Halina Cidrini Ferreira

Lung mechanics and histology during sevoflurane anesthesia in a model of chronic allergic asthma.

BACKGROUND:There are no studies examining the effects of sevoflurane on a chronically inflamed and remodeled airway, such as that found in asthma. In the present study, we sought to define the respiratory effects of sevoflurane in a model of chronic allergic asthma. For this purpose, pulmonary mechanics were studied and lung morphometry analyzed to determine whether the physiological modifications reflected underlying morphological changes. METHODS:Thirty-six BALB/c mice (20–25 g) were randomly divided into four groups. In OVA groups, mice were sensitized with ovalbumin and exposed to repeated ovalbumin challenges. In SAL groups, mice received saline using the same protocol. Twenty-four hours after the last challenge, the animals were anesthetized with pentobarbital sodium (PENTO, 20 mg/kg i.p.) or sevoflurane (SEVO, 1 MAC). Lung static elastance (Est), resistive (&Dgr;P1) and viscoelastic/inhomogeneous (&Dgr;P2) pressure decreases were analyzed by an end-inflation occlusion method. Lungs were fixed and stained for histological analysis. RESULTS:Animals in the OVASEVO group showed lower &Dgr;P1 (38%), &Dgr;P2 (24%), and Est (22%) than animals in the OVAPENTO group. Histology demonstrated greater airway dilation (16%) and a lower degree of alveolar collapse (25%) in the OVASEVO compared with OVAPENTO group. &Dgr;P1 was lower (35%) and airway diameters larger (12%) in the SALSEVO compared with SALPENTO group. CONCLUSION:Sevoflurane anesthesia acted both at airway level and lung periphery reducing (&Dgr;P1 and &Dgr;P2 pressures, and Est in chronic allergic asthma.

Time course of respiratory mechanics and pulmonary structural remodelling in acute lung injury

The aim of this study was to evaluate the time course of in vivo and in vitro respiratory mechanics and examine whether these parameters could reflect the temporal changes in lung parenchyma remodelling in paraquat (PQ)-induced lung injury. Measurements were done 1, 3 and 8 weeks after the intraperitoneal (i.p.) injection of saline (control) or paraquat (7mgkg(-1)) in rats. Airway and tissue resistances increased from control in PQ1 and PQ3 and returned to control values in PQ8, in accordance with the magnitude of bronchoconstriction. Viscoelastic/inhomogeneous pressure, tissue elastance, the number of polymorphonuclear cells, and collagen fibre content in lung parenchyma increased in PQ1 and remained elevated in PQ3 and PQ8. Static elastance increased in PQ1, returned to control values after 3 weeks, and was correlated with the volume fraction of collapsed alveoli. In conclusion, there is a restoration of normal alveolar-capillary lung units with a gradual improvement in airway and tissue resistances and static elastance. However, the on-going fibrotic process kept elevated tissue elastance and viscoelastic/inhomogeneous pressure.

Effects of dexmedetomidine on respiratory mechanics and control of breathing in normal rats

Dexmedetomidine is a highly selective and specific alpha(2)-adrenergic agonist, with sedative, analgesic, and sympatholytic activities. The aim of the present study was to define the effects of DMED in respiratory mechanics in normal rats. In addition, lung morphometry was studied to determine whether the physiological changes reflected underlying morphological changes defining the sites of action of dexmedetomidine. Arterial blood gases were also determined. Twelve adult Wistar rats were randomly assigned to two groups of six animals each: PENTO and DMED. In PENTO group animals were sedated (diazepam, 5mg, i.p.) and anaesthetised with pentobarbital sodium (20mgkg(-1) i.p.). The rats of the DMED group received dexmedetomidine (250mugkg(-1) i.p. followed by intravenous infusion of 0.5mugkg(-1)h(-1)). In spontaneously breathing rats, minute ventilation, respiratory frequency, and neuromuscular inspiratory drive were lower in dexmedetomidine group, which also presented hypercapnia, whereas tidal volume, inspiratory, expiratory, and total respiratory cycle times were higher in dexmedetomidine group compared to the PENTO group. During mechanical ventilation, respiratory mechanical parameters were similar in both groups. These findings were supported by the absence of histological changes. In conclusion, under the conditions studied, dexmedetomidine did not change respiratory mechanical parameters and lung histology, but induced ventilatory depression.

Fisiopatologia e manejo clínico da ventilação seletiva

During one-lung ventilation, the nonventilated lung is excluded from the ventilation, with all tidal volume directed into the ventilated lung. This technique facilitates viewing of intrathoracic structures, thereby providing optimal surgical conditions. However, this procedure has been associated with reduced arterial oxygen tension, principally in patients with a previous history of lung disease, since it reduces the surface area available for gas exchange and causes a loss of normal autonomic respiratory regulation. Therefore, maintaining sufficient oxygenation and elimination of carbon dioxide is the greatest challenge in the management of the one-lung ventilation. It is recommend that the tidal volume administrated to the ventilated lung be similar to that used during conventional mechanical ventilation and that high fractions of inspired oxygen be used. However, several alternative methods have been proposed in order to minimize hypoxemia during one-lung ventilation, including the correct positioning of the double-lumen tube, the use of positive end-expiratory pressure or continuous positive airway pressure, nitric oxide administration, and alveolar recruitment. The management of one-lung ventilation continues to be a challenge in clinical practice.

On the crucial ventilatory setting adjustment from two- to one-lung ventilation

Lung mechanics, histology, oxygenation and type-III procollagen (PCIII) mRNA were studied aiming to evaluate the need to readjust ventilatory pattern when going from two- to one-lung ventilation (OLV). Wistar rats were assigned to three groups: the left lung was not ventilated while the right lung received: (1) tidal volume (V(T))=5 ml/kg and positive end-expiratory pressure (PEEP)=2 cm H(2)O (V5P2), (2) V(T)=10 ml/kg and PEEP=2 cm H(2)O (V10P2), and (3) V(T)=5 ml/kg and PEEP=5 cm H(2)O (V5P5). At 1-h ventilation, V5P2 showed hypoxemia, alveolar collapse and impaired lung function. Higher PEEP minimized these changes and prevented hypoxemia. Although high V(T) prevented hypoxemia and maintained a higher specific compliance than V5P2, a morphologically inhomogeneous parenchyma and higher PCIII expression resulted. In conclusion, the association of low V(T) and an adequate PEEP level could be useful to maintain arterial oxygenation without inducing a possible inflammatory/remodeling response.

Importance of physiotherapy/nursing multidisciplinary integration about update newborn position in the neonatal intensive care unit

Introduction The high-risk newborns may require long periods of hospitalization until they reach clinical stability for hospital discharge. Avoiding babies to be in only one body position may be an effective way to cause respiratory and neuro-psycho-motor benefits, comfort and preventing pressure ulcers.Objectives This study investigated the impact of physiotherapy/nursing integration in update on body positioning of the newborn in the Neonatal Intensive Care Unit.Methods A questionnaire was administered to nurses and nursing technicians of the neonatal unit of Maternity School of UFRJ and nurses of the Advanced Course in Neonatal Nursing from the same institution. Two classes were taught by the physical therapist of the sector and the questions answered before and after these lessons. It was also a brief characterization of professional participants of the study. We used the Students t test to compare the correct answers before (PRE) and after (POST) the classes, considering p < 0.05.Results There was a significant increase in the degree of knowledge of nurses and nursing technicians when compared the responses before (nurses: 68.8%; technicians: 70.1%) and after classes (nurses: 78.4 %; technicians: 88.9%). The nurses were less than five years of graduated (45%) and little time of professional experience in neonatology (60%). Forty-seven percent of technicians had less than five years of training and 82% had less than 10 years of experience.Conclusion The use of training by the nursing staff was significant, showing the importance of multidisciplinary approach and the integration of knowledge in the search for a humanized and effective care.

Mapeamento demográfico e caracterização do perfil de assistência fisioterapêutica oferecida nas unidades de terapia intensiva neonatais do Rio de Janeiro (RJ)

This study aims to map and characterize the profile of physical therapy care offered in intensive care units (ICU) of public and private hospitals in the city of Rio de Janeiro. To this end, a cross-sectional study was conducted by interviews with the heads/routine chiefs of physical therapy services of the hospitals in the city of Rio de Janeiro with neonatal ICU (NICU) from January 2013 to January 2015. The questions comprised the distribution of working hours, organization and institutional location, time of experience in the area, types of physical therapy techniques and resources used. Twenty seven hospitals (17 public and 10 private) were studied as follows: 6 hospitals in the South area of the city, 8 in the North, 8 in the West and 5 in the central area and port area. The total number of physical therapists of the teams was 141, and 59% of them were experts in neonatal intensive care. With regard to the heads/routine chiefs, 16 (59%) were specialists in neonatal intensive care and 21 (79%) had more than five years of experience. Various physical therapy techniques were cited as: motor physical therapy, chest vibration and thoracic-abdominal rebalance. According to the results, there was not a single standard regarding routines, protocols, professional organization and training, and techniques used. In addition, it was found that the physical therapy in ICUs was not held full-time, neither provided the three shifts care.

Mapeo demográfico y caracterización del perfil de asistencia fisioterapéutica ofrecida en unidades de cuidados intensivos neonatales de Río de Janeiro (RJ), Brasil

This study aims to map and characterize the profile of physical therapy care offered in intensive care units (ICU) of public and private hospitals in the city of Rio de Janeiro. To this end, a cross-sectional study was conducted by interviews with the heads/routine chiefs of physical therapy services of the hospitals in the city of Rio de Janeiro with neonatal ICU (NICU) from January 2013 to January 2015. The questions comprised the distribution of working hours, organization and institutional location, time of experience in the area, types of physical therapy techniques and resources used. Twenty seven hospitals (17 public and 10 private) were studied as follows: 6 hospitals in the South area of the city, 8 in the North, 8 in the West and 5 in the central area and port area. The total number of physical therapists of the teams was 141, and 59% of them were experts in neonatal intensive care. With regard to the heads/routine chiefs, 16 (59%) were specialists in neonatal intensive care and 21 (79%) had more than five years of experience. Various physical therapy techniques were cited as: motor physical therapy, chest vibration and thoracic-abdominal rebalance. According to the results, there was not a single standard regarding routines, protocols, professional organization and training, and techniques used. In addition, it was found that the physical therapy in ICUs was not held full-time, neither provided the three shifts care.

Demographic mapping and characterization of physical therapy care profile offered in Neonatal Intensive Care Units in the City of Rio de Janeiro, Brazil

This study aims to map and characterize the profile of physical therapy care offered in intensive care units (ICU) of public and private hospitals in the city of Rio de Janeiro. To this end, a cross-sectional study was conducted by interviews with the heads/routine chiefs of physical therapy services of the hospitals in the city of Rio de Janeiro with neonatal ICU (NICU) from January 2013 to January 2015. The questions comprised the distribution of working hours, organization and institutional location, time of experience in the area, types of physical therapy techniques and resources used. Twenty seven hospitals (17 public and 10 private) were studied as follows: 6 hospitals in the South area of the city, 8 in the North, 8 in the West and 5 in the central area and port area. The total number of physical therapists of the teams was 141, and 59% of them were experts in neonatal intensive care. With regard to the heads/routine chiefs, 16 (59%) were specialists in neonatal intensive care and 21 (79%) had more than five years of experience. Various physical therapy techniques were cited as: motor physical therapy, chest vibration and thoracic-abdominal rebalance. According to the results, there was not a single standard regarding routines, protocols, professional organization and training, and techniques used. In addition, it was found that the physical therapy in ICUs was not held full-time, neither provided the three shifts care.

Single nucleotide polymorphisms in the apo(a) kringle IV type 8 domain are not associated with atherothrombotic serum lipoprotein (a) concentration, in a Portuguese paediatric population.

Lipoprotein (a) (Lp[a]) is a complex of apolipoprotein (a) (apo[a]) and low‐density lipoprotein (LDL), associated with atherothrombotic disease. Most of the interindividual variations in plasma levels of Lp(a) can be attributed to sequence differences linked to the apo(a) gene locus. The aim of this study was to investigate a possible link between single nucleotide polymorphisms (SNPs) in the apo(a) kringle (K) IV type 8 domain and atherothrombotic serum Lp(a) concentrations. Direct sequencing of the two exons and flanking intronic sequences of the apo(a) K IV type 8 domain was performed in a group of 97 paediatric patients, 51 with serum Lp(a) concentration above and 46 with concentration below 30 mg/dl,. We found three SNPs, two in exon 1 (c.66A>C and c.133G>A) and one in intron 1 (c.160+1G>A). The c.66A>C polymorphism was the most common with a heterozygosity frequency of 15.46%. The c.133G>A and c.160+1G>A polymorphisms were found at a frequency of 5.15% and 1.03%, respectively. No statistically significant difference was found in the genotype distribution between the two groups of patients. Our results suggest that these SNPs in the apo(a) K IV 8 domain are not directly associated with atherothrombotic serum Lp(a) concentration in our population.