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PubMed1975

Recognition and significance of maternogenic fetal acidosis during intensive monitoring of labor.

FHR monitoring and microanalysis of fetal blood are mutually complementary procedures, and optimal knowledge of the fetal state is achieved by making use of both, the former for the preliminary screening of all cases at risk and the latter for the purpose of deciding on obstetric management where pathological changes are evident in the FHR. The major difficulty in obtaining a precise value for the fetal acid-base balance lies in the occurence of "falsely abnormal" cases, i.e. cases in which the fetal pH falls during labor but the clinical condition at birth is good (APGAR greater than or equal to 7). In our own series the incidence of such cases among fetuses at risk was 11.2% (Tab. I). In the majority of these cases the fetal acidosis is thought to be a result of increased metabolic acidosis in the mother (maternogenic fetal metabolic acidosis). The importance of the maternogenic fetal acidosis during labor lies in the fact that unless it is recognised, rapid extraction of the fetus will appear necessary on clinical grounds, although it is in fact unnecessary, since this form of acidosis has no adverse effect on the fetus. Various parameters have been proposed for the differential diagnosis of the maternogenic fetal acidosis. These include the feto-maternal difference in base deficit (F/M deltaBD), the materno-fetal differences in pHqu 40 (M/F deltapHqu 40) the materno-fetal difference actual pH (M/F actual deltapH), and the materno-fetal difference in base deficit of the extra-cellular fluid (M/F deltaBDHb5). A critical analysis of these parameters has been carried out on the results of microtests performed during a 5 year period (1968-1972) at the First Clinic of Obstetrics and Gynecology of Milan University. The cases comprised 59 regarded as normal (normal course of pregnancy, spontaneous commencement of labor at term, clear amniotic fluid, regular FHR, spontaneous birth, APGAR at 90 sec between 8 and 10, weight at birth greater than 2500 g), and 335 considered to be at risk (maternal disease, presence of meconium stained amniotic fluid and/or abnormal changes in FHR). In all of these cases the FHR was recorded by cardiotokography, and the tracings were interpreted according to HON. Microsamples of blood were taken from both mother and fetus during labor and the following determinations were carried out: actual pH, pHqu 40, Hb concentration, hemoglobin oxygen saturation, base deficit Hb5 (BDHb5). The maternofetal differences were then calculated. The same determinations were carried out on samples of maternal blood and of arterial and venous cord blood taken immediately after delivery. The clinical condition of the infant was evaluated by the APGAR score at 90 seconds after birth.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Changes in cerebrospinal fluid lactate and pyruvate levels during brain surgery under fluotane anesthesia].

The lactate and pyruvate content in the arterial blood and CSF of 24 patients operated on the brain under fluothane anesthesia with artificial ventilation of the lungs was measured. Towards the end of the operation and anesthesia a sizably elevated lactate level and accumulation of its excess in the blood were noted, these shifts having been more marked with hypocapnic ventilation of the lungs. An increased concentration of lactate and pyruvate in the cerebrospinal fluid was not attended by accumulation of lactate excess.

Acid-Base Equilibrium↗
PubMed1975

[Peroperative resuscitation in abdominal reoperations].

Resuscitation of these patients during operation is the only the logical continuation of their preparation. The authors therefore take up the preceding points while emphasizing: - checking vascular filling, by central venous pressure and hourly diuresis; - the necessity for a supply of carbohydrates, which is even more indispensable when the subjects were submitted to parenteral hyperalimentation previously; - the advantages of performing arterial blood gases in order to check artificial ventilation.

Abdomen↗
PubMed1977

[Determination of acid-base parameters by means of programmable pocket calculators (author's transl)].

The possibility to calculate parameters of acid-base status derived by common laboratory devices without built-in computers is described. The calculation is carried out faster and more exactly than it is possible by nomograms, which is especially suitable when a great quantity of dates occurs. The number of programmable steps in some inexpensive pocket calculators is sufficient for this purpose; this type of "microcomputers" offers advantages of economy and small size so that calculations can be carried out immediately at the site where measurements are taken.

Acid-Base Equilibrium↗
PubMed1975

[Primary management of labor using neuroleptic analgesia].

Within the limits granted, neuroleptanalgesia constitutes a very interesting technique in the major part of management of labour. In particular it has the advantage of preserving maternal consciousness. On the other hand, it allows analgesia of rather long duration, which renders early management of labour possible while still respecting its physiology. The institution of this technique demands the presence at the parturients bedside, not only of the obstetrician and the medwife but also that of a qualified anesthetist. As in all cases of major management of labour it engages the responsability of the obstetrical team which undertakes it and this is even more so, the earlier it is started. To us its indications seem comparable with those of Gamma OH: the early management of labour however has the advantage over the latter of preserving maternal consciouness. Moreover it proved to be particularly interesting in the management of breech presentations. But if its properties are an advantage in the indications which we have just mentioned, they can constitute an invonvenience and restrain its use under different circumstances: its slowness of induction, the absence of narcosis which limits the effect on cervical resistance means that one prefers the Toulouse method using pentothal for the management of labour after 7 centimeters of dilatation. In conclusion, it seems important to us to state that neuroleptanalgesia is not the ideal method for management of labour any more than is thiopental or Gamma-OH. Other techniques merit being studied. Their study must obey strict rules in order to specify the risks and therefore the indications and limits. It should cover different fields which are, pharmacology, the objective assessment, by quantitative criteria, of the effects on uterine contraction, on the mother's clinical and biological state as well as that of the fetus in utero, then that of the child in the first hours of live and up to the first years of his development.

Acid-Base Equilibrium↗
PubMed1975

Hydrogen ion changes and contractile behavior in the perfused rat heart.

The effect of acid-base alterations was analyzed using isolated rat hearts perfused at constant coronary perfusion pressure, and stimulated to contract at constant rat. The amount of shortening in the major axis and its derivative were measured to assess myocardial contractility. Both the 'respiratory' and 'metabolic' alterations affected the contractile behavior to the same extent. In the physiological range studied by us, acidosis depresses and alkalosis increases myocardial contraction. However acidosis seems to depress contractility more than the enhancement produced by the same change in pH towards the alkalotic side. When either amount of shortening or max dl/dt was plotted as a function of hydrogen ion acitvity (aH+) a linear correlation was obtained, either with pure 'metabolic' or 'respiratory' acid-base induced alterations (correlation coefficients higher than -.95; P less than .01). Our findings suggest that in the range studied by us, contraction of the perfused rat heart following acid-base alterations, is a linear function of hydrogen ion activity.

Acid-Base Equilibrium↗
PubMed1975

[Studies on low volume priming heart lung bypass (author's transl)].

This report concerns the feasibility of low volume priming extracorporeal circulation. Through this study, the bubble oxygenator with Zuhdi's heat exchange was used. Moderate hypothermia with surface cooling and hemodilution perfusion with 5 per cent D/W was evaluated in 32 mongrel dogs and 16 clinical open heart cases. The results obtained here were as follow: 1) Body temperature reduction by surface cooling before bypass provided more even cooling than did core cooling by low flow partial bypass alone. 2) In regard to cardiac loading on returning the whole perfusate of the circuit to patient, approximately 20 ml/kg of 5 per cent D/W was feasible as a priming solution. 3) To reduce the blood visicosity, hemodilution technique with 5 per cent D/W was superior, and hemodilution effect during postoperative periods was temporaly. 4) The excess lactate volume postulated by Huckabee was a available index to evaluate metabolic acidosis during the extracorporeal circulation. 5) With aid of surface cooling, the acid-base balance during perfusion was kept to lesser extent than that of core cooling only. 6) This study indicated that the low priming perfusion in conjunction with surface cooling hypothermia was a reliable technique for the open heart operation and may be applied in more prolonged perfusion.

Acid-Base Equilibrium↗
PubMed1975

[Studies on extracorporeal circulation with large volume hemodilution using lactate ringer's solution and low molecular weight dextran: alterations of acid-base balance associated with intentional hemodilution (author's transl)].

Twenty mongrel dogs, weighing between 7.5 and 13.0 kg were used to investigate the percentage limits permissible for hemodilution using a double-helical reservoir heart-lung machine which has a 1,100 ml of priming volume. In both 40 and 50 per cent groups of intentional hemodilution by 30 minute extracorporeal circulation, remarkable anemia was inevitable and recovery was extremely slow, especially in the 50 per cent dilution group. In both 40 and 50 per cent groups of intentional hemodilutions by 30 minute extracorporeal circulation, metabolic acidosis was observed. In 50 per cent group of intentional hemodilution, no improvement of metabolic acidosis was observed even after perfusion. When sodium bicarbonate was administered to 40 per cent hemodilution group, minimum alterations of acid-base balance and of serum electrolytes were observed during and after extracorporeal perfusion. When sodium bicarbonate was administered to 50 per cent hemodilution group, metabolic acidosis was more evident than in 40 per cent hemodilution group accompanied with an increase in serum sodium concentration and a decrease in serum chloride concentration. These data qualify the use of 40 per cent intentional hemodilution using Lactate Ringer's solution or low molecular weight dextran for 30 minute extracorporeal circulation when sodium bicarbonate is administered in adequate amounts.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Accidental peroperative hypothermia during rapid transfusion].

Six cases of grave hypothermias are reported, having arisen during surgical interventions which necessitated a rapid and abundant transfusion of badly warmed blood. The role of favouring factors, surrounding cold due to the air-conditioning, anaesthesia, extent of the area of operation, seems important. The symptomatology permits the individualization of a hypothermic syndrom neighbouring the picture described in toxic accidental hypothermias. Accidents during the warming process associate collapse and disturbances in coagulation. It is therefore necessary to consider certain signs of alarm as important and generalize the conditions for prevention of thermolysis in the operating theatre.

Acid-Base Equilibrium↗
PubMed1975

[Effect of peripheral counterpulsation on the body of an animal with intact heart].

The effect of lasting peripheral counterpulsation upon the haemodynamics and the main biochemical factors of the blood was studied in 14 dogs with intact hearts. In cases of significant tachycardia counterpulsation in a 1:2 regimen results in only a partial reduction of the resistance to the cardiac output. This does not always permit to prevent the formation of the phenomenon of an elevated myocardial contractility. The haemodynamic conditions are most optimal in a 1:1 regimen of counterpulsation. Slowing down of the cardiac rhythm was achieved by means of hypothermia.

Acid-Base Equilibrium↗
PubMed1975

[Effects of acid-base changes upon the chronotropic response to norepinephrine (author's transl)].

The effect of changes in pH produced by changing NaHCO2 at constant pCO2 and by changing pCO2 at constant NaHCO2 concentration was studied in the spontaneous beating rat atrium. Alkalosis produced either by changes in pCO2 or in NaHCO2 concentration increased basal heart rate shifting dose-response curves to norepinephrine upwards. When these dose-response curves were analysed for a horizontal shift, it was found that the necessary dose to produce a given effect was lesser in alkalosis than in acidosis. This shift was significant at the ED10 and at ED30 when the pCO2 was lowered and at ED30, ED50 and ED70 when the NaHCO2 concentration was increased. Beta-adrenergic blockade did not prevent the rate increasing effect of alkalosis. Our results suggest that there is a sensitizing effect to norepinephrine in alkalosis superimposed to a direct effect of pH upon heart rate.

Acid-Base Equilibrium↗
PubMed1975

[Computer experience and further developments in the respiratory function laboratory (author's transl)].

Reported is on satisfactory results obtained with a small-size computer consisting of punching and scanning device, as well as plain writing machine in the respiratory function laboratory. Developed in on- as well as off-line processing by an own technical staff, a diagnostic and teaching program was established for all respiratory function routine methods with the advantages of a large number of cases examined, elimination of sources of error, considerable supply of data and information, automatic documentation and filing, plain writing, interpretation and evaluation of findings. In continuation of such works also the blood gas analysis has been included. These values as the total of disturbances of the pathophysiological acid-base status are considered and interpreted. Clinical correction is forced in this man-machine dialogue by automatic stops of the whole machinery before going on. Subsequently and in addition are computer alveolar-arterial oxygen pressure gradient, venous shunt and oxygen saturation and expressed utilizing the capacity of the small-size computer. Further developments in the respiratory function diagnostic- and teaching program for small-size computers--not too expensive in the building block principle - are intended.

Acid-Base Equilibrium↗
PubMed1975

Acid-base parameters in the dehydrated camel.

The effect of prolonged (10 days) dehydration on acid-base parameters of camel blood was examined. The pH and PCO2 levels rose significantly in the course of dehydration. This state was comparable with compensated non-respiratory alkalosis found in other animals. The plasma sodium, and magnesium levels rose significantly also. The plasma oxygen and calcium levels declined significantly. There were no significant changes in potassium and phosphate levels. It is concluded that the changes found in acid-base status following dehydration are further evidence of water preservation mechanisms in the dehydrated camel.

Acid-Base Equilibrium↗