Intraoperative retinal light damage reflected in electrophysiologic data

In a series of 30 unilaterally pseudophakic patients, electroretinograms and electrooculograms were recorded 6 months postoperatively. The unoperated on fellow eyes served as controls High intraoperative retinal light exposure (3.4–7.3 mW/cm², Zeiss OPMI 6 operating microscope) caused a substantial reduction of electrophysiologic potentials. Light protection prevented deterioration of electroretinogram and electro-oculogram potentials; reducing the bulb voltage, tilting the axis of illumination, filtering short wavelengths and the use of light shields resulted in 4-log-unit lower intensities (0.8–3.7 W/cm²).Abbreviations ACL anterior chamber lens - ECCE extracapsular cataract extraction - ICCE intracapsular cataract extraction - PCL posterior chamber lens     

Merkel cell carcinoma. Prognosis and management.

Seventy patients with Merkel cell carcinoma were treated at Memorial Sloan-kettering Cancer Center between 1969 and 1989. The overall estimated 5-year survival rate was 64%. Factors predictive of improved survival included head and neck site and negative lymph nodes at presentation. Local recurrence was seen in 18 patients (26%) and did not correlate with patient-, tumor-, or treatment-related variables. Nine patients with local recurrence (50%) were free of disease following aggressive reoperation. Regional nodes were involved at some point during the course of the disease in forty-six patients (66%). Regional lymph node involvement was apparent within 2 years of diagnosis in 40 (87%) of 46 patients in whom it occurred. Systemic disease was nearly uniformly preceded by the appearance of nodal metastases and was uniformly fatal regardless of subsequent therapy. This suggests an orderly "cascade" pattern of spread for this tumor, in which elective regional lymph node dissection may be justified. Our recommendations for treatment include a wide excision of the primary tumor and either elective or early therapeutic regional node dissection. The role of adjuvant radiotherapy or chemotherapy remains unproven.     

A method of correcting for linear drift in computed tomography brain scans.

Linear drift of X-ray attenuation coefficients must be corrected if quantitative comparisons are to be made between computed tomography (CT) brain scans of the same individual performed at different times. Such a correction is accomplished by comparing the low (cerebrospinal fluid) end of the attenuation coefficient frequency histograms using a percentile--percentile plot. A "drift correction" permits serial quantitative assessments of the progression or regression of white matter hypodensity, such as occurs in drug induced leukoencephalopathy.     

Rescue missions for totally buried avalanche victims: conclusions from 12 years of experience

Abstract Hohlreider, Matthias, Stephanie Thaler, Walter Wuertl, Wolfgang Voelckel, Hanno Ulmer, Hermann Brugger, and Peter Mair. Rescue missions for totally buried avalanche victims: conclusions from 12 years of experience. High Alt. Med. Biol. 9:229-234, 2008.-The planning and execution of avalanche rescue missions to search for totally buried avalanche victims are mostly based on personal experience and preference, as evidence-based information from literature is almost completely missing. Hence, the aim of this study was to identify major factors determining the survival probability of totally buried victims during avalanche rescue missions carried out by organized rescue teams (Austrian Mountain Rescue Service, Tyrol). During the 12-year period studied, 109 totally buried persons (56 off-piste, 53 backcountry), were rescued or recovered; 18.3% survived to hospital discharge. Median depth of burial was 1.25 m; median duration of burial was 85 min. The majority (61.6%) of the rescue missions were conducted under considerably dangerous avalanche conditions. The probability of survival was highest when located visually and lowest for those located by avalanche transceiver; survival did not significantly differ between those found by rescue dogs and those located with avalanche probes. Multivariate analysis revealed short duration of burial and off-piste terrain to be the two independent predictors of survival. Whenever companion rescue fails, snow burial in an avalanche is associated with extraordinarily high mortality. Searching the avalanche debris with probe lines seems to be equally effective as compared to searching with rescue dogs. The potential hazard for rescuers during avalanche rescue missions comes mainly from self-triggered avalanches, hence thorough mission planning and critical risk-benefit assessment are of utmost importance for risk reduction.     

Thromboprophylaxis with 60 mg enoxaparin is safe in hip trauma surgery

BACKGROUND: Little information is available concerning dosage and optimal initiation of thromboprophylactic therapy with low-molecular-weight heparin (enoxaparin) in nonelective hip surgery. The aim of our prospective study was to evaluate the incidence of clinically apparent deep vein thrombosis (DVT), pulmonary embolism (PE), and major hemorrhage in patients receiving thromboprophylaxis with enoxaparin undergoing hip surgery after hip fracture. METHOD: From 946 consecutive patients admitted with hip fractures, 897 were operated on and received enoxaparin according to the following regimen: Preoperative heparinization from time of admission onwards. Administration of 60 mg enoxaparin, in two doses (20 and 40 mg subcutaneously), during the first 5 days postoperatively. Prophylaxis for a minimum of 5 weeks (40 mg daily). RESULTS: Clinical signs of DVT were present in 37 patients (4.2%), who all underwent venography. In five patients, DVT was confirmed (0.6%). None of these patients suffered from PE. Another four patients (0.4%) developed clinical signs of PE, and suspected diagnosis was confirmed by computed tomographic scan in two (0.2%). No deaths because of PE were observed. Major hemorrhage occurred in 42 patients (4.7%), there was one death from hemorrhage caused by an intracerebral event. No case of heparin-induced thrombocytopenia type II was observed. CONCLUSION: Thromboprophylaxis with 60 mg enoxaparin daily, in split doses, starting before surgery, is safe and appropriate in patients with hip fractures. Clinically apparent DVT and PE are rarely observed, and bleeding complications are comparable to those occurring with a conventional thromboprophylactic regimen.     

Propagation of cutaneous thermal injury: a mathematical model

Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the USA seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Such expansion threatens life and is therefore highly clinically significant. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for intercepting propagation. We show, for example, that if tissue levels of vitamin E tocotrienol are increased, postburn, by five times then this would slow down the lipid peroxide propagation by at least 50%. We chose the alpha-tocotrienol form of vitamin E as it is a potent inhibitor of 12-lipoxygenase, which is known to propagate oxidative lipid damage. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results.     

Assessment of long-term quality of life after laparoscopic and open surgery for Crohn''s disease

OBJECTIVE: Surgery for Crohn's disease (CD) is associated with a high recurrence rate and quality of life (QOL) in these patients is controversial. The aim of this study was to assess QOL in patients after laparoscopic and open surgery for CD by two different validated instruments, a generic nonspecific score and a specific gastrointestinal QOL index. PATIENTS AND METHODS: Patients with CD who underwent elective laparoscopic or open ileocaecal resection with primary anastomosis between 1992 and 2000 were followed for recurrence and surgery-related complications. QOL was assessed by the SF-36 Health Survey containing a mental (MCS) and a physical (PCS) component summary score and by the Gastrointestinal Quality of Life Index (GIQLI) developed by Eypasch. RESULTS: Thirty-seven patients with a mean age of 48.8 +/- 18.4 years including 23 females and 14 males were evaluated at a mean follow-up of 42.6 +/-25.8 months (minimum of 8 months). Twenty-one (57%) patients underwent laparoscopic resection and 16 (43%) open surgery. Both groups were well matched for age, gender, ASA class and body mass index. Fourteen (38%) patients developed recurrent disease and 3 (8%) had postoperative incisional hernias. Overall, QOL scores were 103 +/- 26.8 for the GIQLI, 47.2 +/- 11.8 for the PCS, and 49.2 +/- 11.5 for the MCS. The GIQLI correlated well with the SF36, correlation coefficient = 0.68 for GIQLI vs PCS (95% CI, 0.41,0.95) and 0.67 for GIQLI vs MCS (95%CI, 0.39, 0.95), respectively. When compared to the general US population, mean GIQLI scores (-13.8, P = 0.002) and mean PCS scores (-4.7, P = 0.001) were significantly lower in these patients than in healthy individuals. In a multivariate analysis of impact factors on QOL, recurrence within the follow-up period was the single significant determinant reducing the PCS (-35.1, P = 0.026) and the GIQLI (-36.1, P = 0.018). CONCLUSION: QOL is significantly reduced in patients with CD at long-term follow-up after both laparoscopic and open surgery. Recurrence is the only factor adversely affecting QOL of CD patients in remission irrespective of the operative technique applied.