Bacterial colonization/infection and the surgical management of pressure ulcers

The purpose of this paper is to review the current recommendations and guidelines for the care and treatment of pressure ulcers with specific reference to the control of infection within these wounds and surgical management. After reviewing the literature published between May 1993 and April 1998, it is our contention that no significant changes in the clinical management of this problem are warranted. This may signal the need for further study in this area. Recommendations for the optimal care of clean and infected pressure ulcers are included.

Morbidity and mortality in cirrhotic patients undergoing anesthesia and surgery

BACKGROUND

Patients with cirrhosis have a reduced life expectancy. Anesthesia and surgery have been associated with clinical decompensation in patients with cirrhosis.

METHODS

The authors retrospectively reviewed the records of all patients with the diagnosis of cirrhosis who underwent any surgical procedure under anesthesia at their institution between January 1980 and January 1991 (n = 733). Univariate and multivariate analyses were used to identify the variables associated with perioperative complications and short- and long-term survival.

RESULTS

The perioperative mortality rate (within 30 days of surgery) was 11.6%. The perioperative complication rate was 30.1%. Postoperative pneumonia was the most frequent complication. Multivariate factors that were associated with perioperative complications and mortality included male gender, a high Child-Pugh score, the presence of ascites, a diagnosis of cirrhosis other than primary biliary cirrhosis (especially cryptogenic cirrhosis), an elevated creatinine concentration, the diagnosis of chronic obstructive pulmonary disease, preoperative infection, preoperative upper gastrointestinal bleeding, a high American Society of Anesthesiologists physical status rating, a high surgical severity score, surgery on the respiratory system, and the presence of intraoperative hypotension.

CONCLUSION

Risk factors have been identified for patients with cirrhosis who undergo anesthesia and surgery.

Infraclavicular brachial plexus block: parasagittal anatomy important to the coracoid technique

Infraclavicular brachial plexus block is a technique well suited to prolonged continuous catheter use. We used a coracoid approach to this block to create an easily understood technique. We reviewed the magnetic resonance images of the brachial plexus from 20 male and 20 female patients. Using scout films, the parasagittal section 2 cm medial to the coracoid process was identified. Along this oblique section, we located a point approximately 2 cm caudad to the coracoid process on the skin of the anterior chest wall. From this point, we determined simulated needle direction to contact the neurovascular bundle and measured depth. At the skin entry site, the direct posterior insertion of a needle will make contact with the cords of the brachial plexus where they surround the second part of the axillary artery in all images. The mean (range) distance (depth along the needle shaft) from the skin to the anterior wall of the axillary artery was 4.24 +/- 1.49 cm (2.25-7.75 cm) in men and 4.01 +/- 1.29 cm (2.25-6.5 cm) in women. Hopefully, this study will facilitate the use of this block.

IMPLICATIONS

We sought a consistent, palpable landmark for facilitation of the infraclavicular brachial plexus block. We used magnetic resonance images of the brachial plexus to determine the depth and needle orientation needed to contact the brachial plexus. Hopefully, this study will facilitate the use of this block.

Splenic T lymphocytes die preferentially during heat-induced apoptosis: NuMA reorganization as a marker

We are investigating nuclear events during apoptosis in mouse splenic lymphocytes cultured immediately after isolation (controls) or after heat treatment (42 degreesC, 30 minutes), and have found that hyperthermia increased the level of apoptosis to double that of spontaneous apoptosis in controls within 6 hours. Immunolabelling for Nuclear Mitotic Apparatus Protein (NuMA) suggested that splenocytes were responding heterogeneously to the heat treatment. Whereas all nuclei in controls and about half of nuclei in heat-treated samples showed the usual diffuse nucleoplasmic labelling, 40–60% of nuclei in heated samples also contained numerous bright spots. We then examined whether the heterogeneity in NuMA organization might be an indication of a differential response of B and T lymphocytes to hyperthermia, and whether the presence of NuMA spots is related to the apoptotic process. NuMA labelling of heated fractionated splenocyte populations showed that 90% of nuclei in T-enriched cultures (less than or equal to 4% IgG+ cells), but only 25% of nuclei in B-enriched samples (less than or equal to 80% IgG+ cells), contained spots. As well, 2 hours after heat treatment of unfractionated cultures, greater than or equal to 90% of nuclei that were accumulating DNA strand breaks, as detected by TUNEL, exhibited NuMA spots. These data indicate that cells with NuMA spots are targetted for, or have initiated, the death program. Since most T cells, but few or no B cells, were spotty after heating, we conclude further that hyperthermia induces apoptosis preferentially in splenic T lymphocytes. The observation that the proportion of T cells was, on average, threefold greater in control than in heated samples after 24 hours in culture reinforces this conclusion.

Paraovarian cystadenomas and cystadenofibromas: sonographic characteristics in 14 cases

PURPOSE

To describe the sonographic features of paraovarian cystadenomas.

MATERIALS AND METHODS

We searched the computerized pathology and radiology databases for cases of histopathologically proved paraovarian cystadenomas from January 1993 through December 1996 in which preoperative sonography had also been performed. Fourteen paraovarian cystadenomas or cystadenofibromas were identified in 14 patients aged 20-57 years. Sonographic and pathologic findings were correlated.

RESULTS

Three of the masses appeared as simple cysts sonographically. Of the remaining 11 masses, nine had solid nodular areas within the cyst; three had septations; and four had a thick wall, an irregular wall, or both at sonography. At sonography, four masses were thought to arise outside the ovary, four were erroneously thought to arise in the ovary, and the location was uncertain in six.

CONCLUSION

Paraovarian cystadenomas are cystic masses that usually contain one or more small solid nodules and occasionally contain septations.

Complications of percutaneous ethanol ablation

Percutaneous ethanol injection therapy performed with sonographic visualization is a steadily growing therapeutic method that can be used in the ablation of solid and cystic masses in a variety of anatomic locations. Ethanol has been used for many years as an angiographically administered agent for vascular embolization of tumors such as hepatic and renal neoplasms. It was first used as a percutaneously injected agent for the sclerosis of renal cysts. Local infiltration or intravascular injection of ethanol leads to cell death by causing cell membrane lysis, protein denaturation, and vascular occlusion. Because of the initial success in the sclerosis of renal cysts, percutaneously injected ethanol is now used in the ablation of hepatic cysts and solid tumors, such as hepatocellular carcinomas. As a treatment agent, ethanol combines the benefits of being widely available, inexpensive, efficacious, and relatively easy to administer. Optimal results require that the radiologist have considerable experience in ultrasonographic scanning techniques and facility with percutaneous needle insertion under real-time visualization. Alternatively, the radiologist may choose CT as a method to visualize needle placement. Percutaneous ethanol injection therapy usually is an effective alternative to conventional surgical resection of liver lesions and has a low complication rate. We present two patients in whom hypotensive complications occurred during percutaneous ethanol injection therapy and discuss the likely causative mechanisms.

Borderline findings in fetal cardiac sonography

Borderline or equivocal sonographic findings in the fetal heart are occasionally encountered. Echogenic foci in the ventricles, small pericardial effusions, and mild discrepancy in ventricular size are three such problematic findings. The significance of each of these findings, as currently understood, will be discussed in this article.

Influence of insurance coverage on delays in seeking emergency care in patients with acute chest pain

The time required to decide to seek medical care for acute chest pain is the major modifiable component in the process of care delivery. This study demonstrates that prehospital delay in the setting of acute chest pain was related to the type of health insurance.

Benign and malignant ovarian masses: selection of the most discriminating gray-scale and Doppler sonographic features

PURPOSE

To determine the gray-scale and Doppler sonographic features that best enable discrimination between malignant and benign ovarian masses and develop a scoring system for accurate diagnosis with these features.

MATERIALS AND METHODS

Gray-scale and Doppler sonographic features of 211 adnexal masses were correlated with the final diagnosis; the most discriminating features for malignancy were selected with stepwise logistic regression.

RESULTS

Twenty-eight masses were malignant and 183 benign. All masses with a markedly hyperechoic solid component or no solid component were benign. For masses with a nonhyperechoic solid component, additional features that allowed statistically significant discrimination of benignity from malignancy were, in decreasing order of importance, (a) location of flow at conventional color Doppler imaging, (b) amount of free intraperitoneal fluid, and (c) presence and thickness of septations. A scoring formula that made use of values based on the logistic regression equation had an area under the receiver operating characteristic curve of 0.98 +/- 0.01. The cutoff score with the highest accuracy had a sensitivity of 93% and specificity of 93%.

CONCLUSION

A solid component is the most statistically significant predictor of a malignant ovarian mass. A multiparameter scoring system that uses three gray-scale and one Doppler feature, developed by means of stepwise logistic regression, has high sensitivity and specificity for predicting malignancy.

Modulation of radiation-induced strand break repair by cisplatin in mammalian cells

PURPOSE

To investigate the repair of ionizing radiation-induced DNA lesions in human skin fibroblasts in the presence of cisplatin-DNA adducts and to determine the persistence of DNA repair inhibition by cisplatin.

MATERIALS AND METHODS

Normal human fibroblasts (AG 1522) treated with cisplatin were exposed to 4 Gy 60Co gamma-radiation and assayed for repair of radiation-induced damage under growth-permissive conditions. DNA damage was measured by the fluorescence analysis of DNA unwinding (FADU) and cytokinesis-blocked micronucleus assays.

RESULTS

Rejoining of strand breaks caused by 4 Gy radiation in cells without cisplatin pre-treatment appeared to be biphasic with an initial fast component (up to 15 min of repair time) followed by a slower component, and was completed by 90 min. Cisplatin treatment (10 microg/ml, 30 min) immediately before irradiation had no effect on the fast rejoining component, but inhibited the slow component (p<0.01). The same cisplatin treatment 24 h prior to irradiation inhibited both slow and fast components (p<0.01). In contrast, decreasing the cisplatin exposure to 1.0 microg/ml for 30 min, 24h prior to irradiation, resulted in an increased amount of strand break repair at each time point measured compared with irradiated control cells. This mild cisplatin treatment (95% survival) also resulted in a reduction of radiation-generated micronuclei indicating an adaptive response.

CONCLUSIONS

Cisplatin used in combination with ionizing radiation can produce differential cellular responses depending upon the severity of the cisplatin treatment and the time interval between cisplatin and radiation exposures.

Characterization of the microtubule-binding domain of microtubule-associated protein 1A and its effects on microtubule dynamics

To determine how MAP1a interacts with microtubules we expressed several 6myc-tagged MAP1a fragments in P19 EC and HeLa cells. Confocal immunofluorescence microscopy showed that the fragment consisting of amino acids (aa) 1-281 of MAP1a did not bind while the fragment consisting of aa 1-630 did, indicating that the region of MAP1a between aa 281 and 630 contains a microtubule-binding domain. Deletion of the basic repeats from aa 336-540 did not result in loss of microtubule binding, suggesting that the regions flanking the basic repeats can bind MAP1a to microtubules. These observations were confirmed using an in vitro microtubule binding assay. The levels of acetylation and detyrosination of polymerized microtubules were assessed by quantitative dot blotting in cells expressing MAP1a fragments or MAP2c. Compared with untransfected cells, the polymerized tubulin in cells expressing full-length MAP1a was more acetylated and detyrosinated, but these increases were smaller than those seen in cells expressing MAP2c. Consistent with this, the microtubules in MAP2c expressing cells were more resistant to colchicine than those in cells overexpressing MAP1a. These data implicate aa 281-336 and/or 540-630 of MAP1a in microtubule binding and suggest that MAP1a is less able to stabilize microtubules than MAP2c.

Sonographic evaluation of the placental cord insertion site

OBJECTIVE

Velamentous and marginal umbilical cords are uncommon abnormalities of placental cord insertion that can entail significant fetal risk. We undertook this investigation to assess the ability of prenatal sonography to reveal abnormal insertions of the umbilical cord into the placenta.

SUBJECTS AND METHODS

Forty-six patients had both prenatal sonographic evaluation of the placental cord insertion site and postnatal pathologic examination. Distance from the insertion site to the nearest placental edge was categorized by sonography and pathology as normal if greater than 1 cm and abnormal if less than or equal to 1 cm. Sonographic and pathologic findings were compared.

RESULTS

Thirty-eight singleton and eight twin pregnancies, for a total of 54 cord insertions, were studied. Of the 43 sonographically normal insertions, 38 had normal pathologic findings, and the remaining five insertions had abnormal pathologic findings (all marginal cord insertions). All 11 insertions that showed abnormality on sonography were abnormal on pathologic examination (seven marginal and four velamentous insertions). Sonography was able to reveal a difference between the two types of abnormal insertions in only a single patient, in whom the cord insertion changed from marginal to velamentous during a 7-week interval. Sonography had an overall sensitivity of 69% (11/16), a specificity of 100% (38/38), and an accuracy of 91% (49/54) for revealing abnormal placental cord insertion sites.

CONCLUSION

Targeted sonographic examination of the placental site of umbilical cord insertion will reveal abnormal placental cord insertions, although distinguishing the specific type of abnormal insertion may require the use of color Doppler imaging.

Acute delirium after withdrawal of amantadine in Parkinson's disease

We present three patients who, after long-term therapy with amantadine (4 to 18 years), experienced an acute delirium with confusion, disorientation, agitation, and paranoia on withdrawal. These patients had Parkinson's disease for 5 to 29 years; mean age was 73 years. All had a history of varying degrees of dementia and transient hallucinations in the past. Adjustment of other medications was ineffective in improving their condition and no other cause was found. Only with reinstitution of amantadine did the patients return to baseline status (usually within days).

Unique behaviour of NuMA during heat-induced apoptosis of lymphocytes

Nuclear collapse is a key feature of apoptosis, reflecting the DNA and protein fragmentation observed biochemically. We have compared nuclear events during spontaneous and heat-induced (42 degrees C for 30 min) apoptosis at the level of individual cells, monitoring overall chromatin organization by staining with 4,6'-diamidino-2-phenylindole (DAPI), DNA cleavage by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL), and the nuclear antigens NuMA, PI2, and lamin B by immunofluorescence microscopy. The data were correlated with analyses at the population level by flow cytometry and immunoblotting. We show that heat treatment doubles the level of apoptotic splenocytes with respect to the spontaneous apoptosis in controls within 6 honThe organization and disassembly of nuclear envelope antigens is identical during spontaneous and heat-induced apoptosis and proceeds in a temporally and spatially ordered manner relative to DNA fragmentation and chromatin collapse. In contrast, NuMA organization is affected by heat treatment, with about half of the cells containing many bright spots in addition to the usual diffuse labelling. The spots were still visible in many fully collapsed apoptotic nuclei. Further, this novel reorganization of NuMA and the hyperinduction of apoptosis by heat are correlated, suggesting that lymphocytes with reorganized NuMA are destined to undergo apoptosis. The data also indicate that DNA fragmentation precedes extensive remodelling of the nucleoplasm in these cells, and that chromatin begins to collapse before disassembly of nuclear envelope components.

Purpura fulminans: a disease best managed in a burn center

Victims of purpura fulminans are overcome by a rapidly progressive and sometimes fatal course involving large amounts of tissue loss and multiple organ system failure. From 1986 to 1995, seven children ranging in age from 10 months to 19 years (mean, 6.2 years) were referred to the Shriners Burns Institute in Cincinnati with purpura fulminans. Neisseria meningitidis was identified as the precipitating pathogen in most of the patients. The mean TBSA full-thickness skin loss was 33%. Fourteen extremities were amputated in the seven patients, including three patients with amputations of all four extremities. Transfer to our institution occurred after a mean delay of 20 days, usually after the demarcation of viable tissue. In one patient, however, fasciotomies obviated multiple impending amputations. Monitoring for elevated compartment pressures, early fasciotomies, and expedient transfer to a burn center for a multidiciplinary approach to care should improve the outcome in patients with purpura fulminans.

Risk of patients with severe aortic stenosis undergoing noncardiac surgery

Aortic stenosis (AS) is a major risk factor for perioperative cardiac events in patients undergoing noncardiac surgery. We previously showed that selected patients with AS who were not candidates for, or refused, aortic valve replacement could undergo noncardiac surgery with acceptable risk. We extended our previous experience over a subsequent 5-year period by retrospectively analyzing the perioperative course of all patients with severe AS (aortic valve area index < 0.5 cm2/m2 or mean gradient > 50 mm Hg), determined with Doppler echocardiography or cardiac catheterization, who underwent noncardiac surgery. Nineteen patients underwent 28 surgical procedures: 22 elective and 6 emergency. The types of these procedures were 12 orthopedic, 6 intraabdominal, 4 vascular, 4 urologic, 1 otolaryngologic, and 1 thoracic. Mean age was 75 +/- 8 years. Of the 19 patients, 16 (84%) had > or = 1 symptom: dyspnea, angina, syncope, or presyncope. Mean left ventricular ejection fraction was 61 +/- 11%. The type of anesthesia was general in 26 procedures and continuous spinal in 2. Intraarterial monitoring of blood pressure was used in 20 of the 28 surgical procedures. Intraoperative hypotensive events were treated promptly, primarily with phenylephrine. In all cases the anesthesia team was aware of the severity of the AS and integrated this into the anesthetic plan. Two patients (elective operation in 1 and emergency in 1) had complicated postoperative courses and died. There were no other intraoperative or postoperative events in any of the other patients. Although aortic valve replacement remains the primary treatment for patients with severe AS, selected patients with severe AS, who are otherwise not candidates for aortic valve replacement, can undergo noncardiac surgery with acceptable risk when appropriate intraoperative and postoperative management is used.

Defining the cross-sectional anatomy important to interscalene brachial plexus block with magnetic resonance imaging

BACKGROUND AND OBJECTIVES

Interscalene brachial plexus block is a useful technique to provide anesthesia and analgesia for the shoulder and proximal upper extremity. The initial needle direction at the interscalene groove has been described as being "perpendicular to the skin in every plane" (1). A cross-sectional (axial) approach may offer a more easily conceptualized directed needle placement. The purpose of this study is to define the cross-sectional anatomy and idealized needle angles important to interscalene brachial plexus block.

METHODS

Following IRB approval, 50 patients were studied. Cross-sectional volume coil T1-weighted magnetic resonance images (MRI) were obtained from 50 patients undergoing cervical region imaging for other reasons. At the interscalene groove, a simulated needle path to contact the ventral rami or trunks of the brachial plexus was approximated at the level of C6 or C6-C7 interspace. The angle of this needle path intersecting the sagittal plane was recorded for each patient.

RESULTS

The mean angle of the simulated needle path relative to sagittal plane was determined to be 61.1 +/- 6.1 degrees (range, 50-78 degrees). In 13 of 50 (26%) MRI scans, the cervical nerve roots were not visualized at the level of C6 and were measured at the C6-C7 level.

CONCLUSIONS

These findings suggest initial needle placement at the interscalene groove should be angled less perpendicularly relative to the sagittal plane than is often observed. A cross-sectional approach enables more practical visualization of initial needle placement. A more accurate initial needle placement may minimize the number of needle passes necessary to contact the nerve roots, thereby more efficiently obtaining a successful block.