© Springer Science+Business Media New York 2017Kathirvel Subramaniam and Tetsuro Sakai (eds.)Anesthesia and Perioperative Care for Organ Transplantation10.1007/978-1-4939-6377-5_47
47. Postoperative Management of Composite Tissue Graft Transplantation
Mayo Clinic, Phoenix, AZ, USA
Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 3550 Terrace Street, 6th Floor, Scaife Hall, Pittsburgh, PA 15261, USA
KeywordsComposite tissue allotransplantation (CTA)Postoperative managementVentilator-associated pneumoniaVenous thromboembolismStress ulcerImmunosuppressionAntibiotics
Composite Tissue Allotransplantation (CTA) involves transplantation of body structures such as the limbs, larynx, abdominal wall, tendons, and face. In this chapter, we will discuss general and specific postoperative management of patients following CTA.
The following general preventative measures should be implemented:
Elevation of the Head of the Bed
A particular concern in the intensive care unit is ventilator-associated pneumonia (VAP) , defined as pneumonia that develops more than 48 after initiation of mechanical ventilation. Several preventative strategies have been examined to reduce the risk of VAP, including oropharyngeal decontamination, probiotics, silver coated endotracheal tubes, closed circuit suction tubes, and patient positioning. Elevation of the head of the bed is easy to implement without additional cost or adverse effects. The Center for Disease Control recommends that ventilated patients should ideally be placed in the semi-recumbent position with the head of the bed elevated at an inclination of 30–45°. Several randomized control trials have demonstrated that maintaining patients in the semi-recumbent position decreases the incidence of VAP.
Venous Thromboembolism (VTE) Prophylaxis
Development of venous thromboembolism is believed to evolve from abnormalities in endothelial injury, venous stasis, and hypercoaguability. Non-pharmacologic methods against VTE are available, though pharmacologic methods are preferred. Graduated compression stockings aim to prevent the pooling of blood in the lower extremities and prevent the development of venous clots. When appropriately used, compression stockings have been shown to decrease the rate of deep vein thrombosis. Pneumatic compression stockings applied to the lower extremities similarly operate by intermittently inflating and squeezing blood through the venous system to reduce the risk of venous stasis. Unfractionated heparin is most commonly used for prophylaxis against VTE. Both unfractionated heparin (UFH) and low molecular weight heparins (LMWH) have been shown to decrease the incidence of clinically detected VTE compared to placebo. Standard VTE prophylaxis, using compression stockings and pneumatic compression devices, should be used in all patients. Additionally, UFH can be used carefully in those without recent bleeding and without significant coagulopathy.
Stress Ulcer Prophylaxis
Stress related mucosal injury occurs in ICU patients within the first few days of ICU admission. The most important risk factors for the development of gastrointestinal bleeding are coagulopathy and need for mechanical ventilation. Other risk factors include history of gastrointestinal bleeding, hypotension, and multi-organ system dysfunction. Most of these risk factors are common in prior to and in the immediate postoperative period after transplant. Early trials of acid suppression used antacids, sucralfates, and H2 blockers and reported benefit in decreasing the incidence of both clinically significant and life-threatening gastrointestinal bleeding. Proton pump inhibitors (PPIs) are now commonly used as prophylactic measures against gastrointestinal bleeding. PPIs are more potent than H2 blockers in increasing gastric pH in critically ill patients; however, no study has shown improved efficacy with PPI to prevent gastrointestinal bleeding. Long-term PPI has been associated with increased risk of community acquired pneumonia, as well as healthcare associated pneumonia, and Clostridium Difficile infection.
Postoperative Intensive Care of the Face Transplant Patient
Face transplantation is a complex and long surgery that is associated with significant perioperative challenges, and multiple postoperative complications. Face-grafting techniques require a well-defined organization of all the teams involved. Patients typically spend several days in the ICU.
Patients usually have a tracheostomy tube (size will be variable) in place. Many centers avoid the use of circumferential tracheostomy neck ties that normally fasten the tracheostomy tube. If these ties are used, tight application may lead to neck swelling and potentially venous outflow obstruction of the facial graft.
Postoperative severe graft edema is expected in most patients and head elevation at 30–45° will promote venous drainage and prevent VAP . Extra care must be taken to avoid airway loss because that complication has devastating consequences.
The goal is to have all patients liberated from the mechanical ventilator within the first 24 h after surgery. Combinations of sedatives and narcotics are usually required. Great care should be taken to avoid over sedation. Sedation interruption should be implemented for patients who require ventilation longer than 24 h.
Patients are ventilated with positive pressure volume controlled mode with FiO2 to keep paO2 levels between 100 and 150 mmHg . Pulse oxymetry is helpful to wean or titrate FiO2; however, arterial blood gases are generally required to guide manage acid base balance. The Risk of developing Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) is high partly due to high operative transfusion requirement.
The goal is to have normal hemodynamics and avoid extreme swings (high or low) in blood pressure and heart rate as much as possible.
Hypothermia, hypovolemia, and pain can cause vasoconstriction, which in turn may compromise the free flaps. Normothermia, mean arterial pressure (MAP) of 65 mmHg, urine output up to 0.5–1 ml/kg/h should be the goal. Graft perfusion monitoring is performed by Doppler velocities of the external carotid artery but continuous Doppler probes may be used.
Hypotension and shock can be hypovolemic, hemorrhagic, or vasodilatory and the management should be implemented accordingly. There is no evidence to suggest using one vasopressor or inotrope is better than another so local protocols in managing shock should be utilized.
Graft edema is expected because of the long operation, long ischemia time, and disrupted lymphatic drainage. Elevation of the head 30–45° and relatively negative fluid balance can used to reduce face edema. Use of small does of diuretics may be used if deemed necessary by the team.
Large blood losses are expected intraoperatively due to high vascularity of the face and prolonged procedure time as a result of complex anastomoses during the preparation and grafting phase. Maintaining Hct > 27, Plt > 50K, INR < 1.5 and Fibrinogen > 100 are common clinical practice targets .