PubMed Health⌕ Search

Biomedical subjects

P Newfield

Publications and source records attributed to P Newfield.

At least 19 recordsLinked to original sources
PubMed2001

Pediatric neuroanesthesia. Hydrocephalus.

Hydrocephalus, one of the most common adult and pediatric neurosurgical disorders, is an abnormal accumulation of cerebrospinal fluid in the ventricular system as a result of obstruction to the flow of cerebrospinal fluid. Causes of hydrocephalus include congenital obstruction, hemorrhage, infection, cysts and tumors, and associated neural tube deformities (i.e., myelomeningocele, Arnold-Chiari malformation). Treatment of hydrocephalus involves surgical implantation of shunt systems to drain the cerebrospinal fluid. Anesthetic considerations involve attention to the possibility of increased intracranial pressure and prevention of aspiration through rapid-sequence intravenous induction and modest hyperventilation until the ventricles have been decompressed.

Anesthesia↗
PubMed2001

Pediatric neuroanesthesia. Neural tube defects.

Neural tube defects of the brain and spinal cord, among the most common birth defects in the United States, cause neurologic morbidity from the lesions themselves and from associated hydrocephalus and Arnold-Chiari malformation. Because the myelomeningoceles, and encephaloceles are repaired surgically within hours of birth, neonatal anesthetic management with attention to fluids, body temperature, intravenous access, and monitoring is important. Anesthesia for treatment of hydrocephalus and Arnold-Chiari malformation takes into consideration the presence of intracranial hypertension and the need for manipulation of vital structures in the posterior fossa.

Anesthesia↗
PubMed2001

Pediatric neuroanesthesia. Arteriovenous malformations.

Intracranial arteriovenous malformations can occur singly, multiply, and in conjunction with aneurysms and denovo, family, or in conjunction with connective-tissue disorders. Intracranial hemorrhage is the most common presentation, occurring in 20% to 50% of cases. In children, seizures are the second most common presentation occurring in 15% to 20% of cases. The modalities available treatment of arteriovenous malformations are microsurgery, embolization, and stereotactic radiosurgery with heavy particles, alpha knife, or linear accelerator. Induction, maintenance, and emergence from anesthesia are designed to prevent rupture of arteriovenous malformation and aneurysm and to improve intracranial compliance in the presence of an intracranial hematoma, during both diagnostic (CT, MR scanning) and therapeutic procedures.

Anesthesia↗
PubMed2001

Pediatric eye emergencies.

Anesthesia for pediatric eye emergencies is predicted on prevention of a rise in intraocular pressure and avoidance of extrusion of the intraocular contents in the setting of a full stomach. Sedation or general anesthesia is frequently necessary for adequate examination of the eye.

Child↗
PubMed1992

The effect of the extended (3-year) anesthesia curriculum on anesthesia subspecialty education.

The purpose of this study was to determine the effect of lengthening the anesthesia residency by the American Board of Anesthesiology on the education of anesthesia subspecialists. A survey of anesthesia residency programs was conducted from 1987 to 1991. The most frequent subspecialty practice in the clinical anesthesia (CA) 3 year is cardiovascular anesthesia. However, the percentage of CA3 residents spending extended time (greater than or equal to 6 months) in subspecialty education has significantly decreased. For example, the percentage of CA3 residents spending 12 months in subspecialty education has decreased 83%. There appears to be a slight increase in the number of CA4 or PGY5 residents (fellows) electing subspecialty practice. It is concluded that the 3-year curriculum has produced a negative impact on the education of anesthesia subspecialists.

Anesthesiology↗
PubMed1985

Reduced anesthetic requirement after electrical stimulation of periaqueductal gray matter.

To determine whether electrical stimulation of the periaqueductal gray region decreases anesthetic requirement, the authors studied the effect of such stimulation on the MAC of halothane and 60% nitrous oxide in 33 patients. These patients, who were undergoing implantation of a radio-frequency-coupled receiver and connection of that receiver to electrodes previously implanted in the periaqueductal gray area, were assigned randomly to receive (n = 16) or not receive (n = 17) electrical stimulation 1 h before surgery. The mean value (+/- SEM) for the minimum alveolar concentration of halothane combined with 60% nitrous oxide was significantly less (P less than 0.001) for patients who were stimulated preoperatively (0.15 +/- 0.05%) than for those who were not (0.51 +/- 0.02%). The authors conclude that stimulation of the periaqueductal gray region decreases anesthetic requirements and believe that at least three mechanisms are possible: a nonspecific narcotic-like effect, a specific effect on a pain pathway, or an effect on specific neural pathways that affect anesthetic requirements secondary to changes in regional concentrations of neurotransmitters.

Anesthesia, Inhalation↗
PubMed1982

Decreasing enflurane concentrations and d-tubocurarine neuromuscular blockade.

To study the effect of decreasing the concentration of enflurane on a combined enflurane-d-tubocurarine (dTC) neuromuscular blockade, six ASA class I or II patients were studied using a continuous infusion of dTC and a sequence of decreasing end-tidal concentrations of enflurane. A constant infusion of dTC and a 2.2 per cent end-tidal concentration of enflurane decreased twitch tension to 8 per cent of control. Maintaining this same infusion rate of dTC, but decreasing the end-tidal concentration of enflurane to 1.35 and 0.5 per cent, increased the twitch tension to 57 and 91 per cent of control, respectively. The authors conclude that the enflurane contribution to muscle relaxation dissipates in a dose-dependent manner as the end-tidal concentration of enflurane is reduced. This factor may provide additional safety for patients because the anesthetic produces a component of relaxation that is readily reversible with time without the use of acetylcholinesterase inhibitors.

Adult↗
PubMed1982

Neurosurgery in a different society: the People's Republic of China.

An interdisciplinary clinical neurosciences delegation representing the International Committee of the Congress of Neurological Surgeons visited the neurosurgical departments of major teaching hospitals in five cities of the People's Republic of China. This report describes the clinical and research activities observed, with reference to the unique social, political, economic, and cultural environment in China. Although facilities and equipment are limited, diagnostic accuracy and surgical technique are excellent. Results for certain disorders seemed comparable to those obtained in western neurosurgical centers. Given the clinical expertise of our Chinese colleagues and the large numbers of cases treated in Chinese medical centers, a significant contribution to neurosurgical knowledge can be expected from the exchange of information and future collaboration that have now become possible.

Acupuncture Therapy↗
PubMed1981

Influence of serum protein, serum albumin concentrations and dose on midazolam anaesthesia induction times.

Individual variation occurs in time to induction of anaesthesia with intravenous drugs. Less free drug is available to cross the blood-brain barrier when the drug is highly protein bound. Since this may prolong time to sleep, we correlated the induction time, serum albumin and total protein concentrations, and doses of midazolam, which is a highly protein bound intravenous anaesthetic. There is a poor correlation (r = 0.062) between induction time and serum protein, a weak (r = 0.542) but statistically significant (p = 0.026) correlation between induction time and serum albumin, and a highly significant (p = 0.003) negative correlation (r = 0.579) between drug dose and induction time. The administration of the appropriate dose of midazolam for induction, therefore, appears to affect induction time more significantly than does the serum albumin concentration.

Anesthesia, Intravenous↗
PubMed1978

Clinical evaluation of intravenous nitroglycerin for neurosurgery.

Moment-to-moment control of blood pressure is important in the management of the neurosurgical patient. The ideal agent to control blood pressure or induce hypotension should be non-toxic, maintain cerebrovascular autoregulation, and not alter cardiac output or change intracranial pressure. Intravenous nitroglycerin has been used to control blood pressure in 54 neurosurgical cases. This agent produces a rapid, controllable, but not precipitous fall in blood pressure without rebound, is non-toxic, may not alter cerebrovascular autoregulation, and does not raise intracranial pressure. Our clinical experience with intravenous nitroglycerin indicates that it has an important role as a hypotensive agent for the neurosurgical patient.

Blood Pressure↗
PubMed1977

Air embolism.

Explore the source record for details and available documents.

Embolism, Air↗