Preliminary results of intermittent retrograde cerebral perfusion during proximal aortic arch surgery.

OBJECTIVE: Continuous retrograde cerebral perfusion during aortic arch surgery is associated with cerebral edema. In this report, we describe the clinical use of a new type of intermittent retrograde cerebral perfusion. SUBJECTS AND METHODS: Fourteen patients with a Stanford type A dissection were included in this study. With the usual method of retrograde cerebral perfusion, about 2,500 mL venous blood is drained from bicaval cannulae into a hard-shell reservoir, and oxygenated blood is perfused through the superior vena caval cannula. The flow rate is 300 mL/min. After about 15 min, retrograde perfusion is discontinued, and drainage from the bicaval cannulae is restarted. When a bloodless field is necessary, perfusion also is discontinued. RESULTS: Two to seven cycles of intermittent retrograde cerebral perfusion were administered (average, 3.1+/-0.4, mean+/-SD). The total retrograde perfusion time was 36.0+/-1.9 min which was equivalent to 74.8% of the circulatory arrest time. No patient developed edema of the upper body. The time to wake-up was 3 to 14 h (average, 6.5+/-1.0 h). No patient suffered any neurologic complications even though the time of circulatory arrest was greater than 60 min in four cases. Head magnetic resonance imaging or computed tomography was performed in 12 cases, and no evidence of hypoxic brain injury was detected. CONCLUSIONS: Our clinical experience using a moderate amount of intermittent retrograde cerebral perfusion is superior to continuous retrograde cerebral perfusion for protecting the brain during aortic arch surgery.     

Phase II Trial of Fludarabine Phosphate in Multiple Myeloma Using a Loading Dose and Continuous Infusion Schedule

A phase II trial of fludarabine phosphate using a bolus and continuous infusion regimen in previously treated multiple myeloma was performed. No responses were observed in eleven patients. There was no significant non-hematologic toxicity noted. Fludarabine phosphate is inactive in multiple myeloma using this schedule.     

3,4-Dichlorobenzyloxyacetic acid is extensively metabolized to a taurine conjugate in rats

The metabolism of the antisickling agent 3,4-dichlorobenzyloxyacetic acid (3,4-DCBAA) was examined after ip administration to rats. Within 5 days after administration of radiolabeled 3,4-DCBAA, 77.4 +/- 4.6% of the dose was recovered in the urine and only 3.2 +/- 0.5% was recovered in the feces. Metabolites in the urine were isolated and characterized by HPLC, electron impact MS, and LC/MS, and their identities were confirmed by comparing their spectra with those of synthetic standards. Quantitation of these urinary metabolites revealed that the majority of the radioactive dose was excreted as a taurine conjugate (60.1 +/- 4.4%), while lesser amounts were excreted as 3,4-dichlorohippurate, unchanged 3,4-DCBAA, the glycine conjugate of 3,4-DCBAA, and a polar unknown which is believed to be glycolic acid. A pathway involving an initial O-dealkylation at the benzyl carbon of 3,4-DCBAA and proceeding through the glycine conjugation of 3,4-dichlorobenzoic acid has been proposed to explain the formation of 3,4-dichlorohippurate and the polar unknown. The extensive conjugation of 3,4-DCBAA with taurine is an unprecedented observation in rats, which usually utilize glycine for amino acid conjugation reactions. Further studies with 3,4-DCBAA may provide insight into the enzymatic mechanisms of taurine conjugation, which are not well defined at this time.     

Factors affecting physicians' decisions on caring for an incompetent elderly patient: an international study.

OBJECTIVES: To determine what treatment decisions physicians will make when faced with a hypothetical incompetent elderly patient with life-threatening gastrointestinal bleeding and to examine the relative importance of physician characteristics and factors (legal and ethical concerns, hospital costs, level of dementia, patient's age, physician's religion, patient's wishes and family's wishes) in making those decisions. DESIGN: Survey. SETTING: Family practice, medical and geriatrics rounds in academic medical centres and community hospitals in seven countries. PARTICIPANTS: Physicians who regularly cared for incompetent elderly patients. MAIN OUTCOME MEASURES: A self-administered questionnaire describing the elderly patient. Respondents were asked to choose one of four levels of care and to identify the level of importance factors had in making that decision. Older physicians, those less concerned about litigation, those for whom the level of dementia was important and those for whom the patient's age was important were expected to give less aggressive care than the other physicians. MAIN RESULTS: Supportive care was chosen by 8.1% of the respondents, limited therapeutic care by 41.5%, maximum therapeutic care without admission to the intensive care unit (ICU) by 32.2% and maximum care with admission to the ICU by 18.2%. The patient's wishes were reported by 91.0% as being extremely or very important in choosing the treatment. Stepwise logistic regression analysis revealed that the following variables independently predicted the level of treatment: level of dementia, country of residence, duration of practice, legal concerns, patient's age and ethical concerns. These factors were significantly correlated with the physicians' treatment choices (p less than 0.05). CONCLUSIONS: The importance that the physicians placed on the level of dementia was the strongest predictor of the level of care that would be provided. A societal consensus on the influence of cognitive function on the appropriate level of care as well as training of physicians in ethical issues are required.     

Cryopreserved cadaveric allografts for treatment of unexcised partial thickness flame burns: clinical experience with 12 patients

Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservarive treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision.

Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at −180°C for 30–48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required.

It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days.

Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.     

Quadrivalvular rheumatic heart disease

Three cases of chronic rheumatic heart disease with involvement of all four valves are presented. The involvement of tricuspid and pulmonary valves was suspected clinically and was confirmed by two-dimensional echo, Doppler, hemodynamic and angiographic findings. These findings were also verified surgically and histopathologically in 2 cases. One of the cases died after cardiac catheterization; the other 2 cases were treated surgically with success.     

Should the patella be resurfaced in total knee arthroplasty? Efficacy of patellar resurfacing

To assess the long-term efficacy of patellar resurfacing, 100 knees were evaluated in 84 patients. The operations were performed between 1978 and 1982. The follow-up period ranged from 60 to 103 months. The diagnosis was degenerative joint disease (DJD) in 83%, rheumatoid arthritis in 12%, and miscellaneous in 5% of the knees. The implant (47 knees) and nonimplant (53 knees) groups were comparable with respect to age, body size, and length of follow-up period. The analysis revealed equivocal results. Considering all diagnostic categories combined, rest pain was marginally better in the resurfaced group (p = 0.04), but this difference resulted from an unequal distribution of subjects between mild and zero pain categories. Pain with walking, maximum walking distance, ability to climb stairs and rise from a chair, active arc of motion, extensor lag, and quadriceps strength were similar in the two groups. When the DJD group was considered separately, no significant difference emerged. There was little evidence to support a recommendation for routine patellar resurfacing in total knee arthroplasty.     

Chronic recurrent multifocal osteomyelitis and psoriasis—A report of a new association and review of related disorders

In summary, we have described two patients with CRMO and psoriasis, and have reviewed the musculoskeletal manifestations associated with pustular eruptions of the palms and soles. In view of the frequent occurrence of PPP in patients with CRMO, we suggest that the occurrence of psoriasis in our two patients is more than coincidence, and that noninfectious, inflammatory lesions of bone may be another musculoskeletal manifestation of psoriasis. This rare association, as well as the association of PPP with disorders associated with new bone formation, may shed new insights on the relatively common finding of periosteal elevation associated with psoriatic arthritis and the occasional severe juxta-articular osteolytic destructive bone lesions seen in psoriatic arthritis.     

The mechanism of IL-2-mediated protection against GVHD in mice. II. Protection occurs independently of NK/LAK cells.

We have recently demonstrated that high-dose IL-2, when begun on the day of bone marrow transplantation, has a potent protective effect against graft-vs.-host disease mortality, especially when coadministered with T cell-depleted syngeneic bone marrow cells. Because several groups of investigators have demonstrated that lymphokine-activated killer cells can mediate GVHD protection, we hypothesized that the mechanism of protection by IL-2 administration might involve the in vivo activation of natural killer and/or LAK cells. In order to test this hypothesis, we evaluated the effect of IL-2 administration on the number of NK1+ cells and on NK-mediated cytotoxic activity in recipients of GVHD-producing inocula. Furthermore, we evaluated the effects on IL-2-induced GVHD protection of depleting NK cells and LAK precursor cells in vivo with mAb against NK1.1 or antiserum against asialo GM1. The results demonstrate that: (1) The number of NK1+ cells is not increased in spleens of IL-2-treated compared with control recipients of GVHD-producing inocula; (2) NK activity is not increased in IL-2-treated compared with control recipients of GVHD-producing inocula during or immediately following the period of IL-2 administration; (3) depletion of NK cells and LAK precursors from the donor and host influenced the time course of GVHD-related mortality in a complex fashion; and (4) IL-2-induced GVHD protection is largely independent of the activity of an NK or LAK cell population of donor or host origin. IL-2-induced GVHD protection therefore reflects primarily the activity of non-LAK protective cell populations, or it may be a direct inhibitory effect on responding donor cell populations as they encounter host antigen.     

Right ventricular-pulmonary arterial interactions

The application of pulsatile models to hemodynamic data has made possible a more complete understanding of the relationship of pulmonary pressure and flow. To review the genesis of these concepts, the unique characteristics of the pulmonary artery and right ventricle are outlined as a basis for understanding why differences in their pulsatile properties from the systemic circuit must exist. The pulmonary impedance spectrum is introduced and the concept of optimal right ventricular-pulmonary artery coupling is explored based on a review of extensive experimental data. Finally, available studies of normal pulmonary impedance in man and abnormal impedance in human disease states are reviewed, with emphasis on disturbances in optimal ventricular-vascular coupling. The important implications of these concepts for understanding and treatment of cardiovascular disease are developed.