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Biomedical subjects

N MacKenzie

Publications and source records attributed to N MacKenzie.

6 recordsLinked to original sources
PubMed1990

Sedation during spinal anaesthesia: comparison of propofol and midazolam.

Propofol and midazolam were compared in 40 patients undergoing orthopaedic surgery under spinal anaesthesia. An infusion of either 1% propofol or 0.1% midazolam was given at a rate adjusted to maintain a similar level of sedation. The mean time to reach this required level was similar in both groups. Quality and ease of control of sedation were good in all patients. A mean infusion rate of 3.63 mg kg-1 h-1 was required for propofol and 0.26 mg kg-1 h-1 for midazolam. Immediate recovery, as judged by ability to open eyes and recall date of birth, was significantly more rapid following propofol (P less than 0.001). Similarly, restoration of higher mental function was significantly faster following propofol, measured by choice reaction time and critical flicker fusion threshold. Amnesia for the immediate postoperative period was significantly greater after midazolam (P = 0.0001).

Anesthesia Recovery Period↗
PubMed1989

Low-dose intrathecal diamorphine analgesia following major orthopaedic surgery.

In a randomized double-blind study we examined the effect of adding diamorphine 0.25 mg and 0.5 mg to intrathecal bupivacaine anaesthesia for major orthopaedic surgery. Duration of postoperative analgesia was considerably greater in patients given either doses of intrathecal diamorphine than in a control group of patients given bupivacaine alone (P less than 0.001). However, there was no significant difference between the two diamorphine doses (0.25 mg and 0.5 mg), each providing prolonged analgesia (10.8 and 9.9 h, respectively). Although there was no evidence of late respiratory depression, the frequency of adverse effects, in particular urinary retention, nausea and vomiting, was high in both groups receiving intrathecal diamorphine.

Aged↗
PubMed1987

Superficial bladder cancer: the primacy of grade in the development of invasive disease.

Tumor characteristics thought to predict for development of deep muscle invasion after resection of superficial bladder cancer were retrospectively analyzed in 252 patients with transitional cell carcinoma of the bladder at Stanford University Medical Center. Stage 0 patients accounted for 190 of the patient population (75.5%), while stage A and B1 comprised 51 (20%) and 11 (4.5%), respectively. The median follow-up time was 62 months. Forty-three patients subsequently developed deep muscle invasion; these included 24 (12.6%), 14 (27.5%), and 5 (45.5%) of stage 0, A, and B1 patients (P = .002), or 15 (10%), 15 (9%), and 13 (33%) of grade 1, 2, and 3 tumors (P = .001), respectively. When analyzed by univariate logistic regression, grade (P = .0001) and stage (P = .0118) were significant predictors for invasive disease. Site of tumor and number of tumors at presentation were not significant factors for invasion deep into the bladder wall. When multiple logistic regression was performed, only grade remained as a significant tumor variable to predict for invasive disease (P less than .0091). Risk of invasive disease did not appear to increase with increasing number of recurrences, remaining at approximately an 11% invasion rate through 12 recurrences. In this analysis, grade was the most significant tumor variable in superficial bladder cancer predicting for the development of invasive carcinoma. Future clinical trials for definitive or adjuvant therapy of this disease must stratify for this variable.

Adult↗