Bioelectrical impedance analysis of body composition for the anesthetic induction dose of propofol in older patients.

BACKGROUND: Older people are currently the fastest growing segment of the worldwide population. The present study aimed to estimate propofol dose in older patients based on size descriptors measured by bioelectrical impedance analysis (BIA). METHODS: A cross sectional study in adult and older patients with body mass index equal to or lower than 35 kg/m2 was carried out. BIA and Clinical Frail Scale scoring were performed during pre-operative evaluation. Propofol infusion was started at 2000 mg/h until loss of consciousness (LOC) which was defined by "loss of eye-lash reflex" and "loss of response to name calling". Total dose of propofol at LOC was recorded. Propofol plasma concentration was measured using gas chromatography/ion trap-mass spectrometry. RESULTS: Forty patients were enrolled in the study. Total propofol dose required to LOC was lower in Age ≥ 65 group and a higher plasma propofol concentration was measured in this group. 60% of old patients were classified as "apparently vulnerable" or "frail" and narrow phase angle values were associated with increasing vulnerability scores. In the Age ≥ 65 group, the correlation analysis showed that the relationship between propofol dose and total body weight (TBW) scaled by the corresponding phase angle value is stronger than the correlation between propofol dose and TBW or fat free mass (FFM). CONCLUSIONS: This study demonstrates that weight-based reduction of propofol is suitable in older patients; however FFM was not seen to be more effective than TBW to predict the propofol induction dose in these patients. Guiding propofol induction dose according to baseline frailty score should also be considered to estimate individualized dosage profiles. Determination of phase angle value appears to be an easy and reliable tool to assess frailty in older patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02713698 . Registered on 23 February 2016.

Increased lung inflammation with oxygen supplementation in tracheotomized spontaneously breathing rabbits: an experimental prospective randomized study.

BACKGROUND: Mechanical ventilation is a well-known trigger for lung inflammation. Research focuses on tidal volume reduction to prevent ventilator-induced lung injury. Mechanical ventilation is usually applied with higher than physiological oxygen fractions. The purpose of this study was to investigate the after effect of oxygen supplementation during a spontaneous ventilation set up, in order to avoid the inflammatory response linked to mechanical ventilation. METHODS: A prospective randomised study using New Zealand rabbits in a university research laboratory was carried out. Rabbits (n = 20) were randomly assigned to 4 groups (n = 5 each group). Groups 1 and 2 were submitted to 0.5 L/min oxygen supplementation, for 20 or 75 minutes, respectively; groups 3 and 4 were left at room air for 20 or 75 minutes. Ketamine/xylazine was administered for induction and maintenance of anaesthesia. Lungs were obtained for histological examination in light microscopy. RESULTS: All animals survived the complete experiment. Procedure duration did not influence the degree of inflammatory response. The hyperoxic environment was confirmed by blood gas analyses in animals that were subjected to oxygen supplementation, and was accompanied with lower mean respiratory rates. The non-oxygen supplemented group had lower mean oxygen arterial partial pressures and higher mean respiratory rates during the procedure. All animals showed some inflammatory lung response. However, rabbits submitted to oxygen supplementation showed significant more lung inflammation (Odds ratio = 16), characterized by more infiltrates and with higher cell counts; the acute inflammatory response cells was mainly constituted by eosinophils and neutrophils, with a relative proportion of 80 to 20% respectively. This cellular observation in lung tissue did not correlate with a similar increase in peripheral blood analysis. CONCLUSIONS: Oxygen supplementation in spontaneous breathing is associated with an increased inflammatory response when compared to breathing normal room air. This inflammatory response was mainly constituted with polymorphonuclear cells (eosinophils and neutrophils). As confirmed in all animals by peripheral blood analyses, the eosinophilic inflammatory response was a local organ event.

Idiopathic histiocytoid Sweet syndrome: a case report with clinical and histopathological considerations.

BACKGROUND: Histiocytoid Sweet syndrome is characterized by a predominant neutrophilic dermal infiltrate. Usual clinical differential diagnosis includes erythema multiforme, drug eruption, and erythema nodosum. Histiocytoid Sweet syndrome is considered an uncommon histopathological variant of the disease. METHODS: We evaluated clinical, histopathological, and immunohistochemical findings of a case categorized as idiopathic histiocytoid Sweet syndrome in which clinical-epidemiological data raised the possibilities of Sweet syndrome, leprosy, and drug reaction. RESULTS: Positive reaction to myeloperoxidase (MPO) in histiocytoid cells of the dermal infiltrate, response to oral corticosteroids, clinical and laboratory investigation, and absence of cutaneous lesions or clinical complaints within 1 year of follow-up are consistent with the diagnosis of idiopathic histiocytoid Sweet syndrome. CD68 (PG-M1) and CD15 positive cells were also present among dermal cells. CONCLUSIONS: Epidemiological data are relevant while considering a clinical differential diagnosis of Sweet syndrome that can be further expanded, from a histopathological point of view, when dealing with the histiocytoid variant since neutrophils, macrophages, and immature myelomonocytic cells with histiocytoid morphology are present. The significance of the MPO positive mononuclear dermal cells are not completely established.

Effect of Boussignac continuous positive airway pressure ventilation on Pao2 and Pao2/Fio2 ratio immediately after extubation in morbidly obese patients undergoing bariatric surgery: a randomized controlled trial.

STUDY OBJECTIVE: Pathophysiological changes after laparoscopic Roux-en-Y gastric bypass may increase the risk of pulmonary complications in morbidly obese patients. The purpose of the study was to assess the impact of immediate postextubation use of Boussignac continuous positive airway pressure (CPAP) on arterial oxygenation in morbidly obese patients undergoing laparoscopic Roux-en-Y gastric bypass. The hypothesis is that the use of CPAP may improve oxygenation in the postoperative period when compared to Venturi mask. DESIGN: Randomized controlled study. SETTING: A tertiary referral hospital. PATIENTS: Recruited morbidly obese adult patients undergoing laparoscopic Roux-en-Y gastric bypass. INTERVENTIONS: Boussignac CPAP or Venturi mask was randomly applied immediately after extubation in the operating room and was maintained during the first 2 hours in the recovery room. MEASUREMENTS: Pao2 and Pao2/fraction of inspired oxygen (Fio2) ratio values were measured preoperatively and at 1 (T1), 2 (T2), and 24 hours (T24) after extubation, through arterial blood samples. Secondary outcomes (spirometric parameters) were measured at the same periods. For comparison between groups, Student t test, Mann-Whitney U nonparametric test, and χ(2) test were used. Statistical significance is at P < .05. MAIN RESULTS: Twenty-four patients were included, 12 in each group. There were no differences in preoperative evaluation. There were significant differences between groups in Pao2 and Pao2/Fio2 mean values at T1, T2, and T24, being superior in the Boussignac group. During the 24 hours postextubation, 9% of patients in the Boussignac group and 50% in the Venturi group had a Pao2 less than 60 mm Hg in at least 1 of the evaluations. After extubation, a Pao2/Fio2 ratio value less than 300 was observed in all patients in the Venturi group and in 55% in Boussignac group in at least 1 of the evaluations. There were no differences in spirometric parameters between groups at T1, T2, and T24. CONCLUSIONS: Application of Boussignac CPAP for 2 hours after extubation improved oxygenation but did not improve forced expiratory volume at 1 second and forced vital capacity.