A zoom lens contains a mechanism that changes the magnification of an image. On a still camera, this means that the photographer can get a 'close up' shot while still being some distance from the subject. A video zoom lens can change the position of the audience, either very quickly (a smash zoom) or slowly, without moving the camera an inch, thus saving a lot of time and trouble. The drawbacks to zoom use include the fact that while a dolly shot involves a steady movement similar to the focusing change in the human eye, the zoom lens tends to be jerky (unless used very slowly) and to distort an image, making objects appear closer together than they really are. Zoom lenses are also drastically over-used by many directors (including those holding palmcorders), who try to give the impression of movement and excitement in a scene where it does not exist. Use with caution - and a tripod!
Some users report having mind-expanding, mystical experiences while they’re under the influence of LSD. However, because it’s impossible to control the type of experiences you’ll have, the length of your experience or your reactions to the drug – you cannot predict if you are likely to have terrifying hallucinations or pleasant ones. Even worse, these episodes may continue after you’ve stopped using LSD, interfering with your social and professional life and putting you at risk of anxiety, depression and suicide.
Lithium has a high volume of distribution, a long plasma elimination half-life, and – though the drug is cleared primarily by the kidneys – minimal renal clearance. This unfavorable pharmacokinetic profile makes it difficult to treat lithium poisoning.
Lithium poisoning is treated on a primarily symptomatic basis. Gastric lavage or induced emesis are only helpful in the event of acute overdose (. from a suicide attempt) and if performed within one hour of drug ingestion. Most often lithium has already been absorbed and it is necessary to enhance the excretion of lithium from the body. This can be accomplished using several methods, including saline infusion, fluid therapy while ensuring that kidney function is maintained, and – in the event of severe intoxication – hemodialysis.
The goal of symptomatic treatment is to maintain adequate respiration, stop any cramping which may occur, treat arrhythmias, and restore fluid and electrolyte balance. Cardiovascular-stimulating drugs have to be used in patients exhibiting signs of shock. Changes in thyroid function and the hematopoietic system must be monitored and, if necessary, treated.
In mild cases of lithium intoxication with sodium loss, clearance of lithium can be increased by administering sodium chloride. Severe cases, however, require one or more hemodialysis sessions. The interval between two sessions can be bridged using hemofiltration.
The best form of treatment is determined by the overall clinical picture, serum lithium concentration, and the state of renal function. Comatose patients should undergo immediate hemodialysis. Depending on their general condition, patients with neurological symptoms, but without disturbance of consciousness, should be kept in intensive care and treated symptomatically. If, however, a patient’s serum lithium level is above 3 mmol/l, or if it is above 2 mmol/l and his or her general condition is poor, then he or she should undergo hemodialysis.