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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
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Administration of oxygen at 15 litres per minute by face mask or bag valve mask is often sufficient, but tracheal intubation with mechanical ventilation may be necessary. Suctioning of pulmonary oedema fluid should be balanced against the need for oxygenation. The target of ventilation is to achieve 92% to 96% arterial saturation and adequate chest rise. Positive end-expiratory pressure will generally improve oxygenation. Drug administration via peripheral veins is preferred over endotracheal administration. Hypotension remaining after oxygenation may be treated by rapid crystalloid infusion. Cardiac arrest in drowning usually presents as asystole or pulseless electrical activity. Ventricular fibrillation is more likely to be associated with complications of pre-existing coronary artery disease, severe hypothermia, or the use of epinephrine or norepinephrine.
To counter the effects of high-altitude diseases, the body must return arterial p toward normal. Acclimatization, the means by which the body adapts to higher altitudes, only partially restores p to standard levels. Hyperventilation, the body’s most common response to high-altitude conditions, increases alveolar p by raising the depth and rate of breathing. However, while p does improve with hyperventilation, it does not return to normal. Studies of miners and astronomers working at 3000 meters and above show improved alveolar p with full acclimatization, yet the p level remains equal to or even below the threshold for continuous oxygen therapy for patients with chronic obstructive pulmonary disease (COPD). In addition, there are complications involved with acclimatization. Polycythemia, in which the body increases the number of red blood cells in circulation, thickens the blood, raising the danger that the heart can’t pump it.
In high-altitude conditions, only oxygen enrichment can counteract the effects of hypoxia. By increasing the concentration of oxygen in the air, the effects of lower barometric pressure are countered and the level of arterial p is restored toward normal capacity. A small amount of supplemental oxygen reduces the equivalent altitude in climate-controlled rooms. At 4000 m, raising the oxygen concentration level by 5 percent via an oxygen concentrator and an existing ventilation system provides an altitude equivalent of 3000 m, which is much more tolerable for the increasing number of low-landers who work in high altitude. In a study of astronomers working in Chile at 5050 m, oxygen concentrators increased the level of oxygen concentration by almost 30 percent (that is, from 21 percent to 27 percent). This resulted in increased worker productivity, less fatigue, and improved sleep.
Oxygen concentrators are uniquely suited for this purpose. They require little maintenance and electricity, provide a constant source of oxygen, and eliminate the expensive, and often dangerous, task of transporting oxygen cylinders to remote areas. Offices and housing already have climate-controlled rooms, in which temperature and humidity are kept at a constant level. Oxygen can be added to this system easily and relatively cheaply.
A prescription renewal for home oxygen following hospitalization requires an assessment of the patient for ongoing hypoxemia.
The checks for responsiveness and breathing are carried out with the person horizontally supine. If unconscious but breathing, the recovery position is appropriate. If not breathing, rescue ventilation is necessary. Drowning can produce a gasping pattern of apnea while the heart is still beating, and ventilation alone may be sufficient, as the heart may be basically healthy, but hypoxic. The airway-breathing-circulation (ABC) sequence should be followed, rather than starting with compressions as is typical in cardiac arrest, as the basic problem is lack of oxygen. Five initial breaths are recommended, as the initial ventilation may be difficult because of water in the airways which can interfere with effective alveolar inflation. Thereafter a sequence of two breaths and 30 chest compressions is recommended, repeated until vital signs are re-established, the rescuers are unable to continue, or advanced life support is available.
Attempts to actively expel water from the airway by abdominal thrusts, Heimlich maneuver or positioning head downwards should be avoided as there is no obstruction by solids, and they delay the start of ventilation and increase the risk of vomiting, with a significantly increased risk of death, as aspiration of stomach contents is a common complication of resuscitation efforts.
Treatment for hypothermia may also be necessary. Because of the diving reflex, people submerged in cold water and apparently drowned may revive after a relatively long period of immersion. Rescuers retrieving a child from water significantly below body temperature should attempt resuscitation even after protracted immersion.
All cases of decompression sickness should be treated initially with 100% oxygen until hyperbaric oxygen therapy (100% oxygen delivered in a high-pressure chamber) can be provided. Mild cases of the "bends" and some skin symptoms may disappear during descent from high altitude; however, it is recommended that these cases still be evaluated. Neurological symptoms, pulmonary symptoms, and mottled or marbled skin lesions should be treated with hyperbaric oxygen therapy if seen within 10 to 14 days of development.
Recompression on air was shown to be an effective treatment for minor DCS symptoms by Keays in 1909. Evidence of the effectiveness of recompression therapy utilizing oxygen was first shown by Yarbrough and Behnke, and has since become the standard of care for treatment of DCS. Recompression is normally carried out in a recompression chamber. At a dive site, a riskier alternative is in-water recompression.
Oxygen first aid has been used as an emergency treatment for diving injuries for years. If given within the first four hours of surfacing, it increases the success of recompression therapy as well as decreasing the number of recompression treatments required. Most fully closed-circuit rebreathers can deliver sustained high concentrations of oxygen-rich breathing gas and could be used as a means of supplying oxygen if dedicated equipment is not available.
It is beneficial to give fluids, as this helps reduce dehydration. It is no longer recommended to administer aspirin, unless advised to do so by medical personnel, as analgesics may mask symptoms. People should be made comfortable and placed in the supine position (horizontal), or the recovery position if vomiting occurs. In the past, both the Trendelenburg position and the left lateral decubitus position (Durant's maneuver) have been suggested as beneficial where air emboli are suspected, but are no longer recommended for extended periods, owing to concerns regarding cerebral edema.
The duration of recompression treatment depends on the severity of symptoms, the dive history, the type of recompression therapy used and the patient's response to the treatment. One of the more frequently used treatment schedules is the US Navy Table 6, which provides hyperbaric oxygen therapy with a maximum pressure equivalent to of seawater for a total time under pressure of 288 minutes, of which 240 minutes are on oxygen and the balance are air breaks to minimise the possibility of oxygen toxicity.
A multiplace chamber is the preferred facility for treatment of decompression sickness as it allows direct physical access to the patient by medical personnel, but monoplace chambers are more widely available and should be used for treatment if a multiplace chamber is not available or transportation would cause significant delay in treatment, as the interval between onset of symptoms and recompression is important to the quality of recovery. It may be necessary to modify the optimum treatment schedule to allow use of a monoplace chamber, but this is usually better than delaying treatment. A US Navy treatment table 5 can be safely performed without air breaks if a built-in breathing system is not available. In most cases the patient can be adequately treated in a monoplace chamber at the receiving hospital.
Oxygen first aid treatment is useful for suspected gas embolism casualties or divers who have made fast ascents or missed decompression stops. Most fully closed-circuit rebreathers can deliver sustained high concentrations of oxygen-rich breathing gas and could be used as an alternative to pure open-circuit oxygen resuscitators. However pure oxygen from an oxygen cylinder through a Non-rebreather mask is the optimal way to deliver oxygen to a decompression illness patient.
Recompression is the most effective, though slow, treatment of gas embolism in divers. Normally this is carried out in a recompression chamber. As pressure increases, the solubility of a gas increases, which reduces bubble size by accelerating absorption of the gas into the surrounding blood and tissues. Additionally, the volumes of the gas bubbles decrease in inverse proportion to the ambient pressure as described by Boyle's law. In the hyperbaric chamber the patient may breathe 100% oxygen, at ambient pressures up to a depth equivalent of 18 msw. Under hyperbaric conditions, oxygen diffuses into the bubbles, displacing the nitrogen from the bubble and into solution in the blood. Oxygen bubbles are more easily tolerated. Diffusion of oxygen into the blood and tissues under hyperbaric conditions supports areas of the body which are deprived of blood flow when arteries are blocked by gas bubbles. This helps to reduce ischemic injury. The effects of hyperbaric oxygen also counteract the damage that can occur with reperfusion of previously ischemic areas; this damage is mediated by leukocytes (a type of white blood cell).
Inert gas asphyxiation is a form of asphyxiation which results from breathing a physiologically inert gas in the absence of oxygen, or a low amount of oxygen, rather than atmospheric air (which is largely composed of nitrogen and oxygen). Examples of physiologically inert gases, which have caused accidental or deliberate death by this mechanism, are: argon, helium, nitrogen and methane. The term "physiologically inert" is used to indicate a gas which has no toxic or anesthetic properties and does not act upon the heart or hemoglobin. Instead, the gas acts as a simple diluent to reduce oxygen concentration in inspired gas and blood to dangerously low levels, thereby eventually depriving all cells in the body of oxygen.
According to the U.S. Chemical Safety and Hazard Investigation Board, in humans, "breathing an oxygen deficient atmosphere can have serious and immediate effects, including unconsciousness after only one or two breaths. The exposed person has no warning and cannot sense that the oxygen level is too low." In the US, at least 80 people died due to accidental nitrogen asphyxiation between 1992 and 2002. Hazards with inert gases and the risks of asphyxiation are well established.
An occasional cause of accidental death in humans, inert gas asphyxia with gases including helium, nitrogen, methane, and argon, has been used as a suicide method. Inert gas asphyxia has been advocated by proponents of euthanasia, using a gas-retaining plastic hood device colloquially referred to as a suicide bag.
Nitrogen asphyxiation has been suggested by a number of lawmakers and other advocates as a more humane way to carry out capital punishment. In April 2015, the Oklahoma Governor Mary Fallin signed a bill authorizing nitrogen asphyxiation as an alternative execution method in cases where the state's preferred method of lethal injection was not available as an option.
When humans breathe in an asphyxiant gas, such as pure nitrogen, helium, neon, argon, sulfur hexafluoride, methane, or any other physiologically inert gas(es), they exhale carbon dioxide without re-supplying oxygen. Physiologically inert gases (those that have no toxic effect, but merely dilute oxygen) are generally free of odor and taste. As such, the human subject detects little abnormal sensation as the oxygen level falls. This leads to asphyxiation (death from lack of oxygen) without the painful and traumatic feeling of suffocation (the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising), or the side effects of poisoning. In scuba diving rebreather accidents, there is often little sensation but euphoria—however, a slow decrease in oxygen breathing gas content has effects which are quite variable. By contrast, suddenly breathing pure inert gas causes oxygen levels in the blood to fall precipitously, and may lead to unconsciousness in only a few breaths, with no symptoms at all.
Some animal species are better equipped than humans to detect hypoxia, and these species are more uncomfortable in low-oxygen environments that result from inert gas exposure.
Immediate treatment with 100% oxygen, followed by recompression in a hyperbaric chamber, will in most cases result in no long-term effects. However, permanent long-term injury from DCS is possible. Three-month follow-ups on diving accidents reported to DAN in 1987 showed 14.3% of the 268 divers surveyed had ongoing symptoms of Type II DCS, and 7% from Type I DCS. Long-term follow-ups showed similar results, with 16% having permanent neurological sequelae.
Simple tactile stimulation by touching the skin or patting the infant may stop an apneic episode by raising the infant's level of alertness. Increasing the environmental oxygen level by placing the infant in a tent of hood with supplemental oxygen can diminish the frequency of AOP, and may also help the infant maintain adequate oxygenation during short episodes of apnea. Increased oxygen at low levels can also be delivered using a nasal cannula, which additionally may provide some stimulation due to the tactile stimulation of the cannula. CPAP (continuous positive airway pressure) is sometimes used for apnea when medications and supplemental oxygen are not sufficient. Usually as a last resort, mechanical ventilation is used to support infants whose apnea cannot be controlled sufficiently by other methods and where the potential risk of harm from recurrent hypoxia is felt to outweigh the risks of injury from ventilation.
People generally require tracheostomy and lifetime mechanical ventilation on a ventilator in order to survive. However, it has now been shown that biphasic cuirass ventilation can effectively be used without the need for a tracheotomy. Other potential treatments for Ondine's curse include oxygen therapy and medicine for stimulating the respiratory system. Currently, problems arise with the extended use of ventilators, including fatal infections and pneumonia.
Most people with CCHS (unless they have the Late Onset form) do not survive infancy, unless they receive ventilatory assistance during sleep. An alternative to a mechanical ventilator is diaphragm pacing.
High incidence of relapse after hyperbaric oxygen treatment due to delayed cerebral edema.
For newborn infants starved of oxygen during birth there is now evidence that hypothermia therapy for neonatal encephalopathy applied within 6 hours of cerebral hypoxia effectively improves survival and neurological outcome. In adults, however, the evidence is less convincing and the first goal of treatment is to restore oxygen to the brain. The method of restoration depends on the cause of the hypoxia. For mild-to-moderate cases of hypoxia, removal of the cause of hypoxia may be sufficient. Inhaled oxygen may also be provided. In severe cases treatment may also involve life support and damage control measures.
A deep coma will interfere with body's breathing reflexes even after the initial cause of hypoxia has been dealt with; mechanical ventilation may be required. Additionally, severe cerebral hypoxia causes an elevated heart rate, and in extreme cases the heart may tire and stop pumping. CPR, defibrilation, epinephrine, and atropine may all be tried in an effort to get the heart to resume pumping. Severe cerebral hypoxia can also cause seizures, which put the patient at risk of self-injury, and various anti-convulsant drugs may need to be administered before treatment.
There has long been a debate over whether newborn infants with cerebral hypoxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
Brain damage can occur both during and after oxygen deprivation. During oxygen deprivation, cells die due to an increasing acidity in the brain tissue (acidosis). Additionally, during the period of oxygen deprivation, materials that can easily create free radicals build up. When oxygen enters the tissue these materials interact with oxygen to create high levels of oxidants. Oxidants interfere with the normal brain chemistry and cause further damage (this is known as "reperfusion injury").
Techniques for preventing damage to brain cells are an area of ongoing research. Hypothermia therapy for neonatal encephalopathy is the only evidence-supported therapy, but antioxidant drugs, control of blood glucose levels, and hemodilution (thinning of the blood) coupled with drug-induced hypertension are some treatment techniques currently under investigation. Hyperbaric oxygen therapy is being evaluated with the reduction in total and myocardial creatine phosphokinase levels showing a possible reduction in the overall systemic inflammatory process.
In severe cases it is extremely important to act quickly. Brain cells are very sensitive to reduced oxygen levels. Once deprived of oxygen they will begin to die off within five minutes.
Methylxanthines (theophylline and caffeine) have been used for almost three decades to treat apnea of prematurity. Despite this prevalent use, there are concerns of long term negative effects from the use of caffeine.
Current antidotes for OP poisoning consist of a pretreatment with carbamates to protect AChE from inhibition by OP compounds and post-exposure treatments with anti-cholinergic drugs. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of "-oximes" has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally. These antidotes are effective at preventing lethality from OP poisoning, but current treatment lack the ability to prevent post-exposure incapacitation, performance deficits, or permanent brain damage. While the efficacy of atropine has been well-established, clinical experience with pralidoxime has led to widespread doubt about its efficacy in treatment of OP poisoning.
Enzyme bioscavengers are being developed as a pretreatment to sequester highly toxic OPs before they can reach their physiological targets and prevent the toxic effects from occurring. Significant advances with cholinesterases (ChEs), specifically human serum BChE (HuBChE) have been made. HuBChe can offer a broad range of protection for nerve agents including soman, sarin, tabun, and VX. HuBChE also possess a very long retention time in the human circulation system and because it is from a human source it will not produce any antagonistic immunological responses. HuBChE is currently being assessed for inclusion into the protective regimen against OP nerve agent poisoning. Currently there is potential for PON1 to be used to treat sarin exposure, but recombinant PON1 variants would need to first be generated to increase its catalytic efficiency.
One other agent that is being researched is the Class III anti-arrhythmic agents. Hyperkalemia of the tissue is one of the symptoms associated with OP poisoning. While the cellular processes leading to cardiac toxicity are not well understood, the potassium current channels are believed to be involved. Class III anti-arrhythmic agents block the potassium membrane currents in cardiac cells, which makes them a candidate for become a therapeutic of OP poisoning.
Smothering is the mechanical obstruction of the flow of air from the environment into the mouth and/or nostrils, for instance, by covering the mouth and nose with a hand, pillow, or a plastic bag. Smothering can be either partial or complete, where partial indicates that the person being smothered is able to inhale some air, although less than required. In a normal situation, smothering requires at least partial obstruction of both the nasal cavities and the mouth to lead to asphyxia. Smothering with the hands or chest is used in some combat sports to distract the opponent, and create openings for transitions, as the opponent is forced to react to the smothering.
In some cases, when performing certain routines, smothering is combined with simultaneous compressive asphyxia. One example is overlay, in which an adult accidentally rolls over onto an infant during co-sleeping, an accident that often goes unnoticed and is mistakenly thought to be sudden infant death syndrome. Other accidents involving a similar mechanism are cave-ins or when an individual is buried in sand or grain.
In homicidal cases, the term burking is often ascribed to a killing method that involves simultaneous smothering and compression of the torso. The term "burking" comes from the method William Burke and William Hare used to kill their victims during the West Port murders. They killed the usually intoxicated victims by sitting on their chests and suffocating them by putting a hand over their nose and mouth, while using the other hand to push the victim's jaw up. The corpses had no visible injuries, and were supplied to medical schools for money.
Perinatal asphyxia is the medical condition resulting from deprivation of oxygen (hypoxia) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure or interference during delivery with blood flow to the infant's brain. This can occur as a result of inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
Treatment is usually debridement and excision, with amputation necessary in many cases. Water-soluble antibiotics (such as penicillin) alone are not effective because they do not penetrate ischaemic muscles sufficiently to be effective. Penicillin is effective against C. perfringens. When gas gangrene occurs in such regions as the abdominal cavity, the patient can be treated in a hyperbaric chamber. which contains a pressurized oxygen-rich atmosphere. The oxygen saturates the infected tissues and thereby prevents the growth of the obligately anaerobic clostridia. The growth of C. perfringens is inhibited when the availability of oxygen is equivalent to a partial pressure of around 9–10 kPa (compare to 4–5 kPa in venous blood under normal conditions, with 11–13 kPa in arteries and 21 kPa in air at sea level), so if the treatment is started early, this condition can mostly be cured.
The treatment hospitals use on comatose patients depends on both the severity and cause of the comatose state. Although the best treatment for comatose patients remains unknown, hospitals usually place comatose patients in an Intensive Care Unit (ICU) immediately. Attention must first be directed to maintaining the patient's respiration and circulation, using intubation and ventilation, administration of intravenous fluids or blood and other supportive care as needed. Once a patient is stable and no longer in immediate danger, the medical staff may concentrate on maintaining the health of patient’s physical state. The concentration is directed to preventing infections such as pneumonias, bedsores (decubitus ulcers), and providing balanced nutrition. Infections may appear from the patient not being able to move around, and being confined to the bed. The nursing staff moves the patient every 2–3 hours from side to side and depending on the state of consciousness sometimes to a chair. The goal is to move the patient as much as possible to try to avoid bedsores, atelectasis and pneumonia. Pneumonia can occur from the person’s inability to swallow leading to aspiration, lack of gag reflex or from feeding tube, (aspiration pneumonia). Physical therapy may also be used to prevent contractures and orthopedic deformities that would limit recovery for those patients who awaken from coma.
A person in a coma may become restless, or seize and need special care to prevent them from hurting themselves. Medicine may be given to calm such individuals. Patients who are restless may also try to pull on tubes or dressings so soft cloth wrist restraints may be put on. Side rails on the bed should be kept up to prevent the patient from falling.
Methods to wake comatose patients include reversing the cause of the coma (i.e., glucose shock if low sugar), giving medication to stop brain swelling, or inducing hypothermia. Inducing hypothermia on comatose patients provides one of the main treatments for patients after suffering from cardiac arrest. In this treatment, medical personnel expose patients to “external or intravascular cooling” at 32-34 °C for 24 hours; this treatment cools patients down about 2-3 °C less than normal body temperature. In 2002, Baldursdottir and her coworkers found that in the hospital, more comatose patients survived after induced hypothermia than patients that remained at normal body temperature. For this reason, the hospital chose to continue the induced hypothermia technique for all of its comatose patients that suffered from cardiac arrest.
When the pulmonary capillary pressure remains elevated chronically (for at least 2 weeks), the lungs become even more resistant to pulmonary edema because the lymph vessels expand greatly, increasing their capability of carrying fluid away from the interstitial spaces perhaps as much as 10-fold. Therefore, in patients with chronic mitral stenosis, pulmonary capillary pressures of 40 to 45 mm Hg have been measured without the development of lethal pulmonary edema.[Guytun and Hall physiology]
Hypoxia exists when there is a reduced amount of oxygen in the tissues of the body. Hypoxemia refers to a reduction in PO2 below the normal range, regardless of whether gas exchange is impaired in the lung, CaO2 is adequate, or tissue hypoxia exists. There are several potential physiologic mechanisms for hypoxemia, but in patients with COPD the predominant one is V/Q mismatching, with or without alveolar hypoventilation, as indicated by PaCO2. Hypoxemia caused by V/Q mismatching as seen in COPD is relatively easy to correct, so that only comparatively small amounts of supplemental oxygen (less than 3 L/min for the majority of patients) are required for LTOT. Although hypoxemia normally stimulates ventilation and produces dyspnea, these phenomena and the other symptoms and signs of hypoxia are sufficiently variable in patients with COPD as to be of limited value in patient assessment. Chronic alveolar hypoxia is the main factor leading to development of cor pulmonale—right ventricular hypertrophy with or without overt right ventricular failure—in patients with COPD. Pulmonary hypertension adversely affects survival in COPD, to an extent that parallels the degree to which resting mean pulmonary artery pressure is elevated. Although the severity of airflow obstruction as measured by FEV1 is the best correlate with overall prognosis in patients with COPD, chronic hypoxemia increases mortality and morbidity for any severity of disease. Large-scale studies of LTOT in patients with COPD have demonstrated a dose-response relationship between daily hours of oxygen use and survival. There is reason to believe that continuous, 24-hours-per-day oxygen use in appropriately selected patients would produce a survival benefit even greater than that shown in the NOTT and MRC studies.
Individuals can benefit from a variety of physical therapy interventions. Persons with neurological/neuromuscular abnormalities may have breathing difficulties due to weak or paralyzed intercostal, abdominal and/or other muscles needed for ventilation. Some physical therapy interventions for this population include active assisted cough techniques, volume augmentation such as breath stacking, education about body position and ventilation patterns and movement strategies to facilitate breathing.
Along with the measure above, systemic immediate release opioids are beneficial in emergently reducing the symptom of shortness of breath due to both cancer and non cancer causes; long-acting/sustained-release opioids are also used to prevent/continue treatment of dyspnea in palliative setting. Pulmonary rehabilitation may alleviate symptoms in some people, such as those with COPD, but will not cure the underlying disease. There is a lack of evidence to recommend midazolam, nebulised opioids, the use of gas mixtures, or cognitive-behavioral therapy.
Coma has a wide variety of emotional reactions from the family members of the affected patients, as well as the primary care givers taking care of the patients. Common reactions, such as desperation, anger, frustration, and denial are possible. The focus of the patient care should be on creating an amicable relationship with the family members or dependents of a comatose patient as well as creating a rapport with the medical staff.
A number of treatments have been investigated in the past for IPF, including interferon gamma-1β, bosentan, ambrisentan, and anticoagulants, but these are no longer considered effective treatment options. Many of these earlier studies were based on the hypothesis that IPF is an inflammatory disorder.
"N"-Acetylcysteine (NAC) is a precursor to glutathione, an antioxidant. It has been hypothesized that treatment with high doses of NAC may repair an oxidant–antioxidant imbalance that occurs in the lung tissue of patients with IPF. In the first clinical trial of 180 patients (IFIGENIA), NAC was shown in previous study to reduce the decline in VC and DLCO over 12 months of follow-up when used in combination with prednisone and azathioprine (triple therapy).
More recently, a large randomized, controlled trial (PANTHER-IPF) was undertaken by the National Institutes of Health (NIH) in the USA to evaluate triple therapy and NAC monotherapy in IPF patients. This study found that the combination of prednisone, azathioprine, and NAC increased the risk of death and hospitalizations and the NIH announced in 2012 that the triple-therapy arm of the PANTHER-IPF study had been terminated early.
This study also evaluated NAC alone and the results for this arm of the study were published in May 2014 in the New England Journal of Medicine, concluding that "as compared with placebo, acetylcysteine offered no significant benefit with respect to the preservation of FVC in patients with idiopathic pulmonary fibrosis with mild-to-moderate impairment in lung function".
Acute exacerbations are typically treated by increasing the use of short-acting bronchodilators. This commonly includes a combination of a short-acting inhaled beta agonist and anticholinergic. These medications can be given either via a metered-dose inhaler with a spacer or via a nebulizer, with both appearing to be equally effective. Nebulization may be easier for those who are more unwell. Oxygen supplementation can be useful. Excessive oxygen; however, can result in increased levels and a decreased level of consciousness.
Corticosteroids by mouth improve the chance of recovery and decrease the overall duration of symptoms. They work equally well as intravenous steroids but appear to have fewer side effects. Five days of steroids work as well as ten or fourteen. In those with a severe exacerbation, antibiotics improve outcomes. A number of different antibiotics may be used including amoxicillin, doxycycline and azithromycin; whether one is better than the others is unclear. The FDA recommends against the use of fluoroquinolones when other options are available due to higher risks of serious side effects. There is no clear evidence for those with less severe cases.
For those with type 2 respiratory failure (acutely raised levels) non-invasive positive pressure ventilation decreases the probability of death or the need of intensive care admission. Additionally, theophylline may have a role in those who do not respond to other measures. Fewer than 20% of exacerbations require hospital admission. In those without acidosis from respiratory failure, home care ("hospital at home") may be able to help avoid some admissions.