An induced coma – also known as a medically induced coma (MIC), barbiturate-induced coma, or drug-induced coma – is a temporary coma (a deep state of unconsciousness) brought on by a controlled dose of an anesthetic drug, often a barbiturate such as pentobarbital or thiopental. Barbiturate comas are used to protect the brain during major neurosurgery, as a last line of treatment in certain cases of status epilepticus that have not responded to other treatments, and in refractory intracranial hypertension following traumatic brain injury. Induced coma usually results in significant systemic adverse effects. The patient is likely to completely lose respiratory drive and require mechanical ventilation; gut motility is reduced; hypotension can complicate efforts to maintain cerebral perfusion pressure and often requires the use of vasopressor drugs. Hypokalemia often results. The completely immobile patient is at increased risk of bed sores as well as infection from catheters. Induced coma is a feature of the Milwaukee protocol, a controversial method that is promoted as a means of treating rabies infection in people. Theory
Barbiturates reduce the metabolic rate of brain tissue, as well as the cerebral blood flow. With these reductions, the blood vessels in the brain narrow, resulting in a shrunken brain, and hence lower intracranial pressure. The hope is that, with the swelling relieved, the pressure decreases and some or all brain damage may be averted.
Most often, the parents of an individual with an autosomal recessive disorder are heterozygous carriers, having only one copy of the altered gene, without having signs and symptoms of the disorder.In about one-third of cases of hyperprolinemia, individuals carrying one copy of an altered PRODH gene have moderately elevated levels of proline in their blood, but these levels do not cause any health problems. Individuals with one altered ALDH4A1 gene have normal levels of proline in their blood. Diagnosis
Types
Hyperprolinemia type I
It is difficult to determine the prevalence of hyperprolinemia type I, as many people with the condition are asymptomatic. People with hyperprolinemia type I have proline levels in their blood between 3 and 10 times the normal level. Some individuals with type I exhibit seizures, intellectual disability, or other neurological problems. Hyperprolinemia type II
Hyperprolinemia type II results in proline levels in the blood between 10 and 15 times higher than normal, and high levels of a related compound called pyrroline-5-carboxylate. This rare form of the disorder may appear benign at times, but often involves seizures, convulsions, and intellectual disability.Hyperprolinemia can also occur with other conditions, such as malnutrition or liver disease. In particular, individuals with conditions that cause elevated levels of lactic acid in the blood, such as lactic acidemia, are likely to have elevated proline levels, because lactic acid inhibits the breakdown of proline. Treatment
Dietary restriction of protein intake. Research
A 2005 study on rats suggested that hyperprolininemia causes cognitive dysfunction.