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Glossary of Children's Hospital Terms


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PICU or Pediatric Intensive Care Unit: An inpatient hospital-nursing unit specifically equipped and staffed to care for critically ill children (full-term newborn to 21 years).

PRN: As needed.
PT or Physical Therapy: Therapy involving movement of the body to keep joints and muscles in shape.
Pacemaker: A small battery usually placed under the skin and joined to the heart by wires which measure the pulse and correct a heart rhythm that is too fast or too slow.
Packed red blood cells: A term referring to the blood product given as a transfusion containing only the red blood cells.
Palliative treatment: To palliate a disease is to treat it or the symptoms providing relief, but not necessarily a cure.  Palliation is sometimes called symptomatic treatment.
Paralysis: Loss of voluntary movement (motor function).
Patent: Open, unobstructed, affording free passage.
Pathogen: An agent of disease. Pathogens include bacteria, viruses, fungi, and protozoa.
Peak-flow meter: This hand-held device measures airflow (how fast air is blown out of the lungs). Patients can use peak-flow meters to measure their own airflow regularly which allows asthmatic patients to predict an oncoming attack. The "peak flow" refers to the maximum flow rate of air breathed out during forced expiration.
Pediatric: Pertaining to children.
Pericardial effusion: Fluid collects in the pericardial sac - the outer covering of the heart. It may place pressure on the heart causing it to pump ineffectively. This fluid can be drawn off by using a needle or by taking diuretics.
Periodic breathing: Clusters of breaths separated by intervals of apnea (no breathing) or near-apnea. Newborns may normally have a mild variation of this.
Peristalsis: The rippling motion of muscles in the digestive tract. In the stomach, this motion mixes food with gastric juices, turning it into a thin liquid.
Peritoneal dialysis: see Dialysis.
Peritonitis: Inflammation of the peritoneum (the tissue layer of cells lining the inner wall of the abdomen and pelvis). Peritonitis can result from infection (such as bacteria or parasites), injury and bleeding, or diseases.
Phototherapy: Treatment with light. For example, a newborn with jaundice may be "put under the lights" to decrease bilirubin in the blood.
Plasma: The liquid part of the blood and lymphatic fluid (which makes up about half of blood volume). Plasma does not clot and contains antibodies and other proteins. It is taken from donors and made into medications for a variety of blood-related conditions.
Platelets: A type of blood cell that is necessary to stop bleeding and allow injured areas to form clots. A normal platelet count is 140,000-300,000. A platelet transfusion may be needed (usually with platelet counts <15,000) or to help stop bleeding.
Pneumonia: An inflammation of one or both lungs. Pneumonia is frequently but not always due to infection. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.
Pneumomediastinum: A collection of air in the central chest cavity.
Pneumothorax: Free air in the chest outside the lung.  It can occur spontaneously (out of the blue, with or without underlying lung disease), following a fractured rib, chest surgery, or be deliberately induced in order to collapse the lung. A small pneumothorax without underlying lung disease may resolve on its own. A larger pneumothorax or one associated with underlying lung disease often requires aspiration of the free air and/or placement of a chest tube to evacuate the air and allow lungs to re-expand.
Prescription: A physician's order for the preparation and administration of a drug or device for a patient.
Pressor: Agents used to cause a rise in blood pressure.


Prognosis: The probable outcome or course of a disease or the chance of recovery.

Progressive: Increasing in scope or severity.  In medicine, a disease that is progressive is going from bad to worse.
Prone: Lying on stomach.
Prophylactic: A preventive measure taken in an attempt to fend off a disease or another unwanted consequence.
Prosthesis: An artificial substitute or replacement of a part of the body such as a tooth, eye, hip, knee, leg, arm, etc. A prosthesis is designed for both functional and/or cosmetic reasons.
Pruritus: Itching. Pruritus can result from drug reaction, food allergy, kidney or liver disease, cancers, parasites, aging or dry skin, contact skin reaction, such as poison ivy, and for unknown reasons.
Pulmonary: Having to do with the lungs.
Pulse: The rhythmic dilation of an artery resulting from beating of the heart. It is often measured by feeling the arteries of the wrist. See attachment of "normal pulse" rates based on age of child.
Pulse Oximeter: A sensor that is placed on the hand or foot to monitor the concentration of oxygen in the patient's blood.
Pus: A thick whitish-yellow fluid which results from the accumulation of white blood cells (WBCs), liquefied tissue and cellular debris. Pus is commonly a site of infection or foreign material in the body.
Pyloric stenosis: Narrowing (stenosis) of the outlet of the stomach so that food cannot pass easily from the stomach into the duodenum (intestine), resulting in feeding problems and projectile vomiting. The obstruction can be corrected by a relatively simple surgical procedure.