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Biomedical subjects

R B Smith

Publications and source records attributed to R B Smith.

At least 181 records · Page 10Linked to original sources
PubMed1988

Clinical outcome and adverse effect profile associated with concurrent administration of alprazolam and imipramine.

Clinical outcome and adverse effects associated with concurrent alprazolam and imipramine administration were studied in 29 patients with major depressive disorder who completed a 6-week trial in which they served as their own controls. Alprazolam was added on Day 8 in gradually escalating, then gradually tapering dosages while imipramine dosages remained unchanged. Significant decreases were observed in scores on the Hamilton Rating Scales for Depression and Anxiety at all later evaluation days with Day 8 as baseline. The mean total Symptom and Side Effects score decreased significantly from Day 8 to Day 22 when alprazolam doses were 1 mg q.i.d. For most side effects, total number of reports remained constant or decreased from Day 1 to later evaluation days. Standing diastolic blood pressures were significantly lower on Day 22 than on Day 1. No significant relationship was found between any rating scale score and plasma concentration data.

Adult↗
PubMed1988

Evaluation of rebreathing in patients undergoing cataract surgery.

Ten patients undergoing elective cataract surgery with local anesthesia were evaluated for rebreathing using mass spectrometry and arterial blood gas analysis. Results showed a 10 or 51 oxygen-air mixture with an inspired oxygen concentration of 50% (FIO2) administered via a face tent maintained normal blood gases and a satisfactorily low inspired carbon dioxide (FICO2) in conscious patients who were free of lung disease.

Adult↗
PubMed1988

Surgical treatment of chronic mesenteric arterial insufficiency.

The treatment of 41 patients with chronic mesenteric insufficiency is reviewed: 20 men and 21 women with a mean age of 59 years were treated and observed for an average of 42 months. Thirty-one patients had symptoms of intestinal angina whereas 10 patients underwent prophylactic revascularization during other aortic operations. All but one patient had revascularization of the superior mesenteric artery, alone or in combination with another revascularization. Various surgical techniques were used, including retrograde bypass in 24 patients, antegrade bypass in 11 patients, and endarterectomy in the remaining six patients. Seven patients had acute abdominal symptoms and required emergency operation while in the hospital awaiting elective revascularization. There were two deaths in the perioperative period (4.9%), both caused by bowel necrosis. Six patients are known to have had late revascularization failure, resulting in recurrent symptoms in three patients and two subsequent deaths. All patients who remained asymptomatic after late graft failure had undergone multiple vessel revascularization; no patient revascularized prophylactically had symptoms of intestinal angina during the follow-up period. Early mesenteric revascularization is a safe and effective method of relieving the symptoms of chronic visceral ischemia and may prevent the development of fatal bowel necrosis.

Adult↗
PubMed1988

Infected aortobifemoral prosthesis--a dreaded complication.

From 1980 to 1985 13 patients were identified with infected aortofemoral grafts. Potential predisposing factors identified included a history of multiple femoral arterial procedures (10 patients; 77%) as well as perioperative infections occurring at the time of a prior femoral operation (five patients; 38%). Patients presented with suppurative groin infections (11) or ruptured pseudoaneurysms (2). Two who had previously undergone bilateral amputations were managed by removal of their aortic grafts without revascularization. Eleven other patients were managed by excision of the entire prosthesis (6 aortic grafts), partial graft excision (five graft limbs) or local treatment alone (three graft limbs). Revascularization through uninfected tissue planes was performed on 14 limbs with salvage of 11 (limb salvage 79%); whereas three limbs not revascularized required major amputation (limb salvage 0%). Despite an aggressive surgical approach five patients (38%) required a major amputation and there were three deaths (23% mortality). Once the diagnosis of an infected graft is made, early graft excision and prompt revascularization are encouraged.

Adult↗
PubMed1987

Diabetes in young New Zealanders: results of national survey 1978-82.

Over a four-year period, 1 August 1978-31 July 1982, a national survey attempted to record all newly diagnosed cases of diabetes in persons under the age of 20 years, by seeking voluntary reporting from paediatricians and physicians. There were 282 cases reported--an annual incidence of 5.74 per 100,000. There was an excess of males in the 0-4 years and 15-17 year age groups, and the incidence among Maoris was significantly lower than among nonMaoris. Diabetes was significantly less common among mothers of diabetic children than among their fathers. The peak age at onset was 11 years for girls and 12 years for boys. A threefold geographical variation was noted, but underreporting may have contributed to this variation. Seasonal variation was apparent, but this was statistically significant in only one of the four years of the study. Symptoms were present in all but 3% of the cases, and the median duration of these symptoms was three weeks. More than half of the children who were treated with insulin were given more than one injection per day. It is suggested that better quality information could come from a compulsory national register.

Adolescent↗
PubMed1987

The incidence and significance of seminal vesicle invasion in patients with adenocarcinoma of the prostate.

The incidence and significance of seminal vesicle invasion in patients with adenocarcinoma of the prostate were determined in 139 patients who underwent radical prostatectomy. Of the 36 patients who had seminal vesicle invasion, 27 (75%) also had capsular invasion and 13 (43%) had lymph node metastases. Disease progression rates were 31% and 58% at 5 and 8 years, respectively. Survival rate at 5 years was 90.6% and at 8 years it was 83.7%. Of the 103 patients without seminal vesicle invasion, 21 (20.4%) also had capsular invasion and 11 (12%) had lymph node metastases. Disease progression rates were 2.5% and 15.7% at 5 and 8 years, respectively. Survival rate at both 5 and 8 years was 98.4%. These data suggest that the majority of patients with seminal invasion do not have lymph node metastases on presentation and thus they cannot be detected by lymph node dissection before radical prostatectomy. Improved techniques for preoperative detection of seminal vesicle invasion can assist in patient selection for surgery and improve the results of radical prostatectomy.

Adenocarcinoma↗
PubMed1987

Massive intracerebral hemorrhage following carotid endarterectomy.

To our knowledge, a particularly lethal complication of carotid endarterectomy, intracerebral hemorrhage, has not been given due consideration in the literature concerning carotid surgery. In the Atlanta area, massive intracranial hemorrhage developed in ten patients following routine carotid endarterectomies performed during a recent ten-year period. All ten of the patients in this series died despite a variety of therapeutic interventions. Risk factors may include the following: extreme arterial stenosis with resultant postoperative hyperperfusion, involvement of multiple extracranial cerebral vessels, postoperative systemic hypertension, and administration of anticoagulant or antiplatelet medications. Unfortunately, identification of the subset of patients potentially at risk for this complication is difficult, and, to date, therapy has been generally ineffective.

Aged↗
PubMed1987

Nonoperative management of selected popliteal aneurysms.

In the management of 95 popliteal aneurysms, surgical therapy was initially successful in 90% of operations, while major limb amputation was required in 6%. Durability of surgical reconstruction was improved if autogenous saphenous vein was used and if the reconstruction was performed before development of complications. Twenty asymptomatic popliteal aneurysms were repaired without loss of limb and with a five-year secondary cumulative patency rate of 93%. Among 26 small asymptomatic popliteal aneurysms managed without operation, complications developed in only two (8%) during the period of observation. Because of the demonstrated safety and efficacy of surgical treatment, repair of popliteal aneurysms is recommended in acceptable operative candidates. However, there exists a subgroup of asymptomatic higher-risk patients with small popliteal aneurysms in whom a conservative nonoperative approach is reasonably safe.

Adult↗
PubMed1987

Nighttime dosing of triazolam in patients with liver disease and normal subjects: kinetics and daytime effects.

This study was designed to determine whether the severity of liver dysfunction in cirrhosis affects the kinetics and next-day effects of triazolam after bedtime administration of a single oral dose. Eight patients with biopsy-proven cirrhosis and seven normal subjects matched for age, weight, and sex participated as paid volunteers. The first night was the control night, when no nighttime sedative was administered. The next day, psychomotor testing was performed at 8:30 AM, 2 PM, and 5 PM. Triazolam 0.25 mg was administered at 10:30 PM that evening. Psychomotor testing was repeated on the posttriazolam day in the same manner as on the control day. Blood samples were obtained from a venous catheter at 11 predetermined times in the 14 hours after triazolam administration. Memory testing was also performed. Apparent oral clearance of triazolam was directly related to albumin concentration and indocyanine-green elimination rate constant, and inversely related to partial thromboplastin time expressed as seconds over control. Clearance was 6.69 +/- 2.52 mL/min/kg in the normal subjects and 4.99 +/- 3.14 in the subjects with cirrhosis. There were no significant differences in Cmax between normal subjects (1.43 +/- 0.44 ng/mL) and subjects with cirrhosis (1.62 +/- 0.31 ng/mL) or in tmax (2.0 +/- 1.0 vs 2.5 +/- 1.9 hr) between normal and cirrhosis subjects, respectively. Posttriazolam, cirrhotic subjects took significantly longer to sort cards at 8:30 AM than on the control day. There was a significant correlation between extent of impairment on 8:30 AM card sorting by suit and AUC0-8 (r = 0.687; P = 0.0046).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Pharmacodynamics of triazolam after intravenous administration.

Triazolam pharmacokinetics and effects on sedation, short-term amnesia, and psychomotor performance were evaluated in 25 normal volunteers as part of a safety and tolerance study of intravenous dosing of triazolam. Triazolam kinetics were linear after intravenous administration of doses up to 1.0 mg with no differences among doses in elimination half-life, volume of distribution, or clearance. The hepatic extraction ratio ranged from 0.14 to 0.37, suggesting that triazolam should undergo moderate first-pass metabolism after oral administration. The duration and extent of sedation, decrement in psychomotor performance test scores, and amnesia were dose related, but all subjects returned to baseline alertness and function within eight hours of dosing. The time-course of effects on memory and psychomotor performance were related to triazolam plasma concentration profile using an Emax model for effect and a two-compartment pharmacokinetic model. The probability of a subject being asleep was related to triazolam plasma concentrations using logistic regression. These models indicate that intravenous doses of 0.25 to 0.5 mg triazolam would be effective for use preoperatively for short surgical procedures.

Adult↗
PubMed1987

Influence of dosing regimen on alprazolam and metabolite serum concentrations and tolerance to sedative and psychomotor effects.

The relationships between alprazolam and metabolite concentrations and CNS effects were determined in a double-blind placebo controlled four-way crossover trial in 16 normal male volunteers. Active drug treatments consisted of 4-day regimens of 4 mg alprazolam PO daily as 2 mg bid., 1 mg qid, and 0.25 mg each hour. On days 1 and 4, the kinetics, sedative and psychomotor effects were evaluated. Plasma concentrations of the 4- and alpha-hydroxy metabolites of alprazolam were less than 10% of unchanged alprazolam levels on both days. Accumulation of these metabolites and alprazolam was dependent on alprazolam half-life (11.6 h). Acute and chronic tolerance to the sedative and psychomotor effects was observed with all active drug treatments. All alprazolam treatments resulted in significantly greater sedation than placebo on days 1 and 4. However, on day 4, sedation was 16-36% less than observed on day 1, despite plasma concentrations 1.4-2.76 times the day 1 concentrations. Sedation from alprazolam was reduced in each successive study phase, suggesting a tolerance which was sustained during the 10-day washout between phases. By day 4, psychomotor performance was not different from placebo, indicating more complete development of tolerance than occurred for the sedative effect. Sedation and psychomotor impairment on day 1 were greatest with 2 mg alprazolam bid. During the initiation of therapy, the patient will likely experience less sedation and psychomotor impairment with smaller, more frequent doses. Since tolerance develops to these effects, the advantage of more frequent dosing regimen dissipates by the 4th day.

Adult↗
PubMed1987

Urethral gap in complete disruption of membranous urethra.

In patients with complete disruption of the membranous urethra treated initially with placement of a suprapubic cystostomy, delayed synchronous retrograde and voiding cystourethrograms failed to demonstrate accurately the distance between the two urethral ends. Radiographic exposure obtained during synchronous instrumentation of the anterior and posterior urethra in the anesthetized patient was the most precise method of defining the extent of the urethral gap. Any surgical decision should be based on this type of investigation. In most cases of pelvic crush injuries, the severed membranous urethra probably remains attached in close proximity to the distal segment, thus directing the redescent of the prostate and bladder base in the presence of a contracting pelvic hematoma.

Adult↗
PubMed1987

Metastatic carcinoma to penis: when is total penectomy indicated?

We report on 7 patients with metastatic carcinoma to the penis: 3 had carcinoma of the prostate and 2 had transitional cell carcinoma of the bladder; renal cell carcinoma and squamous cell carcinoma of the rectum were found in 1 patient each. Five patients died within six months; 2 patients are alive three and seven months following diagnosis. One of these patients underwent total penectomy for intractable penile pain. The indications and outcome of this surgical procedure are presented and discussed.

Aged↗
PubMed1987

Use of fine needle aspiration for detection of stage A prostatic carcinoma before transurethral resection of the prostate: a clinical trial.

The incidence of stage A prostatic carcinoma is approximately 10 per cent. We performed a clinical trial to determine if pre-prostatectomy fine needle aspiration could detect reliably stage A prostatic carcinoma. In 102 men with clinically staged benign disease by digital examination we performed a 4-quadrant fine needle aspiration of the prostate before prostatectomy. The cytological diagnosis of the aspirate was compared to the pathological diagnosis obtained at prostatectomy in all patients. The incidence of stage A prostatic carcinoma in this group of patients was 18.6 per cent (19 of 102 men). Sufficient aspirate material for cytological diagnosis was obtained in 98 of 102 men (96 per cent), including 17 with a diagnosis of carcinoma. When adequate diagnostic material was obtained, fine needle aspiration detected all cases of clinical stage A2 prostatic carcinoma but it did not detect stage A1 prostatic carcinoma. There were no false positive diagnoses. We conclude that routine pre-prostatectomy fine needle aspiration of the prostate can be safe, cost-effective and clinically useful.

Aged↗