Intrathoracic positive pressure may lead to a change hemodynamics, with repercussions for the intracranial compartment, thereby altering intracranial pressure (ICP) and cerebral perfusion pressure (CPP). This effect may become more intense when using high positive end expiratory pressure (PEEP) values. The aim of the present study was to measure the impact of different PEEP values on ICP, CPP and mean arterial pressure (MAP). MAP, whereas high PEEP values increase ICP, although without clinical relevance.
This study is a prospective clinical trial, developed in the neurological intensive care unit approved by the ethics committee and research in humans. The charge of each patient had information about the study through the completion of informed consent and signed him when he agreed. Were the following inclusion criteria: adult patients with acute CVA and presence of ventricular drainage catheter for invasive monitoring of ICP and without intracranial hypertension. Were adopted as exclusion criteria: increased intracranial pressure, hemodynamic instability as a criterion of loss was used to expressions of interest in charge to leave. All patients completed the study. All patients were from the surgical implantation of the ventricular catheter, arriving to the ICU intubated orally and manually ventilated with an Ambu bag. Were subjected to routine procedures: adjusting the mechanical ventilator (Inter5, Intermed, BR) during assisted controlled cycled pressure and facility to monitor vital signs. After thirty minutes of stable ICU patient in a supine position with head elevated 30 °, the protocol was initiated to assess the impact of PEEP on ICP. To perform the evaluation of lung mechanics ventilatory mode was changed to control volume with the following parameters: tidal volume (Vt) = 8ml/kg weight, peak flow (PF) = 6 x minute volume, fraction of inspired O2 (FiO2) = 40%, respiratory rate (RR) = 16 bpm, sensitivity = 1 cmH2O. The following variables were monitored: PIC, Blood Pressure (BP), heart rate (HR), peak pressure in the airways (pp.) and plateau pressure of the respiratory system (Ppl.), these values were monitored with PEEP = 5 cmH2O. During the assessment protocol was changed to pressure control ventilation mode with the following values of ventilatory parameters: Pp = 30 cm H2O, inspiratory time = 1s; FiO2 = 40%, RR = 16 bpm; Sensitivity = 1 cmH2O. PEEP employed ranged from 0 to 14 cmH2O. To eliminate a possible physiological accommodation by the progressive increase of PEEP, the range of values was determined by drawing a sealed envelope for each patient, ranging from 2 to 2 cmH2O. At each value of PEEP the patient was ventilated for a period of five minutes to carry out monitoring of ICP, BP, HR, PPC and peripheral oxygen saturation (SpO2). The ICP monitoring catheter was kept closed for drainage and open for monitoring, since the arrival of the surgical block, was only open for drainage if there was an increase in ICP above 20 mmHg. The monitoring was carried out using the multiparameter monitor (Siemens 7000). For ICP monitoring the ventricular catheter was connected to a pressure transducer and this monitor. After the parameters evaluated with seven different PEEP values, the ventilatory mode was changed again to control volume again to evaluate pulmonary mechanics with the same initial parameters.
Allocation: Randomized, Control: Active Control, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
Stroke
lung mechanics ventilatory, Hemodynamic and intracranial pressure
Hospital Português
Recife
Pernambuco
Brazil
Completed
Universidade Federal de Pernambuco
Published on BioPortfolio: 2014-07-24T14:05:59-0400
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Lung Compliance
The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)
Mechanics
The branch of physics which deals with the motions of material bodies, including kinematics, dynamics, and statics. When the laws of mechanics are applied to living structures, as to the locomotor system, it is referred to as BIOMECHANICS. (From Dorland, 28th ed)
Stroke
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
Intracranial Arteriovenous Malformations
Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.
Cerebrospinal Fluid Pressure
Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.