Respiration and pulmonary ventilation in normal nonpregnant, pregnant, and puerperal women

Plass, E.D.; Oberst, Fred W.

doi:10.1016/s0002-9378(38)90813-0

Cited by 39 publications

(11 citation statements)

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“…Such dyspnoea is probably related to subjective awareness of the inappropriate hyperventilation, which is one of the most consistent changes seen during pregnancy (Root and Root, 1923;Plass and Oberst, 1938;Widlund, 1945). This finding in conjunction with the blood gas disturbances in pregnancy (Lucius et al, 1970) has led to the postulation of V/4 abnormalities in early pregnancy.…”

Section: Discussionmentioning

confidence: 99%

Closing volume during normal pregnancy.

Garrard¹,

Littler²,

Redman³

1978

Thorax

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Section: Discussionmentioning

confidence: 99%

Closing volume during normal pregnancy.

Garrard¹,

Littler²,

Redman³

1978

Thorax

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“…Further, eumenorrheic women show a greater hypercapnic ventilatory response (HCVR) at rest in the luteal phase than in the follicular phase [10,[12][13][14]. Thus, the increased ventilatory response in the luteal phase is thought to be due to progesterone lowering the threshold of the medullary respiratory center and increasing its excitability [15].Given the stimulatory effects of progesterone on resting VE [7,16], VE during exercise would also be expected to be higher in the luteal phase than in the follicular phase. While a number of studies have indeed demonstrated an increase in VE during maximal or submaximal exercise in the luteal phase [10,13,14,17,18], other studies have found no differences [19][20][21][22][23].…”

mentioning

confidence: 99%

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confidence: 99%

Modulating Effects of the Menstrual Cycle on Cardiorespiratory Responses to Exercise under Acute Hypobaric Hypoxia.

Takase

Nishiyasu²,

Asano³

2002

JJP

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Anecdotal evidence, recently supported by scientific evidence, suggests that altitude training may offer advantages over sea-level (SL) training [1][2][3][4][5]. As a consequence, many elite athletes, female as well as male, now train at high altitude in an effort to enhance their SL performance. It is known that the menstrual cycle modulates thermoregulatory and cardiorespiratory responses, both at rest and during exercise, but it is not yet clear how this modulation is altered by moving to a higher altitude (Յ3,000 m), either acutely or chronically.In the luteal phase of the menstrual cycle, increased body-core temperature and high levels of progesterone are found. Progesterone has been shown to stimulate minute ventilation (VE) [6,7] and to be associated with a decrease in alveolar carbon dioxide tension in the luteal phase [8][9][10]. Moreover, hypoxic ventilatory response (HVR) at rest is increased in the luteal phase, although amenorrheic women show no such significant modulation in HVR [10,11]. Further, eumenorrheic women show a greater hypercapnic ventilatory response (HCVR) at rest in the luteal phase than in the follicular phase [10,[12][13][14]. Thus, the increased ventilatory response in the luteal phase is thought to be due to progesterone lowering the threshold of the medullary respiratory center and increasing its excitability [15].Given the stimulatory effects of progesterone on resting VE [7,16], VE during exercise would also be expected to be higher in the luteal phase than in the follicular phase. While a number of studies have indeed demonstrated an increase in VE during maximal or submaximal exercise in the luteal phase [10,13,14,17,18], other studies have found no differences [19][20][21][22][23]. As a result of the increased body-core temperature in the luteal phase, oxygen uptake (VO 2 ) dur- Japanese Journal of Physiology, 52, 553-560, 2002 Key words: cycle exercise, altitude training, ventilatory response, luteal phase. Abstract:The purpose of this study was to examine the hypothesis that the menstrual cycleinduced modulation of the cardiorespiratory response to exercise might be altered by acute exposure to altitude. During both the luteal and follicular phases, 9 moderately trained female subjects with normal menstrual cycles performed incremental exercise to maximal effort on a cycle ergometer at sea level (SL) and under hypobaric hypoxia (HH) at the equivalent of 3,000 m altitude. Both at rest and during exercise, minute ventilation (VE) and oxygen uptake (VO 2 ) did not differ between the luteal and follicular phases (either at SL or HH). However, the ratio of VE to VO 2 (VE/VO 2 ), both at rest and during peak exercise, was greater in the luteal phase than in the follicular phase under HH conditions. Furthermore, the partial pressure of end-tidal carbon dioxide (PET CO 2 ) during exercise was lower in the luteal phase than in the follicular phase in HH. These results suggest that the menstrual cycle-induced modulation of the ventilatory response to exercise may be altered under...

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“…The uterus progressively enlarges with advancing pregnancy which elevates the diaphragm and its position can be as much as 4 cm above the non-pregnant level. 10 This would reduce the vertical diameter of the thorax and reduce its volume. The thoracic volume however is not affected because the lost volume due to the reduction of vertical diameter is compensated for by the increase in anterior-posterior diameter and transverse diameter of the thoracic cage.…”

Section: Discussionmentioning

confidence: 99%

A comparative study of static pulmonary function tests in Indian pregnant and non-pregnant women

Fadia¹,

Dhadse²

2016

Int J Res Med Sci

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INTRODUCTIONDeath is an inevitable end of life. For perpetuation of species, reproduction is thus essential. Reproductive life in women is more protracted and dynamic than in men. Pregnancy constitutes an additional alteration in the women's reproductive life. During the course of pregnancy, the fetus gradually grows and therefore, brings about generalized systemic changes in the mother to accommodate and adapt to the needs of developing fetus. Anatomical, physiological and biochemical adaptations that occur during pregnancy and profound changes in respiratory physiology are a part of the same process.1 Pregnancy represents one of the best examples of selective adaptation in terms of respiratory physiology.Static pulmonary function tests permit an accurate and reproducible assessment of the functional state of the respiratory system and allow quantification of the severity of disease. Its precise knowledge allows the clinician to verify the extent of the adaptation in pregnant women and helps to avoid unnecessary treatment of physiological changes misinterpreted as pathological in reference to pre-pregnancy standards.2 This knowledge of the expected or desired changes in pulmonary parameters is fundamental to understanding of how the disease states affect pregnancy and vice versa.3 Understanding of the maternal pulmonary function adjustments helps to avoid inappropriate diagnosis and unnecessary intervention. Information regarding status of pulmonary function is also essential for assessment of fitness for anaesthesia. 4 Various investigators have studied pulmonary function tests during normal pregnancy but their results were conflicting. [5][6][7][8][9] Although there are reports of changes in pulmonary function tests during pregnancy, not much work has been done specifically in third trimester. The above observations gave us an impetus to study the ABSTRACT Background: Pregnancy represents one of the best examples of selective adaptation in terms of respiratory physiology. Objective of the study is to evaluate the changes in static pulmonary function tests (PFTs) in third trimesters of pregnancy (study group) and compare with non-pregnant women (control group). Methods: 65 subjects (study group 35 subjects and control group 30 subjects) from a tertiary care hospital of Mumbai were included in the study. Pulmonary function tests (PFTs) was done by computerized spirometry. Results: Statistical analysis was carried out and paired t-test was applied. Significant increase in mean inspiratory capacity and significant decrease in mean expiratory reserve volume were observed in the third trimester of normal pregnant women as compared to normal non-pregnant women. Conclusions:The present study highlights observation that there is no respiratory impairment due to pregnancy, as adaptive changes in respiratory system compensate for the altered structure and function of the maternal body and very well suffice for the increased needs of pregnancy.

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Respiration and pulmonary ventilation in normal nonpregnant, pregnant, and puerperal women

Cited by 39 publications

References 11 publications

Closing volume during normal pregnancy.

Closing volume during normal pregnancy.

Modulating Effects of the Menstrual Cycle on Cardiorespiratory Responses to Exercise under Acute Hypobaric Hypoxia.

A comparative study of static pulmonary function tests in Indian pregnant and non-pregnant women

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