Surgery Guide

Patients who experience full awareness with explicit recall may have suffered an enormous trauma. Some patients experience posttraumatic stress disorder (PTSD), leading to long-lasting after-effects such as nightmares, night terrors, flashbacks, insomnia, and in some cases even suicide.[10] There is evidence that early psychological counselling and support can reduce the amount of harm and chances of developing PTSD.[citation needed] The patient must be treated sympathetically and with compassion.

The incidence of anesthesia awareness in the United States is believed to be 20,000 to 40,000 cases per year, which represents 0.1 percent to 0.2 percent of all patients undergoing general anesthesia.[7]

The incidence of anesthesia awareness is higher when muscle relaxants are used.[8]

A recent large-scale study reported a much lower rate (0.0068%).[9] The modified patient interview used in this retrospective study did not specifically ask the patient if he/she had experienced awareness during the surgery.

Prompt inspection of the anesthesia equipment and record is important and may help prevent future occurrences. It is also important that a case of suspected awareness be communicated to the patient’s healthcare team, and that the event be scrutinised closely by senior anesthetic medical staff.

There are various levels of consciousness. Wakefulness and general anesthesia are two extremes of the spectrum. Conscious sedation and monitored anesthesia care (MAC) refer to an awareness somewhere in the middle of the spectrum depending on the degree to which a patient is sedated. It is important to note that awareness/wakefulness is not necessarily correlated with pain or discomfort. The aim of conscious sedation or minimal anesthetic care is to provide a safe and comfortable anesthetic while maintaining the patient’s ability to follow commands.

Under certain circumstances, a general anesthetic, whereby the patient is completely unconscious, may be unnecessary and/or undesirable. For instance, with a cesarean delivery, the goal is to provide comfort with neuroaxial anesthetic yet maintain consciousness so that the mother can participate in the birth of her child. Other circumstances may include, but are not limited to, procedures that are minimally invasive or purely diagnostic (and thus not uncomfortable). Sometimes, the patient’s health may not tolerate the stress of general anesthesia. The decision to provide monitored anesthesia care versus general anesthesia can be complex involving careful consideration of individual circumstances.

Patients who undergo conscious sedation or monitored anesthesia care are never meant to be without recall.[6] Whether or not a patient remembers the procedure depends on the type of medications uses, the dosages used, patient physiology, and other factors. Many patients undergoing monitored anesthesia care do not remember the experience.

The most traumatic case of anesthesia awareness is full consciousness during surgery with pain and explicit recall of intraoperative events. In less severe cases, patients may have only poor recollection of conversations, events, pain, pressure or of difficulty in breathing.

The experiences of patients with anesthesia awareness vary widely, and patient responses and sequelae vary widely as well. This experience may be extremely traumatic for the patient or not at all.

Because the medical staff may not know if a person is unconscious or not, it has been suggested that the staff maintain the professional conduct that would be appropriate for a conscious patient.[5]

There are two states of consciousness which may be present:
Awareness. When patients seem to be vigilant and cognizant responding to commands but with no postoperative recall or memory of the events.
Memorization and recall. When patients can recall events postoperatively but were not necessarily conscious enough for responding to commands.

The incidence of a state with both responses in diverse degrees is also possible.[4]

Awareness occurs in 20,000-40,000 patients out of every 20 million US surgeries (or one to two tenths of one percent) every year[1] when patients have anesthesia that is inadequate to keep them unconscious during an operation. In this situation, the patient may feel the pain or pressure of surgery, hear conversations, or feel as if they cannot breathe. The patient may be unable to communicate any distress because they have been given a paralytic/muscle relaxant. If anesthesia awareness does occur about 42% feel the pain of the operation, 94% experience panic/anxiety and 70% experience lasting psychological symptoms.[2]

In some cases, post traumatic stress disorder (PTSD) may arise after intraoperative awareness, causing the patient to require counseling for an extended period.[3]

Anesthesia awareness, or “unintended intra-operative awareness” occurs during general anesthesia, on the operating table, when a patient has not had enough general anesthetic or analgesic to prevent consciousness or waking up during surgery.

However, it can also occur in the post anesthesia care unit (PACU) or in the intensive care unit (ICU), where patients are kept sedated, tranquilized and paralyzed (and intubated) hooked to life support systems, awaiting normalization of their physiology.

The 1958 film Corridors of Blood, starring Boris Karloff, depicts an 1840’s surgeon who experiments with anesthetic gases in an effort to make surgery pain free.

A bestseller by Robin Cook, Harmful Intent has an anesthesiologist as the main character, who uncovers a legal conspiracy aimed at his specialty.

The 1978 film Coma depicts a series of events at the Boston Memorial Hospital in which patients are intentionally put into a comatose state via anesthesia and their organs later sold.

Metallica has a song from their album Kill ‘Em All called (Anesthesia) Pulling Teeth.

Awake, a 2007 suspense thriller, is about anaesthesia awareness[see below].

An AIMS refers to any information system that is used as an automated electronic anesthesia record keeper (i.e., connection to patient physiologic monitors and/or the Anaesthetic machine) and which also may allow the collection and analysis of anesthesia-related perioperative patient data.

The anesthesia record is the medical and legal documentation of events during an anesthetic.[23] It reflects a detailed and continuous account of drugs, fluids, and blood products administered and procedures undertaken, and also includes the observation of cardiovascular responses, estimated blood loss, urinary body fluids and data from physiologic monitors (Anesthetic monitoring, see above) during the course of an anesthetic. The anesthesia record may be written manually on paper; however, the paper record is increasingly replaced by an electronic record as part of an Anesthesia Information Management System (AIMS).