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(klēr) 1. In cardiopulmonary resuscitation, a warning to nearby staff that a patient is about to receive an electrical shock (during cardioversion or defibrillation) and should not be in contact with another person, so that no one involved in the resuscitation will inadvertently be injured by the shock.

PATIENT CARE: The protection of rescuers in a resuscitation is usually ensured by the person in charge of the code. He or she should methodically examine the safe position of all participants in the event and chant (while verifying that no one is in contact with the patient): "I'm clear. You're clear. We are all clear." Only after this should a shock be administered.

2. To remove (something) from the body or from a body compartment or body fluid. 3. In pathology, free of cancer or disease. clearing, n.


(klēr′ăns) 1. In medicine, the rate of removal of a substance from the body, e.g. in feces, the urine, sweat, or exhaled gases. SEE: renal clearance test. 2. In emergency medicine, the use of assessment tools, radiologic images, and/or laboratory tests to determine that a patient is not at risk for a suspected illness or injury.

airway c. The mobilization and removal of mucus from the lungs, bronchi, or trachea.

estimated creatinine c. ABBR: CrCl. The rate of the removal of creatinine from the serum by the kidney. SEE: creatinine clearance test.

lactate c. The removal of accumulated lactic acid from the blood in patients with severe sepsis or shock. Rapid lactate clearance is associated with an increased likelihood of survival in critically ill patients.

nonrenal c. Removal of a substance from the body by any means other than in the urine, i.e., by exhalation, sweat, saliva, or stool.

total c. 1. The sum of the clearances from each organ or tissue participating in the elimination of a substance from the body. 2. The volume or mass of tissue cleared of a substance divided by the time it takes to eliminate the substance from the body.


(klē′văj) [cleave] 1. In chemistry, the splitting of a complex molecule into two or more simpler ones. 2. In embryology, the division of a fertilized egg into many smaller cells or blastomeres. SYN: segmentation. SEE: blastomere; embryo.

cleavage arrest

SEE: under arrest.


(klēv) [OE cléofan, to split] In chemistry, to split a complex molecule into two or more simpler ones.


(klē′vĕrz) Galium aparine.


(kleft) 1. A fissure or elongated opening. 2. Divided or split.


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