Breathlessness in pregnancy ---respiratory resasons
Prof. M.C.Bansal MBBS.,MS. FICOG. MICOG. Founder Principal & Controller ,Jhalawar Medical College And Hospital Jhalawar. Ex Principal & controller MGMC and Hospital , Sitapura Jaipur.
Physiological causes ofBreathlessness in Pregnancy Physiological breathlessness starts as early as 1st or second trimester and increases in incidence as gestation progress. It occurs in 60 -70 % women and thus is the common phenomenon , it is usually mild and seldom incapacitate , the women to perform routine activity. Breathlessness at rest is uncommon and tolerance to light exercise and daily activity are usually not affected.
Physiological breathlessness---- Changes in lung function occur as result of homeostasis owing to increasing demand of O 2 of the growing fetus . , increased maternal BMR . Minute ventilation is increased by 20-40 % ( tidal volume x Respiratory rate ) Tidal volume is increased but respiratory rate is not increased significantly.
Respiratory Causes. Respiratory centre becomes more sensitive to CO2. respiratory rate increases at rest even , Vertical diameter of thoracic cavity decreases due to up pushing of diaphragm by enlarging uterus, Respiration becomes more thoracic as abdominal movements with respiration are restricted , In later period of pregnancy there is flaring out of ribs there by anterio lateral diameter of thoracic cage increase , vital capacity decrease more so in lying down position , supine hypotension due to caval compression by enlarged uterus also cause cardio respiratory distress.
Breathlessness due to RespiratoryDysfunction Dysfunctional breathing is common in young women hence while pregnant ,it may continue. Patient typically complains of breathlessness which is out of proportion to clinical findings and able to perform daily activity . It may occur even at bed rest . Pt describes it as “difficulty in taking full breath “ or “ felling a blockage in the chesty “. Pt may have psychological problem or psychiatric illness. Vocal Cord Dysfunction---Presents as attacks of breathlessness similar to asthma., with which it often co exist.10 % of acute asthma cases may infect be due to vocal cord dysfunction. It can be diagnosed simply by clinical history and spirometry., narrowed inspiratory flow volume loop laryngoscopy will reveal adduction of voal cord on inspiration and some time on expiration.Frank strider / aspiratory wheeze on chest auscultation may be present., Which is absent between attacks of breathlessness. .
Breathlessness Causes, Reasons and Solutions www.normalbreathing.com/d/labored-breathlessness.php#.UPs2GSc73dk 3/5 The main causes of breathlessness and labored breathing (why it is hard to breathe): - constriction of airways due to hypocapnia in the airways - reduced oxygen levels in the diaphragm and chest muscles due to reduced oxygen transport - tense states in the diaphragmatic and chest muscles due to arterial hypocapnia. Exacerbating reasons in the pathophysiology of labored breathing and breathlessness are: - mouth breathing (due to reduction in nitric oxide absorption and alveolar CO2) - chest breathing (due to reduction in arterial oxygenation) - presence of inflammation and mucus in airways, causing further narrowing or an obstruction of air flow (as in COPD). Exertion, mouth breathing, physical exercise with mouth breathing, chest breathing, meals (eating and especially overeating), overheating, anxiety, stress, attempts to inhale deeply, deep breathing exercises with CO2 losses, poor posture, night sleep and many other factors are known causes of hyperventilation. Hence, they worsen breathlessness and labored breathing.
Individual disorders-------- Upper Air Ways – Nasal Obstruction------- Due to rhinitis can occur in 30 % pregnant women . As a result of mucosal edema , hyperaemia ,capillary congestion and mucosal hyper secretion which is caused by increased oestrogen level in pregnancy . This occurs mostly in 3rd trimester and may lead to breathlessness , particularly if severe.
Respiratory causes------- Obstructive Air Ways Disease Asthma is by far most obstructive air ways disease likely to encounter in pregnancy. , occurring in 0.4 -7 % cases and patient are already known to have it. Patient develops intermittent breathlessness with wide spread Expiratory wheeze , bronchial secretion and precipitated by exertion and change in weather / temperature . Peak flow monitoring willreve3al reduced peak flow with variability. Symptoms worse at late night and early morning. Patient respond well to inhaled Beta – agonist( broncho dilators ) Uncontrolled asthma----persistent troublesome symptoms , nocturnal symptoms , frequent use of Beta –agonist inhalation with little relief , limitation of physical activity. They need hospitalization. Asthma in pregnancy worsen in 1/2rd cases , remain unchanged in 1/3rd and rest have improvement in their symptoms there by requiring less dose of corticosteroids. NSAIDS use may trigger or worsen asthma.
Respiratory Causes----- 2. Cystic Fibrosis and Bronchiectasis Usually pre existing and characterized by frequent chest infection , increased cough with viscous discolored expectoration. Breathlessness develops in moderate to severe forms. Haemoptysis and chest pain develop in the phase of exacerbations. Sinusitis is common in both conditions while pneumothorax and steatorrhoea----malabsorption are common in cystic fibrosis . pregnancy carries risk of exacerbations and fetal IUGR / prematurity.
Cystic Fibrosis And Bronchectasis--- Auscultation reveals crackles over affected area. Diagnosis confirmed by X ray chest . High resolution CT scanning will confirm . , but this investigation is deferred in pregnancy.
Chronic Obstructive pulmonarydisease (COPD ) It is seen in pregnant women > 35 years of age with H/O smoking minimum 20 packs per year For 20 years.main symptom is breathlessness on exertion and reduced exercise tolerance. , may be accompanied by morning cough and expectoration . Reduced breath sounds in all fields with wheeze during exacerbations.
Obliterative Bronchiolitis ---- Relatively uncommon and difficult to diagnose. Clinical and X ray findings are indistinguishable with those of Asthma. , with small air ways obstruction , There may be H/O childhood respiratory illness.
Parenchymal and Interstitial lungdiseases 1, Pneumonia---Pneumococcal--- An acute febrile illness with Chills and rigors ,a short history of breathlessness , cough , sticky blood stained sputum , chest pain preceding common cold .Respond well to high dose penicillin therapy. Clinical examination---- Increased respiratory rate ,Bronchial breathing, crepitations , and consolidation Confirmed by X ray . Mycoplasm pneumonia complicates HIV disease and its course run for several weeks, x Ray reveals bilateral interstitial infiltration. Bronchoscopy for Cytological analysis is some time necessary.
Acute Lung Injury Or ARDS ----- Occurs in 0.2-0.3 % cases in pregnancy and may be secondary to pneumonia , aspiration pneumonitis, eclampsia ,amniotic fluid embolism . Its diagnosed by deteriorating condition of patient and worsening X ray consolidation findings through out both the lung
Tuberculosis (TB)----- TB can cause breathlessness when extensive bilateral involvement of lung paranchyma is present. H/O cough , low grade evening rise fever , night sweats, weight loss, loss of appetite , haemoptysis. Three samples on consecutive days for AFB , Xray chest showing consolidation often with cavitations. ATT is to be continued as in case of non pregnant women. Breast feeding is allowed if pt is not an open case / newborn is immunized with Isonex resistance BCG and prophylactic isonex therapy to child.
Pulmonary Metastases Are rare , can easily be diagnosed by X ray chest ----cannon ball metastatic infiltration Symptoms usually develop when multiple lesions are present . Breathlessness ,cough , haemoptysis . Chest auscultation may be normal . Chorio carcinoma is common tumor with lung metastases during pregnancy or following evacuation of malignant vesicular mole / invasive mole. Pleural effusion is common . , when pulmonary metastases are present. The metastases disappear with Chemotherapy following management of primary lesion.
Sarcoidosis-------- It is common in young women of Afro – caribbean origin and is often severe. Breathlessness is common when pulmonary infiltration is wide / enlarged mediastinal lymph nodes press the bronchus. Patient also develops cough , weight loss and involvement of other organs like skin and eyes. Auscultation of chest may be normal or crackles along with wheeze may be present. X ray chest in conjunction with clinical picture , raised serum angiotensin conversion enzyme . Bronchial mucosa biopsy with bronchoscope will confirm the diagnosis.
Drug induced Interstitial LungDisease NFT used for long term treatment of resistant / persistent UTI, can cause severe acute or chronic form of interstitial lung disease with hypoxia . Amioderone used in cardiac arrhythmia can cause acute pneumonitis ( incidence 0.1-0.5 % with dose of 200mg / day ) and subsequent pulmonary fibrosis. Patient develops breathlessness and cough . Chest auscultation reveals bilateral basal fine crepts.
Lymphangio leiomyomatosis Rare but occurs in young women of reproductive age. Clinical manifestation includes interstitial lung disease , recurrent pneumothoraces . May be bilateral with tuberous sclerosis. Chest auscultation may reveal bilateral crackles . Once suspected , it can be confirmed by X ray and high resonance CT .
Lymphangitis carcimatosa Occurs in advance metastatic breast carcinoma. Patient develops profound hypoxia. Like drug induced interstitial lung disease patient develops breathlessness and dry cough .
Extrinsic Allergic Alveolitis Relatively uncommon . Associated with an identifiable trigger antigen , such as inhalation of Thermophylic Actinomycocetes spores in mouldy hay ( farmers lung ) Progressive breathlessness , wheeze and cough occurs with pulmonary infiltrates on X ray chest . , often the upper lobes .
Fibrosing Alveolitis Associated with auto immune diseases , which occur frequently in young women . Auto immune diseases like rheumatoid disease, SLE , scleroderma may be associates. Progressive breathlessness and cough are typical with fine , late aspiratory crackles on auscultation . Finger clubbing may be present . X ray shows bilateral , peripheral , basal interstitial shadows . HR –CT helps in confirmation . Lung function studies reveal reduced diffusion capacity.
Cryptogenic Organizing Pneumonia Also associated with auto immune disease. Patient develops Acute breathlessness . Cough and hypoxia. Parenchyma shadowing is more patchy than fibro sing alveoli is .Note --- Chronic nature of some of these interstitial lung disease may not be compatible with pregnancy .
Vascular diseases causingBreathlessness in Pregnancy Pulmonary embolism( PE ) is an important cause of breathlessness, its risk increases as gravidity , maternal age , BMI increases and LSCS , Family h/o thrombi embolism , DVT , PIH , Thrombophyllia , previous thromboembolism , prolong bed rest , varicose veins, Valvular heart disease etc. Pregnancy itself is also a major risk factor for Peas it is a state of hyper coagulation. It is most common cause of maternal death in developed countries where other causes of MMR are well controlled. Patient suddenly develops breathlessness and chest pain . There may be tachycardia, hypotension , blood stained frothy sputum and cyanosis in severe cases. Auscultation may be normal exce3pt increased respiratory rate. Ventilation /Perfusion (V/Q ) Scanning, X ray chest will help in diagnosis. Computerized tomographic pulmonary angiography ( CTPA) may be needed when V/Q is in conclusive .
Vascular causes of Breathlessness--- Amniotic Fluid Embolism Amniotic fluid embolism is rare occurring in 1in 100 -1000of deliveries. Presents with sudden onset of breathlessness during labor or with in 30 minutes of delivery . There is cardiovascular shock and DIC. Mortality is 60 -90% . , a major cause of maternal death during labor.
Vascular Causes--- Primary Pulmonary Hypertension A rare condition usually occurring in young women . Presenting With breathlessness on exertion. There may be ankle edema and other signs of right sided heart failure. Onset and progression is often insidious and diagnosis is frequently missed early in course of early disease. Ecocardiography will help in diagnostic confirmation.
Vascular causes----- Secondary Pulmonary Hypertension Occurs as a consequent of chronic lung diseases or pulmonary embolism. Present with similar symptoms and signs. There can be significant hypoxia with both types of pulmonary hypertension.
Pleural Causes---- Pleural Effusion Secondary to pneumonia or tuberculosis may cause breathlessness. Rare cause of pleural effusion in pregnancy is chylothorax ( Lymphangomyomatosis ), chorio - carcinoma , breast carcinoma and other metastatic malignancies and rupture of diaphragm in labor. Chest examination will reveal shifting of trachea to opposite side , dull on percussion, absent breath sounds . X ray chest will show collapsed lung and pleural effusion on affected side.
Pleural Causes------ Empyema Findings are same as that of pleural effusion , but patient will be toxic. Fluid drained will be frank pus instead of ecxudate. Pneumothorax Rupture of Emphysematous bullae is the common cause . Often acute in onset , leading to progressive breathlessness as more and more air is trapped in pleural cavity more and more lung is compressed. On chest examination affected side is resonant ., X ray shows collapsed lung an d air in pleural cavity.
Chest wall causes of Breathlessness Obesity (Body Mass Index > 30 ) frequently leads to breathlessness and reduced exercise tolerance. Examination otherwise will be normal. Kyphoscoliosis, Ankylosing spondilitis and neuromuscular disorders may cause breathlessness due to abnormal lung mechanism or paralysis of diaphragm . Such patients should be investigated for Partial pressure of arterial blood for evidence of hypoxia and hypercapnoea Splinting of diaphragm may occur in pregnancy complicated by OHSS, Massive acute Polyhydramnios or plural pregnancy leading to too much distension of uterus leading to Breathlessness.
Metabolic causes--- Anaemia Moderate to severe in pregnancy usually cause tiredness and decreased exercise tolerance , Breathlessness is less common. Thyrotoxicosis may be present with breathlessness in pregnancy . Typical features include tachycardia, weight loss inspite of good diet and appetite, diarrhea, tremors, insomnia and eye signs .There may be goiter in neck. Thyroid function test will confirm the diagnosis. Acute / chronic renal failure / acidosis and systemic sepsis can develop breathlessness.
Clinical Approach-------- History of Present Illness 1. Onset of symptoms in relation in to timing of pregnancy2. Duration, chronicity , nature and severity of breathlessness.3. Exercise tolerance specially in relation to day to day activity .4. Presence / absence of cough , sputum , haemoptysis .5 . Relief with inhaler.6. Palpitation.7. Chest pain.8. Weight loss, fever, anorexia , malaise .9. Leg pain.1o. Nasal and sinus problem .11. Sore throat , arthrelgia and myelgia.
Past Medical history Asthma, allergy , hay fever , eczema. Nasal block. TB, previous BCG vaccination , Cystic Fibrosis , Brochiectasis , other lung disease. Sarcoidosis , Kyphoscoliosis ,Neuromuscular disease, Ankylosing Spondolitis , Herat Disease , Recurrent UTI. Malignancy ( breast ), immunosuppresion (HIV +ve.) Psychiatric illness. Previous history of Pulmonary embolism , DVT , Thrombophillia . Thyrotoxicosis.
Other contributory history------ Drug History NFT , Amioderone , NSAIDs and inhalers. Psychology Anxiety or depression . Rx continuing or stopped ? Family History Clotting disorder , Asthma , Atopy , Lung cancer , TB , sarcoidosis. Social History Ability to lead normal routine life , specially going to work , climbing stairs , doing house hold work and shopping. Living in travel to high prevalence and contact TB.
Physical Examination----- Breast any lump / mammography is better. Neurological muscle wasting , fasciculations , limb weakness, sensory loss ,cerebral signs if any .
Investigations RadiologyThe accepted cumulative dose of X ray radiation to which fetus can be exposed safely is estimated, ---5 rads.This is equivalent to n71 thousand X rays , 50 CTPAs , or 3o V/Q scan. It can be concluded that , for most of the common tests , exposure to radiation is minimal and lease likely to effect the fetus. In the first instance Xray chest is crucial to reach the diagnosis like pneumonia , pleural effusion , hydro /pneumothorax, tuberculosis and sarcoidosis .
Radiological Investigations---- V/Q scanning is essential to diagnose pulmonary embolism , an acute life threatening condition. CTPA is still more important in PE when V/Q is showing only an intermediate probability of PE , and the clinical findings are in favor of PE. HR CT is needed to diagnose bronchiectasis and interstitial lung diseases., could be avoided till puerperium , if the clinical outcome is not affected. . Although ct – is l-safe for fetus but mother also carry an increased risk of carcinoma breast in pregnancy. A radiation of 1 red can increase life time risk of breast cancer as high as 14 % in exposed women at 35 years of age. CPTA Delivers 2-3.5 reds to each breast .
Investigations---- Lung Function Tests Forced Expiratory Volume in one Second (FEV1- )---egg, volume of air blown out in one second . Forced Vital Capacity ( FVC ),e.g. Total volume air the subject is able to blow out in one effort ( man oeuvre) FEV1 / FVC ratio remain unchanged in pregnancy. Normal SpirometryFEV1, FVCand FVC1 / FVC ratio performed with simple hand held spirometry, if normal will exclude any obstructive lung disease like asthma , cystic fibrosis , bronchiectasis and COPD .
Lung Function Tests ------ Low FEV1 /FVC ratio < 70% low FEV1 <80% and a characteristic ‘ scooped out flow curve “ indicates obstruction to the small air ways . Significantly narrowed ‘ aspiratory flow volume Loop” indicates dysfunction vocal cords. Most extensive lung functions like Diffusion capacity ( transfer factor ) and static lung volumes are important to diagnose interstitial lung diseases. Finger attached Asymmetry (on 6minutes walking) helps in diagnosis of unexplained breathlessness indicating how far the patient can walk , and whether or not there is any significant respiratory disorder if there is no fall in O 2 saturation.
Investigations--- Blood Tests- Hob , WBC , Urea ,Electrolytes , Thyroid function tests , D-dimmers ( negative D-Dimmers effectively exclude PE.) Positive D-dimmers increase in pregnancy and are not significant and may be raised in infections also. Significant low PaO2 occurs in these conditions .
WHEN TO CALL RespiratorySpecialist? 1, Unduly troublesome breathlessness. 2, Worsening breathlessness. 3, Acute breathlessness. 4, Abnormal Chest X ray / spirometry. 5, Uncertainty regarding diagnosis. 6, When CT of thorax is indicated. 7, When detailed lung function tests , such as diffusion capacity , static lung volume , or walking oxymetry is needed. 8, Uncertain about performing / interpreting spirometry.
Summary Breathlessness in pregnancy is more due to physiological changes, but can be differentiated from pathological condition by detailed history clinical examination and X ray chest. Simple lung function can be done if necessary, to exclude important respiratory conditions .