RESUMO
Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.
Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.
Assuntos
Humanos , Feminino , Criança , Hemoglobinas Anormais/análise , Hemoglobinas Anormais/genética , Hemoglobinas Anormais/química , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/genética , Anemia , Oxigênio , OximetriaRESUMO
BACKGROUND: Evidence suggests that a preoperative single-dose steroid improves lung function and decreases the incidence of postoperative symptoms; however, this has not been sufficiently proved in modified radical mastectomy for cancer. This study aimed to evaluate the efficacy of preoperative single-dose steroid administration for postoperative lung function and postoperative symptoms in women undergoing modified radical mastectomy for breast cancer. METHODS: In this controlled clinical trial, conducted between June 2014 and October 2018, we examined 81 patients. Patients received a preoperative single dose of 8 mg dexamethasone (n=41; treatment group) or placebo (sterile injectable water; n=40; control group). We obtained data on postoperative nausea and vomiting and pain intensity and performed spirometry 1 h before and 1, 6, 12, and 24 h after surgery. The use of additional analgesic or antiemetic drugs was recorded. We followed up patients 30 days after discharge and recorded any surgical or medical complications. RESULTS: The age distribution and anthropometric variables of the two groups were similar. Almost 50% of the patients in each group also underwent breast reconstruction. In the treatment group, pain intensity was always lower, the incidence of postoperative nausea and vomiting was lower at 6, 12, and 24 h, and additional analgesics or antiemetics were required less frequently (P<0.05 for all). Both treatment and control groups demonstrated a restrictive ventilatory pattern immediately after surgery, which in the treatment group was reversed after 24 h. However, the reconstructed patients had a more intense and prolonged restrictive pattern (P<0.05). Surgical morbidity included one seroma observed in the control group. No infections occurred at the surgical site or at any other level, and no patient developed any metabolic disorder. No mortality was observed in either group. CONCLUSIONS: This study establishes that a single preoperative dose of dexamethasone markedly decreased the incidence of postoperative nausea and vomiting and pain, improved respiratory parameters, and decreased the need for additional postoperative analgesic or antiemetic drugs. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (ID NCT02305173).