A pocket-sized hand held ultrasound system for intraoperative transthoracic echocardiography by anaesthesiologists: A feasibility study.

BACKGROUND: The intraoperative application of focused transthoracic echocardiography (TTE) is often considered to be restricted. Echocardiography with pocket-sized hand held ultrasound systems has been shown to be feasible in various settings. OBJECTIVE: The aim of this study was to investigate the feasibility of the intraoperative application of pocket-sized echocardiography and the comparison of its imaging quality and diagnostic reliability and variability with a standard ultrasound system. METHODS: After written informed consent, TTE was performed on 40 anaesthetised general, vascular, visceral, thoracic surgical and orthopaedic patients according to the FATE protocol: first, with a pocket-sized and second, with a high-end ultrasound system randomly by two anaesthetists. Imaging quality of four basic and three additional FATE views was rated on an established scale from 1 (impossible) to 5 (perfect). Successful TTE was defined, if one basic FATE views would be rated as grade 4 or 5 or alternatively two views as grade 3. Pathologic findings by both ultrasound devices were documented and imaging quality and pathologic findings were compared. RESULTS: All 40 patients presented acceptable imaging quality, resulting in a success rate of 1.0 (97.5%-CI 0.91-1, p= 0.015). The individual imaging ratings of each view were significantly lower with the pocket-sized system, but still showed acceptable imaging quality. With the high-end device more pathologic findings were detected (107 vs. 87), but none of the relevant or severe pathologies were overseen with the hand-held device. CONCLUSION: The application of a pocket-sized echocardiography device for focused intraoperative TTE is feasible and can appropriate be used for the initial evaluation of relevant pathologies in the operating theatre.

Focused intraoperative transthoracic echocardiography by anesthesiologists: a feasibility study.

BACKGROUND: Focused transthoracic echocardiography (TTE) is frequently used perioperatively for hemodynamic monitoring and diagnosis of cardiovascular instability, but less commonly intraoperatively. METHODS: To evaluate the feasibility of intraoperative TTE, we enrolled 222 anesthetised patients from August to November 2012 into a prospective observational study. 162 patients underwent TTE examination according to the Focused Assessed Transthoracic Echocardiography (FATE) protocol after positioning and draping for surgery. Sixty additional hemodynamically unstable subjects were examined during anesthesia and surgery. The imaging quality of four FATE views was rated on a scale from 1 (impossible) to 5 (perfect). TTE was assessed as applicable, if at least two of the four basic FATE views were graded 4 or 5, or three views were assessed as grade 3. RESULTS: Imaging quality was unacceptable in 20 patients, resulting in a feasibility rate of 91% (97.5%-CI 0.86-1, P=0.01). TTE was feasible in hemodynamically unstable subjects (91.7%; 97.5%-CI 0.82-1.0), in orthopedic and trauma patients (>95% respectively, [97.5%-CI 0.83-1]) and in abdominal surgery (78%). CONCLUSION: TTE can be applied in the operating theatre during surgery, although its use during abdominal surgery is somewhat limited.

Root antioxidant responses of two Pisum sativum cultivars to direct and induced Fe deficiency.

The contribution of antioxidant defence systems in different tolerance to direct and bicarbonate-induced Fe deficiency was evaluated in two pea cultivars (Kelvedon, tolerant and Lincoln, susceptible). Fe deficiency enhanced lipid peroxidation and H2 O2 concentration in roots of both cultivars, particularly in the sensitive one grown under bicarbonate supply. The results obtained on antioxidant activities (SOD, CAT, POD) suggest that H2 O2 accumulation could be due to an overproduction of this ROS and, at the same time, to a poor capacity to detoxify it. Moreover, under bicarbonate supply the activity of POD isoforms was reduced only in the sensitive cultivar, while in the tolerant one a new isoform was detected, suggesting that POD activity might be an important contributor to pea tolerance to Fe deficiency. The presence of bicarbonate also resulted in stimulation of GR, MDHAR and DHAR activities, part of the ASC-GSH pathway, which was higher in the tolerant cultivar than in the sensitive one. Overall, while in the absence of Fe only slight differences were reported between the two cultivars, the adaptation of Kelvedon to the presence of bicarbonate seems to be related to its greater ability to enhance the antioxidant response at the root level.

Development of Fe-deficiency responses in cucumber (Cucumis sativus L.) roots: involvement of plasma membrane H(+)-ATPase activity.

One of the mechanisms through which some strategy I plants respond to Fe-deficiency is an enhanced acidification of the rhizosphere due to proton extrusion. It was previously demonstrated that under Fe-deficiency, a strong increase in the H(+)-ATPase activity of plasma membrane (PM) vesicles isolated from cucumber roots occurred. This result was confirmed in the present work and supported by measurement of ATP-dependent proton pumping in inside-out plasma membrane vesicles. There was also an attempt to clarify the regulatory mechanism(s) which lead to the activation of the H(+)-ATPase under Fe-deficiency conditions. Plasma membrane proteins from Fe-deficient roots submitted to immunoblotting using polyclonal antibodies showed an increased level in the 100 kDa polypeptide. When the plasma membrane proteins were treated with trypsin a 90 kDa band appeared. This effect was accompanied by an increase in the enzyme activity, both in the Fe-deficient and in the Fe-sufficient extracts. These results suggest that the increase in the plasma membrane H(+)-ATPase activity seen under Fe-deficiency is due, at least in part, to an increased steady-state level of the 100 kDa polypeptide.

Metabolic responses in cucumber (Cucumis sativus L.) roots under Fe-deficiency: a 31P-nuclear magnetic resonance in-vivo study.

The metabolic responses occurring in cucumber (Cucumis sativus L.) roots (a strategy-I plant) grown under iron-deficiency conditions were studied in-vivo using 31P-nuclear magnetic resonance spectroscopy. Iron starvation induced activation of metabolism leading to the consumption of stored carbohydrates to produce the NAD(P)H, ATP and phosphoenolpyruvate necessary to sustain the increased activity of the NAD(P)H:Fe(3+)-reductase, the H(+)-ATPase (EC 3.6.1.35) and phosphoenolpyruvate carboxylase (EC 4.1.1.31). Activation of catabolic pathways was supported by the enhancement of glycolytic enzymes and concentrations of the metabolites glucose-6-phosphate and fructose-6-phosphate, and by enhancement of the respiration rate. Moreover, Fe-deficiency induced a slight increase in the cytoplasmic (pHc) and vacuolar (pHv) pHs as well as a dramatic decrease in the vacuolar phosphate (Pi) concentration. A comparison was done using fusicoccin (FC), a fungal toxin which stimulates proton extrusion. Changes in pHc and pHv were measured after addition of FC. Under these conditions, a dramatic alkalinization of the pHv of -Fe roots was observed, as well as a concomitant Pi movement from the vacuole to the cytoplasm. These results showed that Fe starvation was indeed accompanied by the activation of metabolic processes useful for sustaining the typical responses occurring at the plasma-membrane level (i.e. increases in the NAD(P)H:Fe(3+)-reductase and H(+)-ATPase activities) as well as those involved in the homeostasis of pHc. The decrease in vacuolar Pi levels induced by Fe-deficiency and FC and movement of Pi from the vacuole to the cytoplasm suggest a possible involvement of this compound in the cellular pH-stat system.

Calcium-dependent phosphorylation regulates the plasma-membrane H(+)-ATPase activity of maize (Zea mays L.) roots.

Phosphorylation/dephosphorylation of the plasma-membrane H(+)-ATPase (EC 3.6.1.35) could act as a regulatory mechanism to control its activity. In this work, a plasmalemma-enriched fraction from maize roots and a partially purified H(+)-ATPase were used to investigate the effects of Ca(2+) and calmodulin on the H(+)-ATPase activity and on its phosphorylation status. Both the hydrolytic and the proton-pumping activities were reduced approximately 50% by micromolar Ca(2+) concentrations while calmodulin did not show any effect either alone or in the presence of Ca(2+). The lack of effect of calmodulin antagonists indicated that calmodulin was not involved in this response. The addition of staurosporine, a kinase inhibitor, abolished the inhibitory effect of Ca(2+). Phosphorylation of plasma membrane and partially purified H(+)-ATPase showed the same behavior. In the presence of Ca(2+) a polypeptide of 100 kDa was phosphorylated. This polypeptide cross-reacted with antibodies raised against the H(+)-ATPase of maize roots. The autoradiogram of the immunodetected protein clearly showed that this polypeptide, which corresponds to the H(+)-ATPase, was phosphorylated. Additional clear evidence comes from the immunoprecipitation experiments: the data obtained show that the H(+)-ATPase activity is indeed influenced by its state of phosphorylation.

Febrile complications in the first 100 days after bone marrow transplantation in children: a single center's experience.

One hundred fifty-six episodes of fever occurred in 102 children during the first 100 days after bone marrow transplantation (BMT) performed at a single institution: fever of undetermined origin (FUO), 40.3%; septicemia, 7.1%; pneumonia, 19.2%; other infections, 33.4% of cases. The overall incidence of mortality was 22.6% and of mortality due to infections 17.4%. All FUO episodes resolved. Pneumonia was the major cause of death; 60% of recipients who developed pneumonia died, accounting for 90% of deaths attributable to febrile complications. Interstitial pneumonia, occurred rarely, in 3.9% of all febrile episodes. The Cox model showed that the presence of graft-versus-host disease (GVHD) was related to an approximately ninefold increase in the risk of a first episode of FUO (P value .03). The risk of developing pneumonia was fourfold greater in children who received a transplant from a matched unrelated donor or a mismatched family donor (P value .01). Developments in diagnostic tools are needed to diagnose febrile episodes earlier and more precisely with the aim of reducing early mortality after BMT.

Mechanical and infective central venous catheter-related complications: a prospective non-randomized study using Hickman and Groshong catheters in children with hematological malignancies.

The aim of this study was to compare the Hickman and Groshong central venous catheters (CVCs) for incidence and severity of catheter-related complications in children. Seventy-three patients with hematological malignancies were observed, 42 with Groshong CVCs and 31 with Hickman CVCs. The number of infective episodes per 100 CVC-days was not significantly different (0.25 in the Hickman group versus 0.13 in the Groshong group; P = 0.24). The most frequent type of CVC-related infection in both groups was microbiologically documented sepsis; in most cases Gram-positive bacteria were isolated. Neutropenia (P < 0.001 for both CVCs) and hospital CVC management (P = 0.0047 for the Hickman group, P < 0.001 for the Groshong group) emerged as the major risk factors for the outbreak of infections. The rate of mechanical complication episodes per 100 CVC-days was similar in both groups (1.01 in the Hickman group versus 1.1 in the Groshong group: P = 0.58). Some complications (fissures, ruptures, total lumen obstruction by clots) occurred only in the Groshong group. Our study did not demonstrate any statistically significant difference in the incidence of mechanical and infective CVC-related complications between these two types of catheter.

Central venous catheter clots: incidence, clinical significance and catheter care in patients with hematologic malignancies.

In a 7-month period we studied 38 Hickman central venous catheters (CVCs) positioned in children with hematologic malignancies with the aim of evaluating the incidence and clinical impact of CVC clots. Clots were found in 74% of the CVCs. Three methods of catheter care were developed for flushing the clotted CVCs: (a) use of a heparinized solution (400 IU/mL) on alternate days, (b) use of a heparinized solution (400 IU/mL) and saline solution containing urokinase (10,000 IU/mL) on alternate days, and (c) use of a saline solution containing urokinase (10,000 IU/mL) daily. Only method b decreased clot formation (33% success rate). There were no major mechanical complications in any of the CVCs with clots. Eighteen percent of patients with clots in their CVCs presented with CVC-related infections while no infective complications were observed in the patients without clots in their CVCs. In conclusion, CVC clots may predispose the patient to infections, which must be correctly treated.