Incomplete compensation of CSF [H+] in man during acclimatization to high altitude (48300 M)

1975 ◽  
Vol 38 (6) ◽  
pp. 1067-1072 ◽  
Author(s):  
H. V. Forster ◽  
J. A. Dempsey ◽  
L. W. Chosy

This study has assessed the regulation of arterial blood and cerebrospinal fluid acid-base status in seven healthy men, at 250 m altitude and after 5 and 10–11 days sojourn at 4,300 m altitude (PaO2 = 39 mmHg day 1 to 48 mmHg day 11). We assumed that observed changes in lumbar spinal fluid acid-base status paralleled those in cisternal CSF, under these relatively steady-state conditions. Ventilatory acclimatization during the sojourn (-14 mmHg PaCO2 at day 11) was accompanied by: 1) reductions in [HCO3-] (-5 to -7 meq/1) which were similar in arterial blood and CSF; 2) substantial, yet incomplete, compensation (70–75%) of both CSF and blood pH; and 3) a level of CSF pH which was maintained significantly alkaline (+0.05 +/- 0.01) to normoxic control values. These data at 4,300 m confirmed and extended our previous findings for more moderate conditions of chronic hypoxia. It was postulated that the magnitude and time course of pH compensation in the CSF during chronic hypoxia and/or hypocapnia are determined by corresponding changes in plasma [HCO2-].

1982 ◽  
Vol 53 (6) ◽  
pp. 1551-1555 ◽  
Author(s):  
D. G. Davies ◽  
W. F. Nolan

Cerebral interstitial fluid (ISF) pH of ventral medulla or thalamus, cisternal cerebrospinal fluid (CSF) pH, and arterial blood pH, PCO2, and [HCO-3] were measured in chloralose-urethan-anesthetized, gallamine-paralyzed New Zealand White rabbits during 30-min episodes of either HCl or NaHCO3 intravenous infusions. ISF pH was measured continuously with glass microelectrodes (1- to 2-microns tip diameter). Cisternal CSF pH was measured continuously with an indwelling pH probe (1-mm tip diameter). Both ventral medullary and thalamic ISF [H+] changed significantly, whereas arterial PCO2 remained constant. CSF [H+] did not change. We conclude from these data that 1) changes in blood acid-base conditions are rapidly reflected in cerebral ISF and 2) transient differences in [H+] and [HCO-3] can exist between cerebral ISF and CSF.


1964 ◽  
Vol 19 (2) ◽  
pp. 319-321 ◽  
Author(s):  
J. W. Severinghaus ◽  
A. Carceleń B.

CSF pH was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3,800 m. In order to further evaluate the possible role of CSF acid-base equilibria in the regulation of respiration, 20 Peruvian Andean natives were studied at altitudes of 3,720–4,820 m. In ten subjects at 3,720 m, means were: CSF pH 7.327, Pco2 43, HCO3- 21.5, Na+ 136, K+ 2.6, Cl- 124, lactate 30 mg/100 ml. Arterial blood: pH 7.43, Pco2 32.5, HCO3- 21.3, Na+ 136, K+ 4.2, Cl- 107, hematocrit 49, SaOO2 89.6. In six subjects at 4,545 m and four at 4,820 m CSF values were not significantly different; mean arterial Pco2 was 32.6 and 32.3, respectively. The only significant variations with altitude were the expected lowering of PaOO2 to 47 and 43.5 mm Hg, and of SaOO2 to 84.2 and 80.7, and increase of hematocrit to 67% and 75%, respectively. The natives differed from recently acclimatized sea-level residents in showing less ventilation (higher Pco2) in response to the existing hypoxia, and less alkaline arterial blood. The difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor. respiratory regulation at high altitude; chronic acclimatization to altitude; peripheral chemoreceptor response to hypoxia; CSF and medullary respiratory chemoreceptors Submitted on June 12, 1963


1994 ◽  
Vol 14 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Jacques J. Sennesael ◽  
Godelieve C. De Smedt ◽  
Patricia Van der Niepen ◽  
Dierik L. Verbeelen

Objective To assess the possible effects of peritonitis on peritoneal and systemic acid-base status. Design pH, pCO2, lactate, and total leukocyte and differential count were simultaneously determined in the overnight dwell peritoneal dialysis effluent (PDE) and arterial blood in noninfected patients (controls) and on days 1, 3, and 5 from the onset of peritonitis. Setting University multidisciplinary dialysis program. Patients Prospective analysis of 63 peritonitis episodes occurring in 30 adult CAPD patients in a single center. Results In controls, mean (±SD) acid-base parameters were pH 7.41 ±0.05, pCO2 43.5±2.6 mm Hg, lactate 2.5±1.5 mmol/L in the PDE, and pH 7.43±0.04, PaCO2 36.8±3.8 mm Hg, lactate 1.4±0.7 mmol/L in the blood. In sterile (n=6), gram-positive (n=34), and Staphylococcus aureus (n=9) peritonitis PDE pH's on day 1 were, respectively, 7. 29±0.07, 7. 32±0.07, and 7.30±0.08 (p<0.05 vs control). In gram -negative peritonitis (n=14) PDE pH was 7.21 ±0.08 (p<0.05 vs all other groups). A two-to-threefold increase in PDE lactate was observed in all peritonitis groups, but a rise in pCO2 was only seen in gram -negative peritonitis. Acid-base profile of PDE had returned to control values by day 3 in sterile, gram -positive and Staphylococcus aureus peritonitis and by day 5 in gramnegative peritonitis. Despite a slight increase in plasma lactate on the first day of peritonitis, arterial blood pH was not affected by peritonitis. Conclusion PDE pH is decreased in continuous ambulatory peritoneal dialysis (CAPD) peritonitis, even in the absence of bacterial growth. In gram-negative peritonitis, PDE acidosis is more pronounced and prolonged, and pCO2 is markedly increased. Arterial blood pH is not affected by peritonitis.


1979 ◽  
Vol 82 (1) ◽  
pp. 345-355
Author(s):  
R. G. BOUTILIER ◽  
D. J. RANDALL ◽  
G. SHELTON ◽  
D. P. TOEWS

Cutaneous CO2 excretion is reduced as the skin dries during dehydration but an increase in breath frequency acts to regulate the arterial blood Pcoco2 and thus pHα. Moreover, the toad does not urinate and water is reabsorbed from the bladder to replace that lost by evaporation at the skin and lung surfaces. The animal does, however, produce a very acid bladder urine to conserve circulating levels of plasma [HCO3-] and this together with an increased ventilation effectively maintains the blood acid-base status for up to 48 h of dehydration in air. Water loss and acid production are presumably also reduced by the animal's behaviour; animals remain still, in a crouched position or in a pile if left in groups. Dehydrated toads are less able than hydrated toads to regulate blood pH during hypercapnia: they hyperventilate and mobilize body bicarbonate stores in much the same fashion as hydrated animals but due to the restrictions on cutaneous CO2 excretion and renal output, there is comparatively little reduction in the PCOCO2 difference between arterial blood and inspired gas thereby resulting in a more severe respiratory acidosis. These factors further contribute to the persistent acidosis which continues even when the animals are returned to air.


1963 ◽  
Vol 18 (4) ◽  
pp. 712-716 ◽  
Author(s):  
Vincent J. Fisher ◽  
Lynn C. Christianson

Comparison of the rate and magnitude of changes in pH, CO2 tension, and bicarbonate concentration in arterial blood, cisternal spinal fluid, and lumbar spinal fluid was made in man during hyperventilation and recovery. CO2 tension changes in cisternal fluid were rapid and significant, although less in magnitude than those in arterial blood, whereas changes in lumbar fluid CO2 tension were minimal and slow, lagging behind cisternal changes by 10–20 min. The different rates of change following altered ventilation explain some of the reported reversals of the normal lumbar spinal fluid to arterial blood CO2 tension gradients. It also suggests that the choroid plexus is one site of removal of CO2 from spinal fluid. Submitted on December 13, 1962


1982 ◽  
Vol 242 (1) ◽  
pp. R157-R161
Author(s):  
L. I. Crawshaw ◽  
R. A. Ackerman ◽  
F. N. White ◽  
M. E. Heath

Largemouth bass (Micropterus salmoides) acclimated to 3 degrees C were placed in a thermal gradient. The bass selected the final thermal preferendum of 28 degrees C in about 18 h. The movement into warmer water was initially rapid but became progressively slower. 2) Other bass were acclimated to 8 degrees C, cannulated in the dorsal aorta, and placed in a temperature-controlled chamber. Oxygen uptake, blood pH, and total CO2 were measured as the chamber temperature was increased to 28 degrees C following a time course similar to that followed by bass in the gradient. 3) Oxygen uptake was always elevated above the resting level, and this elevation increased as higher temperatures were encountered. 4) Just prior to placement in the chamber the pH of the arterial blood was 7.98 +/- 0.05 (mean +/- SE). As the temperature was increased neither the pH nor the total CO2 content of the blood exhibited major changes. At temperatures between 26 and 28 degrees C, the pH (8.01 +/- 0.03) was about 0.3 pH units above predicted normal values. 5) During the return to the final thermal preferendum fish experience overall metabolic rates and extracellular acid-base levels that deviate progressively farther from normal resting levels. Neither factor appears likely to be the major determinant of the behavioral response.


2007 ◽  
Vol 47 (1) ◽  
pp. 35
Author(s):  
Hari Kushartono ◽  
Antonius H. Pudjiadi ◽  
Susetyo Harry Purwanto ◽  
Imral Chair ◽  
Darlan Darwis ◽  
...  

Background Base excess is a single variable used to quantifymetabolic component of acid base status. Several researches havecombined the traditional base excess method with the Stewartmethod for acid base physiology called as Fencl-Stewart method.Objective The purpose of the study was to compare two differentmethods in identifying hyperlactacemia in pediatric patients withcritical illness.Methods The study was performed on 43 patients admitted tothe pediatric intensive care unit of Cipto MangunkusumoHospital, Jakarta. Sodium, potassium, chloride, albumin, lactateand arterial blood gases were measured. All samples were takenfrom artery of all patients. Lactate level of >2 mEq/L was definedas abnormal. Standard base excess (SBE) was calculated fromthe standard bicarbonate derived from Henderson-Hasselbalchequation and reported on the blood gas analyzer. Base excessunmeasured anions (BE UA ) was calculated using the Fencl-Stewartmethod simplified by Story (2003). Correlation between lactatelevels in traditional and Fencl-Stewart methods were measuredby Pearson’s correlation coefficient .Results Elevated lactate levels were found in 24 (55.8%) patients.Lactate levels was more strongly correlated with BE UA (r = - 0.742,P<0.01) than with SBE (r = - 0.516, P<0.01).Conclusion Fencl-Stewart method is better than traditionalmethod in identifying patients with elevated lactate levels, so theFencl-Stewart method is suggested to use in clinical practice.


1988 ◽  
Vol 136 (1) ◽  
pp. 351-361
Author(s):  
LEONA MATTSOFF ◽  
MIKKO NIKINMAA

We studied the effects of acute external acidification on the acid-base status and plasma and red cell ion concentrations of lampreys. Mortality was observed within 24 h at pH5 and especially at pH4. The main reason for the high sensitivity of lampreys to acid water appears to be the large drop in blood pH: 0.6 and 0.8 units after 24 h at pH5 and pH4, respectively. The drop of plasma pH is much larger than in teleost fishes exposed to similar pH values. The difference in the plasma pH response between lampreys and teleosts probably results from the low buffering capacity of lamprey blood, since red cells cannot participate in buffering extracellular acid loads. Acidification also caused a decrease in both Na+ and C− concentrations and an elevation in K+ concentration of plasma. The drop in plasma Na+ concentration occurred faster than the drop in plasma Cl− concentration which, in turn, coincided with the decrease in total CO2 concentration of the blood.


PEDIATRICS ◽  
1975 ◽  
Vol 56 (6) ◽  
pp. 999-1004
Author(s):  
Daniel C. Shannon ◽  
Robert De Long ◽  
Barry Bercu ◽  
Thomas Glick ◽  
John T. Herrin ◽  
...  

The initial acid-base status of eight survivors of Reye's syndrome was characterized by acute respiratory alkalosis (Pco2=32 mm Hg; Hco3-= 22.0 mEq/liter) while that of eight children who died was associated with metabolic acidosis as well (HCO3-=10.0 mEq/liter). Arterialinternal jugular venous ammonia concentration differences on day 1 (299 mg/100 ml) and day 2 (90 mg/ 100 ml) reflected cerebral uptake of ammonia while those on days 3 and 4 (-43 and -55 mg/100 ml) demonstrated cerebral release. Arterial blood hyperammonemia can be detoxified safely in the brain as long as the levels do not exceed approximately 300µg/100 ml. Beyond that level lactic acidosis is observed, particularly in cerebral venous drainage. Arterial blood hyperammonemia was also related to the extent of alveolar hyperventilation. These findings are very similar to those seen in experimental hyperammonemia and support the concept that neurotoxicity in children with Reye's syndrome is at least partly due to impaired oxidative metabolism secondary to hyperammonemia.


PEDIATRICS ◽  
1980 ◽  
Vol 65 (5) ◽  
pp. 1006-1006

In the article "A Diagnostic Approach to Metabolic Acidosis in Children" by Kappy and Morrow (Pediatrics 65:351-356, 1980) on p 351 under "Normal Acid-Base Physiology" the normal arterial blood pH is maintained at 7.40 (H+ = 39.8 nEq/liter not mEq/liter.


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