Frequency of Acid-Base Derangements Among the Neonates Admitted to the Intensive Care Unit

Background: Every year deranged acid-base physiology drives admission to a critical care arena for a vast number of neonates. The neonatal intensive care unit is a fundamental sector for the survival of high-risk newborns. The acid-base disorder must always be considered in the clinical setting. The clinician should, in most cases, be able to predict the type of acid-base imbalance before the blood gas is available. Arterial blood gases (ABG-s) are the gold standard for assessing the adequacy of oxygen delivery, ventilation, and pH. This study aimed to assess the frequency of acid-base derangements among neonates admitted to the intensive care unit. Material & Methods: This was an observational cohort study that was conducted in the Neonatal Intensive Care Unit (I.C.U.) of Dhaka Shishu Hospital, Dhaka, Bangladesh during the period from October 2009 to September 2010. In total 230 neonates admitted to the Neonatal Intensive Care Unit, after fulfilling the inclusion criteria were enrolled in this study as study subjects. For each baby, a detailed history was recorded in a questionnaire form (enclosed herewith) from the mother or other caregiver. It was filled up by the researcher himself containing history (including antenatal history), physical examinations and laboratory findings. Arterial blood gas analysis was done (in a clinical biochemistry laboratory using an automatic analyzer machine) for each neonate at admission and that report was recorded for this study. Results: Among the total study subjects, 127 newborn babies (55.2%) had acid-base imbalances. Mixed acidosis prevailed in the highest frequency (23.9%) Then metabolic acidosis cases were at 17.8% and respiratory acidosis was at 13.9%. Metabolic alkalosis and respiratory alkalosis were absent. Normal blood gas was observed in 44.3% of newborns. All the neonates with pH <7 were dead. After Chi-Square analysis (at df=1), we found a highly significant correlation between mortality outcome with pH <7.35, CO2 >45, HCO3 < 22 mol/l and Base deficit >-10. All modalities of acid-base imbalances were significantly associated with mortality. Conclusion: In this study, a significant number of neonates who were admitted to the intensive care unit, can develop acid-base derangement. Mixed acidosis was found in the highest frequency. Metabolic, respiratory and mixed acidosis all has a significant correlation with death in a NICU. Metabolic alkalosis and respiratory alkalosis were found absent at admission

Sistemática para el manejo del equilibrio ácido-base en pacientes graves / Systemization for the management of acid-base balance in seriously ill patients

Introducción: Las alteraciones del equilibrio ácido-base pueden ser de carácter primario. En la mayoría de los casos dependen de la complicación de una enfermedad preexistente. La frecuencia de estos trastornos es elevada, especialmente, en enfermos hospitalizados en las unidades de atención al paciente grave. Su aparición conlleva implicaciones pronósticas significativas. Objetivo: Sistematizar sobre el estado actual del manejo del equilibrio ácido-base. Método: Se realizó una revisión bibliográfica en la que se utilizaron las herramientas del método científico. Se examinó toda la bibliografía disponible publicada en los últimos cinco años y así, elaborar una síntesis crítica, acorde al criterio y las competencias de los autores sobre la temática. Resultados: Se expone la importancia de la evaluación clínica, que unida a los niveles de PCO2, y de exceso o déficit de bases en una gasometría arterial, permiten identificar el trastorno ácido base existente. Igualmente, se destaca que el CO2 tiene una función clave en el control de la ventilación, así como las modificaciones que produce al flujo sanguíneo cerebral, el pH y el tono adrenérgico. Otro aspecto importante fue la reciente práctica clínica de la "hipercapnia permisiva" para reducir el metabolismo tisular y de esta manera, mejorar la función del surfactante e impedir la nitración de las proteínas. Conclusiones: El manejo de los desequilibrios ácido-base debe ser del dominio de todos los profesionales vinculados a la asistencia médica, pues el retraso de su diagnóstico puede empeorar la evolución y el pronóstico de los pacientes graves(AU)

Introduction: Acid-base balance alterations can be of a primary nature. In most cases, they depend on the complication of a pre-existing disease. The frequency of these disorders is high, especially in patients hospitalized in critical care units. Its appearance carries significant prognostic implications. Objective: To systematize the current state of acid-base balance management. Method: A bibliographic review was carried out, for which the tools of the scientific method were used. All the available bibliography, published in the last five years, was examined; thus, a critical synthesis was prepared, according to the criteria and competences of the authors regarding the subject. Results: The importance of the clinical evaluation is exposed, which, together with PCO2 levels as well as excess or deficit of bases in an arterial blood gas, allow to identify the existing acid-base disorder. Likewise, it is highlighted that CO2 has a key function in ventilation control, together with the modifications it produces on cerebral blood flow, pH and adrenergic tone. Another important aspect was the recent clinical practice of "permissive hypercapnia" to reduce tissue metabolism and thus improve surfactant function and prevent protein nitration. Conclusions: The management of acid-base imbalances should be mastered by all professionals associated to medical care, since any delay in its diagnosis can worsen the evolution and prognosis of seriously ill patients(AU)

Seizures in patients with respiratory disease - a retrospective single center study / Convulsões em pacientes com doença respiratória - estudo retrospectivo de centro único

ABSTRACT Objective: Seizures are a neurological condition commonly experienced during the follow-up period after systemic or metabolic disorders. The aim of the present study was to determine the etiological factors of seizures in patients at a tertiary care chest clinic. Methods: We reviewed all neurology consultations that were requested due to seizures in inpatient clinics in a tertiary care hospital specializing in respiratory disorders between January 2011 and January 2018 were retrospectively reviewed. Results: The present study included 705 of 2793 (25.2%) patients who requested consultations for seizures during the study period. The mean age of the sample was 64.05±17.19 years. Of the 705 patients, 307 (43.5%) had a previous history of epilepsy (Group I) and 398 (56.5%) had a first-time seizure and were considered to have symptomatic seizures (Group II). Multiple factors played roles in the development of seizures in 54.8% of the patients. In most patients, metabolic causes, systemic infections, and drug use were identified and an intracranial metastatic mass lesion was the major cause in patients with lung cancer. Rates of hypoxemia and respiratory acidosis were significantly higher in patients with symptomatic seizures (Group II) than in patients with primary epilepsy (Group I). Conclusions: Blood gas changes such as hypoxemia and respiratory acidosis were among the factors statistically associated with the development of symptomatic seizures in patients with respiratory diseases. Additionally, hypoxemia, hypercapnia, and respiratory acidosis were correlated with mortality in patients hospitalized for respiratory system diseases who requested consultations for seizures.

RESUMO Objetivo: Convulsões são uma condição neurológica comumente vivenciada durante o período de acompanhamento após distúrbios sistêmicos ou metabólicos. O objetivo do presente estudo foi determinar os fatores etiológicos das convulsões em pacientes de uma clínica torácica de atendimento terciário. Métodos: Foram revisadas retrospectivamente todas as consultas neurológicas solicitadas devido a convulsões em clínicas de internação em um hospital terciário especializado em distúrbios respiratórios entre janeiro de 2011 e janeiro de 2018. Resultados: O presente estudo incluiu 705 dos 2.793 (25,2%) pacientes que solicitaram consultas para convulsões durante o período do estudo. A idade média da amostra foi de 64,05±17,19 anos. Dos 705 pacientes, 307 (43,5%) tinham história prévia de epilepsia (Grupo I) e 398 (56,5%) tiveram uma convulsão inicial e foram considerados como tendo crises sintomáticas (Grupo II). Vários fatores desempenharam papel no desenvolvimento de convulsões em 54,8% dos pacientes. Na maioria dos pacientes, causas metabólicas, infecções sistêmicas e uso de drogas foram identificadas e uma lesão em massa metastática intracraniana foi a principal causa em pacientes com câncer de pulmão. As taxas de hipoxemia e acidose respiratória foram significativamente maiores em pacientes com crises sintomáticas (Grupo II) do que em pacientes com epilepsia primária (Grupo I). Conclusões: Alterações dos gases sanguíneos, como hipoxemia e acidose respiratória, foram alguns dos fatores estatisticamente associados ao desenvolvimento de convulsões sintomáticas em pacientes com doenças respiratórias. Além disso, hipoxemia, hipercapnia e acidose respiratória foram correlacionadas com a mortalidade em pacientes hospitalizados por doenças do sistema respiratório que solicitaram consultas para convulsões.

Clinical and blood gas analysis of calves conceived by artificial insemination, in vitro fertilization and animal cloning / Análise clínica e hemogasométrica de bezerros concebidos por inseminação artificial, fertilização in vitro e clonagem animal

In order for successful extra-uterine adaptation to occur, it is necessary for the neonate to be able to establish its respiratory functions effectively, guaranteeing efficient oxygenation and good vitality. Respiratory disorders are the major cause of death during the neonatal period in cattle, and this mortality is even more significant when it comes to calves originated by in vitro fertilization (FIV) or animal cloning (CA). Blood gas analysis assesses acid-base balance changes effectively, and when associated with the neonate's clinical examination, provides subsidies for accurate diagnosis and early treatment of neonatal maladaptation. The objective of this study was to study neonates born from artificial insemination (IA) and to compare them to calves conceived by FIV and CA, regarding blood gas and clinical examination. For that, 20 AI calves, 15 FIV calves, and 15 cloned calves were evaluated immediately after calving and at 6, 12, 24 and 48 hours of life. At all experimental times, venous blood samples were collected for blood gas and clinical examination was performed. In the postpartum evaluation, Apgar score and column length and respiratory amplitude measurements were used. IVF animals showed no alterations, resembling Group IA calves. The calves from CA showed more pronounced acidosis postpartum than expected physiological acidosis mixed for neonates, with decreasing values of bicarbonate (HCO3-), and base excess (BE) and the increase in carbon dioxide pressure (PCO2) when compared to the other groups. This disorder may have reflected lower mean values of Apgar scores and increased heart and respiratory rates. Intensive follow-up of these neonates is suggested, with monitoring by clinical and hemogasometric examination for early diagnosis of this condition and treatment based on oxygen therapy and bicarbonate replacement.(AU)

Para que ocorra adaptação extra-uterina bem sucedida é necessário que o neonato consiga estabelecer suas funções respiratórias de maneira eficaz, garantindo oxigenação eficiente e boa vitalidade. Distúrbios respiratórios são os maiores causadores de óbito durante o período neonatal em bovinos, e essa mortalidade é ainda mais expressiva quando se trata de bezerros originados por fertilização in vitro (FIV) ou clonagem animal (CA). A hemogasometria avalia alterações do equilíbrio ácido-básico de forma eficaz, e quando associada ao exame clínico do neonato, fornece subsídios para diagnóstico acurado e tratamento precoce da má adaptação neonatal. O objetivo deste trabalho foi estudar recém-nascidos bovinos originados por inseminação artificial (IA) e compará-los a bezerros concebidos por FIV e CA, no que se refere a hemogasometria e exame clínico. Para isso, foram utilizados 20 bezerros IA, 15 bezerros FIV e 15 bezerros clonados que foram avaliados imediatamente após o parto e com 6, 12, 24 e 48 horas de vida. Em todos os momentos experimentais foram colhidas amostras de sangue venoso para hemogasometria e foi realizado o exame clínico. Na avaliação pós-parto foram utilizados escore Apgar e mensurações de comprimento de coluna e amplitude respiratória. Os animais FIV não demonstraram alterações, assemelhando-se aos bezerros do Grupo IA. Os bezerros provenientes de CA apresentaram acidose pós-parto mais acentuada do que a acidose mista fisiológica esperada para neonatos, evidenciada pela diminuição dos valores de bicarbonato (HCO3-) e excesso de bases (EB) e pelo aumento de pressão parcial de dióxido de carbono (PCO2) quando comparados aos demais grupos. Esse distúrbio pode ter refletido em valores médios menores de escore Apgar e no aumento das frequências cardíaca e respiratória. Sugere-se acompanhamento intensivo desses neonatos, com monitoramento por meio do exame clínico e hemogasométrico para diagnóstico precoce dessa condição e tratamento baseado em oxigenioterapia e reposição de bicarbonato.(AU)

Hemogasometria arterial pré e pós-rinoplastia em cães braquicefálicos portadores de estenose de narina / Arterial hemogasometry pre and post rhinoplasty in brachyphalic dogs with nostril stenosis

Vinte e seis cães braquicefálicos portadores de estenose de narina, 22 machos e quatro fêmeas, foram submetidos à rinoplastia bilateral. Dezesseis cães eram Buldogues Franceses; dois, Buldogues Ingleses; seis, Pugs; e dois, Shih Tzus, com idade variando de seis meses a seis anos. Foram efetuadas coletas de sangue arterial para análises hemogasométricas no pré-operatório e 30 dias após a cirurgia. Para cada avaliação, foi obtida uma amostra de 0,5mL de sangue coletado da artéria femoral, em seringa plástica heparinizada. Em seguida, procedeu-se à avaliação hemogasométrica em analisador de gases sanguíneos (I-stat-Abbot®). Os resultados da hemogasometria pré e pós-rinoplastia mostraram uma redução nos valores médios de pCO2, TCO2 , HCO3- e BEecf, hematócrito e hemoglobina, e aumento de pH, pO2 e SO2, indicando melhora na condição ventilatória dos animais após a correção cirúrgica da estenose de narina. Isso posto, conclui-se que a hemogasometria arterial é um exame importante no diagnóstico da síndrome respiratória dos cães braquicefálicos, e extremamente útil no acompanhamento da resposta do paciente ao tratamento. A rinoplastia mostrou-se eficaz no tratamento da síndrome respiratória, promovendo melhora nos parâmetros hemogasométricos que indicam acidose respiratória secundária à obstrução das vias aéreas, comum nas raças braquicefálicas.(AU)

Twenty-six brachycephalic dogs with nostril stenosis, 22 males and four females, underwent bilateral rhinoplasty. Sixteen dogs were French Bulldogs; two, English Bulldogs; Six, Pugs; and two, Shih tzus, ranging in age from six months to six years. Blood samples were collected for hemogasometric analysis in the preoperative period and 30 days after surgery. For each evaluation, a 0.5ml sample of blood collected from the femoral artery was obtained in a heparinized plastic syringe. Hemogasometric evaluation was then performed on a blood gas analyzer (I-stat-Abbot®). The results of hemogasometry before and after rhinoplasty showed a reduction in the mean values of pCO2, TCO2, HCO3- and BEecf, hematocrit and hemoglobin, and an increase in pH, pO2 and SO2, indicating an improvement in the ventilatory condition of the animals after surgical correction of Nostril stenosis. Therefore, it is concluded that arterial hemogasometry is an important diagnostic tool for the diagnosis of brachycephalic respiratory syndrome and is extremely useful in monitoring the patient's response to treatment. Rhinoplasty was effective in the treatment of respiratory syndrome, promoting improvement in hemogasometric parameters that indicate respiratory acidosis secondary to airway obstruction, common in the brachycephalic races.(AU)

Effect of acidizing pretreatment in respiratory acidosis on neutrophil inflammatory infiltration in ischemic-reperfusion injury / 解放军医学杂志

[Abstracts] Objective To investigate the effect and mechanism of acidizing pretreatment in respiratory acidosis on ischemia-reperfusion (IR) lung injury in rats. Methods Forty-eight male Sprague-Dawley rats, weighted 250-300 g, were randomly divided into 6 groups (8 each). Rats in control group: the left pulmonary hilum was dissociated without occlusion; in sham group: the respiratory rate was adjusted to maintain the partial pressure of end-tidal carbon dioxide reached 56-65 mmHg for 5 min, the left hilar not blocked; in IR group: the left pulmonary hilum was occluded for 45 min followed by reperfusion for 180 min; in group APC: done as in sham group and blocked the left hilar as in group IR; in group SB+IR: MMP-9 inhibitor SB-3CT 5 mg/kg was intraperitoneally injected, and then treated as in group IR 30 min after; in group SB+APC: done as in group APC, and then SB-3CT 5 mg/kg was injected 30 min after. Rats in all the 6 groups were sacrificed by arterial bleeding when the experiments ended, and lung tissues were taken. HE staining was performed to observe the pathological changes of lung tissues, and immunohistochemistry was used to detect the infiltration of neutrophils (PMN) in lung tissue. Western blotting was used to detect the expression of NF-κB and MMP-9 proteins. Immunofluorescence staining was used to detect the co-expression of NF-κB and MMP-9 proteins. Results Statistically significant differences existed in each group (P0.05). The above indicators were significantly higher in group IR, group APC, group SB+IR and group SB+APC than those in control group and sham group (P0.05). Conclusions In the IR rat model, acidizing pretreatment in respiratory acidosis can alleviate PMN infiltration and IR lung injury. The mechanism may be related to inhibition of NF-κB/MMP-9 protein expression.

Electrolyte and acid-base disturbances in the critically ill patients: A retrospective case control study

Background: Electrolyte and acid-base disturbances are common in critically ill patients. Early appreciation and appropriate interventions to maintain this internal milieu are lifesaving and cost effective for the patients. Objective of the study: To analyze the effects of electrolyte and acid-base disturbances on hospital mortality in critically ill patients. Materials and methods: A retrospective case control study was done on 100 patients in the intensive care unit of our hospital for six months. Results: The incidences of electrolyte and acid-base disturbances were higher in non-survivors than survivors. The serum potassium value had both clinical (4.318 in the survivors vs. 4.815 in the nonsurvivors) and statistical significance (p=0.0298) between the survivor and non-survivor group. Arterial blood HCO3 (0.0304), CO2 (P=0.0396) and pH (P=0.015) at admission were statistically different between the two groups. The incidence rates of hyperkalemia (65%), respiratory acidosis (62.5%) and mixed metabolic acidosis and respiratory acidosis (65%) were higher in the non-survivor group. Conclusion: Electrolyte and acid-base disturbances hyperkalemia, respiratory acidosis and mixed respiratory with metabolic acidosis are highly associated with hospital mortality

A case of epileptic seizure due to lidocaine local anesthesia

Lidocaine is an amide-structured local anesthetic commonly used in practice in anesthesiology. Because of its rapid onset, it is frequently used in topical and infiltration anesthesia, regional blocks, regional intravenous anesthesia (RIVA) and general anesthesia to suppress hemodynamic responses to intubation, as well as some cardiac arrhythmias and epileptic seizures. Here, we present a case with seizures and impaired consciousness following iv lidocaine treatment during sedoanalgesia without a history of epilepsy. A thirty-seven-year-old female patient, who was scheduled for a cervical biopsy operation in the Gynecology and Obstetrics clinic, developed a loss of consciousness due to lidocaine with tonic-clonic epileptic seizures during treatment with sedoanalgesia. The patient was intubated with 2 mg midazolam, 200 mg propofol and 50 mg rocuronium intravenously, while oxygen was provided by mask at 6 liters / min. Anesthesia was maintained with 4 lt / min 50% oxygen and 50% air mixture and 2% sevoflurane. There were signs of respiratory acidosis in the blood gas analysis. She was intubated for half an hour by a mechanical ventilator. The operation was canceled. In blood gas monitoring the values were within normal limits. Sugammadex was applied by the gynecology and obstetrics department. In all cases where local anesthetic is planned, necessary precautions should be taken to cope with rare complications

Anesthetic management of a patient with glucose-6-phosphate dehydrogenase deficiency undergoing robot-assisted laparoscopic surgery: A case report

The authors describe the successful perioperative management of a 3-year-old boy from Dubai with glucose-6-phosphate dehydrogenase (G6PD) deficiency, who underwent robot-assisted laparoscopic pyeloplasty for complete right ureteropelvic junction obstruction. G6PD deficiency is a genetic disorder predisposing patients to hemolytic anemia from oxidative stress. Important considerations in anesthetic management include avoiding oxidative stress, which can be caused by various conditions, and monitoring for hypercapnia, which can cause acidosis and hemolysis. Laparoscopic surgery is usually associated with hypercapnia and therefore an increased risk for respiratory acidosis. During surgery in this particular case, efforts were made to avoid carbon dioxide retention and to keep the patient warm. General anesthesia was induced with thiopental sodium, rocuronium, and fentanyl, and maintained with sevoflurane. There were no signs of hemolysis in the perioperative period and he was discharged owing to his improved condition.

The study of permissive hypercapnia in the treatment of acute lung injury / 国际儿科学杂志

Mechanical ventilation can increase the survival rate of acute lung injury significantly,but the traditional ventilation can cause ventilator-induced lung injury.Permissive hypercapnia can alleviate barotrauma and volutrauma which are caused by the traditional mechanical ventilation,reduce proinflammatory or inflammatory cytokines release,decrease cell apoptosis,improve pulmonary ventilation function,regulate vascular contraction and relaxation and so on.It has a prospect in the treatment of acute lung injury.But it can suppress the immune response and alveolar epithelial repair,reduce pulmonary edema fluid absorption and other adverse effects.Those adverse effects limit clinical application of permissive hypercapnia.

Perinatal Outcomes according to the Types of Fetal Acidosis in Term Newborns with Umbilical Artery Acidosis / 대한주산의학회잡지

PURPOSE:To investigate the significance of umbilical artery acidosis and compare perinatal outcomes according to the types of acidosis for a tertiary hospital population delivered at term. METHODS:We reviewed maternal and neonatal medical records of all term liveborn infants with an umbilical artery pH or =20 mEq/L) and high pCO2 (> or =20 mmHg) were significantly associated with low pH value, the perinatal outcomes were not significantly different according to the level of base deficit or pCO2. CONCLUSION:The mixed acidemia was more associated with pathologic fetal acidemia than pure respiratory or metabolic acidosis. The ability to predict not only metabolic but also respiratory component of fetal acidemia may help in safe management of delivery leading to reduce the fetal acidemia.

COPD Patients with Hypercapnic Respiratory Failure: Response to Therapy and Determinant of Intubation / 결핵

BACKGROUND: The determinants of intubation and the response to therapy in COPD patients with hypercapnic respiratory failure were retrospectively reviewed. METHODS: This study involved a review of 132 episodes of hypercapnic respiratory failure(PaCO2≥50mmHg and pH≤7.35). The time frame for resolution or the time to intubation of patients who were admitted between 1996 and 1999 was analyzed. RESULTS: Out of 132 hypercapnic episodes, 49(37%) required intubation. A comparison was made with the 83 cases that responded to treatment. Patients requiring intubation had greater severity of illness, which included a higher APACHE II (Acute Physiology and Chronic Health Evaluation II) score (20±5 vs 14±4 ; p<0.01), a higher WBC, a higher serum BUM, and greater acidosis (pH, 7.23±0.11 vs 7.32±0.04 ; p<0.01). Those with the most severe acidosis(pH<7.20) had the highest intubation rate(87%) and shortest time to intubation (2±3 h). Conversely, those with an initial pH 7.31 to 7.35 were less likely to be intubated(20%), and had a longer time to intubation(97±121 h). The patients with a pH 7.21 to 7.25(4.1±2.9 day) required longer period of time to respond to medical treatment than patients with a pH of 7.31 to 7.35(2.2±3.1 day). Of those patients requiring intubation, half(55%) were intubated within 8 h of admission, and most (75%) within 24 h. Of those patients responding to treatment medical therapy, half(52%) recovered within 24 h and most (78%) recovered within 48 h. CONCLUSION: Respiratory acidosis at the initial presentation is associated with an increased likelihood of intubation. This shold assist in deciding help with the decision whether to treat patients medically, institute noninvasive ventilation, or proceed to intubation.

Effect of acute respiratory acidosis and alkalosis on the subtypes of intercalated cells in rat kidney / 대한해부학회지

Intercalated cells play a major role in proton and bicarbonate secretion in the collecting duct of kidney. A third type of intercalated cell (non A-non B cell), besides type A and B intercalated cells, and a bipolar cell are known to exist in the kidneys of the rat or the mouse. The third type cell has H(+)-ATPase in the apical membrane like the type A intercalated cell, but has no Cl(-)-HCO(3)- exchanger (AE1) on the basolateral membrane. The bipolar cell was shown to express H(+)-ATPase on both the apical and basolateral membranes. The functions of these cells, however, are not determined yet. This study was intended to know the immunohistochemical changes of the intercalated cell subtypes in the acute respiratory acidosis and alkalosis. After midline tracheostomy, respiratory acidosis and alkalosis were induced and maintained for 4 hours in the Sprague-Dawley rats (450~500 g) using a Rodent Ventilator. The kidneys were preserved for immunohistochemical studies by in vivo perfusion fixation with periodate-lysine-paraformaldehyde solution through the abdominal aorta. To identify the subtypes of intercalated cells and the tubule segments in which they are located, a triple immunolabeling procedure was used. Distal convoluted tubule cells and principal cells in the collecting duct were identified using antibody to thiazide sensitive Na(+)Cl(-) cotransporter and antibody to aquaporin-2, respectively. Antibodies to H(+)-ATPase and AE1 were used to identify subpopulation of intercalated cells. Type A cells were activated in respiratory acidosis with enhanced AE1 activity on the basolateral membrane and H(+)-ATPase reactivity moved to the apical membrane, whereas inactivated in respiratory alkalosis with decreased AE1 reactivity and H(+)-ATPase reactivity moved to the supranuclear cytoplasm. The change in reactivity of type A cells in respiratory acidosis or alkalosis was shown to differ depending on the tubular segments: most of the intercalated cells were activated in the outer medullary collecting duct while only a portion of the type A cells activated in the distal convoluted tubule, connecting tubule and cortical collecting duct. No changes were observed in type B cells in respiratory acidosis and alkalosis. In non A-non B cell which was increased in size in respiratory acidosis, H(+)-ATPase reactivity was seen on the apical membrane in respiratory acidosis, while seen in the supranuclear cytoplasm in respiratory alkalosis. These findings indicated that the renal compensation for respiratory acid-base imbalance was mediated mainly by type A cells rather than by type B or non A-non B cells. Among type A cells, more of those of outer medullary collec-ting duct were thought to be recruited compared with those of the cortical collecting duct and connecting tubule.

Changes of Sodium, Potassium, Chloride and Bicarbonateion Concentrations in Apneic Rabbits / 대한구급학회지

BACKGOUND: During apnea, as in any other acid-base disturbance, ion exchanges between intra- and extracellular compartments are expected, but few studies have reported such findings. The purpose of this study was to observe serum sodium, potassium, chloride and bicarbonate concentrations during apnea until death. METHODS: Seventeen New Zealand White Rabbits (weight 2.0~3.0 kg) were subjected to apneic oxygenation. Then we measured heart rate, blood pressure, intracranial pressure, arterial blood gas analyses and serum electrolytes (sodium, potassium, chloride and bicarbonate) concentrations during apnea until death. RESULTS: Heart rate decreased because of sinus bradyarrythmia at 10 minutes after apnea and thereafter continued to increase. Blood pressure increased up to 30 minutes after apnea and thereafter continued to decrease. Intracranial pressure consistently increased during apnea. Serum bicarbonate and chloride ion concentrations showed reciprocal changes, but there was no significant correlation. Serum sodium and potassium concentrations increased up to 40 minutes and 30 minutes respectively, and thereafter decreased until death. All serum ion concentrations were within normal limits. CONCLUSION: The serum sodium, potassium, chloride and bicarbonate concentrations were maintained within normal limits during apneic oxygenation until death.

Changes of Gas Values in the CSF and Blood during Sustained Hypoventilation / 대한마취과학회지

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.