[Hemodynamic and respiratory changes during lung transplant]. / Alteraciones hemodinámicas y ventilatorias durante el trasplante pulmonar.

OBJECTIVE: To study the hemodynamic and gasometric changes observed during lung transplantation, and discuss the differences between unilateral (ULT) and sequential bilateral lung transplantation (SBLT). PATIENTS AND METHODS: We enrolled 13 consecutive patients (8 ULT and 5 SBLT). Gasometric and hemodynamic readings, including right ventricular (RV) function measured as ejection fraction through a catheter, were recorded at the different phases of surgery. ANOVA and Neumann Keuls tests were used for statistical analysis. RESULTS: During ULT no significant changes in RV function were seen and gasometric alterations stayed within clinically tolerable limits. No significant hemodynamic or gasometric changes were observed during the first implantation during SBLT, although there was a significant increase in pulmonary artery pressure as cardiac index decreased, as well as significant depression of RV function and hypoxemia during reperfusion and ventilation of the first lung transplanted. Extracorporeal circulation was needed in one case. CONCLUSIONS: During SBLT, selective reperfusion and ventilation of the first transplanted lung is a moment of great hemodynamic and ventilatory instability. Exhaustive monitoring of RV function is essential for adequate management.

[Special anesthesia care in heart transplantation. The management of right ventricular failure]. / Cuidados anestésicos especiales en trasplante cardíaco. Manejo del fracaso de ventrículo derecho.

Right ventricular dysfunction is a common clinical event after heart transplantation. The major cause is the failure of right ventricle (RV) to adapt to the pulmonary hypertension (PH) secondary to chronic heart failure. Nevertheless, this dysfunction is usually transient owing to the reversibility of PH, the nature of which is mainly passive. Therefore, it is particularly important to perform a preoperative hemodynamic study to identify those cases in which PH is a permanent component, a situation that excessively increases the risk of postoperative RV failure. Once this occurs, the treatment is complex. The available therapeutic measures include the use of vasodilators such as prostaglandin E1 and nitric oxide.

[Premedication with clonidine in the neurosurgical patient: sedation, anesthetic requirements and hemodynamic perfusion]. / Premedicación con clonidina en el paciente neuroquirúrgico: sedación, requerimientos anestésicos y repercusión hemodinámica.

OBJECTIVES: To analyze the effect of premedication with clonidine on postoperative sedation, anesthetic requirements and hemodynamic repercussions in patients undergoing craniotomy due to supratentorial intracranial pathology. PATIENTS AND METHODS: Twenty ASA I/II patients in a double-blind prospective study were assigned randomly to receive lorazepam (0.03 mg/kg/po, n = 10) or clonidine (0.005 mg/kg/po, n = 10) the night before and 90 minutes before surgery. Arterial pressure and heart rate were monitored continuously during and immediately after surgery (first 24 hours). Anesthetic induction was achieved with thiopental (maximum 6 mg/kg) and maintained with O2/N2O and an infusion of alfentanyl (1 microgram/kg/min). Hemodynamic response to surgical stimulus was treated with additional boluses of alfentanyl up to a maximum dose of 0.1 mg/kg and with an increase in infusion dosage to 2 micrograms/kg/min. When these were ineffective, isoflurane was given. All patients were extubated in the operating room. RESULTS: No differences in level of sedation were found between the two groups. The infusion dose and total amount of alfentanyl given were smaller for patients treated with clonidine (0.8 +/- 0.04 vs 0.6 +/- 0.01 microgram/kg/min and 22.4 +/- 5.3 vs 17.5 +/- 4.9 mg, respectively) (p < 0.05). No differences were found in isoflurane requirements (5/5 vs 2/8). Mean arterial pressure and heart rate were lower with clonidine from 3 minutes after intubation until the patient's arrival in the recovery room (p < 0.05), with marked bradycardia (49 +/- 5 vs 73 +/- 7 bpm) (p < 0.05) upon intubation. CONCLUSIONS: Premedication of neurosurgical patients with clonidine offers no advantages over lorazepam with respect to sedation. Nevertheless, clonidine may offer advantages with respect to the amount of alfentanyl required and attenuation of perioperative adrenergic response.