Left atrium veno-arterial extra corporeal membrane oxygenation as temporary mechanical support for cardiogenic shock: A case report

BACKGROUND

Veno-arterial extra corporeal membrane oxygenation (VA-ECMO) support is commonly complicated with left ventricle (LV) distension in patients with cardiogenic shock. We resolved this problem by transeptally converting VA-ECMO to left atrium veno-arterial (LAVA)-ECMO that functioned as a temporary paracorporeal left ventricular assist device to resolve LV distension. In our case LAVA-ECMO was also functioning as a bridge-to-transplant device, a technique that has been scarcely reported in the literature.

CASE SUMMARY

A 65 year-old man suffered from acute myocardial injury that required percutaneous stents. Less than two weeks later, noncompliance to antiplatelet therapy led to stent thrombosis, cardiogenic shock, and cardiac arrest. Femoro-femoral VA-ECMO support was started, and the patient underwent a second coronary angiography with re-stenting and intra-aortic balloon pump placement. The VA-ECMO support was complicated by left ventricular distension which we resolved via LAVA-ECMO. Unfortunately, episodes of bleeding and sepsis complicated the clinical picture and the patient passed away 27 d after initiating VA-ECMO.

CONCLUSION

This clinical case demonstrates that LAVA-ECMO is a viable strategy to unload the LV without another invasive percutaneous or surgical procedure. We also demonstrate that LAVA-ECMO can also be weaned to a left ventricular assist device system. A benefit of this technique is that the procedure is potentially reversible, should the patient require VA-ECMO support again. A transeptal LV venting approach like LAVA-ECMO may be indicated over ImpellaTM in cases where less LV unloading is required and where a restrictive myocardium could cause LV suctioning. Left ventricular over-distention is a well-known complication of peripheral VA-ECMO in cardiogenic shock and LAVA ECMO through transeptal cannulation offers a novel and safe approach for treating LV overloading, without the need of an additional percutaneous access.

Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions

Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

A regional plan of the Emilia-Romagna regional bureau for Aedes albopictus control--year 2008

Following the outbreak of Chikungunya virus fever occurred in the summer 2007 in Emila Romagna (an administrative region located along the Adriatic (East) coast of Italy) a regional plan for Aedes albopicus control has been implemented. The major items of the plan are here reported and discussed.

Right ventricular failure after left ventricular assist device insertion: preoperative risk factors

Right ventricular failure after left ventricular assist device placement is the major concern on weaning from cardiopulmonary bypass and it is one of the most serious complications in the postoperative period. This complication has a poor prognosis and is generally unpredictable. The identification of pre-operative risk factor for this serious complication is incomplete yet. In order to determine pre-operative risk for severe right ventricular failure after left ventricular assist device support we analyzed preoperative hemodynamics, laboratory data and characteristics of 48 patients who received Novacor (World Heart Corp., Ottawa, ON, Canada). We compared the data from the patients who developed right ventricular failure and the patients who did not. Right ventricular failure occurred in 16% of the patients. There was no significant difference between the groups in demographic characteristics. We identified as preoperative risk factors the pre-operative low mean pulmonary artery and the impairment of hepatic and renal function on laboratory data. Our results confirm in part the findings of the few previous studies. This information may be useful for the patient selection for isolated left ventricular assist device implantation, but other studies are necessary before establishing criteria for patient selection for univentricular support universally accepted.

The need for inotropic drugs in anesthesiology and intensive care

The management of the failing heart represents an increasingly frequent challenge to both anesthesiologists and intensive care physicians, due to the increased prevalence of ventricular dysfunction in the population and to the ever-expanding indications for the surgical treatment of cardiac disease. Inotropic drugs are nowadays invaluable therapeutic tools in the treatment of perioperative heart failure and of the different forms of heart failure found in intensive care unit clinical practice. Postoperative myocardial dysfunction is a major concern in the setting of cardiac surgery since it is extremely frequent and is related to a greater morbidity and mortality. The different forms of heart failure, the rationale and the indications for the use of inotropic drugs in anesthesiology and intensive care are discussed in this review.

Influence of underlying lung disease on early postoperative course after single lung transplantation

BACKGROUND

Single lung transplantation can be a suitable therapeutic option for a wide range of end-stage lung diseases: pulmonary fibrosis, emphysema, primary pulmonary hypertension and Eisenmenger's syndrome. Yet, patients suffering from different diseases have significantly different cardiovascular and respiratory functional profiles that can exert a profound influence on their response to the perioperative procedures. Our purpose is to analyze whether the patient's underlying disease can influence the early postoperative outcome after single lung transplantation.

METHODS

We carried out a retrospective analysis on perioperative charts of patients undergoing single lung transplantation during an 8-year period. We focused our attention on the following data: underlying lung disease, age, sex, baseline cardiorespiratory data (pulmonary artery pressure, cardiac index, forced expired volume, vital capacity, arterial blood gases, body mass index), intraoperative data (duration of graft ischemia, use of cardiopulmonary bypass) and indexes of adverse postoperative outcome (in-hospital death, mechanical ventilatory support >7 days). Patients were gathered in 3 groups (restrictive, obstructive and vascular) according to the kind of disease and functional data and the association between disease and outcome was assessed by means of logistic regression analysis. Moreover, we evaluated whether any of the patient's functional parameters could be considered predictive of adverse postoperative outcome.

RESULTS

We observed a weak association between restrictive disease and adverse postoperative outcome while, on the other hand, obstructive and vascular forms showed a close association with an adverse outcome, with a borderline statistical significance. Among all the considered variables, only intraoperative use of CPB turned out to be predictive of adverse outcome, while other variables simply indicated a trend towards a better outcome.

CONCLUSIONS

Patients with vascular and obstructive diseases have the worst postoperative course, with a higher in-hospital mortality rate and longer duration of ventilation; in particular, the perioperative course of vascular patients is heavily influenced by the intraoperative use of cardiopulmonary bypass.

[Single lung transplantation retrospective analysis of intraoperative cardiovascular problems]

BACKGROUND

Analysis of haemodynamic problems during single-lung transplantation and of methodologies employed for their treatment.

METHODS

DESIGN OF THE STUDY

clinical retrospective study.

SETTING

General University Hospital.

PATIENTS

patients with irreversible lung disease, either parenchymal or vascular, undergoing single lung transplantation.

INTERVENTIONS

recording of circulatory failure episodes and treatment with pharmacologic support or cardiopulmonary bypass. Modifications occurring during the study period with respect to drugs administered. Evaluation of the consequences of cardiopulmonary bypass on the postoperative outcome, namely on the duration of mechanical ventilation and length of stay in the intensive care unit.

RESULTS

During the last 9 years 69 single-lung transplantations have been performed. In 50% of cases a pharmacologic support has been employed; the drug association dobutamine/nitroprusside has been gradually replaced by the association norepinephrine/nitric oxide for the treatment of right ventricular failure. Twenty patients required cardiopulmonary bypass and this caused a significant increase of the duration of mechanical ventilation and length of stay in the intensive care unit.

CONCLUSIONS

Hemodynamic changes during lung transplantation are complex and often severe, leading to a clinical status of right ventricular failure, that sometime requires a mechanical circulatory support. The introduction of nitric oxide in clinical practice significantly contributed to the optimization of intraoperative cardiocirculatory profile of patients, leading to a reduction in the use of vasoactive drugs and cardiopulmonary bypass.

Molecular epidemiology of human T-cell leukemia virus type I (HTLV-1) Brazil: the predominant HTLV-1s in South America differ from HTLV-ls of Japan and Africa, as well as those of Japanese immigrants and their relatives in Brazil

To better understand the origin of human T-cell leukemia virus type l (HTLV-l) in South America, we conducted a phylogenetic study on 27 new HTLV-ls in Brazil. These were obtained from Brazilians of various ethnic origins, such as Japanese immigrants, whites, blacks and mulattos. We amplified and sequenced proviral DNAs of a part of the long terminal repeats. Phylogenetic trees revealed that all but 6 of the new isolates were not only similar to each other but also similar to HTLV-ls of other South American countries, including those from Amerindians. However, the isolates differed from the HTLV-ls of Africa and Japan. The other six isolates were from Japanese immigrants and were phylogenetically almost identical to HTLV-ls in Japan but different from the majority of South American HTLV-ls, including the other new Brazilian HTLV-ls. These findings indicate that the recent introduction of HTLV-1 from Japan is limited to Japanese immigrants. In addition, the results do not support the prevailing hypothesis that HTLV-ls in South America were introduced by blacks who were brought from Africa as slaves. Rather, these results suggest that the majority of HTLV-1s prevailing in South America have spread from Amerindians, some of whom are likely to have possessed this human retrovirus from the beginning of their settlement in South America.

Acute effects of inhaled nitric oxide in adult respiratory distress syndrome

This study evaluated the dose-response effect of inhaled nitric oxide (NO) on gas exchange, haemodynamics, and respiratory mechanics in patients with adult respiratory distress syndrome (ARDS). Of 19 consecutive ARDS patients on mechanical ventilation, eight (42%) responded to a test of 10 parts per million (ppm) NO inhalation with a 25% increase in arterial oxygen tension (Pa,O2,) over the baseline value. The eight NO-responders were extensively studied during administration of seven inhaled NO doses: 0.5, 1, 5, 10, 20, 50 and 100 ppm. Pulmonary pressure and pulmonary vascular resistance exhibited a dose-dependent decrease at NO doses of 0.5-5 ppm, with a plateau at higher doses. At all doses, inhaled NO improved O2 exchange via a reduction in venous admixture. On average, the increase in Pa,O2, was maximal at 5 ppm NO. Some patients, however, exhibited maximal improvement in Pa,O2 at 100 ppm NO. In all patients, the increase in arterial O2 content was maximal at 5 ppm NO. The lack of further increase in arterial O2 content above 5 ppm partly depended on an NO-induced increase in methaemoglobin. Respiratory mechanics were not affected by NO inhalation. In conclusion, NO doses < or =5 ppm are effective for optimal treatment both of hypoxaemia and of pulmonary hypertension in adult respiratory distress syndrome. Although NO doses as high as 100 ppm may further increase arterial oxygen tension, this effect may not lead to an improvement in arterial O2 content, due to the NO-induced increase in methaemoglobin. It is important to consider the effect of NO not only on arterial oxygen tension, but also on arterial O2 content for correct management of inhaled nitric oxide therapy.

Aortic arch surgery: retrospective analysis of outcome and neuroprotective strategies

BACKGROUND

OBJECTIVE

To review intra- and postoperative data regarding surgical reconstruction of the aortic arch performed at our cardiosurgical centre during the past four years, and thus to deepen understanding of neurologic morbidity and of what constitutes the most effective neuroprotection.

EXPERIMENTAL DESIGN

Retrospective study.

SETTING

Regional University Hospital.

PATIENTS

29 patients who underwent reconstruction of aneurysm or dissection of the aortic arch. Intervention. Surgical replacement of the diseased aorta during deep hypothermia, alone or with selective cerebral perfusion (antegrade or retrograde).

MEASURES

Overall mortality rate, neurologic morbidity rate, duration of extracorporeal circulation, of hypothermic circulatory arrest or of selective cerebral perfusion. Evaluation of the importance to neurological outcome of age, modality of operation (emergency or routine), biochemical parameters (glycemia, hematocrit) and perfusion technique. Recording of postoperative time of arousal, and possible correlation with length of selective cerebral perfusion.

RESULTS

We observed a mortality rate of 39% (11 deaths) and a neurologic morbidity rate of 34%. Hypothermic circulatory arrest alone did not assure valid neuroprotection (5 cases, all with severe neurologic impairment), while better results were obtained with selective cerebral perfusion, especially antegrade (14 cases, with only 7% of neurologic morbidity rate). Hyperglycemia (>250 mg%) proved to be significantly associated (p=0.002) with increased incidence of adverse neurologic outcome, and the same association was observed between emergency status and adverse neurologic outcome (p=0.002). Moreover, we found an unexpected linear correlation between time of selective cerebral perfusion and postoperative time of arousal (r=0.728, p=0.000).

CONCLUSIONS

Deep hypothermic circulatory arrest with selective cerebral perfusion currently represent a valid therapeutic option for brain preservation during reconstruction of the aortic arch in adults. It is mandatory to carry out a tight control of perfusion parameters (flow, pressures and temperature gradients) and biochemical variables (avoidance of hyperglycemia and modified ultrafiltration for fluid balance).

HTLV-Is in Argentina are phylogenetically similar to those of other South American countries, but different from HTLV-Is in Africa

To understand the origin and past dissemination of human T-cell leukemia/lymphotropic virus type I (HTLV-I) in Latin America, we conducted a phylogenetic study of five new HTLV-I isolates from Argentina. We sequenced partial fragments of long terminal repeats (LTR) of the new HTLV-Is, and then the sequences were subjected to a phylogenetic analysis for comparison with other HTLV-Is of various geographical origins. Our results indicated that all the isolates were members of the Cosmopolitan group. Furthermore, most (four out of five isolates) of the new HTLV-Is belonged to the Transcontinental (A) subgroup, the most widespread subgroup of the four subgroups in the Cosmopolitan group. In this subgroup, they were closely related to HTLV-Is found in other South American countries including those of Amerindians, and were different from those found in Africa. In contrast, the remaining one HTLV-I (ARGMF) did not show any clear similarity to known HTLV-I isolates belonging to the Cosmopolitan group. The close similarity of South American HTLV-Is strongly suggests a common origin of the virus in this continent. Our results do not support the proposed idea of recent introduction of HTLV-I into South America as a consequence of the slave trade from Africa, where phylogenetically different HTLV-Is predominate.

Study on the flying height of Aedes caspius and Culex pipiens females in the Po Delta area, Italy

We have studied the vertical distribution of Culicidae in the "Ancona di Bellocchio" protected area (Regional Park of the Po Delta, Emilia-Romagna, Italy) by means of nonilluminated CDC traps baited with CO2. Traps were placed at heights of 1.5, 3, 4, and 5 m from the ground in open areas and at 1.5, 3, 4, 5, 6, and 7 m in wooded areas. We calculated the average flying height of the species caught, i.e., in order of decreasing flying height, Culex pipiens Linnaeus s.l., Culex modestus Ficalbi, Coquillettidia richiardii (Ficalbi), Aedes detritus (Haliday), Aedes caspius (Pallas). We also calculated the linear regression lines for both sites and found that 90% of Ae. caspius flew within a height of 1.64 m from the ground level, 95% within 2.68 m, and 99% at a height not exceeding 4 m; whereas 90% of Cx. pipiens moved within 3.45 m from the ground level, 95% within 4.02 m, and 99% within 4.76 m. The vertical distributions of Ae. caspius and Cx. pipiens did not vary significantly over the seasons and were not affected by the presence of trees or variations in temperature and wind velocity within the range of measurements obtained. The data obtained provide useful information for planning Ae. caspius control measures based on a mechanical barrier capable of preventing mosquitoes from moving toward residential settlements and tourist resorts bordering on the protected area as an alternative to aerial treatment with the larvicide Bacillus thuringiensis subsp. israelensis.

Unfavorable mechanical effects of heat and moisture exchangers in ventilated patients

OBJECTIVE

To investigate the mechanical effects of artificial noses.

SETTING

A general intensive care unit of a university hospital.

PATIENTS

10 patients in pressure support ventilation for acute respiratory failure.

INTERVENTIONS

The following three conditions were randomly tested on each patient: the use of a heated humidifier (control condition), the use of a heat and moisture exchanger without filtering function (HME), and the use of a combined heat and moisture exchanger and mechanical filter (HMEF). The pressure support level was automatically adapted by means of a closed-loop control in order to obtain constancy, throughout the study, of patient inspiratory effort as evaluated from airway occlusion pressure at 0.1 s (P0.1). Patient's ventilatory pattern, P0.1, work of breathing, and blood gases were recorded.

MEASUREMENTS AND MAIN RESULTS

The artificial noses increased different components of the inspiratory load: inspiratory resistance, ventilation requirements (due to increased dead space ventilation), and dynamic intrinsic positive end-expiratory pressure (PEEP). The additional load imposed by the artificial noses was entirely undertaken by the ventilator, being the closed-loop control of P0.1 effective to maintain constancy of patient inspiratory work by means of adequate increases in pressure support level.

CONCLUSIONS

The artificial noses cause unfavorable mechanical effects by increasing inspiratory resistance, ventilation requirements, and dynamic intrinsic PEEP. Clinicians should consider these effects when setting mechanical ventilation and when assessing patients' ability to breathe spontaneously.

Respiratory mechanics by least squares fitting in mechanically ventilated patients: applications during paralysis and during pressure support ventilation

OBJECTIVE

To evaluate a least squares fitting technique for the purpose of measuring total respiratory compliance (Crs) and resistance (Rrs) in patients submitted to partial ventilatory support, without the need for esophageal pressure measurement.

DESIGN

Prospective, randomized study.

SETTING

A general ICU of a University Hospital.

PATIENTS

11 patients in acute respiratory failure, intubated and assisted by pressure support ventilation (PSV).

INTERVENTIONS

Patients were ventilated at 4 different levels of pressure support. At the end of the study, they were paralyzed for diagnostic reasons and submitted to volume controlled ventilation (CMV).

MEASUREMENTS AND RESULTS

A least squares fitting (LSF) method was applied to measure Crs and Rrs at different levels of pressure support as well as in CMV. Crs and Rrs calculated by the LSF method were compared to reference values which were obtained in PSV by measurement of esophageal pressure, and in CMV by the application of the constant flow, end-inspiratory occlusion method. Inspiratory activity was measured by P0.1. In CMV, Crs and Rrs measured by the LSF method are close to quasistatic compliance (-1.5 +/- 1.5 ml/cmH2O) and to the mean value of minimum and maximum end-inspiratory resistance (+0.9 +/- 2.5 cmH2O/(l/s)). Applied during PSV, the LSF method leads to gross underestimation of Rrs (-10.4 +/- 2.3 cmH2O/(l/s)) and overestimation of Crs (+35.2 +/- 33 ml/cmH2O) whenever the set pressure support level is low and the activity of the respiratory muscles is high (P0.1 was 4.6 +/- 3.1 cmH2O). However, satisfactory estimations of Crs and Rrs by the LSF method were obtained at increased pressure support levels, resulting in a mean error of -0.4 +/- 6 ml/cmH2O and -2.8 +/- 1.5 cmH2O/(l/s), respectively. This condition was coincident with a P0.1 of 1.6 +/- 0.7 cmH2O.

CONCLUSION

The LSF method allows non-invasive evaluation of respiratory mechanics during PSV, provided that a near-relaxation condition is obtained by means of an adequately increased pressure support level. The measurement of P0.1 may be helpful for titrating the pressure support in order to obtain the condition of near-relaxation.

[Pathogenesis of AIDS: possible role of co-factors in HIV reactivation]

One of the most intriguing aspects concerning the pathogenesis of AIDS is the long period of latency of the HIV in human cells, not causing any cytopatic effect in some and, on the other hand, causing cell destruction, at short periods, in others. The various agents and the mechanisms they adopt to reactivate the latente HIV, were described. Also the frequent epidemiological observation on the presence of both such agents and the HIV in AIDS patients allowed the authors to speculate on the probable important role of a cohort of co-factors which determine the destiny of such individuals. Special considerations were made in respect to the hepatitis B virus, cytomegalovirus, herpesviruses (HHV-1, e and 6), EB virus, HTLV-1 and 2 retroviruses, group B arbovirus Maguary, malaria and other endemic infectious diseases which victimize millions of Brazilians. Accepting the importance of such co-factors acting on the viral gens that regulate the HIV expression in the host cell, it was speculated on the possible role of vaccines, such as the hepatitis B vaccine, and some antiviral drugs which could be useful in the indirect prevention of AIDS-disease in both HIV-carriers and those practising AIDS-high-risk-activities.

High effectiveness of aerosolized chick embryo fibroblast measles vaccine in seven-month-old and older infants

Neither the presence of hypertonic sugar nor the absence of 1% human albumin in the aerosolized chick embryo fibroblast (CEF) measles vaccine was previously found to be responsible for its inadequacy in infants with titers of maternal plaque-neutralizing (PN) antibody at which human diploid cell measles vaccine was immunogenic. Eight weeks after administration of CEF measles vaccine containing 1% human albumin, antibody had developed in all 10 infants 7-10 months old and all 11 children 12-35 months old but in only 26% of 23 infants 3-5 months old and 67% of 9 infants 6 months of age. Failure of antibody development was associated with prevaccination PN antibody titers of greater than or equal to 1:50 (with one exception at a titer of 1:25). The PN antibody response to CEF vaccine (diluted 1:10, approximately 10(5) pfu/ml) in infants under seven months of age (geometric mean titer [GMT], 1:421) was significantly lower (P less than .005) than in older infants (GMT, 1:1,564). At a 1:1,000 dilution of vaccine, only 50% of 10 infants 13-25 months old, 20% of 15 infants 7-10 months old, and none of 8 infants 6 months old developed antibody.

Human leukocyte interferon administration to patients with symptomatic and suspected rabies

Body fluids and brain tissue from rabid human patients have demonstrated only low titers of interferon. Therefore, pharmacokinetic studies of systemically administered and locally injected leukocyte interferon were performed in 2 North American patients with suspected rabies who showed no clinically important side effects of this therapy. Similar therapy was given to 5 patients with symptomatic rabies in Europe and America. Although no prolongation of the clinical course was seen in 3 patients given high-dose intraventricular and systemic therapy, treatment was not initiated until between 8 and 14 days after symptoms were seen. The intraventricular dosage regimen produced cerebrospinal fluid levels that appeared to fall progressively over the 24 hours after injection and demonstrated good but somewhat delayed distribution into the lumbar sac. Titers produced by this therapy were 30- to 10,000-fold higher than those normally observed in this infection, however. In the patients treated at the highest dosage, a diminished and delayed antirabies neutralizing antibody titer was observed, probably a result of the administration of the exogenous interferon.

Treatment of relapsing chronic infections of the respiratory tract. A comparative study of the effectiveness of non specific immunotherapy with the immunoadjuvant P40 and of vaccinotherapy

The treatment of relapsing chronic infections (RCI) encounters many difficulties. In the present study, the use of the immuno adjuvant P40 either alone or in association with vaccinotherapy for the treatment of RCI turned out to be very effective, whereas vaccinotherapy alone was not. It is hypothesized that cell-mediated immunity may play a major role in controlling RCI, since the clinical improvement of the patients kept up with the positivation of previously negative skin tests carried out with either the specific infecting agent or with recall-anti gens.

Naturally acquired antibodies to tetanus toxin in humans and animals from the galápagos islands

A serologic survey using a highly sensitive enzyme-linked immunosorbent assay confirmed the anticipated finding of naturally acquired antibodies to tetanus toxin both in humans and animals on the Galápagos Islands. In 57 inhabitants (mean age, 31.3 years) who had not been vaccinated against tetanus, antibody to tetanus toxin was detected in the blood in varying titers (geometric mean [reciprocal] titer [GMT], 0.015 international units [IU]/ml). In one individual the titer of antibody was greater than 12.5 IU/ml. Two individuals who had never been vaccinated against tetanus but who had reported having had clinical tetanus had titers of antibody to tetanus toxin of 0.02 IU/ml and 0.3 IU/ml, respectively. All nine of the animals studied showed antibody to tetanus toxin (GMT, 0.028 IU/ml).