Base Excess Concentrations Research Articles

What's New in Shock, February 2021?

What's New in Shock, February 2021?

Blood lactate recovery and respiratory responses during diagonal skiing of variable intensity

The aims of the study were to investigate blood lactate recovery and respiratory variables during diagonal skiing of variable intensity in skiers at different performance levels. Twelve male cross-country skiers classified as elite (n=6; [Vdot]O2max=73±3 ml · kg−1 · min−1) or moderately trained (n=6; [Vdot]O2max=61±5 ml · kg−1 · min−1) performed a 48-min variable intensity protocol on a treadmill using the diagonal stride technique on roller skis, alternating between 3 min at 90% and 6 min at 70% of [Vdot]O2max. None of the moderately trained skiers were able to complete the variable intensity protocol and there was a difference in time to exhaustion between the two groups (elite: 45.0±7.3 min; moderately trained: 31.4±10.4 min) (P<0.05). The elite skiers had lower blood lactate concentrations and higher blood base excess concentrations at all 70% workloads than the moderately trained skiers (all P<0.05). In contrast, [Vdot] E/[Vdot]O2 and [Vdot] E/[Vdot]CO2 at the 70% [Vdot]O2max workloads decreased independently of group (P<0.05). Partial correlations showed that [Vdot]O2max was related to blood lactate at the first and second intervals at 70% of [Vdot]O2max (r=−0.81 and r=−0.82; both P<0.01) but not to [Vdot] E/[Vdot]O2, [Vdot] E/[Vdot]CO2 or the respiratory exchange ratio. Our results demonstrate that during diagonal skiing of variable intensity, (1) elite skiers have superior blood lactate recovery compared with moderately trained skiers, who did not show any lactate recovery at 70% of [Vdot]O2max, suggesting it is an important characteristic for performance; and (2) the decreases in respiratory exchange ratio, [Vdot] E/[Vdot]O2, and [Vdot] E/[Vdot]CO2 do not differ between elite and moderately trained skiers.

Outcome predictors of pediatric extracorporeal cardiopulmonary resuscitation.

Extracorporeal cardiopulmonary resuscitation (ECPR) allows clinicians to potentially rescue pediatric patients unresponsive to traditional cardiopulmonary resuscitation (CPR). Clinical and laboratory variables predictive of survival to hospital discharge are beginning to emerge. In this retrospective, historical cohort case series, clinical, and laboratory data from 31 pediatric patients (<21 years of age) receiving ECPR from March 2000 to April 2006 at our university-affiliated, tertiary-care children’s hospital were statistically analyzed in an attempt to identify variables predictive of survival to hospital discharge. Seven patients survived to hospital discharge (23%), and 24 patients died. Survival was independent of gender, age, and CPR duration. ECPR survival was, however, associated with a lower pre-ECPR phosphorus concentration (P = 0.002) and a lower pre-ECPR creatinine concentration (P = 0.05). A classification tree analysis, using, in part, a pre-ECPR phosphorus concentration threshold and a CPR ABG base excess concentration threshold, yielded a 96% nominal accuracy of predicting survival to hospital discharge or death. A large, multicenter, prospective cohort study aimed at validating these predictive variables is needed to guide appropriate ECPR patient selection. This study reveals the potential survival benefit of ECPR for pediatric patients, regardless of CPR duration prior to ECPR cannulation.

Comparison of the Alkalizing Effects of Bicarbonate Precursors in Calves with Experimentally Induced Metabolic Acidosis

The aims of this study were to confirm whether commercial acetated Ringer's solution, which contains 28 mM of sodium acetate, is superior to commercial lactated Ringer's solution in alkalizing effects in calves with experimentally induced metabolic acidosis. Twenty calves with experimentally induced mild acidosis were intravenously administered isotonic saline, DL-lactated, L-lactated or acetated Ringer's solution at a dose of 80 ml/kg body weight (BW). The acetated Ringer's solution induced a significantly greater increase in venous HCO(3)(-) and base excess concentrations than the other fluids during the early phases of extracellular fluid replacement in mild metabolic acidosis. Therefore, the alkalizing effect of commercial acetated Ringer's solution is superior to commercial DL- and L-lactated Ringer's solution in treatment of mild metabolic acidosis in calves.

Uso de bicarbonato e lactato-L para correção da acidose metabólica sistêmica em bovinos com acidose láctica ruminal aguda

Foram utilizados seis novilhos, providos de cânula ruminal, em delineamento experimental cross-over, para comparar a eficiência de soluções de bicarbonato de sódio e lactato-L de sódio na correção da acidose metabólica sistêmica (AMS), causada pela acidose láctica ruminal (ALR). Vinte horas após, quando apresentavam intensa AMS, os animais foram distribuídos aleatoriamente e tratados com cinco litros de 150mMol/l de bicarbonato de sódio ou de lactato-L de sódio, infundidas por via intravenosa, nas quatro horas seguintes. Amostras de sangue, para hemogasometria, foram coletadas no decorrer da infusão a zero, 1, 2, 3, 4, 6 e 8 horas. Ambos os tratamentos elevaram o pH sangüíneo já na primeira hora pós-infusão, corrigindo adequadamente a AMS. O tratamento com lactato-L de sódio aumentou as concentrações de bicarbonato, TCO2 e EAB sangüíneos já na segunda hora pós-infusão; com o bicarbonato essa elevação ocorreu a partir da terceira hora. Não houve diferenças entre tratamentos para pH sangüíneo, bicarbonato, TCO2 e excesso de base. Vinte e quatro horas após o tratamento todos os novilhos apresentaram plena recuperação. O lactato-L pode substituir o bicarbonato na correção da AMS em novilhos com ALR.

Relationship between Depression Score and Acid-Base Status in Japanese Black Calves with Diarrhea

We evaluated the relationship between depression score and acid-base status in 84 purebred and crossbred Japanese Black calves. The bicarbonate (p<0.001) and base excess concentrations (p<0.001) were significantly and negatively correlated with the depression scores of the calves. The proposed diagnostic cutoff point for a depression score that indicates severe metabolic acidosis (BE < -10 mM) is 6.5 based on analysis of the ROC curve. The sensitivity and specificity were 88.4% and 81.2%, respectively. The depression scoring system is a useful tool for evaluation of the acid-base status of purebred and crossbred Japanese Black calves. In addition, a depression score of 6.5 suggests severe metabolic acidosis and that intravenous infusion of sodium bicarbonate solution is necessary.

The Effect of Rapid Intravenous Infusion of Hypotonic Ringer's or Hartmann's Solution with Glucose on the Hemodynamic Status and Acid-Base Equilibrium of Heifers.

We examined the effect of intravenous (IV) rapid infusion of hypotonic Ringer's (RG) or Hartmann's replacement solutions with glucose (HG) on the hemodynamic status and acid-base equilibrium of heifers. Six heifers were equally divided into two groups. The animals were given 30 ml/kg of either RG or HG (20ml/kg/hr), and were monitored for 360 min after the initiation of fluid replacement. The RG and HG infusion induced an increase in relative plasma volume (rPV), reaching 124.6±12.1 % and 133.2±10.4 % at the end of fluid replacement. No changes were seen in the arterial pressure or plasma osmotic pressure. Infusion of RG induced diluted acidification, resulting from significant decreases in venous blood pH (-0.068), bicarbonate (-2.67 mmol/l) and base excess concentrations (-3.67 mmol/l) compared to pre infusion values. No significant changes were observed in these parameters in the HG group ; HG infusion inhibited diluted acidification. Thus, it appears that 30 ml/kg of hypotonic solution at a flow rate of 20 ml /kg/hr can be safely infused into cattle. Infusion of HG may be more beneficial than RG for rehydrating cattle with metabolic acidosis.

Effect of high arterial carbon dioxide tension on efficiency of immunoglobulin G absorption in calves

Abstract Objectives To determine whether high PaCO2 reduced apparent efficiency of IgG absorption (AEA) in calves and whether assisted ventilation of calves with high PaCO2 increased AEA. Animals 48 Holstein calves. Procedures Arterial and venous blood samples were collected 1, 13, and 25 hours after birth; an additional venous sample was collected at 37 hours after birth. Arterial samples were analyzed for PaCO2, PaO2, pH, and bicarbonate and base excess concentrations; venous samples were analyzed for plasma IgG concentrations. On the basis of 1-hour PaCO2, calves were assigned to nonrespiratory acidosis (PaCO2 &lt; 50 mm Hg; n = 19) or respiratory acidosis (PaCO2 ≥ 50 mm Hg; 29) groups. Calves in the respiratory acidosis group were assigned randomly to receive no further treatment (n = 17) or to be given 5 minutes of assisted ventilation (12). All calves received between 1.8 and 2 L of colostrum 2, 14, 26, and 38 hours after birth. Plasma volume and AEA were determined 25 hours after birth. Results 1-hour PaCO2 had no effect on AEA or on plasma IgG concentrations determined 13, 25, or 37 hours after birth. Artificial ventilation had no effect on plasma IgG concentration or AEA. Conclusions and Clinical Relevance Lack of effect of 1-hour PaCO2 on AEA and IgG concentration indicated that calves compensated for moderate acidbase imbalances associated with birth. Calves born with high PaCO2 achieved adequate plasma IgG concentrations if fed an adequate amount of high-quality colostrum early in life. The effect of artificial ventilation on PaCO2 was temporary and did not increase AEA. (Am J Vet Res 1999;60:609–614)

Cardiopulmonary effects of propofol infusion in llamas

Abstract Objective To evaluate selected cardiopulmonary responses to propotol 2 infusion rates in nonpretreated llamas breathing room air. Animals 5 adult llamas (3 males, 2 females) with mean ± SD body weight of 135 ± 17.7 kg. Procedure After anesthesia induction with propofol (2 mg/kg of body weight, IV), llamas received either propofol infusion 0.2 mg/kg/min (group 1) or 0.4 mg/kg/min (group 2) for 60 minutes. Measurements, taken before anesthesia induction and at regular intervals during infusion were: direct blood pressures, heart and respiratory rates, cardiac output, and arterial blood gas tensions. Systemic and pulmonary vascular resistance, cardiac and stroke indices, and plasma bicarbonate and base excess concentrations were calculated. Results At 3 to 60 minutes after either dosage of propofol, PaCO2 and heart rate increased in all llamas; at the same time, PaO2 and arterial pH decreased. Mean pulmonary artery and central venous pressures, and stroke index decreased at 3 to 60 minutes after either dosage of propofol. Mean arterial pressure decreased at 30 to 60 minutes after infusion of 0.4 mg of propofol/kg/min; pulmonary arterial wedge pressure decreased at 20 to 40 minutes and 3 to 60 minutes after infusion of 0.2 and 0.4 mg of propofol/kg/min, respectively. Mean time from termination of infusion to sternal recumbency was 7 (group 1) and 13 (group 2) minutes. Standing was achieved in a mean 11 (group 1) and 22 (group 2) minutes. Conclusion Propofol infusion rate of 0.2 mg/kg/min was considered too low to maintain a suitable depth of anesthesia, but 0.4 mg/kg/min was considered sufficient for noninvasive procedures with minimal cardiopulmonary depression. (Am J Vet Res 1997;58:153–156)

Caudal analgesia induced by epidural or subarachnoid administration of detomidine hydrochloride solution in mares

Summary Seven adult mares were used to determine the analgesic, cns, and cardiopulmonary effects of detomidine hydrochloride solution after epidural or subarachnoid administration, using both regimens in random sequence. At least 1 week elapsed between experiments. A 17-gauge Huber point (Tuohy) directional needle was used to place a catheter with stylet into either the epidural space at the first coccygeal interspace or the subarachnoid space at the lumbosacral intervertebral junction. Catheters were advanced so that the tips lay at the caudal sacral (S5 to S4) epidural space or at the midsacral (S3 to S2) subarachnoid space. Position of the catheter was confirmed radiographically. A 1% solution of detomidine HCl was injected into the epidural catheter at a dosage of 60 µg/kg of body weight, and was expanded to a 10-ml volume with sterile water to induce selective caudal epidural analgesia (cea). A dose of 30 µg of detomidine HCl/kg expanded to a 3-ml volume with spinal fluid was injected into the subarachnoid catheter to induce caudal subarachnoid analgesia (csa). Analgesia was determined by lack of sensory perception to electrical stimulation (avoidance threshold &gt; 40 V, 0.5-ms duration) at the perineal dermatomes and no response to superficial and deep muscular pinprick stimulation at the pelvic limb and lumbar and thoracic dermatomes. Maximal cea and csa extended from the coccyx to spinal cord segments T15 and T14 at 10 to 25 minutes after epidural and subarachnoid drug administrations in 2 mares. Analgesia at the perineal area lasted longer after epidural than after subarachnoid administration (142.8 ± 28.8 minutes vs 127.1 ± 27.7 minutes). All mares remained standing. Both cea and csa induced marked sedation, moderate ataxia, minimal cardiopulmonary depression, increased frequency of second-degree atrioventricular heart block, and renal diuresis. All treatments resulted in significantly (P &lt; 0.05) decreased heart rate, respiratory rate, systemic arterial blood pressure, pcv, and plasma total solids concentration. To the contrary, arterial carbon dioxide tension, plasma bicarbonate, and standard base excess concentrations were significantly (P &lt; 0.05) increased. Arterial oxygen tension, pH, and rectal temperature did not change significantly from baseline values. Results indicate that use of detomidine for cea and csa in mares probably induces local spinal and cns effects, marked sedation, moderate ataxia, mild cardiopulmonary depression, and renal diuresis.

Does amniotic fluid analysis reflect acid-base balance in fetal blood?

The purpose of the study was to examine whether the acid-base balance in amniotic fluid reflects the acid-base state in fetal blood. The pH, PCO2, PO2, bicarbonate, and base excess concentrations were measured in umbilical venous, umbilical arterial, and maternal venous blood and in amniotic fluid samples obtained at fetoscopy. This was performed before intraamniotic termination of 16 normal pregnancies (mean gestation 19.4 weeks), as well as in 14 red blood cell isoimmunized pregnancies (mean gestation 28.4 weeks) undergoing fetoscopy for the diagnosis and treatment of fetal anemia. In normal pregnancies, amniotic fluid pH and bicarbonate were significantly lower than umbilical venous and umbilical arterial blood concentrations, and this was due to the high concentration of base deficit in amniotic fluid. Whereas amniotic fluid PCO2 did correlate significantly with fetal umbilical venous PCO2 values, there was no correlation between other acid-base characteristics. Simultaneous sampling of human fetal umbilical blood and amniotic fluid under the acute conditions of this study did not show significant correlations in acid-base values.

Right displacement of the abomasum and abomasal volvulus in dairy cows: 458 cases (1980-1987)

Summary Clinical and surgical findings in 458 dairy cows with right displacement of the abomasum or abomasal volvulus (av) were analyzed to determine the association between these variables and the outcome (productive, salvaged, or terminal) of the affected cow. Heart rate at initial examination was higher in the salvaged and terminal groups of cows (P &lt; 0.0001) than in the productive group. The plasma Na+ concentration was lower in the salvaged and terminal groups of cows (P &lt; 0.0001) than in the productive group. The plasma C1− concentration was lower in the salvaged group of cows than in cows with either productive or terminal outcomes (P &lt; 0.0001). Anion gap was significantly higher (P &lt; 0.0001) in the salvaged and terminal groups than in cows classified as productive. On the basis of surgical findings, cattle with right displacement of the abomasum were more likely to survive than cows with av. Cows that required fluid decompression of the abomasum via abomasotomy were less likely to survive than those in which gaseous decompression was performed. Cows with evidence of vascular compromise of the abomasal wall were less likely to survive than those with normal abomasal serosa. Preoperative heart rate and anion gap had positive correlations with the presence of abomasal necrosis, whereas temperature, venous blood pH, plasma bicarbonate, and base excess concentrations had negative correlations. Cows in terminal stages of av were likely to have a mixed primary acid-base disturbance, consisting of metabolic alkalosis with superimposed metabolic acidosis. These findings were highly correlated with abomasal necrosis.

Experimental model of hypochloremic metabolic alkalosis caused by diversion of abomasal outflow in sheep

SUMMARY Hypochloremic metabolic alkalosis accompanied by hypokalemia and hyponatremia was induced experimentally in 7 adult sheep by diversion (loss) of gastric contents through an Ivan and Johnston cannula placed in the cranial part of the duodenum just distal to the pylorus. Cannula placement was easily accomplished, and cannulae were tolerated well by the sheep. Volume of effluent produced during the 60- to 120-hour period of diversion ranged from 7.7 to 14.9 L and tended to be greatest during the first 24 hours. All sheep became dehydrated, with mean pcv and plasma total protein concentration increases of 94.2 and 61.7%, respectively. Plasma chloride concentration decreased in linear fashion from a prediversion mean of 113 mEq/L (range, 111 to 117 mEq/L) to an end-point mean of 54 mEq/L (range, 45 to 65 mEq/L). Plasma sodium and potassium concentrations also decreased, though potassium concentration increased terminally. There were rapid increases in arterial blood pH and bicarbonate and base excess concentrations during the first 48 hours after diversion. However, during the final stages of diversion, sheep developed superimposed metabolic acidosis with increased plasma lactate concentration and high anion gap.

Haematological, serum electrolyte and blood gas effects of small volume hypertonic saline in experimentally induced haemorrhagic shock

The effects of treatment with small volume hypertonic (2400 mOsm/litre) and isotonic (300 mOsm/litre) saline on serum electrolyte and biochemical concentrations, haemograms and blood gases were evaluated in 12 horses using a haemorrhagic shock model. Intravascular catheters were placed surgically for sample collection prior to anaesthesia. Controlled haemorrhage was initiated and continued until mean systemic pressure reached 50 to 60 mmHg. Hypertonic or isotonic saline (2 litres) was administered by intravenous infusion and data collected for 2 h. Following haemorrhage, packed cell volume (PCV), haemoglobin, blood glucose concentrations and erythrocyte numbers increased whereas plasma total protein and albumin concentrations decreased. Infusion of hypertonic saline resulted in a further decrease in total protein and albumin concentrations. Glucose concentrations and other haematological variables were unaffected. Isotonic saline administration did not affect electrolyte, total protein or albumin concentrations. Concentrations of sodium and chloride were unaffected by hypotension but increased significantly following hypertonic saline treatment, exceeding normal values during the immediate post treatment period. Serum osmolality increased concurrently. No significant changes in arterial and venous blood gas values were observed with haemorrhage or isotonic saline treatment. A transient decrease in arterial and venous blood pH and a sustained decrease in venous bicarbonate and base excess concentrations occurred following hypertonic saline administration. No significant increases in any serum biochemical concentrations occurred during hypotension or following infusion of either isotonic or hypertonic saline. These results demonstrate that small volume hypertonic saline can be administered safely to horses without producing extreme changes in electrolyte concentrations, blood gases or haematological parameters.

Effect of dietary electrolyte balance on nutrient digestibility determined at the end of the small intestine and over the total digestive tract in growing pigs.

A replicated 4 x 4 Latin square digestion trial was conducted to determine the effect of electrolyte balance (EB = Na + K - Cl meq/kg of the diet) on apparent nutrient digestibilities in pigs fitted with ileal T-cannulas. Experimental diets were composed of corn and soybean meal with dietary EB altered by the substitution of CaCl2 for CaCO3, or NaHCO3 for corn and soybean meal. Electrolyte balance levels examined were -50, 100, 250 or 400 meq/kg of the diet. Increasing dietary EB concentration linearly increased (P less than .05 to P less than .02) apparent ileal digestibility of N, energy, DM and all amino acids, except alanine and methionine. However, nutrient and amino acid digestibilities measured over the total digestive tract were similar (P greater than .16) among EB levels. Increasing dietary EB resulted in a linear and quadratic (P less than .03) effect on daily urinary N excretion, resulting in a linear (P less than .05) improvement in N retention expressed both as a percentage of N intake and of absorbed N. Blood pH, total CO2, HCO3 and base excess concentrations increased linearly (P less than .02 to P less than .001) with increasing dietary EB. Dietary EB concentrations influenced nutrient and amino acid absorption measured near the end of the small intestine. Additionally, the N balance data per unit of N intake or N absorbed are indicative of an improved N utilization in pigs fed increasing dietary EB concentrations from -50 to 400 meq/kg.

The van Slyke equation.

The Henderson-Hasselbalch equation has always occupied a central place in the description of the acid-base status of the blood. An equation of similar importance is the equation for the CO2 equilibration curve of blood in vitro. It is proposed to name this the Van Slyke equation: a - 24.4 = - (2.3 X b + 7.7) X (c - 7.40) + d/(1 - 0.023 X b), where a = bicarbonate concentration in plasma/(mmol/l), b = hemoglobin concentration in blood/(mmol/l), c = pH of plasma at 37 degrees C, d = base excess concentration in blood/(mmol/l). These two equations provide an arithmetic algorithm for calculation of the various acid-base variables of the blood after measuring the pH, the pCO2, and the hemoglobin concentration.

Arterial and mixed venous PCO2 and hydrogen ion, bicarbonate and base excess concentrations in water-depleted dogs.

The arterial (a), mixed venous (v), and arterial-mixed venous differences (A-V) of hydrogen ion concentration ([H+]), PCO2, HCO-3 and base excess (BE) were measured during 3 h in control (C), water-depleted (WD) and water- and salt-depleted (WSD) dogs. In WD animals the difference in hydrogen ion concentration between venous and arterial blood increased because the [H+] increased more in venous than in arterial blood. In WSD animals (A-V) [H+] remained unchanged since both [H+]a and [H+]v increases were parallel. [H+] variations seem to represent the changes in fixed-acid concentration of blood. The difference between both groups of animals in (A-V) [H+] changes could be ascribed to PCO2 variations. [HCO-3] values changed inconsistently. Arterial samples from the experimental groups showed a continuous decrease at the same rate of change. The mean values in WSD were lower than in WD. [HCO-3]v of WSD decreased slowly during the experiment. The rate of decrease of (A-V) [HCO-3] was higher in WD than in WSD. The different behavior of of [HCO-3] between both arterial and mixed venous samples and among experimental groups disappeared if [HCO-3] changes were corrected for bicarbonate generation due to PCO2 variation (respiratory bicarbonate). Thus [HCO-3] corrected for PCO2 variation represents metabolic changes, in good agreement with both [H+] and BE variations. The metabolic acidosis cannot be explained only on the basis of the increase in blood lactate; it is suggested that other fixed acids might contribute to the decrease in blood bicarbonate. In both experimental groups PvCO2 increased continuously. The (A-V) PCO2 showed the same rate of change. There is a good relationship between this increase and the degree of plasma volume change. It therefore might be that PvCO2 increase is a direct consequence of hemodynamic impairment. In WD and WSD, BE decreased progressively in both arterial and mixed venous samples. BEa values were lower than BEv values after the experiment began. (A-V) BE decreased in an exponential manner in both experimental groups; this change could be ascribed to the increased level of deoxygenated hemoglobin in mixed venous blood, thus giving rise to a decrease in fixed acid concentration.

Intra-amniotic infusion of bicarbonate in the treatment of human fetal acidosis

At the time of cesarean section with the use of spinal anesthesia, 40 to 100 mEq. of sodium bicarbonate was infused into the amniotic cavities of 11 near-term pregnant women, the majority of whom had special complications. Eleven other near-term pregnant women served as controls. Five patients in the treated group developed post-spinal-block hypotension, as did 5 patients in the untreated group. All hypotensive episodes were treated by acute hydration. An equilibration period of 15 to 20 minutes was allowed between sodium bicarbonate infusion and delivery. Mean umbilical arterial base excess of the treated group was significantly greater than that of the untreated group (−7.0 vs. −10.9 mEq. per liter, p < 0.05), suggesting that a significant bulk transfer of bicarbonate occurred from the amniotic fluid to the fetus. The probable effect was a partial correction of the metabolic component of the fetal acidosis. pH and base excess concentration gradients between amniotic fluid, gastric aspirate, and fetal blood suggest a route of transfer across the gastric mucosa in treated infants. The bicarbonate-treated group had significantly higher mean 1 and 5 minute Apgar scores than did the untreated group.

Influence of posture and passive tilting on venous return and cardiac output.

ARTICLESInfluence of posture and passive tilting on venous return and cardiac outputFL Abel, and JA WaldhausenFL Abel, and JA WaldhausenPublished Online:01 Nov 1968https://doi.org/10.1152/ajplegacy.1968.215.5.1058MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByUse of Lower Body Negative Pressure to Counter Symptoms of Orthostatic Intolerance in Patients, Bed Rest Subjects, and Astronauts8 March 2013 | The Journal of Clinical Pharmacology, Vol. 33, No. 11Orthostatic Function During a Stand Test Before and After Head-Up or Head-Down Bedrest8 March 2013 | The Journal of Clinical Pharmacology, Vol. 31, No. 10Hemodynamic adjustments to head-up posture in the partly arboreal snake,Elaphe obsoletaJournal of Experimental Zoology, Vol. 235, No. 3Direct and Indirect Cerebral Effects of Deliberate HypotensionThe electrophysiologic effects of upright postureAmerican Heart Journal, Vol. 108, No. 5Respiratory Responses Following Lifting the Legs in Normal ManThe American Journal of the Medical Sciences, Vol. 283, No. 2Arterial and mixed venous $$P_{CO_2 } $$ and hydrogen ion, bicarbonate and base excess concentrations in water-depleted dogsPfl�gers Archiv European Journal of Physiology, Vol. 366, No. 2-3Time course of arteriovenous oxygenation in dogs acutely depleted of water and of water and saltPfl�gers Archiv European Journal of Physiology, Vol. 348, No. 2Influence of body position and pneumoperitoneum on respiratory variation of venous return in anesthetized dogsPfl�gers Archiv European Journal of Physiology, Vol. 340, No. 4The Venous SystemCentral Nervous SystemHeart Rate, Stroke Volume and Vasomotor Regulation in the Cat during Exertion and Postural ChangesEuropean Journal of Clinical Investigation, Vol. 1, No. 3An Integrated Approach to the Study of the Venous System with Steps Toward a Detailed Model of the Dynamics of Venous Return to the Right HeartIEEE Transactions on Biomedical Engineering, Vol. BME-16, No. 4Respiratory and cardiac effects on venous returnAmerican Heart Journal, Vol. 78, No. 2 More from this issue > Volume 215Issue 5November 1968Pages 1058-1066 Copyright & PermissionsCopyright © 1968 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1968.215.5.1058PubMed5687498History Published online 1 November 1968 Published in print 1 November 1968 Metrics

DEVELOPMENT OF NON‐RESPIRATORY COMPONENTS OF ACID‐BASE EQUILIBRIUM IN 250 NORMAL CHILDREN AGED ONE MONTH TO 15 YEARS

SummaryTotal plasma protein, hemoglobin, standard bicarbonate, buffer base; and base excess concentrations were determined in venous blood of 250 healthy normal children of both sexes aged one month to 15 years. In infants up to one year (100 babies in all) the mean standard bicarbonate concentration was round 21 mEq/1, buffer base 43 mEq/1, and base excess – 4 mEq/1. A slight lowering of the buffering capacity of blood due, above all, to decreased hemoglobin concentration was found in these infants.With increasing age all values come near the normal adult values but do not quite reach them even in the oldest age group of children aged 9 to 15 years. Infants especially, but also children from one to three years of age have, in comparison to adults, a marked trend towards non‐respiratory (metabolic) acidosis that, however, cannot be regarded as pathologic.