Oophorectomy is the surgical removal of the ovaries of a female animal. In the case of non-human animals, this is also called spaying. It is a form of sterilization.
The removal of the ovaries together with the Fallopian tubes is called salpingo-oophorectomy. Oophorectomy and salpingo-oophorectomy are not common forms of birth control in humans; more usual is tubal ligation, in which the Fallopian tubes are blocked but the ovaries remain intact.
In humans, oophorectomy is most usually performed together with a hysterectomy - the removal of the uterus. Its use in a hysterectomy when there are no other health problems is somewhat controversial.
In animals, spaying involves an invasive removal of the ovaries, but rarely has major complications; the superstition that it causes weight gain is not based on fact. Spaying is especially important for certain animals that require the ovum to be released at a certain interval (called estrus or "heat"), such as cats and dogs. If the cell is not released during these animal's heat, it can cause severe medical problems that can be averted by spaying or partnering the animal with a male.
Oophorectomy is sometimes referred to as castration, but that term is most often used to mean the removal of a male animal's testicles.
Anesthesia awareness, or "intra-operative awareness" occurs during general anesthesia, when a patient is paralyzed with muscle relaxants but not enough general anesthetic or analgesic to prevent consciousness or, more importantly, recall of events.
The experience is often extremely traumatizing for the patient who is unable to communicate his or her distress due to the muscle relaxants.
Most current cases are attributed to human error. The others are thought to be due to either a predisposed tolerance or a tolerance induced by the interaction of other drugs. Inability to reliably measure consciousness with current technology is another important factor. The causal human errors include inadequate drug dose, inadequate monitoring, and failure to refill the anesthetic machine’s vaporisers with volatile anesthetic.
The prevalence of anesthesia awareness ranges from 0.1% to 0.2 %, or up to 4000 cases per year. The effects usually extend further than the event itself. Many victims experience posttraumatic stress disorder (PTSD), leading to long-lasting after-effects such as nightmares, flashbacks, and insomnia. It is also highly comorbid with alcoholism.
As with all forms of medical error, incidents of awareness are under-reported. Inadequate education about the full impact of awareness leads to an inadequate response by anesthesiologists and delayed treatment for victims. In many cases, doctors have ignored the post-operative complaints and have not referred patients for appropriate counselling.
As an additional preventative measure, some hospitals use a new device called a bispectral index monitor (BIS). BIS monitors the electrical pattern of brain activity which is called the electroencephalogram (EEG). At least one study has shown that the use of BIS by anesthesiologists reduces the incidence of awareness.
Lancet 2004;363:1747,1757-1763. http://www.thelancet.com/journal/vol363/iss9423/full/llan.363.9423.original_rese
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