Controlled Hypotension in Neuroanaesthesia

This book is based on the proceedings of a conference held in Tubingen, West Germany, in 1981, at which anesthesiologists, neuro­ surgeons, pathologists and neurophysiologists met to consider the place of controlled hypotension in neurosurgery. In the first part of the book alternative methods of inducing hypotension are considered, and it is important to emphasize that the techniques which are suitable for neurosurgery may not be so for other types of surgery, and vice versa. In neurosurgery, and par­ ticularly in aneurysm surgery, the emphasis is on lowering intra­ luminal pressure and not mainly on reducing blood flow or limiting tissue oozing. Another special consideration in neurosurgery is the influence of drugs used to induce hypotension on intracranial pressure, with nitroprusside (NTP), and especially nitroglycerine, increasing ICP in the closed skull and increasing brain "bulk" when the skull is open. These and other points are extensively covered. The use of a non-essential technique like controlled hypotension demands that the procedure should carry minimal risk to the patient. Contributions in part IV consider the neuropathology associated with too severe a lowering of oxygen supply through hypotension. In the clinical avoidance of such ischemic changes in individual patients, monitoring of the brain electrical function is much the most import­ ant and practical approach and is discussed in part III. The Editors hope that the publication of these contributions to the Tubingen Symposium will help in the effective and safe appli­ cation of the technique of controlled hypotension in neurosurgery.

Table of Contents:
I Pharmacological and Toxicological Aspects of Drugs Used for Induction of Hypotension.- Pharmacology of Drugs Used in Elective Hypotension for Neurosurgery.- Specific Vascular Mechanisms of Hypotensive Acting Drugs.- Rebound Arterial Hypertension Following Discontinuation of Sodium Nitroprusside: Aetiology and Prevention.- Is There Still Any Indication for Application of Volatile Anesthetics During Induction of Hypotension in Neurosurgery?.- Interactions of Anesthetic Drugs and Muscle Relaxants with Those Drugs Commonly Used for Controlled Hypotension.- II Cerebral Blood Flow and Metabolism Under Conditions of Systemic Hypotension.- Direct and Indirect Cerebral Effects of Deliberate Hypotension.- Autoregulation of Cerebral Blood Flow: Effects of Hypotensive Drugs.- The Deleterious Effect of Excessive Tissue Lactic Acidosis in Brain Ischemia.- Interaction Between Blood Glucose Level, Degree of Cerebral Tissue Acidosis and Cellular K+ Release Under Critical Cortical Flow Conditions.- Controlled Hypotension in Neuroanesthesia.- Membrane Stabilization in the Ischemic Brain: A Mode of Protection?.- Blood Flow and Oxidative Metabolism of the Young Adult and Aging Brain.- III Cerebral Electrical Activity During Systemic Hypotension in Neuroanesthesia.- Electrical Monitoring of the Brain in Induced Hypotension — An Introduction to the Session.- Critical Comparison of Monitoring EEG, Cerebral Function (CFM), Compressed Spectral Array (CSA) and Evoked Response Under Conditions of Reduced Cerebral Perfusion.- The Use of Somatosensory Evoked Potentials in Neurosurgical Practice.- Recent Aspects of Hypotensive Drug Effects on Intracranial Pressure.- IV Morphological Aspects of Controlled Hypotension.- The Neuropathology of Stagnant Hypoxia.- Structural Changes in the Brain DuringCritical Reduction of Blood Flow or Oxygen Tension.- The Significance of Low O2 Tensions in the Brain Cortex for Occurrence of Metabolic Alterations Under Critical Flow Conditions.- V Clinical Aspects of Controlled Hypotension.- Variations of the Instantaneous Heart Rate During Neuroleptanesthesia with Concomitant Continuous Infusions of Althesin and Sodium Nitroprusside.- Limitations of Induced Hypotension.- Pro and Contra Hypotension in Neurosurgery.- Chairman’s Summary.- List of Principal Contributors.