O2 levels drop at night
Question:
> Somewhere I found a study that listed about 20 reasons why asthmatics have > more trouble at night.
I always hear that, for most, asthma is worse at night. I for one am better at night (after 11:00 PM). I think it’s because, where I live, what ever irritant in the air gives me breathing trouble, settles down. Dave Ford Smart Soft – The Developer Training Company http://www.smart-soft.com
Response:
Sorry, I have no idea where I got this originally. Introduction Nocturnal worsening of asthma is a significant clinical problem and must be considered in the management of the disease. Two main strategies should be considered in the treatment of nocturnal asthma: indirect nonpharmacological interventions or drug therapy. The various available treatment options are outlined in the Patient care guidelines. The Size of the Problem Approximately 40% of outpatients with asthma experience nocturnal symptoms every night and 75% awaken at least 1 night a week. [1] This problem is also reflected in mortality statistics. In 1 study, 53% of deaths from asthma occurred at night over a 1-year period; 79% of these patients had prior complaints of asthma affecting their sleep and these occurred every night in 42% of patients. [2] Over 90% of dyspnoeic episodes occur between 10pm and 7am. [1] Circadian Rhythms Play An Important Role Circadian changes in lung function (ranging from 10 to 50% in asthmatic patients vs 5 to 8% in the normal population) play an important role in nocturnal asthma. Peak lung function occurs at approximately 4pm and the nadir at around 4am. [1] Various naturally occurring circadian rhythms are thought to contribute to increased airways inflammation and nocturnal worsening of asthma. [1] Some of these are as follows: [1] Bronchial responsiveness to inhaled constrictors such as histamine, methacholine and acetylcholine is markedly increased in asthmatic patients at night. Levels of eosinophils, neutrophils, superoxide and histamine in the airways increase in the early morning hours. Peak cortisol levels occur upon awakening and trough levels occur in the late evening hours. Adrenaline (epinephrine) levels peak during the afternoon and trough during the early morning. Cholinergic or vagal tone increases at night. In normal individuals, these have only a minor effect on lung function. Additionally, in asthmatic patients with nocturnal asthma, both the number and physiological function of beta2-adrenoceptors are significantly reduced from 4pm to 4am compared with asthmatic patients who do not experience nocturnal worsening or with healthy controls. [1] Indirect Nonpharmacological Methods These focus on the use of mechanical or other approaches to treat sleep-related asthma. Overall, a small percentage of the asthmatic population may benefit from these measures. Favourable carry-over effects on daytime lung function and symptom control may also be seen in treated individuals.[1] CPAP for patients with sleep apnoea Nasal administration of continuous positive airway pressure (CPAP) is useful for patients with nocturnal asthma and sleep apnoea, but is ineffective in patients with nocturnal asthma without sleep apnoea. CPAP improves both morning and evening peak expiratory flow rates (PEFRs) as well as symptoms and medication requirements. The existence of obstructive sleep apnoea should also be considered and appropriately treated. [1] Gastro-oesophageal reflux a factor? The relationship between gastro-oesophageal reflux and controversial. reflux in nocturnal asthma should be based on symptoms of reflux, rather than worsening of asthma. Antacids and H2-antagonists provide little benefit in individuals with reflux and aspiration. [1] Sinusitis/rhinitis a treatable problem Chronic sinusitis and/or postnasal drip are frequent problems in asthmatic patients. Treatment is likely to improve both daytime and nocturnal symptoms (see Patient care guidelines). [1] Train those inspiratory muscles Inspiratory muscle training may have some potential in the treatment of nocturnal asthma. [1] This technique has been shown to increase inspiratory muscle strength and endurance and improve nocturnal symptoms, morning tightness, daytime asthma and cough in patients with nocturnal asthma. [3] A warm, humid environment Normal circadian decreases in body temperature at night (by about 1oC), with concomitant cooling of the airways, are thought to trigger nocturnal asthma. Although a warm, humid atmosphere may benefit some patients, it must be used cautiously, since heat and humidification may exacerbate symptoms in other individuals. Moreover, patient acceptability of this method is low. [1] Drug Therapy Pharmacological approaches for treating nocturnal asthma should take the patient’s symptom profile into account, since the effectiveness of various agents (e.g. inhaled corticosteroids and short-acting beta2-agonists) will differ in patients with prominent nocturnal symptoms compared to those with prominently daytime symptoms. [1] Some agents (e.g. modified-release preparations of oral beta2-agonists and theophylline) may be administered in unequal morning/evening doses to provide additional benefit for nocturnal symptoms. However, such schedules increase the complexity of treatment regimens and may contribute to decreased compliance. [1] Overnight and morning PEFRs should be used as measures of efficacy, together with recording the number of nocturnal awakenings and the amount of short-acting beta2-agonist use. Improvements in quality of life may be achieved by better control of the disease. [1] Beta2-agonists: an increasing role Oral beta2-agonists. Modified-release preparations may be of value in patients with nocturnal asthma as an alternative to theophylline. [4] The use of unequal morning/evening doses (e.g. one-third of the daily dose at 8am and two-thirds at 8pm) may provide additional benefit. [1] Inhaled beta2-agonists. The newer long-acting agents (such as salmeterol) produce bronchodilation for 12 hours after an inhaled dose (see table 1). [1] Salmeterol is currently included in both the UK and US asthma guidelines. [5] Short-acting inhaled beta2-agonists may also be useful for night-time awakenings in all patients with nocturnal asthma. [1] Modified-release theophylline Achieving nocturnal theophylline blood concentrations of around 15 mg/L has been shown to improve nocturnal asthma without attendant adverse effects during sleep. [1] Modified-release preparations may be used in two ways. Higher nocturnal therapeutic plasma theophylline concentrations may be achieved with twice-daily regimens by delivering two-thirds of the daily dose at night and one-third of the daily dose in the morning. Such regimens have been used with varying degrees of success. [1] Alternatively, once-daily preparations may be administered in the evening (around 6 to 7pm) to achieve a similar effect. This has been found to be clinically superior to conventional twice-daily administration. [6,7] Oral corticosteroids: timing important Oral corticosteroids play an important role in the management of nocturnal asthma. Results from several studies indicate that timing of corticosteroid administration is crucial; optimal improvements in overnight lung function may be attained by giving doses at 3pm. [8-12] In 1 study, morning (8am) and evening (8pm) doses did not produce favourable changes when compared with placebo. [12] Of limited benefit . . . Inhaled corticosteroids. In general, improvements in nocturnal lung function seen with inhaled corticosteroid therapy does not exceed 50%. [1] However, where the nocturnal symptoms are an extension of poorly controlled asthma, improving overall control by ensuring correct and regular use of adequate dosage of inhaled corticosteroids is essential. Others. Sodium cromoglycate (cromolyn sodium) and nedocromil are of limited value in the treatment of nocturnal asthma. [1] Overall, inhaled anticholinergics have little effect on overnight falls in pulmonary function; available agents are too short-acting to cover the entire night. [1] Vagolytics, such as intravenous atropine, have been shown to produce better bronchodilation at night than during the day. [13] —- Online Resources Search Medscape’s full text articles and MEDLINE —- Table 1 – Duration of action of some beta2-agonists administered via aerosol inhalation [4] Agent Duration of effecta Rimiterol + 1-2 hours Salbutamol (albuterol) 3-5 hours Terbutaline 3-5 hours Fenoterol + 3-5 hours Salmeterol approximately 12 hours + Rimiterol is not available in Canada, Germany, The Netherlands, Spain, Sweden and the US; fenoterol is not available in the US. a At recommended dosages.
– Hide quoted text — Show quoted text -> Somewhere I found a study that listed about 20 reasons why asthmatics have > more trouble at night. If I come on it, I will post it tomorrow. > Hello > I just came back from my specialist who told me my sleep studies show I > don’t have sleep apnea but my oxygen levels dropped to 80 something during > the night. He is now trying to arrange oxygen for me at night. Anyone > have > this? > — > Shari Rose > You can be upset because rose bushes have thorns, > Or you can rejoice because thorn bushes have roses.
Response:
– Hide quoted text — Show quoted text -> Hello > I just came back from my specialist who told me my sleep studies show I > don’t have sleep apnea but my oxygen levels dropped to 80 something during > the night. He is now trying to arrange oxygen for me at night. Anyone have > this? > — > Shari Rose > You can be upset because rose bushes have thorns, > Or you can rejoice because thorn bushes have roses.
Hi Shari, I used an O2 concentrator for a few months after I had a very bad case of pneumonia (almost two years ago now). According to the pulmonary doctor, my small airways were the main part of the problem. After allergy shots, better treatment of my asthma and a readjustment of the pressure on my CPAP (I have OSA), we were able to eliminate the O2 concentrator. The biggest corrective factor was discovering that I required a higher pressure on my CPAP machine (and ultimately to replace the CPAP machine since it was not holding pressure). The concentrator I had was big, noisy and produced a lot of waste heat. It did make a world of difference when I needed it though. One suggestion… Make sure they give you a concentrator with an O2 sensor on it. It’s always good to know that the machine is working properly and when it’s actually producing O2 (it has to run for a few minutes before it starts to produce it). Dan Rhea "Loyalty is for family, friends and country, not operating systems, compilers and computers" – Dan Rhea, 1986
Response:
Somewhere I found a study that listed about 20 reasons why asthmatics have more trouble at night. If I come on it, I will post it tomorrow.
– Hide quoted text — Show quoted text -> Hello > I just came back from my specialist who told me my sleep studies show I > don’t have sleep apnea but my oxygen levels dropped to 80 something during > the night. He is now trying to arrange oxygen for me at night. Anyone have > this? > — > Shari Rose > You can be upset because rose bushes have thorns, > Or you can rejoice because thorn bushes have roses.
Response:
Hello I just came back from my specialist who told me my sleep studies show I don’t have sleep apnea but my oxygen levels dropped to 80 something during the night. He is now trying to arrange oxygen for me at night. Anyone have this? — Shari Rose You can be upset because rose bushes have thorns, Or you can rejoice because thorn bushes have roses.
Response:
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