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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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Currently no treatment for vegetative state exists that would satisfy the efficacy criteria of evidence-based medicine. Several methods have been proposed which can roughly be subdivided into four categories: pharmacological methods, surgery, physical therapy, and various stimulation techniques. Pharmacological therapy mainly uses activating substances such as tricyclic antidepressants or methylphenidate. Mixed results have been reported using dopaminergic drugs such as amantadine and bromocriptine and stimulants such as dextroamphetamine. Surgical methods such as deep brain stimulation are used less frequently due to the invasiveness of the procedures. Stimulation techniques include sensory stimulation, sensory regulation, music and musicokinetic therapy, social-tactile interaction, and cortical stimulation.
There is limited evidence that the hypnotic drug zolpidem has an effect. The results of the few scientific studies that have been published so far on the effectiveness of zolpidem have been contradictory.
There is currently no definitive evidence that support altering the course of the recovery of minimally conscious state. There are currently multiple clinical trials underway investigating potential treatments.
In one case study, stimulation of thalamus using deep brain stimulation (DBS) led to some behavioral improvements. The patient was a 38-year-old male who had remained in minimally conscious state following a severe traumatic brain injury. He had been unresponsive to consistent command following or communication ability and had remained non-verbal over two years in inpatient rehabilitation. fMRI scans showed preservation of a large-scale, bi-hemispheric cerebral language network, which indicates that possibility for further recovery may exist. Positron emission tomography showed that the patient's global cerebral metabolism levels were markedly reduced. He had DBS electrodes implanted bilaterally within his central thalamus. More specifically, the DBS electrodes targeted the anterior intralaminar nuclei of thalamus and adjacent paralaminar regions of thalamic association nuclei. Both electrodes were positioned within the central lateral nucleus, the paralaminar regions of the median dorsalis, and the posterior-medial aspect of the centromedian/parafasicularis nucleus complex. This allowed maximum coverage of the thalamic bodies. A DBS stimulation was conducted such that the patient was exposed to various patterns of stimulation to help identify optimal behavioral responses. Approximately 140 days after the stimulation began, qualitative changes in behavior emerged. There were longer periods of eye opening and increased responses to command stimuli as well as higher scores on the JFK coma recovery scale (CRS). Functional object use and intelligible verbalization was also observed. The observed improvements in arousal level, motor control, and consistency of behavior could be a result of direct activation of frontal cortical and basal ganglia systems that were innervated by neurons within the thalamic association nuclei. These neurons act as a key communication relay and form a pathway between the brainstem arousal systems and frontal lobe regions. This pathway is crucial for many executive functions such as working memory, effort regulation, selective attention, and focus.
In another case study of a 50-year-old woman who had symptoms consistent with MCS, administration of zolpidem, a sedative hypnotic drug improved the patient's condition significantly. Without treatment, the patient showed signs of mutism, athetoid movements of the extremities, and complete dependence for all personal care. 45 minutes after 5 to 10 mg of zolpidem was administered, the patient ceased the athetoid movements, regained speaking ability, and was able to self-feed. The effect lasted 3–4 hours from which she returned to the former state. The effects were repeated on a daily basis. PET scans showed that after zolpidem was administered, there was a marked increase in blood flow to areas of the brain adjacent to or distant from damaged tissues. In this case, these areas were the ipsilateral cerebral hemispheres and the cerebellum. These areas are thought to have been inhibited by the site of injury through a GABA-mediated mechanism and the inhibition was modified by zolpidem which is a GABA agonist. The fact that zolpidem is a sedative drug that induces sleep in normal people but causes arousal in a MCS patient is paradoxical. The mechanisms to why this effect occurs is not entirely clear.
There is recent evidence that transcranial direct current stimulation (tDCS), a technique that supplies a small electric current in the brain with non-invasive electrodes, may improve the clinical state of patients with MCS. In one study with 10 patients with disorders of consciousness (7 in VS, 3 in MCS), tDCS was applied for 20 minutes every day for 10 days, and showed clinical improvement in all 3 patients who were in MCS, but not in those with VS. These results remained at 12-month follow-up. Two of the patients in MCS that had their brain insult less that 12 months recovered consciousness in the following months. One of these patients received a second round of tDCS treatment 4 months after his initial treatment, and showed further recovery and emerged into consciousness, with no change of clinical status between the two treatments. Moreover, in a sham-controlled, double-blind crossover study, the immediate effects of a single session of tDCS were shown to transiently improve the clinical status of 13 out of 30 patients with MCS, but not in those with VS
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.
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.
Pharmacotherapy is the utilization of drugs to treat an illness. There are several different drugs that have been used to alleviate symptoms experienced after a head injury including anti-depressants such as amitriptyline and sertraline. Use of these drugs has been associated with a decrease in depression and increased functioning in social and work environments. An antidiuretic called Desmopressin Acetate (DDAVP) has also been shown to improve memory performance in patients
Recent studies have examined the preventative effects of progesterone on brain injuries. Phase III trials are currently being conducted at 17 medical centers across the United States. Preliminary results have shown a 50% reduction in mortality in those treated with progesterone and showed an improved functional outcome.
Overall, the efficacy of pharmacotherapuetic treatments is dependent on the treatment being used and the symptoms being targeted by the treatment.
One of the defining characteristics of minimally conscious state is the more continuous improvement and significantly more favorable outcomes post injury when compared with vegetative state. One study looked at 100 patients with severe brain injury. At the beginning of the study, all the patients were unable to follow commands consistently or communicate reliably. These patients were diagnosed with either MCS or vegetative state based on performance on the JFK Coma Recovery Scale and the diagnostic criteria for MCS as recommended by the Aspen Consensus Conference Work-group. Both patient groups were further separated into those that suffered from traumatic brain injury and those that suffered from non-traumatic brain injures (anoxia, tumor, hydrocephalus, infection). The patients were assessed multiple times over a period of 12 months post injury using the Disability Rating Scale (DRS) which ranges from a score of 30=dead to 0=no disabilities. The results show that the DRS scores for the MCS subgroups showed the most improvement and predicted the most favorable outcomes 12 months post injury. Amongst those diagnosed with MCS, DRS scores were significantly lower for those with non-traumatic brain injuries in comparison to the vegetative state patients with traumatic brain injury. DRS scores were also significantly lower for the MCS non-traumatic brain injury group compared to the MCS traumatic brain injury group. Pairwise comparisons showed that DRS scores were significantly higher for those that suffered from non-tramuatic brain injuries than those with traumatic brain injuries. For the patients in vegetative states there were no significant differences between patients with non-traumatic brain injury and those with traumatic brain injuries. Out of the 100 patients studied, 3 patients fully recovered (had a DRS score of 0). These 3 patients were diagnosed with MCS and had suffered from traumatic brain injuries.
In summary, those with minimally conscious state and non-traumatic brain injuries will not progress as well as those with traumatic brain injuries while those in vegetative states have an all around lower to minimal chance of recovery.
Because of the major differences in prognosis described in this study, this makes it crucial that MCS be diagnosed correctly. Incorrectly diagnosing MCS as vegetative state may lead to serious repercussions related to clinical management.
Neither a standard treatment nor a cure is available. Stimulation of muscle reflexes with electrodes (NMES) has been known to help patients regain some muscle function. Other courses of treatment are often symptomatic. Assistive computer interface technologies, such as Dasher, or OptiKey, combined with eye tracking, may be used to help a LIS survivor communicate with their environment in a better way.
Patient education has been shown to be one of the most effective ways to decrease secondary symptoms seen with closed-head injuries. Patient education often includes working with a therapist to review symptom management and learn about returning to regular activities. Educational initiatives have also been shown to decrease the occurrence of PTSD in head-injury survivors.
There is limited data on treating the visual disturbances associated with HPPD, persistent visual aura, or post-head trauma visual disturbances, and pharmaceutical treatment is empirically-based. It is not clear if the etiology or type of illusory symptom influences treatment efficacy. Since the symptoms are usually benign, treatment is based on the patient’s zeal and willingness to try many different drugs. There are cases which report successful treatment with clonidine, clonazepam, lamotrigine, nimodipine, topiramate, verapamil, divalproex sodium, gabapentin, furosemide, and acetazolamide, as these drugs have mechanisms that decrease neuronal excitability. However, other patients report treatment failure from the same drugs. Based on the available evidence and side-effect profile, clonidine might be an attractive treatment option. Many patients report improvement from sunglasses. FL-41 tinted lenses may provide additional relief, as they have shown some efficacy in providing relief to visually-sensitive migraineurs.
Disorders of consciousness are medical conditions that inhibit consciousness. Some define disorders of consciousness as any change from complete self-awareness to inhibited or absent self-awareness and arousal. This category generally includes minimally conscious state and persistent vegetative state, but sometimes also includes the less severe locked-in syndrome and more severe but rare chronic coma. Differential diagnosis of these disorders is an active area of biomedical research. Finally, brain death results in an irreversible disruption of consciousness. While other conditions may cause a moderate deterioration (e.g., dementia and delirium) or transient interruption (e.g., grand mal and petit mal seizures) of consciousness, they are not included in this category.
Disorders of consciousness present a variety of ethical concerns.
Most obvious is the lack of consent in any treatment decisions. Patients in PVS or MCS are not able to decide for the possibility of withdrawal of life-support. It is also a general question whether they should receive life-sustaining therapy and, if so, for how long? The problems regarding a patient's consent also account for neuroimaging studies. Without patient's consent, such studies are perceived as unethical.
Additionally only few patients have created advance directives before losing decision-making capacity.
Typically approval must be obtained from family or legal representatives depending on governmental and hospital guidelines.
But even with the consent of representatives, researchers have been refused grants, ethics committee approval and publication.
Social issues arise from the enormous costs that are caused by people with disorders of consciousness. Especially chronic comatose and vegetative patients, when recovery is highly unlikely and treatment in the ICU is considered futile by clinicians.
In addition to the aforementioned problems, the question rises why medical resources were being used not for the broader public good but for patients who seemed to have only little to gain from them.
Still research is everything but sure about the irreversibility of these conditions. Some studies demonstrated that some patients suffering from disorders of consciousness may be aware despite clinical unresponsiveness. These recent findings could have a major impact on ethical and social issues.
Several drug therapies have been used on patients with KLS, but none of them have been subject to randomized controlled trials. A 2016 Cochrane Review concluded that "No evidence indicates that pharmacological treatment for Kleine-Levin syndrome is effective and safe".
In several cases, stimulants, including modafinil, have been reported to have a limited effect on patients, often alleviating sleepiness. They can cause behavioral problems, but they may pose fewer issues if used in older patients with mild symptoms. In some case reports, lithium has been reported to decrease the length of episodes and the severity of their symptoms and to increase the time between episodes. It has been reported to be effective in about 25 to 60 percent of cases. Its use carries the risk of side effects in the thyroid or kidneys. Anti-psychotics and benzodiazepines can help alleviate psychotic and anxiety related symptoms, respectively. Carbamazepine has been reported to be less effective than lithium but more effective than some drugs in its class. Electroconvulsive therapy is not effective and worsens symptoms.
KLS patients generally do not need to be admitted to hospitals. It is recommended that caregivers reassure them and encourage them to maintain sleep hygiene. It may also be necessary for patients to be prevented from putting themselves in dangerous situations, such as driving.
An open study of cognitive behavior therapy has aimed to help patients reinterpret their symptoms in a nonthreatening way, leading to an improvement on several standardized measures. A standardized treatment for DPD based on cognitive behavioral principles was published in The Netherlands in 2011.
Primary depersonalization disorder is mostly refractory to current treatments. The disorder lacks effective treatment in part because it has been neglected within the field of psychiatry, which, in turn, is partly because funding has mainly been allocated to the search for cures of other illnesses, like alcoholism. However, recognizing and diagnosing the condition may in itself have therapeutic benefits, considering many patients express their problems as baffling and unique to them, but are in fact: one, recognized and described by psychiatry; and two, those affected by it are not the only individuals to be affected from the condition. A variety of psychotherapeutic techniques have been used to treat depersonalization disorder, such as cognitive behavioral therapy. Clinical pharmacotherapy research continues to explore a number of possible options, including selective serotonin reuptake inhibitors, tricyclic antidepressants, anticonvulsants, and opioid antagonists.
Most head injuries are of a benign nature and require no treatment beyond analgesics and close monitoring for potential complications such as intracranial bleeding. If the brain has been severely damaged by trauma, neurosurgical evaluation may be useful. Treatments may involve controlling elevated intracranial pressure. This can include sedation, paralytics, cerebrospinal fluid diversion. Second line alternatives include decompressive craniectomy (Jagannathan et al. found a net 65% favorable outcomes rate in pediatric patients), barbiturate coma, hypertonic saline and hypothermia. Although all of these methods have potential benefits, there has been no randomized study that has shown unequivocal benefit.
Clinicians will often consult clinical decision support rules such as the Canadian CT Head Rule or the New Orleans/Charity Head injury/Trauma Rule to decide if the patient needs further imaging studies or observation only. Rules like these are usually studied in depth by multiple research groups with large patient cohorts to ensure accuracy given the risk of adverse events in this area.
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.
It is extremely rare for any significant motor function to return. The majority of locked-in syndrome patients do not regain motor control, but devices are available to help patients communicate. However, some people with the condition continue to live much longer, while in exceptional cases, like that of Kerry Pink and Kate Allatt, a full spontaneous recovery may be achieved.
Lithium is the only drug that appears to have a preventive effect. In two studies of more than 100 patients, lithium helped prevent recurrence of symptoms in 20% to 40% of cases. The recommended blood level of lithium for KLS patients is 0.8-1.2 mEq/ml. It is not known if other mood stabilizers have an effect on the condition. Anti-depressants do not prevent recurrence.
Brain death is the complete loss of brain function (including involuntary activity necessary to sustain life). It differs from persistent vegetative state, in which the person is alive and some autonomic functions remain.
Brain death is used as an indicator of legal death in many jurisdictions, but it is defined inconsistently. Various parts of the brain may keep functioning when others do not anymore, and the term "brain death" has been used to refer to various combinations. For example, although a major medical dictionary says that "brain death" is synonymous with "cerebral death" (death of the cerebrum), the US National Library of Medicine Medical Subject Headings (MeSH) system defines brain death as including the brainstem. The distinctions can be important because, for example, in someone with a dead cerebrum but a living brainstem, the heartbeat and ventilation can continue unaided, whereas in whole-brain death (which includes brain stem death), only life support equipment would keep those functions going. Patients classified as brain-dead can have their organs surgically removed for organ donation.
The most common treatment for reducing bipolar II disorder symptoms is medication, usually in the form of mood stabilizers. However, treatment with mood stabilizers may produce a flat affect in the patient, which is dose-dependent. Concurrent use of SSRI antidepressants may help some with bipolar II disorder, though these medications should be used with caution because it is believed that they may cause a hypomanic switch.
The pharmaceutical management of bipolar II disorder is not generally supported by strong evidence, with limited randomised controlled trials (RCTs) published in the literature. Some medications used are:
- Lithium - There is strong evidence that lithium is effective in treating both the depressive and hypomanic symptoms in bipolar II. In addition, its action as a mood stabilizer can be used to decrease the risk of hypomanic switch in patients treated with antidepressants.
- Anticonvulsants - there is evidence that lamotrigine decreases the risk of relapse in rapid cycling bipolar II. It appears to be more effective in bipolar II than bipolar I, suggesting that lamotrigine is more effective for the treatment of depressive rather than manic episodes. Doses ranging from 100–200 mg have been reported to have the most efficacy, while experimental doses of 400 mg have rendered little response. A large, multicentre trial comparing carbamazepine and lithium over two and a half years found that carbamazepine was superior in terms of preventing future episodes of bipolar II, although lithium was superior in individuals with bipolar I. There is also some evidence for the use of valproate and topiramate, although the results for the use of gabapentin have been disappointing.
- Antidepressants - there is evidence to support the use of SSRI and SNRI antidepressants in bipolar II. Indeed, some sources consider them to be one of the first line treatments. However, antidepressants also pose significant risks, including a switch to mania, rapid cycling, and dysphoria and so many psychiatrists advise against their use for bipolar. When used, antidepressants are typically combined with a mood stabilizer.
- Antipsychotics - there is good evidence for the use of quetiapine, and it has been approved by the FDA for this indication. There is also some evidence for the use of risperidone, although the relevant trial was not placebo controlled and was complicated by the use of other medications in some of the patients.
- Dopamine agonists - there is evidence for the efficacy of pramipexole from one RCT.
Treatment typically includes three things: the treatment of acute hypomania, the treatment of acute depression, and the prevention of the relapse of either hypomania or depression. The main goal is to make sure that patients do not harm themselves.
Hiccups are normally waited out, as any fit of them will usually pass quickly. Folkloric 'cures' for hiccups are common and varied, but no effective standard for stopping hiccups has been documented. Hiccups are treated medically only in severe and persistent (termed "intractable") cases.
Numerous medical remedies exist but no particular treatment is known to be especially effective. Many drugs have been used, such as baclofen, chlorpromazine, metoclopramide, gabapentin, and various proton-pump inhibitors. Hiccups that are secondary to some other cause like gastroesophageal reflux disease or esophageal webs are dealt with by treating the underlying disorder. The phrenic nerve can be blocked temporarily with injection of 0.5% procaine, or permanently with bilateral phrenicotomy or other forms of surgical destruction. Even this rather drastic treatment does not cure some cases, however.
An anecdotal medical approach is to install lidocaine liniment 3% or gel 2% into the ear canal. Somehow this creates a vagus nerve-triggering reflex through its extensions to the external ear and tympanus (ear drum). The effect can be immediate, and also have lasting effect after the lidocaine effect expires after about two hours.
Haloperidol (Haldol, an anti-psychotic and sedative), metoclopramide (Reglan, a gastrointestinal stimulant), and chlorpromazine (Thorazine, an anti-psychotic with strong sedative effects) are used in cases of intractable hiccups. Effective treatment with sedatives often requires a dose that renders the person either unconscious or highly lethargic. Hence, medicating with sedatives is only appropriate short-term, as the affected individual cannot continue with normal life activities while under their effect.
Persistent digital rectal massage has also been proven effective in terminating intractable hiccups.
The administration of intranasal vinegar was found to ease the chronic and severe hiccups of a three-year-old Japanese girl. Vinegar may stimulate the dorsal wall of the nasopharynx, where the pharyngeal branch of the glossopharyngeal nerve (the afferent of the hiccup reflex arc) is located.
Bryan R. Payne, a neurosurgeon at the Louisiana State University Health Sciences Center in New Orleans, has had some success with an experimental procedure in which a vagus nerve stimulator is implanted in the upper chest of patients with an intractable case of hiccups. "It sends rhythmic bursts of electricity to the brain by way of the vagus nerve, which passes through the neck. The Food and Drug Administration approved the vagus nerve stimulator in 1997 as a way to control seizures in some patients with epilepsy."
Lockhart stated that hiccups can sometimes be cured by pinching the skin that covers the surface of the deltoid muscles, which is supplied by the axillary nerve which shares the c5 nerve root with the phrenic nerve.
Behavioral treatment can be effective in some cases. Sedative hypnotics may also help relieve the symptoms. Additionally, education about normal patterns of the sleep-wake cycle may alleviate anxiety in some patients. For patients with severe depression resulting from the fear of having insomnia, electroconvulsive therapy appears to be a safe and effective treatment.
While the diagnosis of brain death has become accepted as a basis for the certification of death for legal purposes, it should be clearly understood that it is a very different state from biological death - the state universally recognized and understood as death. The continuing function of vital organs in the bodies of those diagnosed brain dead, if mechanical ventilation and other life-support measures are continued, provides optimal opportunities for their transplantation.
When mechanical ventilation is used to support the body of a brain dead organ donor pending a transplant into an organ recipient, the donor's date of death is listed as the date that brain death was diagnosed.
In some countries (for instance, Spain, Finland, Poland, Wales, Portugal, and France), everyone is automatically an organ donor after diagnosis of death on legally accepted criteria, although some jurisdictions (such as Singapore, Spain, Wales, France, Czech Republic and Portugal) allow opting out of the system. Elsewhere, consent from family members or next-of-kin may be required for organ donation. In New Zealand, Australia, the United Kingdom (excluding Wales) and most states in the United States, drivers are asked upon application if they wish to be registered as an organ donor.
In the United States, if the patient is at or near death, the hospital must notify a transplant organization of the person's details and maintain the patient while the patient is being evaluated for suitability as a donor. The patient is kept on ventilator support until the organs have been surgically removed. If the patient has indicated in an advance health care directive that they do not wish to receive mechanical ventilation or has specified a do not resuscitate order and the patient has also indicated that they wish to donate their organs, some vital organs such as the heart and lungs may not be able to be recovered.