Shared and unique risk factors for readmission exist following upper and lower extremity arthroplasty in the 30-day postoperative period

PURPOSE

Joint arthroplasty has become increasingly more common in the United States, and it is important to examine the patient-based risk factors and surgical variables associated with hospital readmissions. The purpose of this study was to identify stratified rates and risk factors for readmission after upper extremity (shoulder, elbow, and wrist) and lower extremity (hip, knee, and ankle) arthroplasty.

METHODS

All patients undergoing upper and lower extremity arthroplasty from 2008-2018 were identified using the National Surgical Quality Improvement Program dataset. Patient demographics, medical comorbidities and surgical characteristics were examined utilizing uni- and multi-variate analysis for significant predictors of 30-days hospital readmission.

RESULTS

A total of 523,523 lower and 25,215 upper extremity arthroplasty patients were included in this study. A number of 22,183 (4.2%) lower and 1072 (4.4%) upper extremity arthroplasty patients were readmitted within 30 days of discharge. Significant risk factors for 30-days readmission after lower extremity arthroplasty included age, Body Mass Index (BMI), operative time, dependent functional status, American Society of Anesthesiologists (ASA) score ≥3, increased length of stay, and various medical comorbidities such as diabetes, tobacco dependency, and chronic obstructive pulmonary disease (COPD). An overweight BMI was associated with a lower odds of 30-days readmission when compared to a normal BMI for lower extremity arthroplasty. Analysis for upper extremity arthroplasty revealed similar findings of significant risk factors for 30-days hospital readmission, although diabetes mellitus was not found to be a significant risk factor.

CONCLUSION

Nearly one in 25 patients undergoing upper and lower extremity arthroplasty experiences hospital readmission within 30-days of index surgery. There are several modifiable risk factors for 30-days hospital readmission shared by both lower and upper extremity arthroplasty, including tobacco smoking, COPD, and hypertension. Optimization of these medical comorbidities may mitigate the risk short-term readmission following joint arthroplasty procedures and improve overall cost effectiveness of perioperative surgical care.

Biceps Tenodesis Has Greater Expected Value Than Repair for Isolated Type II SLAP Tears: A Meta-analysis and Expected-Value Decision Analysis

PURPOSE

To use an expected-value decision analysis to determine the optimal treatment decision between repair and biceps tenodesis (BT) for an isolated type II SLAP injury.

METHODS

An expected-value decision analysis with sensitivity analysis was performed to systematically quantify the clinical decision. To determine outcome probabilities, a decision tree was constructed (repair vs BT) and a meta-analysis was conducted. To determine outcome utilities, we evaluated 70 patients with a chief complaint of shoulder pain regarding age, sex, Shoulder Activity Level, and visual analog scale score in terms of potential outcome preferences. Statistical fold-back analysis was performed to determine the optimal treatment. One-way sensitivity analysis determined the effect of changing the reinjury rate on the expected value of BT.

RESULTS

The overall expected value was 8.66 for BT versus 7.19 for SLAP repair. One-way sensitivity analysis showed that BT was the superior choice if reinjury rates were expected to be lower than 28%. Meta-analysis of 23 studies and 908 patients revealed that the probability of a "well" outcome was significantly greater for BT (87.8%; 95% confidence interval [CI], 74.9%-94.6%; I² = 0.0%) than for SLAP repair (62.9%; 95% CI, 55.9%-69.3%; I² = 65.9%; P = .0023). The rate of reinjury was 1.5% for BT (95% CI, 0.05%-33.8%; I² = 0.0%) and 6.4% for repair (95% CI, 4.2%-9.6%; I² = 24%), which was not statistically significantly different (P = .411). A total of 50 participants (mean age, 25.4 years [standard deviation, 8.9 years]; 76% male patients; 50% overhead athletes) met the inclusion criteria. Forty-six percent of participants had a high Shoulder Activity Level score.

CONCLUSIONS

Decision analysis showed that BT is preferred over repair for an isolated type II SLAP tear based on greater expected value of BT versus repair. Meta-analysis showed more frequent favorable outcomes with BT. Surgeons can use this information to tailor discussions with patients.

LEVEL OF EVIDENCE

Level IV, meta-analysis of Level I-IV studies.

Editorial Commentary: Taking a "PEEK" at Suture Anchor Composition following Arthroscopic Rotator Cuff Repair: Is Bio Really Better?

The advent of modern suture anchor technology has not only revolutionized arthroscopic treatment options for management of complex shoulder pathology, but also engendered a materials science quest to identify the ultimate composition and design. What began as an open procedure with transosseous suture fixation has evolved dramatically with the widespread adoption of an arthroscopic, anchor-based technique for rotator cuff repair. Currently, a litany of commercially available "hard" and "soft" anchors are flooding the market, with limited qualitative comparisons to suggest superiority of one type. Ideally, suture anchor design should permit preservation of native glenohumeral bone stock with gradual osseointegration, limit disruption of local tissue homeostasis, and maintain time-zero mechanical strength until soft-tissue healing has occurred. At present, a vented, open-anchor architecture may facilitate better biologic incorporation with increased bony ingrowth through access to marrow elements, although these radiographic advantages have not conferred any clinically meaningful differences for our rotator cuff repair patients. For anchor composition, the jury is still out, and we need to continue to critically evaluate for perianchor cyst formation and longer term remodeling. In fact, the true merits of increased bony ingrowth and limited osteolysis may only be realized at the time of revision rotator cuff repair, during which prior implant position or secondary cystic change may further dictate suture anchor design, size, and placement.

Anoikis-resistant subpopulations of human osteosarcoma display significant chemoresistance and are sensitive to targeted epigenetic therapies predicted by expression profiling

Background

Osteosarcoma (OS) is the most common type of solid bone cancer, with latent metastasis being a typical mode of disease progression and a major contributor to poor prognosis. For this to occur, cells must resist anoikis and be able to recapitulate tumorigenesis in a foreign microenvironment. Finding novel approaches to treat osteosarcoma and target those cell subpopulations that possess the ability to resist anoikis and contribute to metastatic disease is imperative. Here we investigate anchorage-independent (AI) cell growth as a model to better characterize anoikis resistance in human osteosarcoma while using an expression profiling approach to identify and test targetable signaling pathways.

Methods

Established human OS cell lines and patient-derived human OS cell isolates were subjected to growth in either adherent or AI conditions using Ultra-Low Attachment plates in identical media conditions. Growth rate was assessed using cell doubling times and chemoresistance was assessed by determining cell viability in response to a serial dilution of either doxorubicin or cisplatin. Gene expression differences were examined using quantitative reverse-transcription PCR and microarray with principal component and pathway analysis. In-vivo OS xenografts were generated by either subcutaneous or intratibial injection of adherent or AI human OS cells into athymic nude mice. Statistical significance was determined using student’s t-tests with significance set at α = 0.05.

Results

We show that AI growth results in a global gene expression profile change accompanied by significant chemoresistance (up to 75 fold, p < 0.05). AI cells demonstrate alteration of key mediators of mesenchymal differentiation (β-catenin, Runx2), stemness (Sox2), proliferation (c-myc, Akt), and epigenetic regulation (HDAC class 1). AI cells were equally tumorigenic as their adherent counterparts, but showed a significantly decreased rate of growth in-vitro and in-vivo (p < 0.05). Treatment with the pan-histone deacetylase inhibitor vorinostat and the DNA methyltransferase inhibitor 5-azacytidine mitigated AI growth, while 5-azacytidine sensitized anoikis-resistant cells to doxorubicin (p < 0.05).

Conclusions

These data demonstrate remarkable plasticity in anoikis-resistant human osteosarcoma subpopulations accompanied by a rapid development of chemoresistance and altered growth rates mirroring the early stages of latent metastasis. Targeting epigenetic regulation of this process may be a viable therapeutic strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0466-4) contains supplementary material, which is available to authorized users.

Old dogs and new tricks: length of stay for appendicitis improves with an acute care surgery program and transition from private surgical practice to multispecialty group practice

Acute care surgery (ACS) programs have emerged mainly at academic medical centers to provide timely care for emergency general surgery and trauma patients. We hypothesized that the development of an ACS program in a multispecialty group practice would improve outcomes for patients with acute appendicitis. A retrospective analysis of patients with acute appendicitis was performed in two time periods: 18 months of private practice and the following 12 months with ACS coverage. Length of stay was the primary outcome measure. A total of 871 patients were studied (526 private practice, 345 ACS). The ACS group had a greater proportion of laparoscopic appendectomies (P < 0.001) and more transitions in care between surgeons (P < 0.001). Length of stay was shorter in the ACS group (1.6 ± 1.5 [mean ± standard deviation] vs 1.9 ± 2.4 days, P = 0.01) and a greater proportion of surgeries were performed during the daytime (44.9 vs 36.6%, P = 0.02). Multivariate analysis demonstrated length of stay was related to appendicitis grade (P < 0.001), American Society of Anesthesiologists class (P < 0.001), symptom duration (P = 0.001), and laparoscopic approach (P < 0.001). The initial transition from private practice to ACS resulted in decreased length of stay with no increase in morbidity related to transitions of surgical care in patients with appendicitis.

Old Dogs and New Tricks: Length of Stay for Appendicitis Improves with an Acute Care Surgery Program and Transition from Private Surgical Practice to Multispecialty Group Practice

Acute care surgery (ACS) programs have emerged mainly at academic medical centers to provide timely care for emergency general surgery and trauma patients. We hypothesized that the development of an ACS program in a multispecialty group practice would improve outcomes for patients with acute appendicitis. A retrospective analysis of patients with acute appendicitis was performed in two time periods: 18 months of private practice and the following 12 months with ACS coverage. Length of stay was the primary outcome measure. A total of 871 patients were studied (526 private practice, 345 ACS). The ACS group had a greater proportion of laparoscopic appendectomies ( P < 0.001) and more transitions in care between surgeons ( P < 0.001). Length of stay was shorter in the ACS group (1.6 ± 1.5 [mean ± standard deviation] vs 1.9 ± 2.4 days, P = 0.01) and a greater proportion of surgeries were performed during the daytime (44.9 vs 36.6%, P = 0.02). Multivariate analysis demonstrated length of stay was related to appendicitis grade ( P < 0.001), American Society of Anesthesiologists class ( P < 0.001), symptom duration ( P = 0.001), and laparoscopic approach ( P < 0.001). The initial transition from private practice to ACS resulted in decreased length of stay with no increase in morbidity related to transitions of surgical care in patients with appendicitis.

Down regulation of Wnt signaling mitigates hypoxia-induced chemoresistance in human osteosarcoma cells

Osteosarcoma (OS) is the most common type of solid bone cancer and remains the second leading cause of cancer-related death for children and young adults. Hypoxia is an element intrinsic to most solid-tumor microenvironments, including that of OS, and is associated with resistance to therapy, poor survival, and a malignant phenotype. Cells respond to hypoxia through alterations in gene expression, mediated most notably through the hypoxia-inducible factor (HIF) class of transcription factors. Here we investigate hypoxia-induced changes in the Wnt/β-catenin signaling pathway, a key signaling cascade involved in OS pathogenesis. We show that hypoxia results in increased expression and signaling activation of HIF proteins in human osteosarcoma cells. Wnt/β-catenin signaling is down-regulated by hypoxia in human OS cells, as demonstrated by decreased active β-catenin protein levels and axin2 mRNA expression (p<0.05). This down-regulation appears to rely on both HIF-independent and HIF-dependent mechanisms, with HIF-1α standing out as an important regulator. Finally, we show that hypoxia results in resistance of human OS cells to doxorubicin-mediated toxicity (6–13 fold increase, p<0.01). These hypoxic OS cells can be sensitized to doxorubicin treatment by further inhibition of the Wnt/β-catenin signaling pathway (p<0.05). These data support the conclusion that Wnt/β-catenin signaling is down-regulated in human OS cells under hypoxia and that this signaling alteration may represent a viable target to combat chemoresistant OS subpopulations in a hypoxic niche.

Abstract A70: Chemotherapy-resistant subpopulations in a tumor-initiating cell model of human osteosarcoma

Introduction: Tumor-initiating cells (TICs) are a subpopulation of therapy resistant cells in osteosarcoma. To date, TICs have been experimentally defined based on the chosen isolation technique. Common to all isolation methods, TICs demonstrate a high degree of the multi-drug resistance phenotype, are more invasive, metastasize readily, and have increased capacity for tumorigenesis. Given this phenotype TICs represent a viable therapeutic target. Cultivating cells in low-adherence, serum-deprived conditions results in spherical colony formation. Certain growth factors present in serum drive epithelial-to-mesenchymal transition, and typically confound TIC models of carcinoma. The effect of serum on mesenchymal-based sarcoma TIC models is less clear. Recent literature suggests that merely the presence of low-adherence conditions can enrich in TICs. We have shown that osteosarcoma cells cultured in low-adherence conditions in the presence of 10% fetal bovine serum (FBS) form spheres, exhibit an increased expression of genes implicated in developmental programs and stem cells, are more resistant to chemotherapy, and more readily initiate tumors than adherent cells when injected into mice.

Methods: The osteosarcoma cell lines 143B, mHOS, and MG-63 were cultured in low-adherence plates using DMEM or MEM media supplemented with 10% FBS. Spheres were routinely grown for 4-6 days between passages and dissociated using 0.05% trypsin. Relative mRNA expression levels of Nanog, Sox2, Oct4 and Axin2 was assessed using quantitative-PCR (SYBR Green). Resistance to chemotherapy (doxorubicin and cisplatin) was determined by comparing both adherent cells and spheres (in low adherence 96-well plates) grown to at least the second passage. After 72 hours IC50 values were calculated using the CellTitre Glo luminescence assay. To assess in vivo tumorgenicity, adherent and sphere cells were dissociated and injected into the flanks of nude mice at a density of 10,000 cells. Upon tumor formation the mice were euthanized and the tumors re-implanted into a second set of mice to test their ability to serially transplant.

Results: Sarcospheres can be successfully and reproducibly grown and passaged in low-adherent culture conditions in media supplemented with 10% FBS. Expression profiling demonstrates increased expression of Sox2, Oct4, Nanog, and Axin2, all genes that have been identified to be associated with developmental programs and stem cells. Sarcospheres also displayed increased chemoresistance compared to adherent cultures to both cisplatin (IC50 change of 1.9, 6.9, and 6.2-fold in 143B, mHOS and MG-63, respectively) and more so to doxorubicin (IC50 change of 12.7, 35 and greater than 74-fold in 143B, mHOS, and MG-63, respectively). Additionally, in a pilot subcutaneous xenograft study, using sphere and adherent cells, differential growth was observed within the TIC-enriched populations demonstrating (1) earlier tumor initiation and (2) a lower overall proliferation rate among the primary and serially transplanted tumors confirming a persistence of the TIC phenotype through in vivo passaging.

Conclusions: Osteosarcoma cells cultured in low-adherence conditions in the presence of serum display many of the characteristics of putative tumor-initiating cells including robust sphere formation, upregulation of key stemness mediators, enhanced chemoresistance, and in vivo tumor initiation and serial transplantability. Using this system, we aim to further evaluate these stem-like populations in order to elucidate potential therapies targeting this specialized, chemoresistant niche.

Citation Format: Jessica M. Foley, Noel R. Monks, Donald J. Scholten, II, David J. Monsma, Dawna Dylewski, Paula J. Davidson, Matthew R. Steensma. Chemotherapy-resistant subpopulations in a tumor-initiating cell model of human osteosarcoma. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A70.

Targeting receptor-activator of nuclear kappaB ligand in aneurysmal bone cysts: verification of target and therapeutic response

Aneurysmal bone cyst (ABC) is a benign tumor of bone presenting as a cystic, expansile lesion in both the axial and appendicular skeleton. Axial lesions demand special consideration, because treatment-related morbidity can be devastating. In similar lesions, such as giant cell tumor of bone (GCTB), the receptor-activator of nuclear kappaB ligand (RANKL)-receptor-activator of nuclear kappaB (RANK) signaling axis is essential to tumor progression. Although ABC and GCTB are distinct entities, they both contain abundant multinucleated giant cells and are osteolytic characteristically. We hypothesize that ABCs express both RANKL and RANK similarly in a cell-type specific manner, and that targeted RANKL therapy will mitigate ABC tumor progression. Cellular expression of RANKL and RANK was determined in freshly harvested ABC samples using laser confocal microscopy. A consistent cell-type-specific pattern was observed: fibroblastlike stromal cells expressed RANKL strongly whereas monocyte/macrophage precursor and multinucleated giant cells expressed RANK. Relative RANKL expression was determined by quantitative real-time polymerase chain reaction in ABC and GCTB tissue samples; no difference in relative expression was observed (P > 0.05). In addition, we review the case of a 5-year-old boy with a large, aggressive sacral ABC. After 3 months of targeted RANKL inhibition with denosumab, magnetic resonance imaging demonstrated tumor shrinkage, bone reconstitution, and healing of a pathologic fracture. Ambulation, and bowel and bladder function were restored at 6 months. Denosumab treatment was well tolerated. Post hoc analysis demonstrated strong RANKL expression in the pretreatment tumor sample. These findings demonstrate that RANKL-RANK signal activation is essential to ABC tumor progression. RANKL-targeted therapy may be an effective alternative to surgery in select ABC presentations.

C(X)CR in silico: Computer-aided prediction of chemokine receptor-ligand interactions

This review will focus on the construction, refinement, and validation of chemokine receptor models for the purpose of structure-based virtual screening and ligand design. The review will present a comparative analysis of ligand binding pockets in chemokine receptors, including a review of the recently released CXCR4 X-ray structures, and their implication on chemokine receptor (homology) modeling. The recommended protein-ligand modeling procedure as well as the use of experimental anchors to steer the modeling procedure is discussed and an overview of several successful structure-based ligand discovery and design studies is provided. This review shows that receptor models, despite structural inaccuracies, can be efficiently used to find novel ligands for chemokine receptors.:

Pharmacological characterization of a small-molecule agonist for the chemokine receptor CXCR3

BACKGROUND AND PURPOSE

The chemokine receptor CXCR3 is a GPCR found predominantly on activated T cells. CXCR3 is activated by three endogenous peptides; CXCL9, CXCL10 and CXCL11. Recently, a small-molecule agonist, VUF10661, has been reported in the literature and synthesized in our laboratory. The aim of the present study was to provide a detailed pharmacological characterization of VUF10661 by comparing its effects with those of CXCL11.

EXPERIMENTAL APPROACH

Agonistic properties of VUF10661 were assessed in a chemotaxis assay with murine L1.2 cells transiently transfected with cDNA encoding the human CXCR3 receptor and in binding studies, with [(125)I]-CXCL10 and [(125)I]-CXCL11, on membrane preparations from HEK293 cells stably expressing CXCR3. [(35)S]-GTPγS binding was used to determine its potency to induce CXCR3-mediated G protein activation and BRET-based assays to investigate its effects on intracellular cAMP levels and β-arrestin recruitment.

KEY RESULTS

VUF10661 acted as a partial agonist in CXCR3-mediated chemotaxis, bound to CXCR3 in an allosteric fashion in ligand binding assays and activated G(i) proteins with the same efficacy as CXCL11 in the [(35)S]-GTPγS binding and cAMP assay, while it recruited more β-arrestin1 and β-arrestin2 to CXCR3 receptors than the chemokine.

CONCLUSIONS AND IMPLICATIONS

VUF10661, like CXCL11, activates both G protein-dependent and -independent signalling via the CXCR3 receptor, but probably exerts its effects from an allosteric binding site that is different from that for CXCL11. It could stabilize different receptor and/or β-arrestin conformations leading to differences in functional output. Such ligand-biased signalling might offer interesting options for the therapeutic use of CXCR3 agonists.

Pharmacological modulation of chemokine receptor function

G protein-coupled chemokine receptors and their peptidergic ligands are interesting therapeutic targets due to their involvement in various immune-related diseases, including rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, chronic obstructive pulmonary disease, HIV-1 infection and cancer. To tackle these diseases, a lot of effort has been focused on discovery and development of small-molecule chemokine receptor antagonists. This has been rewarded by the market approval of two novel chemokine receptor inhibitors, AMD3100 (CXCR4) and Maraviroc (CCR5) for stem cell mobilization and treatment of HIV-1 infection respectively. The recent GPCR crystal structures together with mutagenesis and pharmacological studies have aided in understanding how small-molecule ligands interact with chemokine receptors. Many of these ligands display behaviour deviating from simple competition and do not interact with the chemokine binding site, providing evidence for an allosteric mode of action. This review aims to give an overview of the evidence supporting modulation of this intriguing receptor family by a range of ligands, including small molecules, peptides and antibodies. Moreover, the computer-assisted modelling of chemokine receptor-ligand interactions is discussed in view of GPCR crystal structures. Finally, the implications of concepts such as functional selectivity and chemokine receptor dimerization are considered.

A comparison of two different prophylactic dose regimens of low molecular weight heparin in bariatric surgery

BACKGROUND

Deep venous thrombosis (DVT) is a significant risk in patients undergoing surgery for morbid obesity and may be associated with significant morbidity and mortality. In a consecutive group of patients in one bariatric surgery practice, the initial group of patients who received prophylaxis for DVT was given enoxaparin 30 mg q12h while the later group was given enoxaparin 40 mg q12h.

METHODS

481 patients who underwent primary and revisional bariatric surgery over 38 months (October 1997-December 2000) were evaluated. All patients received a multi-modality DVT prophylaxis protocol that included: early ambulation, graduated compression stockings, intermittent pneumatic compression, and enoxaparin (LMWH) in two dosage groups. The first 92 patients (19%) in the series (Group I) received LMWH 30 mg q12h while the subsequent 389 patients (81%) (Group II) received LMWH 40 mg q12h.

RESULTS

Group I patients were not different from Group II patients in body mass index (BMI) (51.7 vs 50.3 kg/m2), age (43.7 vs 44.3 yrs), sex (men 20.2% vs 15.8%) or history of previous DVT (3.2% vs 3.9%). Group I patients did have significantly longer procedure times (213 vs 175 min, p < 0.05) and hospital stays (5.67 d vs 3.81 d, p < 0.05) than Group II. There were a total of 7 (1.4%) postoperative DVT complications. 5 DVT complications occurred in Group I (5.4%) compared with 2 DVT complications in Group II (0.6%) (p < 0.01 by Fisher Exact Test two-tailed). One patient in each group required treatment for hemorrhage.

CONCLUSION

A multi-modality prophylaxis treatment protocol in patients undergoing bariatric surgery is feasible and achieves a low incidence of postoperative DVT complications. The use of a higher dose of enoxaparin, 40 mg q12h, may reduce the incidence of DVT complications in patients following bariatric surgery without an increase in bleeding complications.

A comparison of long-term outcome in first-episode schizophrenia following treatment with risperidone or a typical antipsychotic

BACKGROUND

Most reports assessing the efficacy and tolerability of risperidone have involved patients previously treated with typical antipsychotics. Such patients are more likely to have a greater resistance or intolerance to treatment, thus restricting our interpretation of the impact a new treatment might have on the course of schizophrenia and possibly biasing the results. The present study examines the relative effectiveness of risperidone and typical antipsychotics in patients being treated for their first episode of schizophrenia.

METHOD

From a cohort of 126 patients, 2 groups of 19 first-episode DSM-III-R/DSM-IV schizophrenia patients matched for age, gender, length of illness, and length of treatment and treated with either a typical antipsychotic or risperidone for a minimum of 1 year were compared on a number of outcome dimensions during their course of treatment and at follow-up. Treatment allocation was not random, and patients were judged to be compliant with medication. Patients treated with typical antipsychotics were followed up for a statistically nonsignificantly longer time (mean = 2.7 vs. 1.9 years).

RESULTS

Six patients (31.6%) from the typical antipsychotic group were admitted to the hospital within the first year following the index admission compared with 1 patient (5.3%) in the risperidone group (admitted at month 14). Patients in the risperidone group showed a statistically significantly lower length of first hospitalization (p < .01), utilization of inpatient beds during the course of treatment (p < .001), and use of anticholinergic medication (p < .05). There were no statistically significant differences in symptom levels, either during the course of treatment or at follow-up; in the use of antidepressant, antianxiety, or mood-stabilizing drugs; or in changes in living circumstances or employment.

CONCLUSION

These findings confirm at least equal long-term efficacy of typical antipsychotics and risperidone, but a possible advantage for risperidone in decreased service utilization and decreased use of anticholinergic drugs.

Concomitant blunt enteric injuries with injuries of the liver and spleen: a dilemma for trauma surgeons

Prompt identification of enteric injuries after blunt trauma remains problematic. With the increased utilization of nonoperative management of blunt abdominal trauma gastrointestinal disruptions may escape timely detection and repair. The purpose of this study was to evaluate blunt enteric injuries requiring operative repair in adult patients and the association of concomitant hepatic and/or splenic injuries. Over a 10-year period (January 1990 through December 1999) 1648 patients suffered blunt liver, spleen, and/or enteric injuries, with 87 (5.3%) of these requiring operative repairs of the enteric injury. These patients had enteric injury only (EI) (60.9%; 53 of 87), concomitant enteric/splenic injury (ESI) (10.3%; 9 of 87), concomitant enteric/hepatic injury (EHI) (13.8%; 12 of 87), and enteric/hepatic/splenic injury (EHSI) 14.9% (13 of 87). A delay in treatment of >8 hours from presentation of EI compared with either EHI or ESI was not significantly different between the two groups. EHSI had exploratory laparotomy more expeditiously related to hemodynamic instability. Mortality rates were higher with EHI related to hemorrhagic shock and/or severe traumatic brain injury. Morbidity was not related to a delay in diagnosis until the period of delay was greater than 24 hours. The nonoperative management of blunt solid organ injury does not delay the detection and treatment of concomitant bowel injuries compared with isolated blunt enteric injuries. Occult enteric injury with solid organ injury has a low incidence and represents a continuing challenge to the clinical acumen of the trauma surgeon.

Concomitant Blunt Enteric Injuries with Injuries of the Liver and Spleen: A Dilemma for Trauma Surgeons

Prompt identification of enteric injuries after blunt trauma remains problematic. With the increased utilization of nonoperative management of blunt abdominal trauma gastrointestinal disruptions may escape timely detection and repair. The purpose of this study was to evaluate blunt enteric injuries requiring operative repair in adult patients and the association of concomitant hepatic and/or splenic injuries. Over a 10-year period (January 1990 through December 1999) 1648 patients suffered blunt liver, spleen, and/or enteric injuries, with 87 (5.3%) of these requiring operative repairs of the enteric injury. These patients had enteric injury only (EI) (60.9%; 53 of 87), concomitant enteric/splenic injury (ESI) (10.3%; 9 of 87), concomitant enteric/hepatic injury (EHI) (13 8%-12 of 87), and enteric/hepatic/splenic injury (EHSI) 14.9% (13 of 87). A delay in treatment of >8 hours from presentation of EI compared with either EHI or ESI was not significantly different between the two groups. EHSI had exploratory laparotomy more expeditiously related to hemodynamic instability. Mortality rates were higher with EHI related to hemorrhagic shock and/or severe traumatic brain injury. Morbidity was not related to a delay in diagnosis until the period of delay was greater than 24 hours. The nonoperative management of blunt solid organ injury does not delay the detection and treatment of concomitant bowel injuries compared with isolated blunt enteric injuries. Occult enteric injury with solid organ injury has a low incidence and represents a continuing challenge to the clinical acumen of the trauma surgeon.

Prospective study of blunt aortic injury: Multicenter Trial of the American Association for the Surgery of Trauma

BACKGROUND

Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years.

METHODS

This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma.

RESULTS

There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia.

CONCLUSIONS

Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

Failure of antiseptic bonding to prevent central venous catheter-related infection and sepsis

Infection associated with the use of triple lumen catheters in hospitals is a frequent and serious complication. The prevailing hypothesis for the origin of catheter-related infection (CRI) is bacterial colonization and subsequent infection of the skin insertion site and catheter interface. The recently released ARROWgard catheter contains a bonded synergistic combination of silver sulfadiazine and chlorhexidine, which is thought to render the catheter resistant to bacterial colonization and subsequent sepsis. The purpose of this study is to compare the incidence of CRI and catheter-related sepsis (CRS) between a standard triple lumen catheter and ARROWgard antiseptic coated catheter in patients receiving total parenteral nutrition (TPN). A randomized, prospective clinical trial was conducted at a community referral center from January 1993 through April 1994. One-hundred-ninety-one patients with need for TPN were randomized to receive either the ARROWgard or a standard triple lumen catheter placed under a strict sterile protocol. CRI was defined as >/= 15 colony forming units by semiquantitative culture technique of the catheter tip or intracutaneous segment. CRS was defined as growth of the same organism on the catheter and at least one peripheral blood culture. All catheters were cultured. Ninety-two patients received the ARROWgard catheter, and 99 patients received the standard catheter. There were no differences between the average age, sex, length of hospital stay, days on TPN, number of catheters/patient, indications for TPN, primary diagnoses, or duration of the central line between the two groups. The overall rate of CRI was 11.5 per cent, and CRS was 8.4 per cent in this study. The rate of CRI for the ARROWgard was 10.9 per cent, compared with 12.9 per cent for the standard catheter (P = NS). The rate of CRS for the ARROWgard was 8.7 per cent, compared with 8.1 per cent for the standard catheter (P = NS). The coating of central venous catheters with silver sulfadiazine and chlorhexidine does not reduce the rate CRI or CRS when compared with standard central venous catheters in patients receiving TPN.

Failure of methylprednisolone to improve the outcome of spinal cord injuries

The infusion of methylprednisolone (MP) within 8 hours of injury for spinal cord injuries (SCI) has been advocated to improve the motor function of patients after this catastrophic injury. However, clinical improvement in the outcome of SCI has not been consistently identified, despite the use of MP. We reviewed the outcome of SCI patients with MP to those without MP (No-MP) at two Level I Trauma Centers from 1989-1992. Acute SCI patients were identified from the trauma registries with trauma demographics and hospital data obtained from registry and medical records. Rehabilitation data for Functional Independence Measure (FIM) was obtained from the rehabilitation institute database. Primary outcome parameters were mortality, and for survivors, patient mobility (6 point scale) and FIM scores. There were 145 acute SCI patients: 80 treated with MP and 65 with No-MP. FIM data was available on 45 MP and 25 No-MP patients. There was no difference in the admission trauma score, ICU length of stay (LOS), or hospital LOS between the two groups. The MP patients were significantly younger (30 years vs 38 years, P = < 0.05) and had lower ISS scores (24 vs 31, P = < 0.05). There was no statistically significant difference in mortality (MP, 3.8% vs No-MP, 10.7%) between the two groups. Although admission mobility was not statistically different (MP, 5.99 vs No-MP, 5.90), there was a significantly poorer discharge mobility in the MP group when compared to the No-MP group (MP, 5.16 vs No-MP, 4.67, P = < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The continuing clinical dilemma of primary tumors of the small intestine

Small intestinal tumors are relatively rare, notoriously difficult to diagnose, and often advanced at the time of definitive treatment. The purpose of this study is to compare the differences between benign and malignant tumors of the small intestine and between symptomatic and asymptomatic tumors with respect to their clinical presentation, efficacy of diagnostic procedures, and surgical management with correlation to pathologic findings. Forty-nine patients with primary small intestinal tumors between 1981-1993 had 17 benign and 32 malignant tumors. Benign tumors more commonly presented with acute gastrointestinal hemorrhage (29% versus 6%, P < 0.05), and were often asymptomatic (47% versus 6%, P < 0.05). Malignant tumors more commonly presented with abdominal pain (63% versus 24%, P < 0.05) and weight loss (38% versus 0%, P < 0.05). The total number of diagnostic tests/patient averaged 2.3 +/- 0.3, and the average time from onset of symptoms to resection was 30.2 +/- 6.6 weeks. Upper endoscopy, angiography, and upper gastrointestinal contrast studies had the most useful sensitivity rates. Surgical treatment of tumors included biopsy/excision, limited bowel resection, segmental resection with regional lymphadenectomy, or a bypass procedure. The most common types of benign and malignant tumors were leiomyoma (41%) and adenocarcinoma (53%), respectively. Histologically, tumors were evenly distributed throughout the small intestine. Small intestinal tumors remain difficult to diagnose because of an atypical presentation and renew the need for appropriate suspicion when treating patients with vague abdominal symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Assuring trauma system quality by outcomes reporting in two voluntary regional trauma networks

1. Providing optimal trauma care for large populations requires the collaboration and cooperation of hospitals providing all levels of care. 2. Those who are seriously injured or who have complex injuries requiring special resources are to be referred in a timely fashion to a trauma center capable of providing optimal care. 3. In two regional trauma networks, 24% of injured patients were referred to a trauma center for definitive care. Overall survival was excellent.

Experience with surgical resident training in a combined program in plastic surgery

Healthcare reform may impact graduate medical education (GME) to reduce both specialty training positions and the length of training in these programs. General Surgery residencies often provide prerequisite training for surgery specialty training and will be affected by these changes. The purpose of this study is to identify the quality, outcome, and differences between PGYI-PGYIII categorical general surgery residents (GS) and matched prerequisite plastic surgery residents (PS). Concurrent comparisons analyzed American Board of Surgery Inservice Training Examinations (ABSITE) data from 1980-1992 as well as the surgery operative logs (SOL) and the curriculum of matched residents from 1989-1992. Outcome was assessed by board performance and from a piloted questionnaire to all PS graduates of the combined (3-year GS and 2-year PS) program. ABSITE analysis demonstrated satisfactory performance for both PS and GS at each PGY level, with significant increases each year for GS, but only between PGYI and PGYII for PS; there was a significant difference between PS and GS at all PGY levels. SOL analysis paralleled the curriculum and demonstrated more plastic surgery for PS compared to GS, with no difference in general surgery or hand surgery. PS program graduate respondents (32/44-72.7%) identified that the GS training/PS training was appropriate (71.9%/93.8%), effective (90.7%/93.8%) and of appropriate duration (87.5%/75.1%). 87.5 per cent of PS graduates completed ABPS certification. Combined PS training in all PS programs would reduce GME payments by over $20 million. Combined PS training is effective, appropriate, resource-efficient, and has an excellent outcome, but it requires a specific curriculum and close coordination between General Surgery and Plastic Surgery programs.

Hospitalization and injury influence on the prosecution of drunk drivers

The influence that injury and hospitalization from alcohol-related motor vehicle crashes may have on subsequent prosecution for drunk driving was studied utilizing concurrent controls consisting of three cohorts of drivers. The cohorts were drunk and injured drivers, drunk and not injured drivers, and sober and injured drivers. Even though the majority of intoxicated drivers were identified by police as having been drinking, evidentiary testing was not uniform. Culpability for the crash was high in the drunk cohorts compared with the sober drivers, and yet there was a statistically significant difference in the conviction rate of injured drunk drivers (59%) compared with uninjured drunk drivers (100%). Injury and hospitalization for drunk drivers after motor vehicle crashes affords protection from prosecution, and may enable ongoing risk-taking behavior by the drunk driver.

Multi-institutional survey of laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) is being used more frequently in patients undergoing gallbladder removal. Most initial studies have centered on the limited experience of a few select surgeons or institutions and may not accurately reflect the current state of LC. We used written and telephone survey tools to 103 community hospitals in Michigan to identify the utilization of LC, the criteria for training and credentialing, and patient outcome. Of 103 hospitals, 75 (73%) were involved with LC and 56% of these had < 100 beds. We found a large variation in the indications, contraindications, equipment, methods, and credentialing criteria. Major complications, including some not previously reported, were identified and occurred more frequently than previously described. LC is being widely applied and the majority of hospitals have < 100 beds. LC may carry higher risks than previously reported. Collected series and registry data that include community hospital experiences should better delineate the outcome of LC.

Factors influencing pregnancy outcome after trauma

Trauma complicating pregnancy represents a significant threat to maternal survival and successful pregnancy outcome. Combining trauma center and perinatal center capabilities may provide improved outcome for pregnant trauma victims. The authors report their experience with 39 patients over a 10-year period to identify factors that influenced pregnancy outcome. There was 100 per cent maternal survival with a 77 per cent successful pregnancy rate. Unsuccessful pregnancy was associated with significantly higher injury severity score (ISS); regional abdominal abbreviated injury scores (AIS) and hospital charges; longer hospital and intensive care unit lengths of stay; a higher incidence of intubation and placenta abruptio; and a lower admission systolic blood pressure. Fetal ultrasound or Doppler were routinely used and contributed to trauma management. These findings support close cooperation and coordination of trauma and perinatal services to achieve optimal maternal and pregnancy outcomes.

Surgical residents as teachers

Surgical program directors have assumed that residents take on the role of teachers of medical students, and they have seldom questioned this assumption. The purpose of this study was to: determine the extent to which surgical residents teach and evaluate medical students; assess how surgical residents are prepared for and evaluated on their teaching responsibilities; and to identify surgical program directors' opinions about residents as teachers. Written surveys were sent to program directors of surgical residencies. A response rate of 79 percent was achieved. All programs taught medical students and involved residents in the process. Surgical residents taught medical students in a variety of settings and were responsible for student evaluation Approximately half of the programs, however, did not offer formal instruction in teaching skills to their residents and 60 percent of program directors did not believe it was important. In addition residents rarely received evaluations from medical students or program directors on their teaching.

Failure of BCAA supplementation to promote nitrogen retention in injured patients

The purpose of this study was to determine if supplementing total parenteral nutrition (TPN) with lipids or the branched chain amino acids (BCAA) leucine, isoleucine, and valine influences nitrogen balance in the injured patient. Four TPN study solutions were used, with each patient receiving two of the solutions for 4 days each. Group A received solutions consisting of 19% and 44% BCAA, with nonnitrogen calories supplied by 100% carbohydrate. Group B received a 7:3 carbohydrate-to-lipid ratio of nonnitrogen calories as a fuel source. Neither BCAA supplementation nor varying fuel substrates promoted a difference in nitrogen retention. The added cost of BCAA supplementation, along with the lack of an effect upon nitrogen accretion, indicates that greater benefits must be demonstrated before widespread use of BCAA supplementation can be recommended in the injured patient.

DRGs and outliers in surgical critical care

The authors evaluated the charges, outcome, and characteristics of patients requiring prolonged stay in the Surgical Intensive Care Unit (SICU) as if all reimbursement was from the Medicare DRG system. The records of patients staying in the SICU longer than 20 days over an 18 month period were reviewed. Age, mortality, service, length of stay, hospital charge, and projected DRG reimbursement were recorded. Patients whose hospital stay exceeded the maximum expected for their DRG were considered day outliers. The 51 study patients had a mean age of 59 +/- 17.6 years. They comprised 1.3 per cent of all patients in the SICU and 30.7 per cent of all SICU patient days during the study period. Mortality was 39.2 per cent. Thirty-two patients (62.7%) were day outliers. The mean hospital charge per patient was $59,552 while the mean projected DRG reimbursement was $10,435, for a total projected loss in billed charges of $2,504,428. DRG reimbursement for patients requiring prolonged SICU stay is inadequate to meet their charges and may severely limit future SICU use.

In vitro preservation of traumatic human skin autografts in a massive degloving injury

The in vitro preservation of human skin autografts is a valuable technique in the management of severe degloving injuries. The authors describe the storage of traumatically induced human skin autografts involving nearly one third of the total body surface of a patient. These autografts were preserved in tissue-culture medium for 19 days and then transplanted onto the patient's prepared wounds, successfully acting as biologic dressings and permanent grafts. To the authors' knowledge, this is the largest clinical application of skin-storage techniques for the preservation of traumatic human skin autografts that is known to have been reported.

Long bone fractures in the polytrauma patient. The role of early operative fixation

The role of early operative fixation in polytrauma patients with long bone fractures was analyzed by comparing length of stay, intensive care unit days and ventilator days, incidence of pulmonary complications, infectious complications, orthopedic complications, and mortality in three groups: traction only, operative fixation later than 48 hours after admission, and operative fixation within 48 hours of admission. Patients in all groups were similar in mode of injury, age, and Injury Severity Scores. Patients with early operative fixation of long bone fractures had significantly (P less than .05) fewer pulmonary complications than either the traction or the late operative fixation group. No group routinely required ventilator support, even with attendant abdominal and chest trauma. Operative fixation of long bone fractures within 48 hours of admission in the multiply injured patient reduces pulmonary complications.

Carnitine femoral arterial-venous differences in the stressed critically ill

Femoral arterial and venous carnitine concentrations from critically ill patients were measured in order to determine if the large urinary carnitine excretions seen in these patients was associated with a net loss of carnitine from skeletal muscle. Bloods were drawn two or three times during the 7-day study period. A 24-hr urine sample was obtained on the same day. The arterial-venous difference for free carnitine plus short chain acylcarnitine was -2.8 +/- 0.9 microM (means +/- SEM), and -2.7 +/- 1.0 microM for total carnitine. Both values were significantly less than zero (p less than 0.05). Median urinary free carnitine excretion was 1237 mumol/day while the median acylcarnitine excretion was 544 mumol/day. We conclude that skeletal muscle in these patients is in negative carnitine balance, and is at least one source of the increase in carnitine excretion seen in critically ill patients.

Increased plasma carnitine in trauma patients given lipid-supplemented total parenteral nutrition

The purpose of this study was to determine the effects of altering the fuel substrate mix of total parenteral nutrition (TPN) on plasma and urinary carnitine in trauma patients. TPN solutions were either 100% carbohydrate (CHO) based or lipid based (70% CHO, 30% lipid). There were statistically significant (p less than 0.05) increases in plasma levels of free carnitine, short-chain acyl carnitine, and total carnitine in trauma patients receiving lipid-based TPN. No significant differences in urinary carnitine excretion were noted between groups. We conclude that the use of lipids in the TPN of trauma patients leads to an alteration in plasma carnitine metabolism.

Pulmonary artery diastolic and wedge pressure relationships in critically ill and injured patients

To study pulmonary artery wedge pressure (PAWP) and pulmonary artery diastolic pressure (PADP) relationships, we measured these simultaneously with cardiac outputs 1922 times in 128 patients who were critically ill or in an intensive care unit. In 356 (18.5%) of the readings, the PAWP exceeded the PADP, indicating that the PAWP reading might be erroneous. In 106 (5.5%) of these readings, the PAWP was 6.0 mm Hg or more higher than the PADP, indicating that the PAWP was almost certainly erroneous. In virtually all instances in which this discrepancy was recognized, changing the position of the catheter tip provided a PAWP value equal to or lower than the PADP. On the other extreme, in 49 (30%) of the patients, the PADP was 6.0 mm Hg or more higher than the PAWP. The pulmonary vascular resistance in these patients averaged (+/- SD) 257 +/- 145 dyne/s/cm-5 (normal, 80 to 160 dyne/s/cm-5). The mean pulmonary vascular resistance in the other 74 patients was significantly lower (158 +/- 72 dyne/s/cm-5). The mortality rate with the increased PADP-PAWP gradients was 59% (24/49). This was significantly higher than the mortality rate (34%, or 27/79) seen with lower PAWP-PADP gradients. Thus, the relationship between the PADP and PAWP should be examined closely in critically ill patients. A PAWP higher than the PADP indicates that the PAWP measurement may be erroneous. On the other hand, if the PADP exceeds the PAWP by 6.0 mm Hg or more, the patient has probably developed pulmonary hypertension and has a much poorer prognosis.

Pancreaticoduodenectomy for trauma: a life-saving procedure

The purpose of this report is to examine our experience with pancreaticoduodenectomy for trauma in a community trauma center. Five patients underwent pancreaticoduodenectomy for severe combined injury to the pancreas and duodenum from July 1980 to December 1986. All five patients survived. The average age of the patients was 29 years. Four patients sustained blunt trauma and one sustained penetrating trauma. The average length of operation was 5 hours. There was an average of two injured organs per patient in addition to pancreatic and duodenal injuries. The average hospital stay was 24 days. Two patients had postoperative complications requiring reoperation. All patients were discharged tolerating oral feedings without the need for insulin or pancreatic exocrine supplements. This report confirms the utility of pancreaticoduodenectomy for severe combined pancreatic and duodenal trauma.

A comparison between intrarectal ultrasound and CT scanning in staging of experimental rectal tumors

The purpose of this study was to compare the accuracy of preoperative staging of experimental rectal tumors by digital rectal exam, intrarectal ultrasound (IRUS), and CT scanning with pathologic exam. Rectal tumor masses were induced in 10 mongrel dogs by submucosal injection of 2-3 cc of Freund's complete adjuvant. One week later, the animals underwent digital rectal exam, IRUS, and pelvic CT scans. Pelvic exenteration specimens were submitted for pathologic evaluation. Evaluations and interpretations were done in blinded fashion by independent examiners. The rectal "tumor" was detected in 9 of 10 digital exams, 10 of 10 IRUS exams, and 1 of 10 CT scans. Correct Duke's staging occurred in 70% of digital exams, 90% of IRUS exams, and 10% of CT exams compared to pathological staging. Lymph nodes were detected on pathologic exam in all animals (8.7/animal, range 3-16), on IRUS in all animals (6.4/animal, range 5-13), and in none of the digital or CT examinations. IRUS was significantly more accurate in detecting (P less than 0.0001) and locally staging tumors (P less than 0.0001), and in detecting and localizing lymphadenopathy compared to CT scan. Intrarectal ultrasound is a simple, highly accurate device for assessing depth of wall penetration of rectal tumors and in detecting pararectal lymph nodes and should be considered the preoperative staging procedure of choice for rectal cancer.

Plasma vitamin and mineral status in home parenteral nutrition patients

Home parenteral nutrition (HPN) provides long-term nutritional support for persons whose absorptive capacity is compromised by a variety of intestinal malabsorption problems. However, the presence of vitamin and mineral deficiency syndromes that normally would not have time to develop in the hospitalized patient receiving total parenteral nutrition has been reported in patients receiving HPN. This study entails a longitudinal survey of plasma concentrations of vitamins A, E, and 1,25-dihydroxyvitamin D, as well as the minerals zinc, copper, and selenium, in patients receiving HPN. Plasma samples from eight patients who had been on HPN for 1-92 months before the study began were obtained once a month over a 12-month period. The blood was drawn immediately before their evening infusion of TPN in order to approximate fasting plasma nutrient concentrations. Patient values were compared to fasting control values and to published norms. Values for vitamin A, 1,25-dihydroxyvitamin D, and zinc all were within the normal range, and there was no evidence of metabolic bone disease. Plasma vitamin E and copper concentrations exceeded the normal range for most of the 12-month period. Of all of the nutrients studied, only plasma selenium concentrations were consistently in the low-normal to below-normal range. Selenium levels in patients on HPN should be monitored regularly, and supplementation may be necessary if clinical conditions warrant.

Primary appendiceal adenocarcinoma

Primary appendiceal adenocarcinoma is rare, with fewer than 300 reported cases. This report reviews 23 cases of appendiceal adenocarcinoma at Butterworth Hospital from 1968 to 1985. Clinical presentation, operative findings, treatment, and length of survival were recorded. Common clinical presentations included acute appendicitis and progressive abdominal distention. This disease was frequently an incidental finding during unrelated elective surgery and was often associated with other primary malignancies. Surgical treatment included appendectomy, right hemicolectomy, and interval hemicolectomy after initial appendectomy. Improved survival was noted in patients who had localized and noninvasive disease. Prognosis was most closely related to tumor grade. No patient who had localized, well-differentiated tumor died from the disease or had evidence of tumor recurrence after surgical treatment. All patients with poorly differentiated tumors died from widespread carcinomatosis. Appendectomy appears to be sufficient treatment for well-differentiated, localized, mucus secreting adenocarcinomas of the appendix.

Pulmonary artery catheterization: a prospective study of internal jugular and subclavian approaches

We compared complications of pulmonary artery catheter (PAC) insertion and maintenance at internal jugular (IJ) vs. subclavian (SC) sites. Patients were randomized into groups using an IJ or SC route, and insertions were timed. An air-permeable dressing and anticontamination shield were used. Catheters were removed 72 h after insertion. If PAC monitoring was still needed, a new catheter was either inserted over a guidewire at the initial insertion site or inserted at a new site. On removal, the catheter tip, introducer-sheath tip, and catheter within the shield were submitted for semiquantitative culture. Sixty-six catheters were initially inserted, and 26 were changed. No determinative differences in the time for venous cannulation were found, but the IJ route was slightly faster. In 3% of the catheterizations, serious complications arose. The infection rate was 2% for initial catheters, 8% for second catheters placed over a guidewire, and 15% for second catheters placed at a new site. These differences were not consequential. No local infection or catheter-related sepsis occurred. Thus, using a standard, sterile-insertion technique and a catheter-maintenance protocol yielded a low risk of insertion and infectious complications at either the IJ or SC site. Our data indicated that PACs can be changed safely over a guidewire at 72 h, avoiding further insertion risks without increasing infectious complications.

Pericardial laceration and fatal cardiac herniation in an improperly restrained six-month-old infant

We present the youngest reported patient to suffer pleuropericardial laceration with fatal cardiac herniation from blunt chest trauma, apparently related to the improper use of an infant restraint device. Pericardial laceration with cardiac herniation occurs infrequently, but should be suspected in this setting when a patient in electromechanical dissociation is unresponsive to standard resuscitation measures.

Addition of branched-chain amino acids to parenteral nutrition of stressed critically ill patients

We compared the efficacy of a total parenteral nutrition solution supplemented with 44.6% branched-chain amino acids (BCAA) to standard total parenteral nutrition (19.0% BCAA) in the support of critically ill patients. After a 4-day administration of a randomly assigned solution, amino acids were assayed from femoral venous and arterial samples. The BCAA-supplemented solution caused increases in arterial concentrations of valine, isoleucine, and leucine compared to the control solution. The femoral arteriovenous differences for these BCAA were more positive in patients given the control solution. There were no significant differences in nitrogen balance. Since previous studies showing promotion of nitrogen balance with BCAA did not use a balanced substrate for nonprotein caloric support, the lack of a significant difference in the present study may be due to effective utilization of lipid as a fuel source by both groups.

Pneumothorax from nasoenteric feeding tube insertion. A report of five cases

This report describes five patients who developed pneumothorax following misplacement of a nasoenteric feeding tube. Three of the patients required tube thoracostomy. Of these, one was subsequently discharged; one required two chest tubes, yet died 2 days later; the third patient developed a chronic empyema that ultimately required chest wall reconstruction for resolution. The development of pneumothorax from nasoenteric feeding tube misplacement was influenced by the type of tube and the general characteristics of the patients. The use of a cuffed endotracheal tube did not afford protection against misplacement. The significant morbidity and mortality associated with pneumothorax following nasoenteric feeding tube insertion argue for careful evaluation of the clinical setting when considering enteral nutritional support with a nasoenteric feeding tube.

Directed manual recruitment of collapsed lung in intubated and nonintubated patients

Four patients with collapsed lung are presented that demonstrate the utility of the directed manual recruitment technique (DMRT) in a range of clinical situations presented by weaning difficulties, recurrent acute atelectasis, and acute respiratory failure in the nonintubated patient. DMRT is an easily applied noninvasive method of lung expansion in the treatment of patients with segmental and lobar collapse and is safe when carried out with appropriate precautions.