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Biomedical subjects

F Chung

Publications and source records attributed to F Chung.

108 records · Page 6Linked to original sources
PubMed1989

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: significance of intraoperative myocardial ischemia and hemodynamic control.

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic, preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1989

Cognitive impairment after neuroleptanalgesia in cataract surgery.

This study was undertaken to evaluate the mental recovery of patients following cataract operations under neuroleptanalgesia. Mental function was assessed by Mini-Mental State (MMS) preoperatively and at 6 and 24 hours postoperatively. Preoperatively, 18.7% of the elderly had cognitive impairment of mental function while none in the younger group had any impairment (P less than 0.02). At six hours postoperatively, 29.7% of the elderly had cognitive impairment compared with 4% of the younger group (P less than 0.01). At 24 hours postoperatively, the percentage of elderly and younger patients with cognitive impairment had returned to preoperative levels. Baseline score and age were found to be significant predictors (P less than 0.004) of the 6-hour score and 24-hour score. In conclusion, cognitive impairment of mental function occurred in patients undergoing cataract operation with retrobulbar block and intravenous sedation at 6 hours postoperatively; MMS has the potential for use as a screening preoperative test for outpatients to identify those at risk for developing cognitive impairment.

Adult↗
PubMed1989

Timing of the anesthetist's preoperative outpatient interview.

Hospitalization arouses anxiety among patients admitted for day bed surgery. The effect of the anesthetist's routine preoperative interview on the anxiety levels of 63 unpremedicated women scheduled for elective outpatient therapeutic abortions was examined using the State-Trait Anxiety Inventory. The anesthetist's preoperative interviews were performed at the following times: Group 1, in the outpatient clinic one week before surgery; group 2, in the day bed unit at the time of admission to hospital; group 3, outside the operating room immediately prior to surgery. State anxiety was measured before and after patients were seen by the anesthetists. In group 1, and in groups 1 and 2, it was readministered outside the operating room immediately before surgery. Baseline anxiety Trait and State scores were not significantly different in the 3 groups (Trait: group 1, 43.3 +/- 2.2; group 2, 36.9 +/- 2.3; group 3, 38.8 +/- 2.2. State: group 1, 50.6 +/- 3.5; group 2, 43.0 +/- 2.4; group 3, 49.0 +/- 3.0). Only in group 3 did the anesthetist's interview significantly reduce patient's anxiety (before visit 49.1 +/- 3.0; after visit 46.0 +/- 2.8; P less than 0.05). A small but statistically significant reduction in State anxiety scores is achieved when patients are seen by the anesthetist immediately prior to surgery.

Abortion, Therapeutic↗
PubMed1988

Cutaneous allergic response in atopic dogs: relationship of cellular and histamine responses.

We studied the cutaneous response to intradermal antigen using clinical, histologic, and physiologic criteria in ragweed-sensitized dogs. The clinical response was measured early (the wheal at 20 minutes) and late (induration at 6 hours). We assessed cutaneous responsiveness to histamine before and 6 hours after injection (intradermally) of ragweed (n = 5, antigen group) and diluent (n = 4, 10% glycerin in 0.9% NaCl, sham group); we measured the wheal in response to histamine (1.0 ng to 0.1 mg, intradermally), constructed a dose-response curve, and interpolated the provocative dose (milligrams) of histamine required to create a wheal 10 mm larger than the response to saline control. Skin biopsy specimens were obtained before and after injection of either ragweed or diluent. Consistent with the human late-phase response, neutrophils and eosinophils were present in the dermis at 1 hour, maximal at 6 hours, and decreased at 24 hours. Mononuclear cells increased significantly at 6 hours and were the predominant cells present at 24 hours after antigen. The late clinical response correlated only with influx of eosinophils (rs = 0.85; p less than 0.005). Histamine responsiveness increased markedly after antigen (p less than 0.0001), did not change after glycerin diluent (sham), and was correlated with the intensity of neutrophil influx at 6 hours (rs = 0.69; p less than 0.05), and to a much greater degree with mononuclear cell influx at 6 hours (rs = 0.85; p less than 0.005).

Animals↗
PubMed1988

Calcium channel blockade does not offer adequate protection from perioperative myocardial ischemia.

This study aimed to detect the difference in hemodynamic and electrocardiographic responses during the prebypass period in patients undergoing coronary bypass grafting who were receiving beta-adrenergic blocking drugs, calcium entry blocking drugs, or both beta-adrenergic and calcium entry blocking drugs. Electrocardiographic evidence of myocardial ischemia was noted significantly more frequently in patients receiving calcium entry blocking drugs alone at induction of anesthesia (P less than 0.03), skin incision (P less than 0.05), and sternotomy (P less than 0.002). Heart rate at sternotomy was significantly higher in patients receiving calcium entry blocking drugs (P less than 0.02) as compared to patients receiving beta-adrenergic blocking drugs or the combination of both drugs. In conclusion, patients treated with calcium entry blocking drugs alone had significantly higher incidence of perioperative ischemic ECG changes compared with patients receiving beta-adrenergic blocking drugs alone or in combination with calcium channel blocking drugs.

Adrenergic beta-Antagonists↗
PubMed1988

Postoperative recovery after general anaesthesia with and without retrobulbar block in retinal detachment surgery.

This study was to determine whether general anaesthesia plus retrobulbar block would be a better anaesthetic technique than general anaesthesia alone in retinal detachment surgery. Twenty-eight patients were allocated randomly to either general anaesthesia with retrobulbar block or general anaesthesia alone. The anaesthetist involved was blinded as to whether a retrobulbar block was performed or not. Significantly fewer patients in the general anaesthesia plus block group complained of postoperative pain than patients in the general anaesthesia group (21.4% as compared with 64.3%, p less than 0.05). Those who received general anaesthesia plus block recovered significantly more rapidly than those receiving general anaesthesia alone. The time to opening of eyes on command (p less than 0.05), telling the correct date of birth (p less than 0.01), reaching a full recovery score (p less than 0.005) and performing a simple motor task (p less than 0.025) was shorter in patients with general anaesthesia plus block. Thus general anaesthesia plus retrobulbar block was superior to general anaesthesia alone in terms of pain and recovery after operation.

Anesthesia Recovery Period↗
PubMed1988

Affinity purification of orbital membrane antigens for the study of the pathogenesis of Graves' ophthalmopathy.

We characterized 22 human monoclonal antibodies (MCAB) reactive with human orbital antigens. Most of these monoclonal antibodies had variable degrees of reactivity with eye muscle, orbital connective tissue, thyroid, and extra-thyroid tissue preparations when tested in an enzyme-linked immunosorbent assay (ELISA). Eight of the MCABs, selected on the basis of their reactivity with human eye muscle or orbital connective tissue antigens, were used to affinity purify orbital membrane antigens. All purified fractions were tested in the ELISA for reactivity with the MCAB used for their purification. Four of the purified antigens with a high reactivity were not proteins. To increase the specificity of the reactivity of serum autoantibodies with affinity-purified antigens, we developed a competitive binding ELISA in which the MCAB-immunoglobulin was directly labeled with alkaline phosphatase. We tested the serum of 24 patients with Graves' ophthalmopathy, 10 patients with a history of Graves' hyperthyroidism and no eye disease, 14 patients with Hashimoto's thyroiditis without eye disease, 8 patients with other nonautoimmune thyroid disorders, and 20 normal subjects for reactivity with an affinity-purified nonprotein orbital antigen. The levels of serum autoantibodies against this antigen in patients with Graves' ophthalmopathy were significantly higher than those in normal subjects or patients with Graves' hyperthyroidism with no eye disease. Although unlikely to be of primary pathogenetic significance, it is possible that levels of this antibody in patients with Graves' ophthalmopathy may reflect the extent of orbital inflammation and, therefore, be useful as a clinical marker.

Adult↗
PubMed1985

Low-dose fentanyl: haemodynamic response during induction and intubation in geriatric patients.

Twenty-eight surgical patients aged 65-84 were randomly assigned to either a control group (12) induced with thiopentone alone, or a treatment group (16), induced with 3 micrograms . kg-1 fentanyl followed by thiopentone, to determine whether the use of fentanyl during induction would attenuate the cardiovascular response to laryngoscopy and intubation. Patients in the fentanyl group required 47 per cent less thiopentone for induction. Increases in systolic (SBP) and diastolic (DBP) blood pressure were significantly smaller in the group receiving fentanyl at one minute post intubation. SBP rose by 56 mmHg in the control group, compared to 15 mmHg in the fentanyl group; DBP increased 42 mmHg compared to 20 mmHg, respectively. Increases in rate-pressure product were twice as great in the control group compared to the fentanyl group (72.2 vs 36.0 per cent, respectively). Thus, fentanyl, as an adjunct to barbiturate induction, effectively lowered the thiopentone requirement and attenuated the pressor response to laryngoscopy and intubation.

Aged↗
PubMed1984

Cardiac arrest following protamine administration.

A case report of fatal cardiac arrest following protamine reversal of systemic heparinization during vascular surgery is presented. Patients who have received protamine zinc insulin, NPH insulin, and those with previous exposure to protamine sulphate or allergy to fish are more likely to have a reaction to protamine. Protamine-induced hypotension can be mediated by immunological or non-immunological mechanisms. Several alternative methods of heparin reversal which may avoid similar catastrophes are presented.

Anaphylaxis↗
PubMed1982

Cancer, chemotherapy and anaesthesia.

The main principle in anaesthetic management of cancer patients is caution in dosage because of the possibility of decreased cardiac and respiratory reserve, and possible obscured hepatic and renal impairment. The anaesthetic problems which should be anticipated in cancer patients who are on therapy are discussed and summarised in Table III. An understanding of these problems ensures greater safety during operation and quicker recovery in the postoperative period.

Anesthesia, General↗
PubMed1982

Sleep apnoea syndrome and anaesthesia.

The sleep apnoea syndrome is reviewed, defined, and classified. Particular emphasis is placed on the identification of a patient population that is prone to sleep apnoea and the diseases and syndromes that are associated with it. For anaesthetists, direct enquiry into daytime and nighttime sleep abnormalities and careful examination of the upper airway are important for preoperative detection of these patients and especially patients with obstructive sleep apnoea who might present for anaesthesia and operation. A typical case is reported and details of the preoperative, peroperative and postoperative management are discussed.

Airway Obstruction↗
PubMed1981

Excessive requirement for heparin during cardiac surgery.

A case of excessive heparin requirement during cardiopulmonary bypass is reported. A patient with sepsis secondary to a myocardial abscess require 13.5 mg x kg-1 of heparin to increase his activated coagulation time to a therapeutic level. This phenomenon might be due to individual variability, lupus vasculitis, septicaemia, repeated thromboembolic phenomenon with hypercoagulable state, or chronic disseminated intravascular coagulation with partial antithrombin deficiency.

Aged↗
PubMedDate not supplied

Are discharge criteria changing?

The safe and expeditious conduct of ambulatory surgical care can succeed only by careful selection of patients and surgical procedures, appropriate intraoperative and postoperative anesthesia care, and prudent and timely discharge of patients. Practical discharge criteria or a postanesthesia discharge scoring system should be implemented in every ambulatory surgery center to ensure safe recovery and discharge after anesthesia. The PADSS is simple, practical, and easy to remember. It provides an uniform assessment of all patients, it may have added medicolegal value, and it establishes a routine of repeated reevaluation of home readiness. We recommend using the postanesthesia recovery score (Aldrete score) to evaluate the initial recovery of the patient. Once the Aldrete score is met, home readiness can be evaluated by the PADSS or modified PADSS (Tables 3 and 4). If the patient satisfies the criteria of the PADSS or modified PADSS, he or she can be discharged home. At the Toronto Hospital, we have discharged 30,000 patients home safely with the PADSS. However, any discharge criteria scoring system must be used with common sense and clinical judgment. Home readiness does not mean street fitness. Further studies on adverse outcomes after discharge and the return to normal function (e.g., work readiness) are warranted.

Ambulatory Surgical Procedures↗
PubMedDate not supplied

Effective discharge preparation of elderly cataract day surgery patients.

Nurses should ensure that prior to discharge, cataract surgery patients acquire basic knowledge about the surgical procedure, postsurgical recovery, and safe, appropriate health-care practices during early convalescence. The Modified Knowledge Test may be a functional, easy to administer tool to assess and track patient's knowledge about their post-cataract surgery recovery and safe, appropriate health-care practices during the early convalescent period. Patients can acquire most of the requisite knowledge regarding cataract extraction surgery prior to hospitalization. Some patients require reinforcement or remedial health teaching during hospitalization.

Aged↗
PubMedDate not supplied

Impact of patient-controlled analgesia on required nursing time and duration of postoperative recovery.

BACKGROUND AND OBJECTIVES: Patient-controlled analgesia (PCA) offers effective postoperative pain management. However, the evidence of economic benefits associated with its use is lacking. Although suggestive, the potential economic advantages of PCA in saving nursing time and shortening hospital stay need objective documentation. METHODS: This study compared the effects of morphine administered by PCA systems with intramuscular (i.m.) morphine injection on patient analgesic response, satisfaction, nursing time requirements, and postoperative recovery in 23 patients undergoing "open" cholecystectomy and 44 patients undergoing lumbar laminectomy and bony fusion. After the operation, patients in the PCA group received 1.5-2 mg morphine with a lockout of 5-10 minutes on demand, whereas those in the i.m. group received 0.15-0.2 mg/kg every 4 hours on demand. Visual analog scale (VAS) pain scores and satisfaction scores were evaluated at 4-hour intervals while nursing time spent on both analgesia-related and non-analgesia-related activities was recorded continuously by a team of independent observers on the ward. Recovery time profile for the return of bowel function, activities of daily living, ambulation without support, and length of hospital stay was also recorded. RESULTS: It was found that morphine consumption, VAS, and satisfaction scores were similar in both PCA and i.m. treatment groups following both types of surgery. However, the delay in nurse response to i.m. morphine request ranged from 27.2 +/- to 42.1 +/- 11.8 minutes. The demand of nursing time on analgesia administration was less with PCA. The magnitude of time saving was 10 min/patient/d in cholecystectomy patients and 13 min/patient/d in laminectomy patients. The speed of postoperative patient recovery was similar between the two analgesia groups. Length of hospital stay following cholecystectomy was shorter--92.0 +/- 5.9 hours with PCA versus 128.6 +/- 22.2 hours with i.m. (not statistically significant)--whereas that following laminectomy was not different. CONCLUSIONS: Data in this study have demonstrated some beneficial effects of PCA on nursing time requirements when it was used following cholecystectomy and lumbar laminectomy at the University of Toronto: however, the magnitude of these benefits was less than previously reported. The effects of PCA on postoperative recovery and hospital stay, however, were not significantly different from i.m. therapy.

Adult↗