Measurement of extradural pressure and its relationship to other intracranial pressures: An experimental and clinical study

Abstract

SUMMARY Disadvantages associated with the use of ventricular catheters for the prolonged measurement of intracranial pressure have resulted in the search for an alternative technique. Measurement of pressure from the extradural space is one such possibility, but widespread acceptance of this procedure has been limited by the technical difficulties associated with this measurement and lack of information on the relationship between cerebrospinal fluid and extradural pressures. A study to investigate this relationship and to develop a simple and effective technique for measuring extradural pressure is described.In certain patients with head injuries and intracranial space-occupying lesions, acute rises in intracranial pressure producing brain shift or impairment of the cerebral circulation-with subsequent secondary brain damage-may occur before changes in vital signs are recognized. Furthermore, the reduction of intracranial pressure by means of one of the several methods currently available is too often unpredictable. For these reasons patient management may be greatly assisted, and more readily programmed, if intracranial pressure is directly monitored (Lundberg, Troupp, and Lorin, 1965;Johnston, Johnston, and Jennett, 1970 The aims of this study were: (1) to explore the relationship between extradural pressure, supratentorial subarachnoid pressure and ventricular pressure; (2) to assess the use of latex balloons as pressure-sensing devices in the extradural and subarachnoid spaces; (3) to evaluate a metal capsule, to be described, for clinical use in measuring extradural pressure over prolonged periods with minimal discomfort to the patient. METHODSANIMAL STUDIES The experiments were carried out on 12 dogs, but two baboons were also studied because the dura mater in these primates is more like that in man, being only loosely attached to the skull. The dogs were intubated after induction with thiopentone sodium, and anaesthesia maintained with nitrous oxide, oxygen, and halothane. Artificial ventilation to normocarbia and normoxia was achieved with the aid of muscle relaxants. Body temperature was maintained at 370 C. The baboons were premedicated with phencyclidine 0 5-1 mg/kg 514

Fiber optic intensity-modulated sensors: a review in biomechanics

“…However, while a significant correlation between the anterior fontanel pressure and ICP was reported, the same was not observed by others [59]. It seems the extradurally technique has the disadvantage of signal damping and a tendency to read higher than the true ICP [60].…”

Messtechnik Systematik und Methoden der intrakraniellen Druckmessung

“…Sie fanden eine systematische Erhöhung des epiduralen Drucks gegenüber dem intraventrikulären von 6-7 mmHg [10]. Sie fanden eine systematische Erhöhung des epiduralen Drucks gegenüber dem intraventrikulären von 6-7 mmHg [10].…”

Some principles of postoperative epidural pressure monitoring

“…For example, the condition of head injury patients may remain poor in the absence of intracranial hypertension when brain stem or diffuse brain injury is present ~, 3-~; patients with slowly growing tumours may develop a very high ICP with few clinical 0001-6268/81/0055/0227/$ 03.80 signs, and in comatose patients complications may be difficult to recognize. For these reasons, ICP monitoring has been increasingly employed in neurosurgical practice ~2 since the development by Guillaume and Janny in 1951 of a technique for continuous monitoring of ventricular fluid pressure (VFP), 6 and its more extensive application by Lundberg 26 These authors realized that sporadic measurements may be unreliable. Continuous ICP monitoring now has a place as an additional parameter in patient assessment for diagnostic, therapeutic and prognostic purposes.…”