Biomaterial Database

Effects of positive end-expiratory pressure on intracranial pressure and compliance in brain-injured patients. 1977

E A Frost

Hypoxic pulmonary disorders and head injuries associated with increased intracranial pressure (ICP) frequently co-exist. Positive end-expiratory pressure (PEEP) improves hypoxemia but has been reported to impede cerebral venous return, potentially causing a further increase in ICP. This study examined the effects of PEEP on ICP at different levels of brain compliance. continuous ICP recordings were obtained after insertion of Scott cannulas to the lateral ventricles of seven comatose patients. Brain compliance was assessed by calculation of the pressure volume index. Patients were maintained in a 30 degrees head-up position. Maintenance of PEEP to levels of 40 cm H2O pressure for as long as 18 hours did not increase ICP in patients with either normal or low intracranial compliance, and did not increase ICP in the absence of pulmonary disease. Central venous pressure and pulmonary artery wedge pressure increased proportionately as PEEP was increased. No consistent changes were found in blood pressure recordings, nor were there any reductions in cardiac output found during the studies. Abrupt discontinuation of PEEP did not result in increased ICP except for a transient rise on two occasions when respiratory secretions became copious and the patients were inadequately ventilated. Improved oxygenation in two patients as a result of PEEP was concomitant with improved intracranial compliance and neurological status. In patients with brain injuries, PEEP improves arterial oxygenation without increasing ICP as previously supposed. Consequently, PEEP is a valuable form of therapy for the comatose patient with pulmonary disorders such as pneumonia or pulmonary edema.

UI	MeSH Term	Description	Entries
D007427	Intracranial Pressure	Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity.	Intracerebral Pressure,Subarachnoid Pressure,Intracerebral Pressures,Intracranial Pressures,Pressure, Intracerebral,Pressure, Intracranial,Pressure, Subarachnoid,Pressures, Intracerebral,Pressures, Intracranial,Pressures, Subarachnoid,Subarachnoid Pressures
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011175	Positive-Pressure Respiration	A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.	Positive End-Expiratory Pressure,Positive-Pressure Ventilation,End-Expiratory Pressure, Positive,End-Expiratory Pressures, Positive,Positive End Expiratory Pressure,Positive End-Expiratory Pressures,Positive Pressure Respiration,Positive Pressure Ventilation,Positive-Pressure Respirations,Positive-Pressure Ventilations,Pressure, Positive End-Expiratory,Pressures, Positive End-Expiratory,Respiration, Positive-Pressure,Respirations, Positive-Pressure,Ventilation, Positive-Pressure,Ventilations, Positive-Pressure
D011651	Pulmonary Artery	The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.	Arteries, Pulmonary,Artery, Pulmonary,Pulmonary Arteries
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D001930	Brain Injuries	Acute and chronic (see also BRAIN INJURIES, CHRONIC) injuries to the brain, including the cerebral hemispheres, CEREBELLUM, and BRAIN STEM. Clinical manifestations depend on the nature of injury. Diffuse trauma to the brain is frequently associated with DIFFUSE AXONAL INJURY or COMA, POST-TRAUMATIC. Localized injuries may be associated with NEUROBEHAVIORAL MANIFESTATIONS; HEMIPARESIS, or other focal neurologic deficits.	Brain Lacerations,Acute Brain Injuries,Brain Injuries, Acute,Brain Injuries, Focal,Focal Brain Injuries,Injuries, Acute Brain,Injuries, Brain,Acute Brain Injury,Brain Injury,Brain Injury, Acute,Brain Injury, Focal,Brain Laceration,Focal Brain Injury,Injuries, Focal Brain,Injury, Acute Brain,Injury, Brain,Injury, Focal Brain,Laceration, Brain,Lacerations, Brain
D002496	Central Venous Pressure	The blood pressure in the central large VEINS of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.	Venous Pressure, Central,Central Venous Pressures,Pressure, Central Venous,Pressures, Central Venous,Venous Pressures, Central
D003128	Coma	A profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. Coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem RETICULAR FORMATION.	Comatose,Pseudocoma,Comas,Pseudocomas
D003187	Compliance	Distensibility measure of a chamber such as the lungs (LUNG COMPLIANCE) or bladder. Compliance is expressed as a change in volume per unit change in pressure.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man