence the action of neuromuscular blocking agents. In virtro animal studies by Funk et al.(1980) suggested that the neuromuscular blocking action of Org NC 45(NC) was minimally depressed above pH 7.68 and significantly potentiated under acidotic conditions(pH 7.05). They proposed that this was the result of an increase in NC metabolism by alkaline hydrolysis in the alkalotic state and greater molecular stability during acidosis. This study was performed to determine the effects of the neuromuscular blocking action of NC during respiratory acidosis and alkalosis. The patients were divided in to 3 groups: 1, ll & lll and experienced normocarbia, hypocarbia and hypercarbia, respectively. Hypocarbia was induced by hyperventilation and hypercarbia by adjustment of a rebreathing valve in the CO2 absorber in the semiclosed system. Simultaneously, arterial blood samples were collected from radial arteries for arterial blood gas analysis including pH and pCO2. Following the administration of succinylcholine(SCC) and the recovery of a 75% twitch height, ED95 of NC was given to the patient and the results were recorded by an evoked electromyograph (NMT, Datex). The results are follows: 1) The number of patients in groups l, ll and lll were 22, 13 and 8, respectively. The patients in each group were evenly distributed with respect to age, body weight and anesthesia. 2) The end-tidal CO2 tension in group l, ll and lll group was 38.86+/-4.62, 20.23+/-2.42 and 52.00+/-4.86mmHg, and the arterial pCO2(pH) was 37.36+/-5.71(7.461+/-0.054), 23.00+/-1.51(7.649+/-0.032) and 53.29+3.35 mmHg(7.314+/-0.026), resptectively. The end-tidal CO2 tension, arterial CO2 tension and pH in group ll and lll were significantly different from those of group l(p<0.05). 3) The onset time of SCC in group ll and lll was shorter than that in group l (p<0.05), but within 1 min in all groups. The duration of SCC in group lll(19.56+/-6.15min) was longer than that in group l (14.74+/-4.56min) (p<0.05). 4) Although there was no significant difference among the groups with respect to onset time and duration, the recovery index in group ll(10.29+/-2.21min) was significantly different from group l and lll(14.76+/-5.26 and 13.50+/-13.67 min, respectively) (p<0.05). After administration of NC in 5 min intervals, twitch tension was measured and the results were inserted into a regression equation which emphasized the delayed recovery in group lll(r=0.87). In conclusion, the recovery index in alkalosis shortened and the initial twitch tension in acidosis following NC administration was delayed compared to that in normocapnis and alkalosis. Patients with alkalosis may require more frequent doses of NC and continuous monitoring following repeated or continuous infusion in acidosis.
Acid-Base Equilibrium ; Acidosis ; Acidosis, Respiratory ; Alkalosis ; Anesthesia ; Anesthesia, Inhalation ; Animals ; Arterial Pressure ; Blood Gas Analysis ; Body Weight ; Humans ; Hydrogen-Ion Concentration ; Hydrolysis ; Hyperventilation ; Metabolism ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Radial Artery ; Vecuronium Bromide* ; Ventilation

BACKGROUND: Tetanic spasm is often noted in hyperventilating patients coming in to emergency departments. Classical explanation far this phenomenon was decreased ionized calcium levels due to respiratory alkalosis precipitated by the hyperventilation. Clinically these symptoms were observed in hypocalcemia and were thought as such without doubt. But clinical investigation on the levels of ionized calcium levels have not been clarified. Recent investigations on hyperventilating volunteers have suggested other pathophysiology for tetanic spasm in hyperventilating patients which is the decrement of ionized magnesium level rather than ionized calcium. We wanted to see if these results applied to our hypeventilating patients and see if ionized magnesium level was a factor producing tetanic symptoms. METHOD AND MATERIAL : 35 patients with diagnosis of hyperventilation syndrome by emergency physician were studied retrospectively. Hyperventilating patients arriving at Severance hospital Emergency Center from Jan.1996 to Feb. 1998 were included. Patients with cardiovascular, pulmonary diseases, history of renal or liver disease were excluded. Ion-selective method was used to detect ionized calcium, magnesium levels and arterial blood gas features. Average levels were compared to reference ranges and Wilkoxon-rank. sum test was used to compare hyperventilating patients with tetanic spasm and those with other symptoms such as dyspnea, chest pain and palpitations. RESULTS: 1) Sodium, potassium and chloride levels were 138mmol/L, 3.6mmo1/L, 106mmol/L each which were within a normal range. 2) Degrees of hyperventilation were similar with average of PH 7.54(7.4-7.71), pCO2 23.6mmHg, showing respiratory alkalosis. 3) Ionized calcium and ionized magnesium each showed 0.61mg/dL, 0.16mg/dL lower values than the lowest reference ranges which were 4.5-5.6mg/dL for ionized calcium and 1.19-1.63 for ionized magnesium. 4) No statistical difference points were observed between the tetanic spasm group and group without spasm. Female preponderance were noted in tetanic spasm group. CONCLUSION: We conclude that ogler than decrement of ionized calcium, decrement of ionized magnesium could be a factor far inducing tetanic spasm in respiratory alkalosis caused by hyperventilation.
Alkalosis, Respiratory ; Calcium* ; Chest Pain ; Diagnosis ; Dyspnea ; Emergencies ; Emergency Service, Hospital ; Female ; Humans ; Hydrogen-Ion Concentration ; Hyperventilation* ; Hypocalcemia ; Liver Diseases ; Lung Diseases ; Magnesium* ; Potassium ; Reference Values ; Retrospective Studies ; Sodium ; Spasm ; Volunteers