Role of 3D printing for the protection of surgical and critical care professionals in the COVID-19 pandemic. / Papel de la impresión 3D para la protección de los profesionales del área quirúrgica y críticos en la pandemia de COVID-19.

BACKGROUND AND OBJECTIVE: There is a shortage of supplies for the protection of professionals during the COVID-19 pandemic. 3D printing offers the possibility to compensate for the production of some of the equipment needed. The objective is to describe the role of 3D printing in a health service during the COVID-19 pandemic, with an emphasis on the process to develop a final product ready to be implemented in the clinical environment. METHODS: A working group was formed between the healthcare administration, clinicians and other public and private institutions in Cantabria, Spain coordinated by the Valdecilla Virtual Hospital. The process included receiving the printing proposals, learning about the printing resources in the region, selecting the devices, creating a team for each project, prototyping, evaluation and redesign, manufacturing, assembly and distribution. RESULTS: The following supplies are produced: 1) devices that help protect providers: face protection screens (2,400 units), personalized accessories for photophores (20 units) and ear-protection forks for face-masks (1,200 units); 2) products related to the ventilation of infected patients: connectors for non-invasive ventilation systems; and 3) oral and nasopharyngeal swabs (7,500 units) for the identification of coronavirus carriers with the aim of designing action protocols in clinical areas. CONCLUSIONS: 3D printing is a valid resource for the production of protective material for professionals whose supply is reduced during a pandemic.

Perioperative management of pulmonary hypertension during lung transplantation (a lesson for other anaesthesia settings).

Patients with pulmonary hypertension are some of the most challenging for an anaesthesiologist to manage. Pulmonary hypertension in patients undergoing surgical procedures is associated with high morbidity and mortality due to right ventricular failure, arrhythmias and ischaemia leading to haemodynamic instability. Lung transplantation is the only therapeutic option for end-stage lung disease. Patients undergoing lung transplantation present a variety of challenges for anaesthesia team, but pulmonary hypertension remains the most important. The purpose of this article is to review the anaesthetic management of pulmonary hypertension during lung transplantation, with particular emphasis on the choice of anaesthesia, pulmonary vasodilator therapy, inotropic and vasopressor therapy, and the most recent intraoperative monitoring recommendations to optimize patient care.

[Comparative study of two preservation solutions in the initial function after bilateral human lung transplantation]. / Estudio comparativo de dos soluciones de preservación en la función inicial del trasplante bipulmonar en humanos.

OBJECTIVE: Compare the influence of two preservation liquids, Euro-Collins (EC) and Perfadex (P) in the pulmonary graft function in the initial phase of lung transplant in humans. DESIGN: Retrospective study. SCOPE: Lung transplant unit of the ICU of a university hospital. PATIENTS: A total of 79 patients were subjected to a transplant of both lungs. The pulmonary grafts were preserved with EC in 23 cases and with P in 56 cases. VARIABLES OF INTEREST: Pulmonary function was assessed on admission in the intensive care unit (ICU) with the PaO2/FiO2 ratio. Mortality, graft dysfunction stay in ICU and time of mechanical ventilation were also assessed at 30 days. RESULTS: The PaO2/FiO2 ratio was significantly greater in the P group than in the EC both on admission (p<0.006) and at 12 hours (p=0.032) in the ICU. Graft dysfunction incidence was less in group P than in EC (p<0.045). There were no differences in regards to mortality at 30 days, stay in ICU and time of mechanical ventilation between both groups. CONCLUSION: Preservation of the pulmonary graft with P as preservation liquid compared with EC is associated with better graft function in the initial phases of transplant of both lungs and with a decrease in the incidence of graft dysfunction.

Influence of preservation solution on early lung function (Euro-Collins vs Perfadex).

BACKGROUND: This clinical study was performed to evaluate the efficiency of 2 different preservation solutions (Euro-Collins [EC] vs Perfadex [P]) on organ function in human lung transplantation. METHODS: The donor lungs for 46 patients were flushed either with EC solution (25 cases, EC group) or Perfadex (21 cases, P group). Transplant function was assayed using PaO2/FiO2 ratio after transplantation upon intensive care unit (ICU) arrival and at 12 and 24 hours later (T1, T2, and T3, respectively). We also compared the duration of mechanical ventilatory support and ICU stay. RESULTS: The PO2/FiO2 ratio was significantly better in the P than EC group at T1, T2, and T3. The duration of mechanical ventilatory support and ICU stay were lower also in P group, whereas age, sex, aetiology of lung disease, donor, PaO2/FiO2 ratio, and ischemia time did not show differences between the 2 groups. CONCLUSIONS: Our data on graft function tend to confirm better graft preservation using the P preservation solution.

[Simulators in anesthesiology]. / Simuladores en anestesia.

The work of an anesthesiologist and that of a flight pilot share certain attributes. As pilots use simulators to obtain risk-free practice in recognizing and controlling situations that might lead to disaster, simulation programs are now emerging as a new way to learn and train anesthesiology is being conceived as a new task that integrates scientific knowledge and human factors. Simulators have been introduced into teaching and training programs as a powerful tools that allow anesthesiologists to learn, practice and train in a multitude of situations without putting human life at risk. Experience is limited so far, but acceptance has been high and simulators seem to accelerate the acquisition of skills and knowledge, although their effect on performance in critical situations has not been proven yet. Two types have been applied in anesthesiology: computer screen and mannequin. The usefulness of simulators ranges from training for situations that require the systematic application of protocols and the understanding of new drugs being introduced into clinical practice to the practice of how to use resources for managing anesthetic emergencies. It is still too early to use simulators for certifying and evaluating clinical performance, as further studies are needed to identify the type of events that reflect typical situations and to determine which procedures should be evaluated.

[Changes in PCO2 and pH gradients in a canine model of experimental acute hemorrhage]. / Modificaciones de las diferencias arteriovenosas de PCO2 (Da-vPCO2) y pH (Da-vpH) en un modelo experimental canino de hemorragia aguda.

OBJECTIVE: To study changes in arterial-venous PCO2 pressures (Da-vPCO2) and in pH (Da-vpH) in an experimental dog model of acute bleeding. To emphasize the utility of monitoring these variables in situations of acute bleeding. ANIMALS AND METHOD: Eighteen dogs were anesthesized and monitored while being subjected to gradual bleeding. Gasometric and hemodynamic variables were recorded at the following moments: baseline, stage I (15% of volemic loss), stage Ib (20%), stage II (25%), stage IIb (30%) and stage III (35%). RESULTS: No significant differences in pH or PCO2 in either arterial or mixed venous blood were found. Bleeding induced a constant and progressive increase in Da-vPCO2 that correlated with changes in volume (r = -0.56, p < 0.001), SvO2 (r = 0.71; p < 0.001), Da-vO2 gradient (r = 0.62; p < 0.001) and cardiac output (r = 0.63; p < 0.001). CONCLUSIONS: Gradual bleeding caused a constant and significant increase of Da-vPCO2. Monitoring such changes in states of circulatory insufficiency may be useful for evaluating tissue ischemia.

Orthotopic liver transplantation from a donor with abdominal situs inversus.

The good results reported for liver transplantation have encouraged a much wider application of the procedure, broadening the list of indications and increasing the number of candidates. The shortage of organs for transplantation is a main problem that limits hepatic replacement in the potential recipients. Consequently, the number of contraindications for donor selection has been reduced over the last years. Some factors that were previously thought to preclude successful transplantation have now been relegated to relative contraindications, while others are no longer included. This has frequently led to the use of livers under suboptimal conditions or with anatomical anomalies. This is the case of donors with abdominal situs inversus. In this article, we report an orthotopic liver transplantation using a donor with abdominal situs inversus. Immunosuppressive protocol following surgery was composed of a classic three-drug therapy (cyclosporine, azathioprine, and prednisolone). The modified piggyback technique was performed over the right suprahepatic vein with orthotopic position of the graft. The graft showed good long-term function in the recipient, with a normal hepatic biopsy 5 months after the transplantation. There was no patient readmission or other medical problem after a 2 1/2-year follow-up.

Could the piggyback operation in liver transplantation be routinely used?

OBJECTIVE: To determine if orthotopic liver transplantation with inferior vena cava preservation, performed without using caval cross clamping or venovenous bypass, can minimize hemodynamic instability and low renal perfusion pressure. DESIGN: A prospective case series of 44 consecutive adult orthotopic liver transplantations, with a maximum follow-up of 30 months. SETTING: An institutional university referral center. PATIENTS: Between November 1990 and May 1993, 39 consecutive adult liver transplant recipients underwent transplantation with the following primary diagnoses: alcoholic cirrhosis (n = 23), viral cirrhosis (n = 9), primary biliary cirrhosis (n = 2), Wilson's disease (n = 2), primary sclerosing cholangitis (n = 1), fulminant hepatic failure (n = 1), and secondary hepatic malignant neoplasm (n = 1); five had repeated orthotopic liver transplantation. INTERVENTION: Orthotopic liver transplantations were performed using the piggyback technique, but with placement of the vascular clamp on the inferior vena cava laterally instead of across it so that it remained patent throughout the anhepatic stage. Favorable anatomic conditions in the recipients were not considered; venovenous bypass was not used. MAIN OUTCOME MEASURES: Intraoperative hemodynamic profile, blood loss and replacement, surgical time and complications, and patient survival. RESULTS: No significant hemodynamic changes with lateral clamping and no increases in surgical complications, rate of retransplantation, blood product requirements, or survival rate compared with the standard procedure. CONCLUSION: The piggyback operation could be routinely used in orthotopic liver transplantation.