R40.2 - Coma

Clinical Information

• Akinetic Mutism-. a syndrome characterized by a silent and inert state without voluntary motor activity despite preserved sensorimotor pathways and vigilance. bilateral frontal lobe dysfunction involving the anterior cingulate gyrus and related brain injuries are associated with this condition. this may result in impaired abilities to communicate and initiate motor activities. (from adams et al., principles of neurology, 6th ed, p348; fortschr neurol psychiatr 1995 feb;63(2):59-67)
• Brain Death-. a state of prolonged irreversible cessation of all brain activity, including lower brain stem function with the complete absence of voluntary movements, responses to stimuli, brain stem reflexes, and spontaneous respirations. reversible conditions which mimic this clinical state (e.g., sedative overdose, hypothermia, etc.) are excluded prior to making the determination of brain death. (from adams et al., principles of neurology, 6th ed, pp348-9)
• Coma-. a profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem reticular formation.
• Coma, Post-Head Injury-. prolonged unconsciousness from which the individual cannot be aroused, associated with traumatic injuries to the brain. this may be defined as unconsciousness persisting for 6 hours or longer. coma results from injury to both cerebral hemispheres or the reticular formation of the brain stem. contributing mechanisms include diffuse axonal injury and brain edema. (from j neurotrauma 1997 oct;14(10):699-713)
• Comamonadaceae-. a family of gram-negative aerobic bacteria in the order burkholderiales, encompassing the acidovorans rrna complex. some species are pathogenic to plants.
• Comamonas-. a genus of gram-negative, straight or slightly curved rods which are motile by polar flagella and which accumulate poly-beta-hydroxybutyrate within the cells.
• Comamonas testosteroni-. a species of gram-negative, aerobic rods formerly called pseudomonas testosteroni. it is differentiated from other comamonas species by its ability to assimilate testosterone and to utilize phenylacetate or maleate as carbon sources.
• Convulsive Therapy-. convulsions induced in order to treat mental disorders. it is used primarily in the treatment of severe affective disorders and schizophrenia.
• Delftia acidovorans-. a species of gram-negative rod-shaped bacteria found ubiquitously and formerly called comamonas acidovorans and pseudomonas acidovorans. it is the type species of the genus delftia.
• Diabetic Coma-. a state of unconsciousness as a complication of diabetes mellitus. it occurs in cases of extreme hyperglycemia or extreme hypoglycemia as a complication of insulin therapy.
• Glasgow Coma Scale-. a scale that assesses the response to stimuli in patients with craniocerebral injuries. the parameters are eye opening, motor response, and verbal response.
• Hepatic Encephalopathy-. a syndrome characterized by central nervous system dysfunction in association with liver failure, including portal-systemic shunts. clinical features include lethargy and confusion (frequently progressing to coma); asterixis; nystagmus, pathologic; brisk oculovestibular reflexes; decorticate and decerebrate posturing; muscle spasticity; and bilateral extensor plantar reflexes (see reflex, babinski). electroencephalography may demonstrate triphasic waves. (from adams et al., principles of neurology, 6th ed, pp1117-20; plum & posner, diagnosis of stupor and coma, 3rd ed, p222-5)
• Hyperglycemic Hyperosmolar Nonketotic Coma-. a serious complication of type 2 diabetes mellitus. it is characterized by extreme hyperglycemia; dehydration; serum hyperosmolarity; and depressed consciousness leading to coma in the absence of ketosis and acidosis.
• Insulin Coma-. severe hypoglycemia induced by a large dose of exogenous insulin resulting in a coma or profound state of unconsciousness from which the individual cannot be aroused.
• Santalaceae-. a plant family of the order santalales, subclass rosidae, class magnoliopsida. they are parasites that form connections (haustoria) to their hosts to obtain water and nutrients. the one-seeded fruit may be surrounded by a brightly colored nut-like structure.
• Frontal Lobe-. the part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.
• Reticular Formation-. a region extending from the pons & medulla oblongata through the mesencephalon, characterized by a diversity of neurons of various sizes and shapes, arranged in different aggregations and enmeshed in a complicated fiber network.
• Delftia-. a genus of gram-negative, strictly aerobic chemoorganotrophic bacteria, in the family comamonadaceae.

Specific Coding for Coma

Non-specific codes like R40.2 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for coma:

Patient Education

Coma

A coma is a deep state of unconsciousness. An individual in a coma is alive but unable to move or respond to his or her environment. Coma may occur as a complication of an underlying illness, or as a result of injuries, such as brain injury.

A coma rarely lasts more than 2 to 4 weeks. The outcome for coma depends on the cause, severity, and site of the damage. People may come out of a coma with physical, intellectual, and psychological problems. Some people may remain in a coma for years or even decades. For those people, the most common cause of death is infection, such as pneumonia.

NIH: National Institute of Neurological Disorders and Stroke

Code History

• FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
• FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
• FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
• FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
• FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
• FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
• FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
• FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)