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PubMed2002

Magnesium sulfate therapy after aneurysmal subarachnoid hemorrhage.

OBJECT: Vasospasm remains a significant source of neurological morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH), despite advances in current medical, surgical, and endovascular therapies. Magnesium sulfate therapy has been demonstrated to be both safe and effective in preventing neurological complications in obstetrical patients with eclampsia. Evidence obtained using experimental models of brain injury, cerebral ischemia, and SAH indicate that Mg may also have a role as a neuroprotective agent. The authors hypothesize that MgSO4 therapy is safe, feasible, and has a beneficial effect on vasospasm and, ultimately, on neurological outcome following aneurysmal SAH. METHODS: A prospective randomized single-blind clinical trial of high-dose MgSO4 therapy following aneurysmal SAH (Hunt and Hess Grades II-IV) was performed in 40 patients, who were enrolled within 72 hours following SAH and given intravenous MgSO4 or control solution for 10 days. Serum Mg++ levels were maintained in the 4 to 5.5 mg/dl range throughout the treatment period. Clinical management principles were the same between groups (including early use of surgery or endovascular treatment, followed by aggressive vasospasm prophylaxis and treatment). Daily transcranial Doppler (TCD) ultrasonographic recordings were obtained, and clinical outcomes were measured using the Glasgow Outcome Scale (GOS). The patients' GOS scores and the TCD recordings were analyzed using the independent t-test. Forty patients were enrolled in the study: 20 (15 female and five male patients) received treatment and 20 (11 female and nine male patients) comprised a control group. The mean ages of the patients in these groups were 46 and 51, respectively, and the mean clinical Hunt and Hess grades were 2.6 +/- 0.68 in the MgSO4 treatment group and 2.3 +/- 0.73 in the control group (mean +/- standard deviation [SD], p = 0.87). Fisher grades were similar in both groups. Mean middle cerebral artery velocities were 93 +/- 27 cm/second in MgSO4-treated patients and 102 +/- 34 cm/second in the control group (mean +/- SD, p = 0.41). Symptomatic vasospasm, confirmed by angiography, occurred in six of 20 patients receiving MgSO4 and in five of 16 patients receiving placebo. Mean GOS scores were 3.8 +/- 1.6 and 3.6 +/- 1.5 (mean +/- SD, p = 0.74) in the treatment and control groups, respectively. Significant adverse effects from treatment with MgSO4 did not occur. CONCLUSIONS: Administration of high-dose MgSO4 following aneurysmal SAH is safe, and steady Mg++ levels in the range of 4 to 5.5 mg/dl are easily maintained. This treatment does not interfere with neurological assessment, administration of anesthesia during surgery, or other aspects of clinical care. We observed a trend in which a higher percentage of patients obtained GOS scores of 4 or 5 in the group treated with MgSO4, but the trend did not reach a statistically significant level. A larger study is needed to evaluate this trend further.

Aneurysm, Ruptured↗

PubMed2002

Management pitfalls in the use of embolization for the treatment of severe epistaxis.

Angiographic embolization for the treatment of severe recurrent epistaxis was added to the traditional treatment options--nasal packing, cauterization, and surgical vessel ligation--in 1974. Since then, clinical experience has shown that this procedure is safe and effective. When epistaxis cannot be controlled with cautery, nasal packing is the most common next step. As such, it is often performed by emergency physicians and other clinicians who are not otolaryngologists. We report two cases in which intranasal neoplasms were obscured as a result of a significant distortion of the normal anatomy. This distortion was secondary to emergency-room treatment of severe epistaxis by repeated nasal packing followed by angiographic embolization. Pre-embolization angiographic studies and subsequent postembolization endoscopic evaluations did not reveal the presence of the occult neoplasms because of the presence of inflammation and edema after treatment. Clinicians should be aware that nasal packing and embolization can obscure the underlying source of epistaxis, and follow-up radiologic studies and endoscopic evaluations are essential to avoid delays in diagnosis.

Adult↗

PubMed1983

Burn units as a source of methicillin-resistant Staphylococcus aureus infections.

During a 3 1/2-year period (January 1978 through June 1981), 245 patients in a university hospital became colonized or infected with methicillin-resistant Staphylococcus aureus. During the first 18 months, the incidence of colonization and infection was only 0.05%. After a focal outbreak of methicillin-resistant S aureus in the burn unit, acquisition of the organism by patients on other wards increased significantly. Nonburn patients acquired the organism more often during time periods when newly admitted burn patients acquired methicillin-resistant S aureus. After the burn unit was closed, acquisition of the organism among nonburn patients on adult surgical and medical services decreased significantly. A questionnaire survey of other institutions disclosed that large outbreaks of this infection occurred more frequently in hospitals with burn units. These studies suggest that the occurrence of methicillin-resistant S aureus infections in burn units may lead to increased transmission of the organism to nonburn patients and that control of the infection in such units may reduce spread of the organism to patients without burns.

Burn Units↗

PubMedDate not supplied

Identification and management of the patient at high risk for wound infection.

Despite the use of perioperative antibiotics, wound infection remains a major source of morbidity after contaminated head and neck cancer surgery. Most adjunctive methods designed to control wound infection include techniques to reduce bacterial wound contamination. Additional methods include predicting the high risk patient and the bacteriology of subsequent wound infection, which allows antibiotic prophylaxis to be used on a selective basis. This article reviews relevant experimental and clinical data that evaluated these methods. Based on these results, as well as personal observations, guidelines are suggested for controlling wound infection in patients undergoing contaminated head and neck surgery.

Anti-Bacterial Agents↗

PubMed1983

Childhood brain tumor update.

In this review of recent studies of the cerebellar tumors of childhood we have discussed the limitations of traditional approaches to the classification of childhood brain tumors for the purposes of estimating prognosis. While these traditional approaches have provided considerable information about cells of origin, they have left behind the ancient tradition of pathology of considering the tumor in all its aspects, not just its histologic features. As an alternative we have introduced an approach that does not depend ona priori assumptions but rather allows prognosis to be estimated directly from histologic features or from clusters of histologic, clinical, and surgical features-- namely the use clustering strategies as applied to the cerebellar tumors. We have also discussed the preliminary work of the Childhood Brain Tumor Consortium, which has collected a large amount of data to serve as a source of prognostic information in the design of studies of alternative therapies. The preliminary data indicate that there is a disquietingly wide array of overlapping histologic features in three common childhood brain tumors-- medulloblastomas, pilocytic astrocytomas, and ependymomas. Clinicians who seek to reduce the number of deaths among children with brain tumors need specific prognostic information to decide among alternative therapies and to design studies of therapies for biologically homogeneous tumors, rather than studies of therapies of tumor "names" that encompass extraordinarily wide ranges of histologic features. Clinicians must also be extremely wary of "historical" controls; they cannot allow themselves to fall into the trap of believing that a new therapy is better because their patients "would have been expected" to have succumbed sooner. For each proposed therapy new studies must be designed, each with its control population, no matter how difficult this is. Historical controls assume that 1) the tumors were classified properly, 2) the sites of the tumors in different groups of patients were comparable, and 3) tumors with the same name (each encompassing an extremely wide range of histologic features) are comparable in every histologic respect to the study population, and 4) the outlook for patients with tumors with this name has not changed over the half century since the name came into common usage (i.e., that the morbidity associated with these tumors has not changed). For these reasons the use of historical controls must be condemned and all studies of therapies based on such controls discarded. Studies of therapies must compare populations of patients homogeneous as to site, histologic features, and such clinical features as age.

Astrocytoma↗

PubMedDate not supplied

Alanine-glutamine dipeptide (AGD) inhibits expression of inflammation-related genes in hemorrhagic shock.

BACKGROUND: Inflammatory factors play an important role in the production of cellular damage after shock and reperfusion. Glutamine has been used to modulate the inflammatory response. Alanine-glutamine dipeptide (AGD) is a glutamine source. The hypothesis of the present study is that AGD given during resuscitation will suppress postshock expression of messenger ribonucleic acid (mRNA) for tumor necrosis factor (TNF-alpha), interleukin-1 (IL-1beta) and inducible nitric oxide synthase (iNOS). METHODS: Male Sprague-Dawley rats (n = 74, 350 g +/- 30 g) were randomly assigned to 5 groups. Under isoflurane anesthesia, the femoral artery and vein were cannulated. Hemorrhagic shock was induced by withdrawing blood through the arterial cannula until the mean arterial pressure (MAP) was 25-30 mm Hg and maintained at the level for 30 minutes with further withdrawals. Resuscitation was carried out by giving 21 mL/kg Ringer's lactate (LR) with or without the administration of AGD (936 mg/kg) and returning the shed blood. Controls were normal (anesthesia only), sham (surgical preparation), and shock (preparation and shock). Rats (n = 45, 9 per group) were killed 30 minutes after completion of resuscitation. Liver samples were collected, and total RNA was isolated for reverse transcription-polymerase chain reaction analysis of mRNA (TNF-alpha, IL-1beta, iNOS, and beta-actin). RESULTS: MAP recovered more quickly in the AGD group than in the LR group. Increased expression of liver mRNA for TNF-alpha, IL-1beta, and iNOS was seen after hemorrhagic shock and resuscitation. AGD treatment significantly reduced mRNA expression for all 3. CONCLUSIONS: AGD modified the expression of genes controlling cytokines and iNOS in the liver. This agent is a potential treatment for hemorrhagic shock.

Alanine↗

PubMed1983

The radiology of cardiac pacemakers.

Electronic control of the heart rate and rhythm has proven useful in a variety of patients. However, pacemaker technology provides a new source of complications for the patient. Though such complications are primarily the responsibility of the cardiologist and the thoracic surgeon, the radiologist can be helpful in diagnosing a number of complications associated with these devices. Plain film radiology, fluoroscopy, and ultrasound are valuable resources in the management of patients with cardiac pacemakers.

Cardiac Pacing, Artificial↗

PubMed1993

Surveillance for diabetes mellitus--United States, 1980-1989.

PROBLEM/CONDITION: In the United States, diabetes mellitus is the most important cause of lower-extremity amputation and end-stage renal disease; the major cause of blindness among working-age adults; a major cause of disability, premature mortality, congenital malformations, perinatal mortality, and health-care costs; and an important risk factor for the development of many other acute and chronic conditions (e.g., diabetic ketoacidosis, ischemic heart disease, stroke). Surveillance data describing diabetes and its complications are critical to increasing recognition of the public health burden of diabetes, formulating health-care policy, identifying high-risk groups, developing strategies to reduce the burden of this disease, and evaluating progress in disease prevention and control. REPORTING PERIOD COVERED: In this report, data are summarized from CDC's diabetes surveillance system; trends in diabetes and its complications are evaluated by age, sex, and race for the years 1980-1989. DESCRIPTION OF SYSTEM: CDC has established an ongoing and evolving surveillance system to analyze and compile periodic, representative data on the disease burden of diabetes and its complications in the United States. Data sources currently include vital statistics, the National Health Interview Survey, the National Hospital Discharge Survey, and Medicare claims data for end-stage renal disease. RESULTS AND INTERPRETATION: In 1989, approximately 6.7 million persons in the United States reported that they had diabetes mellitus, and a similar number probably had this disabling chronic disease without being aware of it. The disease burden of diabetes and its complications is large and is likely to increase as the population grows older. Effective primary, secondary, and tertiary prevention strategies are needed, and these efforts need to be intensified among groups at highest risk, including blacks. Important gaps exist in periodic and representative data for describing the disease burden. ACTIONS TAKEN: CDC is assisting diabetes control programs in 26 states and one territory. These programs attempt to reduce the burden of diabetes by preventing blindness, lower-extremity amputations, cardiovascular disease, and adverse outcomes of pregnancy among persons with diabetes. Because of important limitations in measuring the burden of diabetes, CDC is exploring sources of surveillance data for blindness, adverse outcomes of pregnancy, and the public health burden of diabetes among minority groups.

Adult↗

PubMed1996

Effectiveness of interventions to prevent delirium in hospitalized patients: a systematic review.

OBJECTIVE: To determine the effectiveness of interventions to prevent delirium in hospitalized patients. DATA SOURCES: Two databases, MEDLINE and CINAHL, were searched for relevant articles published from January 1966 to May 1995 and from January 1982 to May 1995 respectively. The bibliographies of identified articles were searched for additional references. STUDY SELECTION: Ten articles met the following three inclusion criteria: (a) original research article, (b) published in English or French and (c) controlled trial (nonrandomized or randomized) of an intervention to prevent delirium in hospitalized patients. The validity of the studies was independently assessed according to the criteria for intervention studies proposed by the Evidence-Based medicine Working Group. DATA EXTRACTION: Information about study design, patient population, sample size, diagnostic criteria, interventions and results was systematically abstracted from each report. Absolute risk reduction (ARR) for delirium was calculated for each study. DATA SYNTHESIS: Eight trials involved surgical patients and two involved elderly medical patients; most of the studies had serious methodological limitations. Among the surgical patients the ARRs ranged from -13% to 81% and were not related to the type or timing of the intervention, or to the personnel involved. Among the elderly medical patients the ARRs ranged from -3% to 3%. CONCLUSION: Interventions to prevent delirium among surgical patients may be modestly effective, but further trials are necessary.

Delirium↗

PubMed1997

The roles of multimodality treatment and lymphadenectomy in the management of esophageal cancer.

PURPOSE: To review the current status of multimodality treatment and lymphadenectomy in the management of esophageal cancer. DATA SOURCES: Literature review. STUDY SELECTION: Multimodality treatment and lymphadenectomy in esophageal cancer. DATA EXTRACTION: Results in research papers published selected by literature search. RESULTS: Numerous studies have been carried out attempting to define the roles of various neoadjuvant or adjuvant regimens in the treatment of esophageal cancer. These included the use of radiotherapy or chemotherapy alone or in different combinations, with or without surgical resection. Randomized trials have failed to show significant improvement compared with surgical resection alone, although downstaging of disease and benefits on subgroups of patients could be demonstrated. Whether the extent of resection can influence outcome was tested by varying the surgical approach, and by increasing the extent of lymphadenectomy. Although indirect evidence exists suggesting more extensive resection may improve long term prognosis, definitive proof is lacking. CONCLUSIONS: More well organized randomized controlled trials are needed to further elucidate the roles of these approaches in the treatment of esophageal cancer.

Combined Modality Therapy↗

PubMed2004

Completion pancreatectomy for postoperative peritonitis after pancreaticoduodenectomy: early and late outcome.

HYPOTHESIS: Completion pancreatectomy in patients with pancreatic leakage associated with postoperative peritonitis after pancreaticoduodenectomy is a viable salvage procedure. DESIGN: Retrospective analysis from a cohort of consecutive patients admitted between January 1, 1989, and December 31, 1999, for postoperative peritonitis originating from pancreaticojejunostomy leakage. SETTING: Tertiary referral center with surgical intensive care unit specializing in the treatment of intra-abdominal sepsis. PATIENTS: Eight consecutive patients with postoperative peritonitis originating from pancreaticojejunostomy after pancreaticoduodenectomy, with a mean Acute Physiology and Chronic Health Evaluation II score of 18.6. We excluded patients with pancreatic fistulas or abscesses amenable to percutaneous drainage or other conservative treatment. INTERVENTION: Completion pancreatectomy. MAIN OUTCOME MEASURES: Mortality, morbidity, and long-term outcome, which was assessed by interview. RESULTS: Three patients died in the postoperative period: 2 required early reoperation during the postoperative period and died of hemorrhage and sepsis, and 1 died of multiorgan failure without reoperation. Recurrence of carcinoma was responsible for late death of 2 other patients. CONCLUSIONS: Postoperative peritonitis after pancreaticoduodenectomy still has high mortality; however, completion pancreatectomy may represent the only means to achieve source control of infection in cases of postoperative peritonitis.

Adenocarcinoma↗

PubMed1986

Adenoid cystic salivary gland carcinoma. A histopathologic review of treatment failure patterns.

Seventy-one cases of adenoid cystic salivary gland carcinoma were reviewed according to treatment modality and clinical course. Thirty-six patients (51%) were treated by combined surgery and radiation therapy. The tumors were classified by their histologic patterns into tubular, cribriform, and solid forms. Distant metastases, in 52%, were the most frequent and ominous sources of failure. In 35% of cases, distant metastases developed despite local control at the primary site. In this group, the disease had a more fulminant course with shorter survival. Histopathologically, the cribriform subtype was associated with multiple local recurrences, greater local aggressiveness, and a poorer salvage rate as compared with the tubular subtype. Late onset of local recurrences and distant metastases was especially associated with the cribriform subtype. Overall prognosis in terms of distant metastases and survival was worst for the solid subtype. Control of local disease is best achieved with combined surgery and radiation therapy. The high incidence of distant metastases may not be affected by this regimen. The ultimate outcome of therapy is poorly predicted. Survival appears to be based on the pattern in which distant metastases develop. Overly aggressive and mutilating surgical approaches for these tumors are not recommended in many instances. The need for the development of new, more effective forms of therapy is emphasized.

Aged↗

PubMed1989

In vitro release of pancreatic hormones following 99% pancreatectomy in the chicken.

In vitro assessment was made of the hormone-release capability of splenic pancreatic tissue 16 days after adult chickens had 99% of the pancreatic mass surgically removed. The objective of this study was to evaluate if the enlargement of the splenic lobe remnant after 99% pancreatectomy was attended by alterations in the responsivity of hormone release and, if so, were such changes reflective of all pancreatic hormones. After a 24-hr fast, splenic lobe tissue was obtained from young adult chickens on Postoperative Day 16, diced into 18-22 mg cubes, and incubated in vitro in media containing varying amounts of glucose with or without added somatostatin (SRIF). At 15-min intervals, the tissue cubes were transferred to fresh media and samples of each medium measured for insulin, glucagon, and APP. Viability of the tissue after 75 min was tested by tissue response to added 5 mM phenylalanine. The results obtained indicated that while total content of all four hormones (including SRIF) increased with tissue enlargement, the concentration of each decreased significantly except for SRIF, which remained at control levels. Further, the sensitivity of the B-cell in releasing insulin when confronted by a glucose challenge was not altered by previous pancreatectomy, while that of glucagon release from the A-cell was depressed. A-cell responsivity to SRIF does not appear to be adversely affected by previous 99% pancreatectomy. APP release was least affected by SRIF addition to the media, although depression by high glucose occurred. It is concluded that differential alterations occur in chicken pancreatic hormone-releasing cells as a result of 99% pancreatectomy. The efficacy in maintaining low, but still adequate, plasma I/G molar ratios (reported earlier) by the splenic remnant tissue either reflects a remarkable functional readjustment to surgical removal of 99% of the pancreatic mass in chickens or, alternatively, suggests the existence of extrapancreatic sources of insulin and glucagon, but not APP.

Animals↗

PubMed2005

Assessment of cardiac dysfunction in a randomized trial comparing doxorubicin and cyclophosphamide followed by paclitaxel, with or without trastuzumab as adjuvant therapy in node-positive, human epidermal growth factor receptor 2-overexpressing breast cancer: NSABP B-31.

PURPOSE: Trastuzumab is effective in treating human epidermal growth factor receptor 2 (HER2) -positive breast cancer, but it increases frequency of cardiac dysfunction (CD) when used with or after anthracyclines. PATIENTS AND METHODS: National Surgical Adjuvant Breast and Bowel Project trial B-31 compared doxorubicin and cyclophosphamide (AC) followed by paclitaxel with AC followed by paclitaxel plus 52 weeks of trastuzumab beginning concurrently with paclitaxel in patients with node-positive, HER2-positive breast cancer. Initiation of trastuzumab required normal post-AC left ventricular ejection fraction (LVEF) on multiple-gated acquisition scan. If symptoms suggestive of congestive heart failure (CHF) developed, source documents were blindly reviewed by an independent panel of cardiologists to determine whether criteria were met for a cardiac event (CE), which was defined as New York Heart Association class III or IV CHF or possible/probable cardiac death. Frequencies of CEs were compared between arms. RESULTS: Among patients with normal post-AC LVEF who began post-AC treatment, five of 814 control patients subsequently had confirmed CEs (four CHFs and one cardiac death) compared with 31 of 850 trastuzumab-treated patients (31 CHFs and no cardiac deaths). The difference in cumulative incidence at 3 years was 3.3% (4.1% for trastuzumab-treated patients minus 0.8% for control patients; 95% CI, 1.7% to 4.9%). Twenty-seven of the 31 patients in the trastuzumab arm have been followed for > or = 6 months after diagnosis of a CE; 26 were asymptomatic at last assessment, and 18 remained on cardiac medication. CHFs were more frequent in older patients and patients with marginal post-AC LVEF. Fourteen percent of patients discontinued trastuzumab because of asymptomatic decreases in LVEF; 4% discontinued trastuzumab because of symptomatic cardiotoxicity. CONCLUSION: Administering trastuzumab with paclitaxel after AC increases incidence of CHF and lesser CD. Potential cardiotoxicity should be carefully considered when discussing benefits and risks of this therapy.

Antibodies, Monoclonal↗

PubMed2002

Percutaneous embolotherapy for life-threatening hemoptysis.

STUDY OBJECTIVES: The management of life-threatening hemoptysis frequently poses a therapeutic dilemma because such patients are often poor surgical risks. Less often, patients refuse surgical intervention. The value of percutaneous embolotherapy, a useful alternative in these situations, was assessed. DESIGN, SETTING, PATIENTS, INTERVENTIONS: Sixteen consecutive patients who underwent percutaneous embolotherapy for life-threatening hemoptysis in a tertiary-care hospital were evaluated retrospectively. The bronchial arteries, as well as other intrathoracic arteries, were evaluated and selectively embolized if they were considered to supply the pathologic area from which the hemoptysis arose. RESULTS: The most common cause for hemoptysis was posttuberculous bronchiectasis (n = 12) with or without mycetomas. Ten patients required blood transfusions before embolotherapy. Pleural disease was noted on the chest radiograph in 13 patients and was generally associated with the presence of nonbronchial systemic collateral vessels. In three patients, arteries other than the bronchial arteries were the only source of hemoptysis. Percutaneous embolotherapy was successful in controlling the hemoptysis in all patients. The only complication documented was a transient paraparesis in one patient. Six patients did not return for follow-up. Of the remaining 10 patients, 3 patients had minor episodes of hemoptysis that were treated conservatively with success. One patient had significant recurrent hemoptysis that was managed with radiotherapy. One patient subsequently underwent a lobectomy. CONCLUSION: Percutaneous embolotherapy is a useful therapeutic modality in the management of life-threatening hemoptysis. The contribution of nonbronchial systemic collateral vessels, particularly where there is evidence of coexistent pleural disease, should always be suspected. In experienced hands, this is a safe and potentially life-saving procedure.

Adult↗

PubMed1999

Surgical management of intrapleural infections.

Most patients with empyema require surgical intervention. Selection of therapy is based on the patient's overall condition, on the cause of the empyema, and on the stage of empyema progression. Parapneumonic effusions in the exudative or early fibrinopurulent stage may be responsive to tube thoracostomy and may not require further intervention in 65% of patients. More complicated parapneumonic effusions require thoracoscopic or open thoracotomy for debridement or decortication and are successfully managed in over 95% of patients. Empyemas that develop postoperatively are more challenging to diagnose and treat. Open thoracotomy is usually necessary unless patients are too ill to tolerate major surgery, in which case simple open drainage is an alternative. Closure of any bronchopleural fistula is necessary before an empyema can be eradicated. In patients with empyema associated with an extrapulmonary infectious process, control of the primary source of infection is required before definitive therapy of the empyema is undertaken. The overall success rate of therapy for empyema is greater than 90% and the associated mortality rate is about 8%.

Drainage↗

PubMedDate not supplied

Dose maintenance for Partial Liquid Ventilation: passive heat-and-moisture exchangers.

Partial Liquid Ventilation (PLV), a promising method for the treatment of acute lung failure, has been evaluated in many animal studies. It has recently progressed to the point of controlled clinical trials in which patients of all ages on conventional mechanical ventilation (CMV) have their lungs substantially filled with a perfluorochemical (PFC) liquid, perflubron (PFB). During PLV, it is desirable to both maintain humidification and minimize the evaporation of PFB in order to maintain a desired dose in the lung and to reduce dose consumption and redosing effort. Heat-and-moisture exchangers (HMEs) have been used for years as a passive means of minimizing water vapor loss from the respiratory tract during CMV support of intensive care and surgical patients. In the current study, research was undertaken to leverage the operating principles of existing HMEs such that specialized "fluorophilic" HMEs (FHMEs), devices optimized for both water and PFB conservation, could be realized. A patient simulator (involving both water vapor and PFB vapor sources) was constructed and used in the in-vitro evaluation of various FHME concepts. Dose-retention efficiencies were determined with the aid of an infrared instrument and a digital thermohygrometer. Although no larger than commercial HMEs in terms of dead space (gas-occupying volume), efficient FHMEs resulted, offering less flow resistance (delta P) than their commercial counterparts. Additionally, the presence of PFB vapor did not appear to compromise the water-exchange efficiency of certain HME configurations. One promising FHME design was also tested in swine undergoing 12-hour PLV treatments. A mean conservation efficiency of 63% at an average tidal volume of 550 mL was shown, although somewhat lower efficiencies may result in adult patients because efficiency was found to trend downward with increasing tidal volume. The use of an FHME is expected to sustain dose levels in patients for longer periods with less frequent dosing and reduced dose consumption, saving treatment labor and cost.

Adult↗

PubMed1990

Conjunctival intraepithelial and invasive squamous cell carcinomas treated with strontium-90.

Twenty-seven patients with malignant epithelial tumors of the conjunctiva were treated between 1967 and 1987. Histological diagnosis was intraepithelial epithelioma in 15 cases (56%) and squamous cell carcinoma in 12 (44%). All patients were treated with a strontium-90 source on cup-shaped applicators of different sizes according to the extension of the tumor. Surface dose ranged from 60 Gy in a single treatment to 140 Gy in 7 fractions, depending on the thickness of the lesion. Fifteen patients were previously untreated, 7 were irradiated after some type of surgical treatment and 5 were treated for recurrence after multiple surgical excisions. Follow-up period ranged from 2 to 15 years. No patient died of his tumor. There were four local recurrences, three of them in patients with intraepithelial carcinoma. Two of the recurrences were salvaged with a new beta-ray treatment and the other two with enucleation. Since 1981, standard policy was to irradiate the entire conjunctiva in patients with diagnosis of intraepithelial epithelioma. Five patients developed cataracts. Considering the high primary control rate and minimal morbidity, strontium irradiation should be considered as a first-choice treatment for conjunctival tumors.

Adult↗