PubMed Health⌕ Search

Biomedical subjects

D Blackstock

Publications and source records attributed to D Blackstock.

12 recordsLinked to original sources
PubMed2001

An inventory of Canadian anesthesiology. Human research from 1995 through 1999.

PURPOSE: The year 2000 provides a symbolic opportunity to assess the past initiatives in anesthesia research. As in many other fields, medical research has benefited from utilizing computerized data bases to facilitate enumerating areas of interest. We have created a baseline survey of past research in the fields of anesthesia, anesthetics, analgesia, and analgesics to highlight Canadian studies. METHODS: The survey was undertaken using the Medical Literature Analysis and Retrieval System (MEDLARS) medical literature archive for the years 1995 through 1999. The principal categories and sub-categories of MEDLARS' anesthesia classifications were counted for 70 countries contributing to the archive. RESULTS: Canadian contributions ranged from 141 (1992) to 185 (1999) and represented annually 3% of the world total in the anesthesia categories. The greatest number of studies (30-38%) were about adults aged 19 to 44 yr, and there were between 4% and 14% more studies of females than males. "Pharmacology" and "therapeutic use" were the most frequent topics, lidocaine, fentanyl, and propofol were the most studied anesthetics, and non-steroidal anti-inflammatories, opium, morphine, and fentanyl were the most studied analgesics. Among the types of studies, those classified as "quality of health care" occurred most frequently (16%). Canadian trends closely follow world trends. CONCLUSION: The collected counts provide a comprehensive overview of research trends for the past five years.

Adult↗
PubMed2000

Effects of propofol on cerebral oxygenation during cardiopulmonary bypass in children.

PURPOSE: Neurologic complications occur following cardiopulmonary bypass surgery. We conducted a randomized, controlled, single-blind study to determine the effect of propofol on the redox status of cytaa3, and to evaluate its potential for decreasing neurologic complications. METHODS AND MATERIALS: Twenty-four children (median age: 3.3 yr; median weight: 14.4 kg) scheduled for elective cardiopulmonary bypass surgery were assigned to either the experimental group (Group P, given sufficient propofol to eliminate brain electrical activity as measured on EEG (i.e. burst suppression)) or the control group (Group C, no propofol). Near infrared spectroscopy data were collected at one-second intervals throughout the surgical procedures. Pre- and postoperative neurologic examinations were completed by a physician blinded to the group to which the patient was assigned. Change in cytochrome aa3 data at 10-min intervals (10, 20, 30, 40 min) following start of bypass were compared between groups by repeated measures analysis of variance. RESULTS: The patterns of change in redox state of cytochrome were different between the two groups (P < 0.002). The pattern of change within Group P was similar to that in hypothermic patients in Group C. There were correlations between change in cytaa3 redox status and temperature in the control subjects. There were no gross neurologic complications in either group. CONCLUSIONS: Propofol appears to stabilize the energy supply/demand equilibrium of the brain during cardiopulmonary bypass surgery and thus theoretically could reduce the incidence or severity of neurologic complications.

Anesthetics, Intravenous↗
PubMed1999

Canadian anesthesia physician resources: 1996 and beyond.

PURPOSE: To report physician resource information from the 1996 national anesthesia physician and residency programme surveys in Canada. The findings are used to discuss the potential effects on availability of future specialist anesthesia services in Canada. METHODS: Twenty-six hundred and ninety-three physicians (2,206 specialists, 487 family physicians) providing anesthesia services were surveyed. Information on demographics and patterns of clinical practice were sought. Anesthesia programme directors provided trainee information. Projections of the potential number of practicing anesthesiologists to 2026 were made based on the number of available training positions and age distribution of anesthesiologists. RESULTS: There was a 58.3% response rate to the national survey. Since 1986 there has been a 10% increase in the number of specialist anesthesiologists. Marked regional variations in age distribution and changes in the number of specialist anesthesiologists were noted. Most specialists remain in the region or province of postgraduate training. Sixty percent of specialists were either re-entry trainees or international medical graduates. Changes in anesthesia practice patterns have resulted in 40% of the anesthesiologist's work now occurring outside of the operating room. Anesthesia training positions have decreased by at least 15%. The population of Canada is projected to increase by 33.8% between 1996 and 2026. If current government and position allocation policies continue, it is projected there will be 0% increase in the number of specialist anesthesiologists over the same time period. CONCLUSIONS: Changes in anesthesia practices have exacerbated the current shortages of anesthesiologists. These shortages will worsen if the number of, and restrictions to, available residency positions is unchanged.

Anesthesiology↗
PubMed1995

Intraoperative hyperthermia in a paediatric patient with cystinosis.

Cystinosis is a rare autosomal recessive inherited disorder of amino acid metabolism. Little is known of the affects of general anaesthesia on the disease (Tobias 1993) and complications relating to anaesthesia have not been previously reported. Infantile cystinosis presents as progressive renal failure and the Fanconi syndrome and metabolic bone disease often develop. We describe the case of a child who presented with signs of apparent malignant hyperthermia (MH) under general anaesthesia and was treated with dantrolene. During a repeat 'trigger-free' general anaesthetic he developed a fever which responded to paracetamol. The metabolic effects of cystinosis and its similarity to MH will be discussed.

Anesthesia, General↗
PubMed1993

Propofol anaesthesia reduces early postoperative emesis after paediatric strabismus surgery.

Propofol anaesthesia may reduce postoperative emesis. The purpose of this study was to compare the incidence of emesis after propofol anaesthesia with and without nitrous oxide, compared with thiopentone and halothane anaesthesia, in hospital and up to 24 hr postoperatively, in outpatient paediatric patients after strabismus surgery. Seventy-five ASA class I or II, unpremedicated patients, aged 2-12 yr were randomly assigned to one of three groups: Thiopentone, 6.0 mg.kg-1 i.v. induction followed by halothane and N2O/O2 for maintenance (T/H); propofol for induction, followed by propofol and oxygen for maintenance (P/O2); and propofol for i.v. induction, followed by propofol infusion and N2O/O2 for maintenance (P/N2O). All received vecuronium, controlled ventilation, and acetaminophen pr. Morphine was given as needed for postoperative analgesia. There were no differences in age, weight, number of eye muscles operated upon, duration of anaesthesia or surgery. The P/N2O group (255 +/- 80 micrograms.kg-1 x min-1) received less propofol than the P/O2 group (344 +/- 60 micrograms.kg-1 x min-1) (P < or = 0.0001) and had shorter extubation (P < 0.001) and recovery (P < 0.01) times. Emesis in the hospital, in both the P/N2O (4.0%) and P/O2 group (4.0%) was less than in the T/H group (32%) (P < 0.01). Antiemetics were required in four patients in the T/H group (16.0%). Overall emesis after surgery was not different among the groups: T/H (48%), P/O2 (28%) and P/N2O (42%). The use of propofol anaesthesia with and without N2O decreased only early emesis. This supports the concept of a short-acting, specific antiemetic effect of propofol.

Ambulatory Surgical Procedures↗
PubMed1991

Tracheal extubation in children: halothane versus isoflurane, anesthetized versus awake.

The authors compared the incidence of respiratory complications and arterial hemoglobin desaturation during emergence from anesthesia in children whose tracheas were extubated while they were anesthetized or after they were awake and to whom halothane or isoflurane had been administered. One hundred children 1-4 yr of age undergoing minor urologic surgery were studied. After a standard induction technique, patients were randomized to receive either isoflurane or halothane. In 50 patients tracheal extubation was performed while they were breathing 2 MAC of either halothane or isoflurane in 100% oxygen. The remaining 50 patients received 2 MAC (volatile agent plus nitrous oxide) during the operation, but tracheal extubation was delayed until they were awake. A blinded observer recorded the incidence of respiratory complications and continuously measured hemoglobin saturation for 15 min after extubation. When tracheal extubation occurred in deeply anesthetized patients, no differences were found between the two volatile agents. When tracheal extubation of awake patients was performed, the use of isoflurane was associated with more episodes of coughing and airway obstruction than was halothane (P less than 0.05). Awake tracheal extubation following either agent was associated with significantly more episodes of hemoglobin desaturation than was tracheal extubation while anesthetized.

Anesthesia Recovery Period↗
PubMed1989

Analysis of an anaesthetic gas scavenging system hazard.

The collapse of the reservoir bag in a circle circuit was observed during anaesthesia. This resulted from the incomplete closure of the pressure relief valve on the absorber whie it was connected to the scavenging system. Although the scavenging system was operating and installed according to the manufacturer's recommendations and to the CSA standard on Anaesthetic Gas Scavenging Systems (Z168.8), the patient was not protected from this hazard. Introducing an air break into the scavenging interface device will protect the patient. However, such a system would not meet the CSA standard and would make the relief valves on the scavenging interface device unnecessary.

Air Pollution↗
PubMed1988

Anaesthetic implications of the trismus pseudocamptodactyly (Dutch-Kentucky or Hecht Beals) syndrome.

The trismus pseudocamptodactyly syndrome is a relatively rare, autosomal dominant condition first described in 1969. Affected patients classically present with two main features: limited excursion of the mandible and flexion deformity of the fingers that occurs with wrist extension (pseudocamptodactyly). Foot deformities and a shorter-than-normal stature may also be present. The underlying abnormality is short muscle tendon units, which prevent normal growth and development. We reviewed the anaesthetic experience in three paediatric patients with the trismus pseudocamptodactyly syndrome and the pertinent clinical findings in three other members of the same family, spanning three generations. Limited mandible excursion was present in all six cases, but was not obvious preoperatively in the patients because of its subtle presentation. All three cases were successfully managed using mask anaesthesia with spontaneous ventilation, avoiding muscle relaxants. Attempts to visualize the larynx under anaesthesia were unsuccessful in two cases. Blind nasotracheal intubation was successful in one patient. Postoperatively, there were no problems with the airway.

Adult↗
PubMed1986

Negative pressure in the middle ear in children after nitrous oxide anaesthesia.

A study was conducted to measure the pressure in the middle ear in healthy children, following nitrous oxide anaesthesia. Premedication with chloral hydrate and scopolamine orally was similar in all patients and awake patients received thiopentone 4-5 mg X kg-1 for induction of anaesthesia. All received nitrous oxide (66 per cent) in oxygen and halothane or isoflurane as required. Exposure to nitrous oxide varied from 17-100 minutes, mean 47 minutes. All patients developed negative pressure in one or both ears in the first day following anaesthesia. This is a higher incidence than previously reported and may be explained by the inability of children to equilibrate negative middle ear pressure via the eustachian tube.

Acoustic Impedance Tests↗