Epinephrine, also known as adrenaline, is a medication and hormone. As a medication, it is used to treat several conditions, including anaphylaxis, cardiac arrest, asthma, and superficial bleeding. Inhaled epinephrine may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not effective. It is given intravenously, by injection into a muscle, by inhalation, or by injection just under the skin.Common side effects include shakiness, anxiety, and sweating. A fast heart rate and high blood pressure may occur. Occasionally, it may result in an abnormal heart rhythm. While the safety of its use during pregnancy and breastfeeding is unclear, the benefits to the mother must be taken into account.Epinephrine is normally produced by both the adrenal glands and a small number of neurons in the brain, where it acts as a neurotransmitter. It plays an essential role in the fight-or-flight response by increasing blood flow to muscles, heart output, pupil dilation, and blood sugar. Epinephrine does this through its effects on alpha and beta receptors. It is found in many animals and some single-celled organisms, but the medication is produced synthetically and is not harvested from animals.Jōkichi Takamine first isolated epinephrine in 1901, and it came into medical use in 1905. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2017, it was the 263rd most commonly prescribed medication in the United States, with more than one million prescriptions.
Causes
It is important to distinguish association and causation. The vast majority of trigger digits are idiopathic, meaning there is no known cause. Some speculate that repetitive forceful use of a digit leads to narrowing of the fibrous digital sheath in which it runs, but there is little scientific data to support this theory. The relationship of trigger finger to work activities is debatable and there are arguments for and against a relationship to hand use with no experimental evidence supporting a relationship. Diagnosis
Diagnosis is made on interview and physical examination. More than one finger may be affected at a time. It is most common in the thumb and ring finger. The triggering more often occurs while gripping an object firmly or during sleep when the palm of the subject’s hand remains closed for an extended period of time. Upon waking, the affected person may have to force the triggered fingers open with their other hand. In some, this can be a daily occurrence. Treatment
Corticosteroid injections can cure trigger digits. Treatment consists of injection of a corticosteroid such as methylprednisolone often combined with a local anesthetic (lidocaine) at the A1 pulley in the palm. The infiltration of the affected site is straightforward using standard anatomic landmarks. There is evidence that the steroid does not need to enter the sheath. The role of sonographic guidance is therefore debatable. Injection of the tendon sheath with a corticosteroid is effective over weeks to months in more than half of people.