Evaluation of Respiratory Function During Reeves Stretcher Use

Objective. We were aware of a small number of cases in our EMS system where patients in respiratory distress had a worsening of their condition after being removed from the home on a Reeves® stretcher (RS). We sought to determine if this prehospital lifting device causes additional respiratory effort used in normal subjects by describing changes in heart rate, pulse oximetry, tidal volume, minute ventilation, andrespiratory rate. Methods. Forty-nine subjects were entered into this study. Data were collected while the subject was supine on the floor in the RS andonce while suspended over the floor in the device. A randomized crossover design was used. Ten subjects were excluded because of inadvertent omission of a nose plug during spirometry. Data points were recorded in the final minute of a 3-minute exposure. Three minutes was chosen to simulate a prehospital transport time from the scene to the ambulance. Minute ventilation, tidal volume, heart rate, pulse oximetry, andrespiratory rate were recorded for each subject during each phase. Subjects were also asked to rate the difficulty of breathing using the modified Borg scale. Results. Data were obtained for 39 subjects. The mean respiratory rate while suspended was 9.9 ± 3.0 breaths per minute compared to 9.1 ± 2.5 breaths per minutes supine on the floor (p = 0.007). The mean minute ventilation while suspended in a RS was 8.17 ± 3.25 L/min versus 7.37 ± 2.37 while lying flat (p = 0.03). There was no difference in tidal volume, heart rate, pulse oximetry, or subjective modified Borg scale ratings. Conclusions. Subjects suspended in a RS for 3 minutes had statistically higher respiratory rates andminute ventilation than the same subjects lying flat. Although these modest changes are clinically insignificant in normal subjects, they could present a significant challenge to subjects in respiratory distress.     

Conservative,open or percutaneous repair for acute rupture of the Achilles tendon

Purpose. To review the complications and recovery of patients with Achilles tendon rupture managed by percutaneous repair, open repair, and non-operative means in a tertiary referral centre between 2001 and 2003.

Methods. The operating theatre register and logbooks of the Consultants were used to identify surgically managed patients, while plaster room records were used for conservatively managed patients. We collated demographic and management details.

Results. The number of plaster changes (p < 0.001), median length of time in cast (p < 0.001), and number of outpatient visits (p < 0.05) was greater in conservatively managed patients. We performed no formal statistical analysis given the small numbers. Conservative management was the least expensive and open surgery the most costly modality of management. Percutaneous surgery was approximately a third of the cost of open surgery when performed under local anaesthetic.

Conclusion. In our setting, percutaneous repair and conservative management are viable alternatives to open surgery, which carries higher complications rates and was the most costly of the three. Individual patients will have different needs due to their age, occupation, or level of sporting activity.     

Improving the quality of kidneys from non-heart-beating donors,using streptokinase: an animal model

BACKGROUND: Non-heart-beating donors (NHBD) offer a promising potential to increase the cadaveric organ donor pool, especially for kidneys. However, almost half of NHBD kidneys are discarded after viability assessment. This wastage is costly in both human and monetary terms. Intravascular thrombosis at the time of donor death is an event leading to failure in the viability assessment. We have developed an animal model to investigate the effects of the addition of streptokinase to the in situ flush medium before transplant in an attempt to redress the situation. METHODS: Two groups of eight healthy young Landrace Yorkshire white pigs were entered into the study. Both groups were subjected to approximately 70 min warm ischemia. Both groups received an intravascular flush with 4 L of Marshall's solution with heparin (1000 IU/L); one group of pigs also had streptokinase (1.5 MIU/L) added. After donor nephrectomy, all kidneys were machine perfused for 4 hr. Data on perfusion characteristics were taken and samples of kidney effluent were assayed for tissue damage biomarkers, glutathione S-transferase (GST) and alanine aminopeptidase (Ala-AP). Wedge sections of porcine kidneys were taken at the end of perfusion, for histological analysis. RESULTS: Data on machine perfusion parameters (temperature, mean pressure index, resistance) indicate better cooling, lower resistance, and lower mean pressure index in the streptokinase-treated group of pigs. GST and Ala-AP levels were increased in the nonstreptokinase group perfusates. Histopathological analysis of porcine kidneys indicated more ischemic injury and tissue damage in the nonstreptokinase group. CONCLUSION: The use of streptokinase in this porcine NHBD model conferred benefits to donor kidneys when assessed by machine perfusion. Markers of biochemical injury indicated that less renal tissue damage occurred with the incorporation of streptokinase in the in situ flush medium.     

Selective brain cooling in rats ameliorates intracerebral hemorrhage and edema caused by penetrating brain injury: possible involvement of heme oxygenase-1 expression

Brain edema formation associated with trauma-induced intracerebral hemorrhage (ICH) is a clinical complication with high mortality. Studies have shown that heme oxygenase-1 (HO-1) plays an important role in ICH-induced brain edema. In order to understand the role of HO-1 in the protective effect of selective brain cooling (SBC), we investigated the time course of HO-1 changes following penetrating ballistic-like brain injury (PBBI) in rats. Samples were collected from injured and control animals at 6, 24, 48, and 72 h, and 7 days post-injury to evaluate HO-1 expression, heme concentration, brain water content, and immunohistochemistry (IHC). Following a 10% frontal PBBI, HO-1 mRNA and protein was increased at all time points studied, reaching maximum expression levels at 24-48 h post-injury. An increase in the heme concentration and the development of brain edema coincided with the upregulation of HO-1 mRNA and protein during the 7-day post-injury period. SBC significantly decreased PBBI-induced heme concentration, attenuated HO-1 upregulation, and concomitantly reduced brain water content. These results suggest that the neuroprotective effects of SBC may be partially mediated by reducing the heme accumulation, which reduced injury-mediated upregulation of HO-1, and in turn ameliorated edema formation. Collectively, these results suggest a potential value of HO-1 as a diagnostic and/or therapeutic biomarker in hemorrhagic brain injury.     

Coronary revascularisation with Genous stent helps reduce the waiting time for lung resection

Patients suitable for lung resection for primary lung cancer and with myocardial ischaemia due to significant coronary artery stenosis, despite optimal medical therapy, are considered for either percutaneous or surgical revascularisation prior to thoracic surgery. Percutaneous coronary intervention (PCI) with bare metal stent (BMS) requires patients to initially receive dual anti-platelet therapy of clopidogrel and aspirin for at least 6 weeks, which delays the waiting time for curative lung resection. We report the successful use of the Genous endothelial progenitor cell (EPC) capture stent in two patients requiring PCI for significant coronary artery disease prior to lung resection. Following PCI with Genous stent implantation, both patients received dual anti-platelet therapy for 1 week. Clopidogrel was then discontinued and a week later both safely underwent curative lung resection receiving aspirin alone. At 6 months’ follow-up, neither patient had symptoms or electrocardiograph changes suggestive of angina. Our report suggests that in patients requiring PCI prior to lung resection the Genous EPC capture stent is suitable and reduces their waiting time for surgical resection to 2 weeks instead of 6.     

Bone marrow stem cells for urologic tissue engineering

OBJECTIVES: Experiments in rats and dogs have demonstrated the potential of bone marrow-derived mesenchymal stem cells (MSCs) for urinary tract tissue engineering. However, the small graft size in rats and a failure to identify the MSCs in engineered tissues made it difficult to assess the true potential of these cells. Our goals were to characterize MSCs from pigs, determine their ability to differentiate into smooth muscle cells (SMCs) and use them in an autologous augmentation cystoplasty. METHODS: MSCs were isolated from pigs and analyzed for common markers of MSCs by flow cytometry. SMC differentiation was determined by immunoblotting. MSCs were isolated, genetically labeled, expanded in vitro, seeded onto small intestinal submucosa (SIS) and used for autologous bladder augmentation. RESULTS: Porcine MSCs are morphologically and immunophenotypically similar to human MSCs. Culturing MSCs at low density enhances proliferation rates. MSCs consistently differentiate into mature SMCs in vitro when maintained at confluence. Labeled MSCs grew on SIS over one week in vitro and survived a 2-week implantation as an autologous bladder augment in vivo. Some label-positive cells with SMC morphology were detected, but most SMCs were negative. Notably, many cells with a urothelial morphology stained positively. CONCLUSIONS: Porcine MSCs have similar properties to MSCs from other species and consistently undergo differentiation into mature SMC in vitro under specific culture conditions. Labeled MSCs within SIS may assist tissue regeneration in augmentation cystoplasty but may not significantly incorporate into smooth muscle bundles.     

Differentially modulated dendritic cells induce regulatory T cells with different characteristics

Dexamethason (DEX) treated DC display several features that establish them as candidates for specific allogeneic tolerance induction. We report the results of in vitro studies of polarization of the alloimmune T cell response with two types of differentially modulated human DC. Both DEX treated DC triggered by LPS for 6 h (DEX6-DC) and DEX treated DC triggered by LPS for 48 h (DEX48-DC) acquired low levels of costimulatory, adhesion, and MHC class II molecules compared with mature DC (mDC). In contrast to mDC, both DEX6-DC and DEX48-DC did not produce any IL-12. DEX6-DC were able to produce significant amounts of IL-10 whereas DEX48-DC did not actively produce IL-10. Conversely, the induction of IL-10 producing cells was significantly increased when PBL were stimulated with DEX48-DC compared with DEX6-DC. Both stimulation of PBL with DEX6-DC and DEX48-DC led to the induction of cell populations able to suppress the proliferative alloimmune response of primed T cells in a cell-cell contact independent and antigen-nonspecific manner. Tregs obtained after stimulation with DEX48-DC were also able to inhibit the IFN-gamma production of the effector cells and this effect could be blocked by anti-IL-10. Tregs induced by DEX6-DC produced similar amounts of IL-10, yet were not able to inhibit IFN-gamma production of the effector T cells, indicating a different mechanism. In summary, we show that differential modulation of DC results in the induction of different populations of regulatory T cells.     

Artificial chordae for pediatric mitral and tricuspid valve repair.

OBJECTIVE: To evaluate pediatric atrioventricular valve repair with artificial chordae. METHODS: Between February 2001 and January 2006, artificial chords were used in 21 children with severe mitral or tricuspid valve regurgitation. Patients with AVSD were excluded. Median age was 84 (1-194) months. Five patients had isolated tricuspid valve anomalies, 16 had mitral valve anomalies (associated tricuspid annular dilatation in 4). Tricuspid neochordae were placed to anterior (three patients) and septal (two patients) leaflets. Mitral neochordae were placed to anterior (15 patients) and posterior (1 patient) leaflets. Additional ring annuloplasties were performed in 12 (mitral 11, tricuspid 1), as well as 2 de Vega tricuspid annuloplasties. Patch insertion was used in acute endocarditis (tricuspid one). All echocardiographic studies were reviewed and analyzed by a single cardiologist. RESULTS: No mortality occurred. Follow-up was complete (mean 28+/-18 months). Two patients were reoperated, one for mitral ring dehiscence and one for recurring mitral valve insufficiency. Both valves were replaced by mechanical valve prosthesis. At last follow-up tricuspid insufficiency was mild (three) or moderate (two). Moderate insufficiency occurred due to remaining restriction of the septal leaflet after repair in endocarditis (one) and remaining prolapse of the anterior leaflet (one). Mitral insufficiency was absent (five), mild (seven), or moderate (two). Moderate insufficiency was caused by recurrent anterior leaflet shortening after valve repair in rheumatic valve disease (two). Valve restriction caused by artificial chordae was not found. CONCLUSIONS: Mitral and tricuspid valve repair with artificial chordae in children demonstrated acceptable results. Despite patient growth, valvular restriction by the artificial chordae was not observed ad mid-term follow-up.