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Biomedical subjects

G Rooth

Publications and source records attributed to G Rooth.

At least 19 recordsLinked to original sources
PubMed1992

The variability of cardiopulmonary adaptation to pregnancy at rest and during exercise.

OBJECTIVE: To examine the cardiopulmonary adaptation to normal pregnancy in sitting women during rest and bicycle exercise. DESIGN: A longitudinal study beginning early in pregnancy and ending 8-12 months after delivery. SETTING: University Hospital, Zurich, Switzerland. SUBJECTS: 20 women were monitored every second week during pregnancy from 8 to 14 weeks gestation, twice in the puerperium and twice 6-8 weeks and twice 8-12 months after delivery. All the women finished the study, but not all of them participated in every visit. MEASUREMENTS AND MAIN RESULTS: The results obtained 8-12 months after delivery are considered the non-pregnant data and are presented first so that any change in pregnancy will be more obvious. Values given below refer to the median except when stated otherwise. At rest: 1. Oxygen consumption increased significantly from a median of 182 ml/min in the non-pregnant state to 256 ml/min by 8-11 weeks gestation, and peaked at 300 ml/min at 32 weeks. At 6-8 weeks after delivery the value was 225 ml/min. 2. Oxygen consumption per kg increased significantly from 3.0 ml/min in the non-pregnant state to 4.3 ml/min by 8-11 weeks gestation and peaked at 5.0 ml/min soon after delivery. At 6-8 weeks after delivery the value was 3.4 ml/min. 3. Carbon dioxide production generally showed changes similar to those of oxygen consumption. 4. Respiratory quotient did not show any significant changes. 5. Ventilation increased from a median of 9.4 l/min in the non-pregnant state to 10.5 l/min by 8-11 weeks and then slowly increased to 12.6 l/min in late pregnancy. 6. Respiratory rate did not change significantly. 7. Tidal volume showed a median of 563 ml in the non-pregnant women and rose significantly to 632 ml in early pregnancy, peaking at 715 ml in late pregnancy. 8. Alveolar ventilation increased significantly from a non-pregnant value of 3.4 l/min to 6.2 l/min in early pregnancy, peaking at 6.7 l/min at term; 6-8 weeks after delivery the value was 4.5 l/min. 9. Ventilation equivalent for oxygen fell significantly from the median non-pregnant value of 52 to 42 in early pregnancy and remained at that level until 6-8 weeks after delivery when it was 44. 10. Ventilation equivalent for carbon dioxide showed similar changes to those for oxygen. 11. Alveolar carbon dioxide tension fell significantly from a median non-pregnant level of 4.6 kPa (34 mmHg) to 4.0 kPa (30 mmHg) in early pregnancy. It began to increase in the puerperium and was 4.3 kPa (33 mmHg) 6-8 weeks after delivery. 12. Mixed venous carbon dioxide tension fell significantly from a median of 5.9 kPa (44 mmHg) to 5.2 kPa (39 mmHg) during pregnancy. 13. Transcutaneous carbon dioxide tension decreased significantly in early pregnancy from 8.8 kPa (66 mmHg) in the non-pregnant women, and from 20 weeks gestation remained at 6.9 kPa (52 mmHg). 14. Transcutaneous oxygen tension showed a non-significant increase from 10.0 kPa (75 mmHg) in the non-pregnant women to 11.1 kPa (83 mmHg) during pregnancy. 15. Cardiac frequency increased gradually from a non-pregnant median of 80 b.p.m. to about 90 b.p.m. in the last 2 months of pregnancy. In the puerperium the median was 75 b.p.m. 16. Cardiac output increased significantly by almost 50% from the non-pregnancy level to that at 8-11 weeks gestation. 17. Cardiac output per kg also increased significantly by 50% from the non-pregnant level to that at 8-11 weeks gestation. From mid-pregnancy there was a gradual fall until delivery. 18. Stroke volume increased significantly from a median of 31 ml in the non-pregnant state to 51 ml in early pregnancy, and remained at this level until delivery. In the puerperium the stroke volume was 63 ml. 19. Oxygen pulse increased significantly from a median of 2.2 ml in the non-pregnant women to 3.1 ml in early pregnancy and remained at that level. 20. Individual curves.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1989

Peer review through perinatal statistics.

The purpose here is to demonstrate that perinatal statistics serve as a powerful tool for peer review, thereby improving the standard of maternity care. These data were used as an instrument for peer review, first by comparing perinatal mortality between one country and another. More detailed statistics, rapidly fed back to the delivery units, acted as a strong inducement to practitioners at all levels who wanted to do at least as well as their neighbors. Examples are given from Sweden, Scotland and Germany.

Female↗
PubMed1979

Time factor in oxygen transfer from mother to fetus.

The time factor in the oxygen transfer from mother to fetus was studied by the tcPO2 technique. When a fairly constant fetal circulation made estimation possible, the decrease in fetal tcPO2 synchronous with and due to the uterine contractions in more than 400 events was always delayed 50--60 sec. Since the time lag in the increase in fetal tcPO2 following administration of pure oxygen to the mother was found to be of the same order of magnitude, the placental part of the delay in the oxygen transfer from mother to fetus can be assumed to be 50--60 sec. This determination supports the prevalent hypothesis that type II dips or late decelerations in the fetal heart rate are caused by hypoxia while type I dips or early decelerations are initiated by other factors.

Female↗
PubMed1979

Integrated interpretation of fetal heart rate, intrauterine pressure and fetal transcutaneous PO2.

By a study of the patterns of changes and the temporal relationship in fetal heart rate, intrauterine pressure, fetal tcPO2 and 'flow', a series of ten typical examples of combined patterns are described. Fetal tcPO2 is affected by the level of the fetal oxygenation and by the blood flow beneath the electrode. Should the latter be below a certain critical level fetal tcPO2 will be lower than fetal scalp blood PO2. By the integrated analysis of the four simultaneously recorded variables the different factors dominating fetal tcPO2 may be identified.

Female↗
PubMed1979

Interpretation of the tcPO2 curve in adult patients in an intensive care unit.

From the data collected on 135 adult patients in an intensive care unit the following conclusions of the interpretation of the transcutaneous PO2 curve in this type of patient may be drawn: 1) One to four minutes after the electrode was attached a nadir (= the lowest initial point) was reached and then there was a gradual increase which ended with an initial plateau. This plateau could be predicted from the lowest initial point by adding 30 mm Hg. 2) If the lowest initial point was 35 mm Hg or less, it was expected that the final tcPO2 level would be lower than the actual PaO2. 3) No correlation was seen between the lowest initial point of the tcPO2 curve and the time until the initial plateau was reached. In 75% of the cases the plateau was reached within 20 minutes. 4) A slight positive correlation was found between arterial blood pressure and lowest initial point. The difference between the means of the lowest initial point for a group with blood pressure less than or equal to 90 mm Hg and another group with blood pressure greater than 120 mm Hg was highly significant. 5) Transcutaneous PO2 measurements were more likely to represent the arterial PO2 level if blood pressure was greater than 120 mm Hg than if it was less than or equal to 90 mm Hg. 6) The lower the initial tcPO2 level, the more likely it was that the arterial level was higher than the tcPO2 level (see also point 2). 7) The differences between PaO2 and tcPO2 were independent of the arterial PO2 level. 8) The overall correlation between PaO2 and tcPO2 in this material was 0.91; the slope was 0.90 and the intercept -8 mm Hg. The correlation coefficient within each individual patient was higher. 9) The correlation coefficient between PaO2 and tcPO2 for those patients in whom PaO2 was 60 mm Hg or less was comparatively low. This may be explained by the bad condition of these patients followed by a reduced blood flow. 10) An initial drop in tcPO2 to zero level indicates a reduced peripheral circulation, but this must be suspected when the initial drop is below 35 mm Hg.

Adolescent↗
PubMed1978

Effect of respiratory physiotherapy on arterial oxygen tension.

The effect of deep breathing on arterial oxygen tension was investigated in 45 postoperative patients. Arterial oxygen tension was estimated by the transcutaneous oxygen tension method, which allows continuous non-invasive measurement of the arterial oxygen tension changes. Three deep breaths in 1 min, assisted by three respiratory therapy devices, were compared to a standard physiotherapy programme. A peak increase in arterial oxygen tension of 3--4.5 mmHg occurred after 1 min, and significantly increased values were seen for 2--4 min following deep breathing with the three respiratory devices. From the various physiotherapeutic procedures, verbally and manually assisted deep breathing gave a 7 mmHg PO2 peak and significantly increased values for 6 min. The sign mechanism is discussed in the light of the present knowledge of airway closure, which gives a satisfactory explanation of the short-lasting increase in oxygen tension.

Closing Volume↗
PubMed1977

[Asphyxia].

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Acidosis↗