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Biomedical subjects

Gregory L Bryson

Publications and source records attributed to Gregory L Bryson.

8 recordsLinked to original sources
PubMed2006

Evidence-based clinical update: general anesthesia and the risk of delirium and postoperative cognitive dysfunction.

PURPOSE: The purpose of this structured, evidence-based, clinical update was to identify the best evidence comparing general and regional anesthesia and their influence on delirium or cognitive dysfunction (POCD) in the postoperative period. SOURCE: In June 2005 a structured search of MEDLINE from 1966 to present using OVID software was undertaken. Medical subject headings and textwords describing both delirium and POCD were employed. OVID's Therapy (sensitivity) algorithm was used to maximize the detection of randomized trials. The bibliographies of eligible publications were hand-searched to identify trials not identified in the electronic search. Publications enrolling children were excluded. Levels of evidence and grades of recommendations were scored using Centre for Evidence Based Medicine criteria. PRINCIPAL FINDINGS: A total of 18 unique randomized controlled trials were identified: two evaluating delirium; ten evaluating POCD; and six evaluating both. Outcomes for delirium were abstracted from eight trials that enrolled 765 patients (387 regional anesthesia; 378 general anesthesia). Outcomes for POCD were identified from 16 trials that enrolled 2,708 patients (1,313 regional anesthesia; 1,395 general anesthesia). Both delirium (11-43%) and POCD (15-25%) were relatively common in trials actively seeking these outcomes. Consistent Level 2b evidence suggests no significant increase in delirium in patients receiving general anesthesia compared with those receiving regional anesthesia. Similarly, consistent Level 1 evidence indicates that exposure to general anesthesia is not significantly associated with POCD. CONCLUSION: Available randomized controlled trials suggest that there is no significant difference in the incidence of delirium or POCD when general anesthesia and regional anesthesia are compared.

Anesthesia, Conduction↗
PubMed2006

Acute diastolic dysfunction in thoracoabdominal aortic aneurysm surgery.

PURPOSE: To report transesophageal echocardiographic (TEE) findings consistent with intraoperative acute diastolic dysfunction in a series of patients undergoing thoracoabdominal aortic aneurysm (TAAA) repair. METHODS: A series of nine consecutive patients underwent TAAA repair with intraoperative TEE monitoring. Surgical repair was performed with the adjunct of a left atrio-femoral bypass. Invasive arterial and venous pressures were monitored. Intraoperative TEE was utilized to assess the diastolic function before, and during aortic cross clamping. Diastolic dysfunction was defined as a mitral inflow pulsed wave Doppler (E: A ratio) < 1. RESULTS: All patients demonstrated an E: A ratio > 1 (1.3 +/- 0.08) before aortic cross clamping. During cross clamp, the E: A ratio decreased to < 1 (0.75 +/- 0.05) in six of nine patients consistent with diastolic dysfunction. The three patients who did not develop E: A changes were receiving ss-blockers pre-operatively. Patients with diastolic dysfunction were treated with nitroglycerin infusions, which resulted in restoration of their E: A ratios > 1 (1.2 +/- 0.09). Three of the patients with intraoperative diastolic dysfunction developed postoperative myocardial infarction. CONCLUSIONS: Chronic diastolic dysfunction is a well-known entity. This report describes acute diastolic dysfunction, which was observed frequently in patients undergoing TAAA during aortic cross clamp. Further research is required to confirm this phenomenon and determine its possible association with increased postoperative cardiac morbidity.

Acute Disease↗
PubMed2006

Preoperative testing is inconsistent with published guidelines and rarely changes management.

PURPOSE: The Canadian Anesthesiologists' Society (CAS), the Ontario Preoperative Task Force (OPTF) and The Ottawa Hospital (TOH) have published guidelines detailing the indications for preoperative testing. The purpose of this study was to: (a) document compliance of testing practice at TOH-Civic Campus with published guidelines; and (b) determine the impact of preoperative testing on clinical management. METHODS: Following Research Ethics approval all patients undergoing elective surgery at TOH-Civic Campus in the first three months of 2004 were identified. One hundred charts from each month were randomly selected and analyzed retrospectively by a single reviewer. The ordering and results of four preoperative tests were characterized. The indication for preoperative testing was identified from preoperative notes and the source of non-compliant orders was identified. Compliance with the CAS, OPTF, and TOH guidelines was documented. Abnormal test results were analyzed for evidence of a subsequent change in clinical management. RESULTS: The charts of 294 of the 2,116 patients who underwent elective surgery at TOH-Civic Campus in the first three months of 2004 were reviewed. A total of 534 tests were ordered on 198 patients (67%). Non-compliance rates varied significantly (5-98%) depending on test and guideline analyzed. Results of 329 tests (61.6%) were normal. Management was changed by 14 of 534 tests ordered (2.6%). Surgery proceeded as scheduled in all cases. CONCLUSION: The majority of elective surgical patients undergo preoperative testing. Non-compliance with guidelines ranged from 5 to 98%. The results of most tests were normal and influenced management in only 2.6% of cases.

Anesthesia Department, Hospital↗
PubMed2004

Patient selection in ambulatory anesthesia - an evidence-based review: part I.

PURPOSE: To identify and characterize the evidence supporting decisions made in the care of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: the elderly, heart transplantation, hyper-reactive airway disease, coronary artery disease, and obstructive sleep apnea. SOURCE: A structured search of MEDLINE (1966-2003) was performed using keywords for ambulatory surgery and patient condition. Selected articles were assigned a level of evidence using Centre for Evidence Based Medicine (CEBM) criteria. Recommendations were also graded using CEBM criteria. PRINCIPAL FINDINGS: The elderly may safely undergo ambulatory surgery but are at increased risk for hemodynamic variation in the operating room. The heart transplant recipient is at increased risk of coronary artery disease and renal insufficiency and should undergo careful preoperative evaluation. The patient with reactive airway disease is at increased risk of minor respiratory complications and should be encouraged to quit smoking. The patient with coronary artery disease and recent myocardial infarction may undergo ambulatory surgery without stress testing if functional capacity is adequate. The patient with obstructive sleep apnea is at increased risk of difficult tracheal intubation but the likelihood of airway obstruction and apnea following ambulatory surgery is unknown. CONCLUSION: Ambulatory anesthesia is infrequently associated with adverse outcomes, however, knowledge regarding specific patient conditions is of generally low quality. Few prospective trials are available to guide management decisions.

Aged↗
PubMed2004

Patient selection in ambulatory anesthesia - an evidence-based review: part II.

PURPOSE: This is the second of two reviews evaluating the management of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: diabetes mellitus; morbid obesity; the ex-premature infant; the child with an upper respiratory infection; malignant hyperthermia; and the use of monoamine oxidase inhibitors. SOURCE: Medline search strategies and the framework for the evaluation of clinical evidence are presented in Part I. PRINCIPAL FINDINGS: Diabetes mellitus has not been linked with adverse events following ambulatory surgery. The morbidly obese patient is at an increased risk for minor respiratory complications in the perioperative period but these events do not increase unanticipated admissions. The ex-premature infant may be considered for ambulatory surgery if post-conceptual age is > 60 weeks and hematocrit is > 30%. The child with a recent upper respiratory tract infection is at an increased risk for perioperative respiratory complications, particularly if endotracheal intubation is required. Patients with malignant hyperthermia may undergo outpatient surgery but require four hours of postoperative temperature monitoring. Sporadic cases of drug interactions have been reported when meperidine and indirect-acting catecholamines are administered in the presence of monamine oxidase inhibitors. Ambulatory anesthesia and surgery is safe if these combinations of drugs are avoided. CONCLUSION: Ambulatory anesthesia can be performed in, and is being offered to, a variety of patients with significant coexistent disease. In many cases there is little evidence documenting the outcomes expected in such patients. Prospective observational and interventional trials are required to better define perioperative management.

Adult↗
PubMedDate not supplied

EMLA cream is an effective topical anesthetic for bronchoscopy.

BACKGROUND: EMLA cream (AstraZeneca Inc, Canada) (1:1 eutectic mixture of lidocaine 2.5% and prilocaine 2.5%) has traditionally been used for topical anesthesia of the skin. Recent reports of EMLA's use for anesthesia of the oral mucosa suggest an application in topical anesthesia for bronchoscopy. OBJECTIVES: To evaluate the amount of local anesthetic administered during bronchoscopy; to assess the time required to obtain topical anesthesia; to assess the quality of the topical anesthesia as described by bronchoscopists; and to document any complications. METHODS: Fifty-seven unpremedicated patients had 4 mL of EMLA cream applied to the posterior third of their tongues on arrival in the bronchoscopy suite. Liquid lidocaine was applied through the bronchoscope for laryngeal anesthesia. RESULTS: The mean time from the application of EMLA cream to insertion of the bronchoscope was 5.10+/-0.48 min. Fifty-six patients (98.2%) required no supplemental anesthesia. Bronchoscopy conditions were described as 'excellent' in 55 cases (96.5%) and 'good' in the remaining two cases (3.5%). CONCLUSIONS: EMLA is an effective alternative for oropharyngeal topical anesthesia that is well-tolerated by patients.

Adult↗