SLEEP IN PATIENTS WITH CHRONIC RESPIRATORY DISEASES – A Wake Up Call for Chest Physicians DR. J.C.SURI MD, DTCD, DNB, FNCCP Consultant, Professor & Head Dept. of Pulmonary, Critical Care & Sleep Medicine Vardhman Mahavir Medical College & Safdarjang Hospital, New Delhi
46
Embed
SLEEP IN PATIENTS WITH CHRONIC RESPIRATORY DISEASES – A Wake Up Call for Chest Physicians DR. J.C.SURI MD, DTCD, DNB, FNCCP Consultant, Professor & Head.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
SLEEP IN PATIENTS WITH CHRONIC RESPIRATORY DISEASES – A Wake Up Call for Chest Physicians
DR. J.C.SURIMD, DTCD, DNB, FNCCP
Consultant, Professor & HeadDept. of Pulmonary, Critical Care & Sleep
MedicineVardhman Mahavir Medical College &
Safdarjang Hospital, New Delhi
PHYSIOLOGY OF BREATHING
Respiratory center is under the influence of Behavioral inputs from cortical centers via
reticular activating system Chemical inputs from chemoreceptors
responding to PaO2, PaCO2 and pH Mechanoreceptors in the airway, lungs and
Motor OutputUpper airwaysDiaphragmIntercostal muscleAccessory muscles
Pattern Generator
Reticular formation
Respective network
RhythmGenerator
Effect of Sleep on Ventilation
Decreased neural output (i.e. drive to breath) Hypotonia of intercostal and accessory muscles
during REM Sleep Shift of ventilatory burden exclusively on the
diaphragm Increased upper airway resistance Decreased responsiveness to hypoxemia and
hypercapnia (i.e. chemosensitivity) Presence of SDB or OHS may further worsen
ventilation
SPECIAL EFFECTS OF REM SLEEP ON ACCESSORY & POSTURAL MUSCLES
REM sleep causes 1. Widespread cortical and medullary neuronal activity 2. Postural & accessory muscle atonia (including upper
airway)3. Intermittent disruption of diaphragm EMG activity.
The ventilatory consequences are 1. Greater dependence on diaphragmatic contraction2. Both VT and f are more variable than in NREM3. A more collapsible upper airway
REM HYPOVENTILATION IN COPD
Fletcher. JAP 1983;54:632-9
SLEEP-DISORDERED BREATHING SECONDARY TO POST-POLIO SYNDROME AND KYPHOSCOLIOSIS
C3/A2
O2/A1
ROC/A1
LOC/A2
Chin EMG
Right Anterior Tibialis
Left Anterior Tibialis
ECG
Nasal/oral Airflow
Respiratory Effort – Chest
Respiratory Effort – Abdomen
Oximetry
-100%
-- 50%
-- 0%
Stage 2
SaO2 = 88%
Stage 2 Stage 2
Muscle artifact in the LOC and ROC channels
HYPOVENTILATION IN REM SLEEP CAUSED BY LOSS OF ACCESSORY MUSCLE USE IN POST-POLIO PATIENT
C3/A2
O2/A1
ROC/A1
LOC/A2
Chin EMG
Right Anterior Tibialis
Left Anterior Tibialis
ECG
Nasal/oral Airflow
Respiratory Effort – Chest
Respiratory Effort – Abdomen
Oximetry
-100%
-- 50%
-- 0%
Stage REMStage REM Stage 1
SaO2 = 70%
Phasic twitches in leg EMG
Effect of Sleep on Respiratory Muscles
Inspiratory muscles
Awake (Healthy)
Awake (Resp. Disease)
NREM REM
Diaphragm Normal activity High activity Normal activity
Increased
Intercostal Low activity High activity Increased activity
Markedly reduced
Accessory Low activity High activity Normal activity
Markedly reduced
Airway Resistance
Upper airway resistance increases during sleep compared to wakefulness
Marked loss of tonic activity in tongue, pharyngeal, laryngeal and intercostal muscles in REM
Hudgel DW, Martin RJ. J Applied Physiol 1984:56:133-137
Lower airway patency may be compromised . Nocturnal broncho-contriction seen in 50% asthmatics compared to 8% normal subjects
Hetzel MR, Clark TJH. Thorax 1980;35:732-738
J Appl Physiol 1996;81:282-289
RESISTANCE AND VENTILATION DURING SLEEP
Mouth occlusion pressure (P 0.1) in five adults patients after Added Resistance
Ventilatory compensation to resistive loading occurs during NREM, but whether this compensation is as marked as during wakefulness is not clear
During REM, ventilatory compensation is markedly reduced Wakefulness & NREM before and after addition of
inspiratory resistance of 17 cm H2O/L/s
Iber C J Appl Physiol 1982;52:607-614
Hypoxic Ventilatory Response to Sleep
Douglas NJ Clin Chest Med 1985;6:563
In adult men the hypoxic ventilatory response in NREM sleep is 2/3rd that in wakefulness, falling to 1/3rd of level of wakefulness during REM
In adult women: no change in hypoxic response between wakefulness & NREM but response in REM is ½ that in other stages
Hypercapnic Ventilatory Response
Hypercapnic ventilatory response in adults drops during NREM to about ½ the level in wakefulness and falls further during REM to about 1/3 the level of wakefulness
Gender differences may exist
Douglas NJ Clin Chest Med 1985;6:563
Effect of Sleep Disorders
Obstructive Sleep Apnea Syndrome Sleep related Obesity Hypoventilation
Syndrome Both produce respiratory failure in sleep
Sleep
Cortical
Inputs
Respiratory
Center
sensitivity
Chemoreceptor &
Mechanoreceptor
sensitivity
Respiratory
Muscle
contractility
Lung mechanics:
Airflow resistance
FRC
V/Q relationships
Hypoventilation
Hypoxemia
Hypercapnia
EFFECTS OF SLEEP ON RESPIRATION
CLINICAL SEQUELAE OF HYPOVENTILATION AND DECREASED CHEMOSENSITIVITY
Increase in pCo2 by 2-8 mmHg
Decrease in pO2 by 3-10 mmHg or
2% decrease in SaO2
The drop in pO2 , Sao2 and rise in pCO2 is much
more in patients of chronic resp. diseases
Disruption of sleep architecture.
Effect of sleep related hypoventilation in health and disease
No significant harmful effect in
healthy individuals because of
typical shape of the ODC curve.
Significant hypoxia and
hypercapnia develops in patients
with chronic lung disease.
Baseline values of low PO2 and
high PCO2
Significant use of accessory
muscles during wakefulness.
Instability of the upper airways
PATHOGENESIS OF DIURNAL RESPIRATORY FAILURESleep
Nocturnal HypoventilationPo2 pCo2
Frequent Arousal
Sleep Disruption
Poor quality of sleep
Sleep deprivation
Decreased Ventilatory Drive to Co2
Bicarbonate retention from the kidney
Normalization of pH
Decreased respiratory drive
Multiple episodes of micro & macro sleep
Daytime Hypersomnolence
Elevated pCo2
Diurnal respiratory failure
Hypoventilation
CONSEQUENCES OF SLEEP RELATED HYPOXEMIA IN PATIENTS WITH RESPIRATORY DISEASES
Conclusions High-intensity NPPV is better tolerated by patients with severe chronic hypercapnic COPD and has been shown to be superior to the conventional and widely-used form of low-intensity NPPV in controlling nocturnal hypoventilation. High-intensity NPPV therefore offers a new promising therapeutic option for these patients.
Nocturnal mean6SD arterial carbon dioxide tension (Paco2) at baseline and at follow-up visits
Dreher et al. Thorax 2010;65:303e308
NIV in pulmonary rehabilitation of COPD patients
Thomas Ko¨hnlein et al. Respiratory Medicine (2009) 103, 1329e1336
Conclusion: nocturnal NIPPV is feasible and enhances the effects of pulmonary rehabilitation in advanced stage COPD.
Effect of NIV on stable COPD (Comparison of Costs)
Enrico M. Clini. Respiration 2009;77:44–50
Impact of sleep on patients with neuromuscular or chest wall disease
Specific diseases
The history of a particular disease may also be helpful in some cases.
Patients with polio who had initial involvement of respiratory, trunk, or bulbar muscles, particularly with associated scoliosis or vocal cord paralysis, are more likely to develop abnormalities of gas exchange during sleep.
Kyphoscoliosis, even in the absence of neuromuscular disease, is associated with nocturnal hypoventilation and obstructive sleep apnea.
Indications for a nighttime sleep study in patients with neuromuscular and chest wall disease
There are no randomised-controlled trials concerning the outcome of noninvasive ventilation in these conditions, but studies have shown an improved quality of life, physical activity and haemodynamics, normalisation of blood gases and slight improvement in other physiological measures, such as the vital capacity and maximal mouth pressures. Survival in chest wall disorders is 90% at 1 yr and 80% at 5 yrs, and similar figures have been obtained in nonprogressive neuromuscular conditions. If, however, the underlying disorder is deteriorating, particularly if it involves the bulbar muscles, it may limit survival despite the provision of adequate noninvasive ventilatory support.
Shneerson et al. Eur Respir J 2002; 20: 480–487
Kyphoscoliotic Ventilatory Insufficiency Effects of Long-term Nocturnal NIV
Blood Gas Levels and Lung Function Breathing Pattern and Respiratory Muscle Strength*
Cruz Gonzalez. Chest 2003;124;857-862
CONCLUSIONS
Lung diseases can present with a vast array of sleep related breathing abnormalities and symptoms
Sleep induced hypoventilation is the common cause of worsening failure
If night-time symptoms are present or suspected, overnight PSG with the determination of optimal treatment in a laboratory setting are recommended
Treatment of the underlying lung disease is an important first step
Nocturnal NIV can significantly improve daytime symptoms and ABGs