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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.
In people with stable OHS, the most important treatment is weight loss—by diet, through exercise, with medication, or sometimes weight loss surgery (bariatric surgery). This has been shown to improve the symptoms of OHS and resolution of the high carbon dioxide levels. Weight loss may take a long time and is not always successful. Bariatric surgery is avoided if possible, given the high rate of complications, but may be considered if other treatment modalities are ineffective in improving oxygen levels and symptoms. If the symptoms are significant, nighttime positive airway pressure (PAP) treatment is tried; this involves the use of a machine to assist with breathing. PAP exists in various forms, and the ideal strategy is uncertain. Some medications have been tried to stimulate breathing or correct underlying abnormalities; their benefit is again uncertain.
While many people with obesity hypoventilation syndrome are cared for on an outpatient basis, some deteriorate suddenly and when admitted to the hospital may show severe abnormalities such as markedly deranged blood acidity (pH<7.25) or depressed level of consciousness due to very high carbon dioxide levels. On occasions, admission to an intensive care unit with intubation and mechanical ventilation is necessary. Otherwise, "bi-level" positive airway pressure (see the next section) is commonly used to stabilize the patient, followed by conventional treatment.
Obesity hypoventilation syndrome is associated with a reduced quality of life, and people with the condition incur increased healthcare costs, largely due to hospital admissions including observation and treatment on intensive care units. OHS often occurs together with several other disabling medical conditions, such as asthma (in 18–24%) and type 2 diabetes (in 30–32%). Its main complication of heart failure affects 21–32% of patients.
Those with abnormalities severe enough to warrant treatment have an increased risk of death reported to be 23% over 18 months and 46% over 50 months. This risk is reduced to less than 10% in those receiving treatment with PAP. Treatment also reduces the need for hospital admissions and reduces healthcare costs.
Central hypoventilation syndrome (CHS) is a respiratory disorder that results in respiratory arrest during sleep. CHS can either be congenital (CCHS) or acquired (ACHS) later in life. It is fatal if untreated. It is also known as Ondine's curse.
ACHS can develop as a result of severe injury or trauma to the brain or brainstem. Congenital cases are very rare and involve a failure of autonomic control of breathing. In 2006, there were only about 200 known cases worldwide. As of 2008, only 1000 total cases were known. The diagnosis may be delayed because of variations in the severity of the manifestations or lack of awareness in the medical community, particularly in milder cases. However, as there have been cases where asymptomatic family members also were found to have CCHS, it may be that these figures only reflect those found to require mechanical ventilation. In all cases, episodes of apnea occur in sleep, but in a few patients, at the most severe end of the spectrum, apnea also occurs while awake.
Although rare, cases of long-term untreated CCHS have been reported and are termed late onset CCHS (LO-CCHS). Cases that go undiagnosed until later life and middle age, although the symptoms are usually obvious in retrospect. There have, however, even been cases of LO-CCHS where family members found to have it have been asymptomatic. Again, lack of awareness in the medical community may cause such a delay. CCHS susceptibility is not known to be affected by gender.
Respiratory stimulants such as nikethamide were traditionally used to counteract respiratory depression from CNS depressant overdose, but offered limited effectiveness. A new respiratory stimulant drug called BIMU8 is being investigated which seems to be significantly more effective and may be useful for counteracting the respiratory depression produced by opiates and similar drugs without offsetting their therapeutic effects.
If the respiratory depression occurs from opioid overdose, usually an opioid antagonist, most likely naloxone, will be administered. This will rapidly reverse the respiratory depression unless complicated by other depressants. However an opioid antagonist may also precipitate an opioid withdrawal syndrome in chronic users.
As a side effect of medicines or recreational drugs, hypoventilation may become potentially life-threatening. Many different central nervous system (CNS) depressant drugs such as ethanol, benzodiazepines, barbiturates, GHB, sedatives and opioids produce respiratory depression when taken in large or excessive doses, or mixed with other depressants. Strong opiates (such as fentanyl, heroin, or morphine), barbiturates, and certain benzodiazepines (short acting ones and alprazolam) are known for depressing respiration. In an overdose, an individual may cease breathing entirely (go into respiratory arrest) which is rapidly fatal without treatment. Opioids, in overdose or combined with other depressants, are notorious for such fatalities.
People with neuromuscular disorders or hypoventilation syndromes involving failed respiratory drive experience central hypoventilation. The most common treatment for this form is the use of non-invasive ventilation such as a BPAP machine.
One treatment for obstructive hypopnea is continuous positive airway pressure (CPAP). CPAP is a treatment in which the patient wears a mask over the nose and/or mouth. An air blower forces air through the upper airway. The air pressure is adjusted so that it is just enough to maintain the oxygen saturation levels in the blood. Another treatment is sometimes a custom fitted oral appliance. The American Academy of Sleep Medicine's protocol for obstructive sleep apnea (OSA) recommends oral appliances for those who prefer them to CPAP and have mild to moderate sleep apnea or those that do not respond to/cannot wear a CPAP. Severe cases of OSA may be treated with an oral appliance if the patient has had a trial run with a CPAP. Oral Appliances should be custom made by a dentist with training in dental sleep medicine. Mild obstructive hypopnea can often be treated by losing weight or by avoiding sleeping on one's back. Also quitting smoking, and avoiding alcohol, sedatives and hypnotics (soporifics) before sleep can be quite effective. Surgery is generally a last resort in hypopnea treatment, but is a site-specific option for the upper airway. Depending on the cause of obstruction, surgery may focus on the soft palate, the uvula, tonsils, adenoids or the tongue. There are also more complex surgeries that are performed with the adjustment of other bone structures - the mouth, nose and facial bones.
Treatment of the underlying cause is required. Endotracheal intubation and mechanical ventilation are required in cases of severe respiratory failure (PaO2 less than 50 mmHg). Respiratory stimulants such as doxapram are rarely used, and if the respiratory failure resulted from an overdose of sedative drugs such as opioids or benzodiazepines, then the appropriate antidote (naloxone or flumazenil, respectively) will be given.
There is tentative evidence that in those with respiratory failure identified before arrival in hospital, continuous positive airway pressure can be useful when started before conveying to hospital.
The rate of BPD varies among institutions, which may reflect neonatal risk factors, care practices (e.g., target levels for acceptable oxygen saturation), and differences in the clinical definitions of BPD.
Currently there are no official tests or treatments for ROHHAD. Each child has the symptoms above at different ages, yet most symptoms are eventually present. Many children are misdiagnosed or are never diagnosed until alveolar hypoventilation occurs.
Orofaciodigital syndrome type 1 can be treated with reconstructive surgery or the affected parts of the body. Surgery of cleft palate, tongue nodules, additional teeth, accessory frenulae, and orthodontia for malocclusion. Routine treatment for patients with renal disease and seizures may also be necessary. Speech therapy and special education in the later development may also be used as management.
In closed circuit SCUBA (rebreather) diving, exhaled carbon dioxide must be removed from the breathing system, usually by a scrubber containing a solid chemical compound with a high affinity for CO, such as soda lime. If not removed from the system, it may be re-inhaled, causing an increase in the inhaled concentration.
Treatment is supportive. Hamman's syndrome tends to be benign and self-limiting. It is important to differentiate it from far more serious conditions that have similar symptoms, such as Boerhaave's syndrome.
In renal compensation, plasma bicarbonate rises 3.5 mEq/L for each increase of 10 mm Hg in "Pa"CO. The expected change in serum bicarbonate concentration in respiratory acidosis can be estimated as follows:
- Acute respiratory acidosis: HCO increases 1 mEq/L for each 10 mm Hg rise in "Pa"CO.
- Chronic respiratory acidosis: HCO rises 3.5 mEq/L for each 10 mm Hg rise in "Pa"CO.
The expected change in pH with respiratory acidosis can be estimated with the following equations:
- Acute respiratory acidosis: Change in pH = 0.008 X (40 − "Pa"CO)
- Chronic respiratory acidosis: Change in pH = 0.003 X (40 − "Pa"CO)
Respiratory acidosis does not have a great effect on electrolyte levels. Some small effects occur on calcium and potassium levels. Acidosis decreases binding of calcium to albumin and tends to increase serum ionized calcium levels. In addition, acidemia causes an extracellular shift of potassium, but respiratory acidosis rarely causes clinically significant hyperkalemia.
Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD syndrome) is a very rare disease affecting approximately 75 people worldwide. Patients with ROHHAD, as well as patients with congenital central hypoventilation syndrome (CCHS) have damage to the mechanism governing proper breathing. ROHHAD syndrome is a disease that is potentially lethal and incurable. Fifteen patients with ROHHAD were evaluated by Diego Ize-Ludlow et al. work published in 2007.
Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood's pH (a condition generally called acidosis).
Carbon dioxide is produced continuously as the body's cells respire, and this CO will accumulate rapidly if the lungs do not adequately expel it through alveolar ventilation. Alveolar hypoventilation thus leads to an increased "Pa"CO (a condition called hypercapnia). The increase in "Pa"CO in turn decreases the HCO/"Pa"CO ratio and decreases pH.
There is evidence to show that steroids given to babies less than 8 days old can prevent bronchopulmonary dysplasia. However, the risks of treatment may outweigh the benefits.
It is unclear if starting steroids more than 7 days after birth is harmful or beneficial. It is thus recommended that they only be used in those who cannot be taken off of a ventilator.
Hypercapnia, also known as hypercarbia and CO retention, is a condition of abnormally elevated carbon dioxide (CO) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs.
Hypercapnia normally triggers a reflex which increases breathing and access to oxygen (O), such as arousal and turning the head during sleep. A failure of this reflex can be fatal, for example as a contributory factor in sudden infant death syndrome.
Hypercapnia is the opposite of hypocapnia, the state of having abnormally reduced levels of carbon dioxide in the blood. Hypercapnia is from the Greek "hyper" = "above" or "too much" and "kapnos" = "smoke".
Vestronidase alfa-vjbk (Mepsevii) is the only drug approved by U.S. Food and Drug Administration for the treatment of pediatric and adult patients.
With liver transplantation, the 5 year survival rate is 74%, which is comparable to patients who undergo liver transplants who do not suffer from hepatopulmonary syndrome.
Hypoxemia (PaO2 6.0kPa).
The basic defect in type 2 respiratory failure is characterized by:
Type 2 respiratory failure is caused by inadequate alveolar ventilation; both oxygen and carbon dioxide are affected. Defined as the buildup of carbon dioxide levels (PCO) that has been generated by the body but cannot be eliminated. The underlying causes include:
- Increased airways resistance (chronic obstructive pulmonary disease, asthma, suffocation)
- Reduced breathing effort (drug effects, brain stem lesion, extreme obesity)
- A decrease in the area of the lung available for gas exchange (such as in chronic bronchitis)
- Neuromuscular problems (Guillain–Barré syndrome, motor neuron disease)
- Deformed (kyphoscoliosis), rigid (ankylosing spondylitis), or flail chest.
Currently the only definitive treatment is liver transplantation. Alternative treatments such as supplemental oxygen or somatostatin to inhibit vasodilation remain anecdotal.
Let us consider some scenarios where there is a defect in ventilation and/ or perfusion of the lungs.
In condition such as pulmonary embolism, the pulmonary blood flow is affected, thus the ventilation of the lung is adequate, however there is a perfusion defect with defect in blood flow. Gas exchange thus becomes highly inefficient leading to hypoxemia as measured by arterial oxygenation. A ventilation perfusion scan or lung scintigraphy shows some areas of lungs being ventilated but not adequately perfused. This also leads to a high A-a gradient which is not responsive to oxygen
In conditions with right to left shunts, there is again a ventilation perfusion defect with high A-a gradient. However, the A-a gradient is responsive to oxygen therapy. In cases of right to left shunts more of deoxygenated blood mixes with oxygenated blood from the lungs and thus to a small extent the condition might neutralize the high A-a gradient with pure oxygen therapy.
Patient with parenchymal lung diseases will have an increased A-a gradient with moderate response to oxygen therapy.
A patient with hypoventilation will have complete response to 100% oxygen therapy
To date, no prospective controlled clinical trial has shown a significant mortality benefit of exogenous surfactant in adult ARDS.