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Saturday, April 12, 2014

oxygen therapy



Oxygen Therapy

Introduction & history
Oxygen is an essential molecule for life. However oxygen is a commonly and wrongly prescribed drug. Oxygen was isolated by Joseph Priestley in 1772. Thomas Beddoes used oxygen for the first time in early 1800s for medical disorders. Oxygen was commercially produced first time by Carl Von Linde in 1895 by fractional distillation of liquid air.  However in last few decade only oxygen use have gained momentum. Response to hypoxia is variable among individual organs and cells. Neurons, cardiomyocytes, and renal tubular cells are highly sensitive to a sudden reduction in oxygen supply and are unable to survive long periods of hypoxia. After complete cessation of cerebral perfusion, nuclear magnetic resonance (NMR) measurements show a 50% decrease in cellular adenosine triphosphate (ATP) within 30 seconds and irreversible damage occurs within 3 minutes. Kidneys and liver can tolerate 15–20 minutes of total hypoxia, skeletal muscle 60–90 minutes, and vascular smooth muscle 24–72 hours. The most extreme example of hypoxic tolerance is that of hair and nails which can grow for several days after death. Goal of oxygen therapy is to-
         Treat hypoxaemia
         Decrease work of breathing
         Decreased myocardial work

Oxygen transport
Knowledge of oxygen transport mechanism is an important to understand oxygen therapy. Only the salient points of oxygen transport mechanism are given. Key steps in oxygen transport are uptake in the lungs, carrying capacity of blood, global delivery from lungs to tissue, regional distribution of oxygen delivery, diffusion from capillary to cell and cellular use of oxygen. The delivery of oxygen from capillary blood to the cell depends on:
• Factors that influence diffusion
• Rate of oxygen delivery to the capillary (DO2);
• Position of the oxygen-haemoglobin dissociation relationship
• Rate of cellular oxygen utilisation and uptake (VO2).

Figure1 : Oxygen transport from atmosphere to mitochondria. Values in parentheses for a normal 75 kg individual (BSA 1.7 m2) breathing air (FIO2 0.21) at standard atmospheric pressure (PB 101 kPa). Partial pressures of O2 and CO2 (PO2, PCO2) in kPa; saturation in %; contents (CaO2, CvO2) in ml/l; Hb in g/l; blood/gas flows (Qt, Vi/e) in l/min. P50 = position of oxygen haemoglobin dissociation curve; it is PO2 at which 50% of haemoglobin is saturated (normally 3.5 kPa). DO2 = oxygen delivery; VO2 = oxygen consumption, VCO2 = carbon dioxide production; PIO2, PEO2 = inspired and mixed expired PO2; PECO2 = mixed expired PCO2; PAO2 = alveolar PO2.

Clinical feature
Early detection of tissue hypoxia is essential for successful treatment. But it is not always easy as the clinical features are often non­specific. Clinical manifestations of hypoxia are highly variable and nonspecific and depend on both duration of the hypoxia (acute or chronic) and the individual response to it. Symptoms and signs associated with acute hypoxia include changes in mental status, dyspnea, tachypnea, respiratory distress, and cardiac arrhythmias. Alterations in mental status due to hypoxia range from impaired judgment to confusion or coma. Cyanosis which is considered a hallmark of hypoxia, occurs only when the concentration of reduced hemoglobin in the blood is 1.5 g/dl or greater. But this is not a reliable sign, as it may be absent in anemia and during periods of poor peripheral perfusion.

Organ specific sign and symptoms of hypoxia
System
Sign and symptoms
Respiratory
Tachypnea, breathlessness, dyspnea, cyanosis
cardiovascular
Increased cardiac output, palpitations, tachycardia, arrhythmias, hypotension, angina, vasodilatation, diaphoresis, and shock
CNS
Headache, impaired judgment, inappropriate behavior, confusion, euphoria, delierium, restlessness, papilledema, seizures, obtundation, coma
neuromuscular
Weakness, tremor, asterixis,
hyper-reflexia, incoordination
metabolic
Sodium and water retention, lactic acidosis
Mechanism of hypoxia
Hypoxia is deficiency of oxygen in tissue and hypoxemia is deficiency of oxygen in blood. Hypoxia may occur even in absence of hypoxemia. There are several mechanisms of hypoxia. Understanding of these mechanisms will help to treat the patient adequately. The various mechanisms is being summarised in table 1.
Table1 : Mechanism of hypoxemia
Mechanism
Clinical conditions
Diagnostic criteria
General treatment
Response to oxygen therapy
Low FiO2
High altitude, fire, smoke
History, low atmospheric pressure of oxygen
Supportive care
Rapid
Hypoventilation
Neuromuscular disease, CNS depression, narcotics
Increase in PaCO2 similar to decrease in PaO2
ventilator care (invasive/non invasive)
Good initial response
V/Q mismatch
COPD
Increase PAO2-PaO2, corrected by 100% O2
Bronchodilator, bronchial hygine
Moderately rapid
Right to left shunt
Pneumonia, collapse, pulmonary edema
Not corrected by 100% O2
Antibiotics, diuretics, PEEP
variable
Diffusion defect
Interstitial lung diseases
Low vital capacity, low diffusion capacity
Corticosteroids, immunosupresant etc
Moderately rapid

Indications of oxygen therapy
In acute care/ emergency setting
Role of oxygen therapy in acute care setting is very essential. Restoration of global oxygen delivery is an important goal in early resuscitation but thereafter circulatory manipulation to sustain “supranormal” oxygen delivery does not improve survival and may be harmful. There are conditions where oxygen is life saving particularly in acute conditions. Timely administration of oxygen and in adequate dose is very important. There are diseases where oxygen need to be give in higher dose and in some conditions it need to be give in controlled amount.
Table 2: indications of oxygen in emergency care setting

Clinical conditions (grade of recommendations)
Comment
Critical illnesses requiring high levels of supplemental oxygen
Cardiac arrest or resuscitation(Grade D)
Shock, sepsis, major trauma,
near-drowning, anaphylaxis,
major pulmonary haemorrhage(Grade D)
Major head injury(Grade D)
Carbon monoxide poisoning(Grade C)
  • The initial oxygen therapy is a reservoir mask at 15 l/min.
  • Once stable, reduce the oxygen dose and aim for target saturation range of 94–98%
  • If oximetry is unavailable, continue to use a reservoir mask until definitive treatment is available.
  • Patients with COPD and other risk factors for hypercapnia who develop critical illness should have the same initial target saturations as other critically ill patients pending the results of blood gas measurements, after which these patients may need controlled oxygen therapy or supported ventilation if there is severe hypoxaemia and/or hypercapnia with respiratory acidosis
Serious illnesses requiring moderate levels of supplemental oxygen if the patient is hypoxaemic
Acute hypoxaemia
(cause not yet diagnosed) (Grade D)
Acute asthma (Grade C)
Pneumonia ( Grade C)
Lung cancer (Grade C)
Postoperative breathlessness (Grade D)
Acute heart failure (Grade D)
Pulmonary embolism (Grade D)
Pleural effusions (Grade D)
Pneumothorax (Grade C & D)
Deterioration of lung fibrosis
or other interstitial lung
disease (Grade D)
Severe anaemia Grade B & D)
Sickle cell crisis (Grade B)
The initial oxygen therapy is nasal cannulae at 2–6 l/min (preferably) or simple face mask at 5–10 l/min unless stated otherwise.
conditions requiring controlled or low-dose oxygen therapy
COPD(Grade C)
Exacerbation of CF(Grade D)
Chronic neuromuscular
Disorders(Grade D)
Chest wall disorders(Grade D)
Morbid obesity (Grade D)
  • Prior to availability of blood gases, use a 28% Venturi mask at 4 l/min and aim for an oxygen saturation of 88–92% for patients with risk factors for hypercapnia but no prior history of respiratory acidosis. [Grade D]
  • Adjust target range to 94–98% if the PaCO2 is normal (unless there is a history of previous NIV or IPPV) and recheck blood gases after 30–
            60 min [Grade D]
Conditions for which patients should be monitored closely but oxygen therapy is not required unless the patient is
hypoxaemic
Myocardial infarction and acute
coronary syndromes(Grade D)
Stroke (Grade B)
Pregnancy and obstetric
Emergencies (Grade A- D)
Hyperventilation or dysfunctional
Breathing (Grade C)
Most poisonings and drug
Overdoses (Grade D)
Poisoning with paraquat or
Bleomycin (Grade C)
Metabolic and renal disorders (Grade D)
Acute and subacute neurological
and muscular conditions
producing muscle weakness (Grade C)

  • If hypoxaemic, the initial oxygen therapy is nasal cannulae at 2–6 l/min or simple face mask at 5–10 l/min unless saturation is ,85% (use reservoir mask) or if at risk from hypercapnia
  • The recommended initial target saturation range, unless stated otherwise, is 94–98%
  • If oximetry is not available, give oxygen as above until oximetry or blood gas results are available


Long term oxygen therapy
Long term oxygen therapy (LTOT) is a mode of delivery oxygen particular for chronic respiratory diseases with hypoxia. Initially it was established in patient of chronic obstructive pulmonary  disease (COPD) and later on extrapolated in various other diseases like interstitial lung disease, bronchiectasis, cystic fibrosis, khyphoscoliosis, sleep apnea, severe cardiac failure etc. Nocturnal oxygen therapy trial (NOTT) and medical research council oxygen therapy trial long back has established the role of LTOT in COPD patient.
General selection criteria for LTOT-
  1. A definitive documented diagnosis of chronic hypoxemia (3 week apart)
  2. Patient is on optical medical management and stable
  3. Oxygen administration should have been shown to improve hypoxemia and provide clinical benefit
Specific criteria for LTOT-
  1. At rest, in non recumbent position, the PaO2 of 55 mm Hg or less
  2. Patient with  PaO2 between 55 to 60 mm Hg is considered for LTOT if-
    1. Patient on optimal medical treatment with demonstrable hypoxic organ dysfunction like secondary pulmonary arterial hypertension, cor pulmonale, polycythemia or CNS dysfunction
    2. When there is demonstrable fall in PaO2 < 55 mm Hg during sleep, associated with disturbed sleep pattern, cardiac arrhythmias or pulmonary hypertension. These patient may be benefited from nocturnal oxygen therapy.
    3. When there is demonstrable fall in PaO2 during exercise and oxygen administration is shown to improve exercise performance, duration or capacity. These patient may be benefited from oxygen therapy during exercise.
For LTOT oxygen supply source can be compressed gas cylinder, liquid oxygen system and oxygen concentrator. Delivery devices includes nasal cannulae, prongs and masks. There are some oxygen conserving devices which reduce wastage and cost. These devices includes reservoir oxygen delivery, electromechanical pulsing device, transtracheal catheter etc.
Oxygen delivery devices
Method of oxygen delivery is determined by degree of hypoxaemia, required precision,                                                                                                 comfort of the patient, cost and availability. Oxygen delivery systems are basically two types-
  1. Rebreathing systems
    1. Have a CO2 absorber
    2. Used in anaesthesia
  2. Non-rebreathing systems
a)      Low flow (variable performance)
b)      High flow (fixed performance)
Table3: low flow and high flow system
Low flow system
High flow system
Nasal cannula and catheters
Facemasks
-Simple facemask
-Reservoir masks
-Partial rebreather
-Non rebreathers
Endotracheal and tracheostomy tubes with T Piece
Venturi masks
Non rebreathing reservoir mask with blending device and high flow meters



Endotracheal and tracheostomy tubes with mechanical ventilation

FiO2 depends upon:
         Size of available oxygen reservoir
         Flow rate
         Breathing pattern (VT and RR)

FiO2 depends on:
         velocity of the jet (the size of orifice and oxygen flow rate)
         size of the valve ports
High flow systems deliver about 40 l/min of gas through the mask, which is usually sufficient to meet the total respiratory demand
This ensures that the breathing pattern will not affect the FiO2


Table4 :Following is an example how FiO2 depends on ventilatory minute volume and flow rate of oxygen.

Patient in respiratory distress
Stable patient
Ventilatory
minute volume
(Respiratory
rate x
tidal volume)
30 l/min
(40 breaths/min x
750 ml/breath)
5 l/min
(10 breaths/min x
500 ml/breath)
Oxygen
flow rate
2L/min
2L/min
Calculation
of inspired
oxygen
concentration
(FiO2)
2 l/min of 100% oxygen
+
28 l/min of air drawn into the
mask (21% oxygen)
=
30 l/min minute volume
Thus
FiO2 =
(1.0x2) + (0.21x28) /30
= 0.26 (26%)
2 l/min of 100% oxygen
+
3 l/min of air drawn into the
mask (21% oxygen)
=
5 l/min minute volume
Thus
FiO2 =
(1.0x2) + (0.21x3)/
5= 0.53 (53%)

Table5 : delivery devices and FiO2
Delivery devices
Oxygen flow(lit/min)
FiO2
Nasal cannula
1
2
3
4
5
6
24%
28%
32%
36%
40%
44%
Simple face mask
6-10
40-60%
Reservoir mask
6-10
40-60%
Partial rebreathing
8-10
35-80%
Non rebreahting
8-10
40-100%

Unconventional oxygen delivery
In critically ill patient conventional oxygen delivery system may not work all the time. Therefore alternate modalities of oxygen carriers have developed and are being used in certain clinical situation. They have shown some early promising result and may play a bigger role in days to come. Theses alternate systems includes-
  1. Blood substitutes-
Due to complication related to blood transfusion and need for safer alternative to blood that can carry oxygen scientist has developed several blood substitute. These artificial oxygen carriers are of two types-
    1. Hemoglobin based oxygen carriers (HBOC)-
In HBOC hemoglobin is modified to improve oxygen off loading by decreasing oxygen affinity. This at present in investigational stage. Other red cell substitutes under trial are polymerized, pyridoxylated, stroma free human hemoglobin and oligomeric hemoglobin solution.
    1. Perfluorocarbon based oxygen carriers-
Chemically inert synthetic molecules and can augent oxygen delivery to tissue.
  1. Extracorporeal membrane oxygenation (ECMO)-
It is a artificial technique to provide life support when lung is unable to maintain sufficient oxygenation of the body’s organ system. It is a modified cardiopulmonary bypass technique where patient’s circulation is connected to a external blood pump and membrane oxygenator.
  1. Heliox therapy-
It is a mixture of helim and oxygen with reduced density and viscosity of oxygen in a concentration depended manner. Clinical utility of heliox has been observer in decompression illness, severe asthma, COPD, upper airway obstruction, broncholitis, croup, post extubation stridor etc.
How to calculate required FiO2 ?
The amount of required FiO2 can be calculated from alveolar gas equation-
PAO2=FIO2(PB-PH2O)-PACO2[FIO2 + (1-FIO2) / R]
Where PAO2 is partial pressure of alveolar oxygen, FiO2 is fraction of inspired oxygen, PB barometric pressure, PH2O water vapor pressure (usually 47mmHg), PACO2 is partial pressure of alveolar carbon dioxide (which is usually similar to PaCO2 that is partial pressure of carbon dioxide in arterial blood) and R is the respiratory quotient (0.8)
In abbreviated from the alveolar gas equation is PAO2=FIO2(PB-47)-1.2(PaCO2)
FiO2 is calculated for the equation bellow after calculation PAO2 from alveolar gas equation
FiO2 = (PAO2 + PaCO2 / R )/ PB-PH2O
For example a patient has a PaO2 of 41mmHg on FiO2 of 40% (0.4) and PaCO2 is 25 mmHg, his arterial (A - aO2) oxygen gradient calculated as follows
PAO2=FIO2 (PB-47)-1.2(PaCO2)
PAO2=0.4(760-47)-1.2(25)=285.2-30=255.2
Therefore arterial (A - aO2) oxygen gradient is 255.2- 41= 214.2
To increase PaO2 to 60 mmHg the inspired oxygen tension should be 214.2+60= 274.2
Therefore required FiO2 is
(PAO2 + PaCO2 / R)/ PB-PH2O= (274.2+ 30)/713= 0.42
Oxygen in flight
Some patient required oxygen during flight. The following table shows the British Thoracic Society recommendations. Since hypoxic challenge test is not available widely in India we have to recommend according to SpO2 level.
Table 6:
Pulse oxymetry
recommendation
SpO2 >95%
Oxygen not required
SpO2 92-95% without risk factors
Oxygen not required
SpO2 92-95% with risk factors (eg COPD, asthma, previous venous thromboembolism etc)
Hypoxic challenge test
SpO2 <92%
In flight oxygen
After Hypoxic challenge test
Blood gas report
recommendation
PaO2 >55 mmHg
Oxygen not required
PaO2 50-55 mmHg
borderline
PaO2 <50 mmHg
In flight oxyen


How to write an oxygen prescription?
In study it has been found that 21% of prescriptions inappropriate and 85%patients inadequately supervised. Oxygen should always be prescribed or ordered on a designated Document. The use of oxygen by paramedics, nurses, doctors, physiotherapists and others in emergency situations is similar to the use of all other medicinal products by these people. Clinical governance requires that the intentions of the clinician who initiates oxygen therapy should be communicated clearly to the person who actually administers oxygen to the patient and an accurate record must be kept of exactly what has been given to the patient Safe and effective treatment prescriptions should contain-
Ø  The indication
Ø  flow rate
Ø  delivery system
Ø  duration
Ø  how to monitoring of treatment
Ø  specific instruction during exercise and sleep if indicated
Side effect
Inappropriate dose and failure to monitor treatment can have serious consequences. Vigilant monitoring to detect and correct adverse effects swiftly is essential. The toxic effects of oxygen on the lung occur due to physiological disturbances caused by excess oxygen administration or free radical production during hyperoxic exposure that override the intrinsic antioxidant defence mechanism. Physiological complications includes-
  1. Suppression of hypoxic ventilator drive seen patient with chronic hypoxemia and hypercapnea whose ventilator drive is primarily driven by hypoxia (eg COPD). This can be prevented by controlled oxygen delivery.
  2. Absorption atelectasis seen in patient receiving very high FiO2.
  3. FiO2 >80% cause mild increase in peripheral vascular resistance and mild decrease in cardiac output.
  4. Inhalation of 100% FiO2 causes about 10% decrease in minute ventilation and decrease in diffusion capacity.
Excess free radicals interact with cellular components, resulting in cytotoxic events which produce a characteristic cascade of biochemical, cellular, morphologic, and physiological changes. The biochemical reactions, in turn, result in a sequence of characteristic cellular and morphologic changes. Four basic phases constitute the development of oxygen toxicity in lung tissue. The first three phases—initiation, inflammation, and destruction—occur during exposure to both lethal and sublethal doses of hyperoxia. The fourth phase—proliferation and fibrosis—occurs if there is re-exposure to sublethal oxygen levels. Therefore it is essential to administer oxygen in adequate dose and stop oxygen therapy when it is no longer indicated.

Pulmonary Changes during Hyperoxic Exposure in Humans
O2 at 1 atm
Duration of exposure
Pathophysiological changes
100%
>12 h
Decreased tracheobronchial clearance; decreased forced vital capacity; cough; chestpain

>24hr
Altered endothelial function

>36hr
Increased alveolar-arterial oxygen gradient; decreased carbon monoxide diffusing capacity

>48hr
Increasing alveolar permeability; pulmonary
edema; surfactant inactivation

>60hr
Acute respiratory distress syndrome
60%
7 days
Mild chest discomfort without changes in lung
mechanics; possible changes in morphometry
24-28%
months
Subclinical pathological changes; no clinical toxicity
documented

Bibliography

1.      D F Treacher, R M Leach. Oxygen transport—1. Basic principles BMJ 1998;317:1302-1306

  1. Jindal Sk, Agarwal R Oxygen therapy 2nd edition 2008 Jaypee
  2. N T Bateman, R M Leach. Acute oxygen therapy: BMJ 1998;317:798­801
  3. BTS guideline for emergency oxygen use in adult patients. Thorax 2008;63(Suppl VI):vi1–vi68.

  1. Warrel DA, Edwards RHT, Godfrey S, et al. Effect of controlled oxygen therapy onarterial blood gases in acute respiratory failure. BMJ 1970;2:452–5.

  1. Campbell EJM. The management of acute respiratory failure in chronic bronchitisand emphysema. Am Rev Respir Dis 1967;96:26–639.

  1. Thomson AJ, Webb DJ, Maxwell SR, et al. Oxygen therapy in acute medical care. BMJ 2002;324:1406–7.

  1. Aubier M, Murciano D, Milic Emili J, et al. Effects of the administration of O2 on ventilation and blood gases in patients with chronic obstructive pulmonary disease during acute respiratory failure. Am Rev Respir Dis 1980;122:747–54.

  1. Oxygen Therapy and Pulmonary Oxygen Toxicity .Fishman’s pulmonary disease and disorders.5th edition

Tuesday, March 11, 2014

WORLD SLEEP DAY 2014

WORLD SLEEP DAY 2014 WILL BE CELEBRATED ON 14TH MARCH

WE ARE DOING THE FOLLOWING ACTIVITY ON BEHALF OF NORTH EAST SLEEP SOCIETY-

  • PRESS MEET ON 13TH MARCH AT 3 PM, GUWAHATI PRESS CLUB

  • SLEEP APNEA AWARNESS CAMP ON 14TH MARCH, FROM 10AM TO 5PM, INTERNATIONAL HOSPITAL, GUWAHATI                                                                                                                                                                                                                                                   
  • CME ON SLEEP MEDICINE, 14TH MARCH, 6.30 PM, HOTEL GATEWAY GRANDEUR, GUWAHATI
  •  
World Sleep Day (WSD) has grown steadily since its inception. The first WSD was held on March 14th 2008, under the slogan ‘Sleep well, live fully awake’. It is organized by the World Sleep Day Committee of the World Association of Sleep Medicine (WASM). World sleep day is an annual event intended to be a celebration of sleep and a call to action on important issues related to sleep. The aims to lessen the burden of sleep problems on society through better prevention and management of sleep disorders. This year’s “Restful Sleep, Easy Breathing, Healthy Body” is the theme in order to raise awareness of world sleep day. The objective of the 2014 slogan is to raise awareness of factors that are modifiable that can improve the quality of sleep and reduce the burden of fatigue and daytime somnolence.

RESTFUL SLEEP is one of the pillars of health. Three key elements of good quality sleep are:
1. Duration: The length of sleep should be sufficient for the sleeper to be rested and alert the following day
2. Continuity: Sleep periods should be seamless without fragmentation
3. Depth: Sleep should be deep enough to be restorative

Failure to obtain quality sleep may lead to poor alertness, lack of attention, reduced concentration, decreased work and academic productivity, and even motor vehicle accidents.

EASY BREATHING during sleep is a treasured commodity. Sleep-related respiratory disturbances, or sleep apnea, can lead to numerous health problems, such as hypertension, heart disease, stroke and diabetes. When breathing in sleep is an effort, quality sleep is reduced. There are modifiable risk factors that can build up to disrupt easy breathing in sleep. People who are obese may have accumulation of fat in the upper airway that along with a thick, large tongue disrupt the easy flow of air. A large abdomen interferes with the pumping action of the diaphragm. Obesity which has become epidemic in developing countries can be controlled and when doing so, sleep apnea is prevented. Children with large inflamed tonsils may have obstruction of the upper airway and significant sleep apnea. Sleep apnea in children may delay physical and mental growth. Removing the tonsils can be curative. Some individuals take medicines that reduce the activity of the respiratory centers and aggravate sleep apnea. Among such medicines are the sedatives and ironically the sleeping pills. Codeine-containing pain killers may also reduce the force of the respiratory effort in sleep and worsen sleep apnea.

HEALTHY BODY is the premise that leads to a restful sleep. Sick individuals do not sleep well. Alleviating disease and avoiding unhealthful habits contribute to improve the quality of sleep.
 

Saturday, February 1, 2014

International ERS/ATS guidelines on definition, evaluation and treatment of severe asthma

NEW GUIDELINES FROM EUROPEAN RESPIRATORY SOCIETY  AND AMERICAN THORACIC SOCIETY ON SEVERE ASTHMA

Very useful guidelines for all

please follow the link to get the full guidelines

http://erj.ersjournals.com/content/43/2/343.abstract

Definition of severe asthma for patients aged >=6 years
Asthma which requires treatment with guidelines suggested medications for GINA steps 4–5 asthma (high dose ICS# and LABA or leukotriene modifier/theophylline) for the previous year or systemic CS for >50% of the previous year to prevent it from becoming ‘‘uncontrolled’’ or which remains ‘‘uncontrolled‘‘ despite this therapy
Uncontrolled asthma defined as at least one of the following:
1) Poor symptom control: ACQ consistently .1.5, ACT ,20 (or ‘‘not well controlled’’ by NAEPP/GINA guidelines)
2) Frequent severe exacerbations: two or more bursts of systemic CS (.3 days each) in the previous year
3) Serious exacerbations: at least one hospitalisation, ICU stay or mechanical ventilation in the previous year
4) Airflow limitation: after appropriate bronchodilator withhold FEV1 ,80% predicted (in the face of reduced FEV1/FVC defined as less than
the lower limit of normal)
Controlled asthma that worsens on tapering of these high doses of ICS or systemic CS (or additional biologics)

Tuesday, November 19, 2013

COPD - know about your disease (FOR PATIENT EDUCATION PURPOSE)




                    
 Chronic obstructive pulmonary disease (COPD) affects many people worldwide. COPD is a disease of the lung, that blocks the airways, causing difficulty in breathing. COPD is usually caused by smoking but it may also occur after exposure to fumes, chemicals, smoke from wood or other biomass fuel used for cooking and heating or working in very dusty places for prolonged periods. Apart from direct smoking, passive smoking may also lead to COPD. Apart from Chula smoke (biomass fuel) other form of smoking like bidi, hukka, cigar etc are equally harmful and can cause COPD.
·         Worldwide, one in 10 adults over the age of 40 may have COPD.  Currently COPD is the 4th leading cause of death worldwide surpassed only by heart attack, stroke, and acute lung infections, but threatens to be the 3rd leading cause of death by 2030 according to World Health Organisation.
·         Around 3 million people die from COPD every year worldwide. It kills more people than cancer, and as many people as HIV/AIDS. Around 90% COPD death occur in low and middle income countries.
·         The burden of COPD includes both direct costs and indirect costs. Direct costs are due of medication, hospitalization, and other health care for people with COPD, while indirect costs relate to people who miss work because they are sick, or because they must care for relatives with COPD.

Patients usually have a history of exposure to risk factors for the disease and are older than 40 years. Patients usually have symptoms like persistent cough, expectoration of phlegm or mucus while coughing, getting out of breath while doing physical activity, like walking up a flight of stairs, walking the dog, shopping, during washing and dressing. Symptoms are similar to asthma and COPD is sometimes confused with asthma. However both diseases are different.
The best way to find out if a person has COPD is to do a lung function test called spirometry. COPD obstructs and slows the flow of air into and out of the lungs.  Spirometry is a simple, painless test that is done at a clinic or doctor’s office. It measures the amount of air a person can breathe out, and the amount of time taken to do so. As COPD progresses, spirometry values decline.



COPD is a disease of the lung, although it affects other organs as well. Once a person is diagnosed to have COPD there are many things to do in order to reduce symptoms, prevent exacerbation and decelerate progression of the disease.

·         Stop smoking. If a person has COPD and continues to smoke, lungs will get worse and the disease will be fatal. In case of a smoker who has COPD, the only way to stop COPD from getting worse is to quit smoking. In case of smokers who has not yet develop COPD, the best way to prevent the disease from developing is to quit smoking. Smoking cessation is the only and most effective measure to prevent further progression of the disease. If needed patients should request help from competent health authorities to quit smoking. There should be a strong commitment to quit smoking. This can be done through counseling, nicotine replacement therapy or other medications, avoidance of company of smokers etc.
·         There are certain medications a patient needs to take regularly. Most medicines are given via inhaler, which are effective with fewer side effects. Inhalers are the best and safest method of drug delivery for all types of patients. But there are several wrong perceptions among general public and even among some physicians that inhalers are given at later stages of the disease and is habit forming. This misconception leads to discontinuation and lesser use of inhaled medication which in turn leads to rapid decline of the underlying disease. Apart from inhaled medication patient sometimes also needs some oral drugs.

The symptoms of COPD may change over time. In case of worsened symptoms the patient should inform his/her doctor immediately. Patients can help prevent exacerbations and maintain lung health through simple steps like-
  • Preventing respiratory infections by pneumococcal vaccination and yearly flu vaccinations. Washing hands frequently, using hand sanitizer, and practicing good hygiene to reduce chance of catching a respiratory infection.
  • Patient should stop smoking and stay away from secondhand smoke.
  • Take medicines according to the doctor’s instructions. Patient should understand how to use his/her inhaler. Compliance to medication prevents rapid decline in patient’s health conditions.
  • If a patient has exacerbations, he or she should get treatment immediately to help minimize its effects.

COPD is a disease primarily involving the lungs. However COPD  in the long run can lead to other health conditions like cardiovascular disease, high blood pressure, osteoporosis obesity/weight loss, diabetes etc. Pulmonary rehabilitation is recommended for patients of COPD. Rehabilitation training helps to reduce symptoms and improve other health conditions at the same time. Participation in a rehabilitation program, maintaining a healthy weight and smoking cessation will help patients to have a healthy heart, strong bones ,a great body and not to forget…………  healthy  lungs as well!

World COPD Day 2013 will take place on Wednesday, November 20 around the theme “It’s Not Too Late.” This positive message was chosen to emphasize the meaningful actions people can take to improve their respiratory health, at any stage before or after a COPD diagnosis.

Monday, November 18, 2013

WORLD COPD DAY 2013 20TH NOVEMBER

TOMORROW 20TH NOVEMBER 2013 IS WORLD COPD DAY

IT IS A DAY TO INCREASE AWARENESS ON COPD

WE ARE DOING-
  • PRESS MEET
  • FREE SPIROMETRY CAMP
  • PUBLIC AWARENESS MEETING
 
 
ME AND DR SURESH AT PRESS MEET

COOSMIC SLEEP LAB

since 2011 serving the people of north east............

COOSMIC SLEEP LAB PROVIDE ALL TYPE OF SOLUTION TO YOU SLEEP PROBLEMS IN GENERAL AND SLEEP APNEA IN PARTICULAR IN GUWAHATI AND NORTH EAST REGION OF INDIA, MOSTLY FOCUS ON HOME BASED SLEEP STUDY TEST

CONTACT
08811095389

email- coosmicsleeplab@gmail.com

welcome and disclaimer

i welcome all of you to this new blog on respiratory, critical careand sleep medicine

DISCLAIMER:

Information provided here is for medical education only. It is not intended as and does not substitute for medical advice. If you are a patient, please see your doctor for evaluation of your individual case. The web site should not be used as a substitute for competent medical advice from a licensed physician. By accessing the web site, the visitors acknowledge that there is no physician-patient relationship between them and the author. Under no circumstances will the author be liable to you for any direct or indirect damages arising in connection with use of this website.
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All case descriptions are fictional, similar to the descriptions you can find in a multiple choice questions textbook for board exam preparation. Cases course and description do not follow real cases. Many of the images on this blog are my own. Few of them are from friends. Some of them are from textbooks/journals. I have provided references and given credit where applicable I would be glad to take off any images/posts that you think violates your copyright policy. Please post to respicriticalcareandsleep@gmail.com