A comparison of four different models of acute respiratory distress syndrome in sheep.

BACKGROUND: Acute respiratory distress syndrome (ARDS) can have various causes. The study objective was to investigate whether different pathophysiologic models of ARDS would show different respiratory, cardiovascular and inflammatory outcomes. METHODS: We performed a prospective, randomized study in 27 ventilated ewes inducing ARDS using three different techniques to mimic the pulmonary causes of ARDS (ARDSp): warm saline lavage (n = 6), intratracheal hydrochloric acid (HCl; n = 6), intratracheal albumin (n = 10), and one technique to mimic an extrapulmonary cause of ARDS (ARDSexp): intravenous lipopolysaccharide (LPS iv; n = 5). ARDS was defined when PaO2 was < 15 kPa (112 mmHg) when ventilated with PEEP 10 cm H2O and FiO2 = 1.0. The effects on gas exchange were investigated by calculating the oxygenation index (OI) and the ventilation efficacy index (VEI) every 30 min for a period of 4 h. Post mortem lung lavage was performed to obtain broncho-alveolar lavage fluid (BALF) to assess lung injury and inflammation. Lung injury and inflammation were assessed by measuring the total number and differentiation of leukocytes, the concentration of protein and disaturated phospholipids, and interleukine-6 and -8 in the BALF. Histology of the lung was evaluated by measuring the mean alveolar size, alveolar wall thickness and the lung injury score system by Matute-Bello et al., as markers of lung injury. The concentration of interleukin-6 was determined in plasma, as a marker of systematic inflammation. RESULTS: The OI and VEI were most affected in the LPS iv group and thereafter the HCl group, after meeting the ARDS criteria. Diastolic blood pressure was lowest in the LPS iv group. There were no significant differences found in the total number and differentiation of leukocytes, the concentration of protein and disaturated phospholipids, or interleukin-8 in the BALF, histology of the lung and the lung injury score. IL-6 in BALF and plasma was highest in the LPS iv group, but no significant differences were found between the other groups. It took a significantly longer period of time to meet the ARDS criteria in the LPS iv group. CONCLUSIONS: The LPS model caused the most severe pulmonary and cardiovascular insufficiency. Surprisingly, there were limited significant differences in lung injury and inflammatory markers, despite the different pathophysiological models, when the clinical definition of ARDS was applied.

The effects of dexamethasone and oxygen in ventilated adult sheep with early phase acute respiratory distress syndrome.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a life-threating condition with high morbidity and mortality. Inflammation is the main factor in the pathogenesis of ARDS. Therefore systemic corticosteroids are a rational therapeutic approach, but the effect of corticosteroids is still unclear. In this study, we looked at the effects of corticosteroids in ventilated sheep with ARDS, induced by lung lavage. METHODS: We performed a prospective, randomised study in 64 ventilated sheep with ARDS, to evaluate the effect of corticosteroids and oxygen concentration on gas exchange and lung injury. Oxygenation index (OI) and ventilation efficacy index (VEI) were calculated to evaluate gas exchange. Lung injury was assessed by inflammatory response in broncho-alveolar lavage fluid (BALF) and plasma and histology of the lung. RESULTS: OI, VEI, lung inflammation, surfactant production, or lung histology was not influenced by corticosteroids. In the 100 % oxygen groups, OI was higher and total number of cells and disaturated phospholipids were lower in BALF. CONCLUSION: Our study showed that corticosteroids did not influence inflammation in early phase ARDS and that hyperoxia aggravated lung injury which could not be modulated by dexamethasone in early phase ARDS.

Comparison of recruitment manoeuvres in ventilated sheep with acute respiratory distress syndrome.

BACKGROUND: Recruitment manoeuvres are widely used in clinical practice to open the lung and prevent lung injury by derecruitment, although the evidence is still discussed. In this study two different recruitment manoeuvres were compared to no recruitment manoeuvres (control) in ventilated sheep with acute respiratory distress syndrome (ARDS), induced by lung lavage. METHODS: We performed a prospective, randomised study in 26 ventilated sheep with ARDS, to evaluate the effect of two different recruitment manoeuvres on gas exchange, blood pressure and lung injury. The two different recruitment manoeuvres, the high pressure recruitment manoeuvre (HPRM), with high peak pressure, and the smooth and moderate recruitment manoeuvre (SMRM), with lower peak pressure, were compared to controls (no recruitment) after disconnection. Oxygenation index and ventilation efficacy index were calculated to evaluate gas exchange. Lung injury was assessed by inflammatory response in broncho-alveolar lavage fluid (BALF) and blood and histology of the lung. RESULTS: Oxygenation index improved significantly after both recruitment manoeuvres compared with controls, but no significant difference was found between the recruitment manoeuvres. Blood pressure decreased after HPRM but not after SMRM. HPRM induced a higher number of total cells and more neutrophils in the BALF. In the histology of the lung, mean alveolar size was increased in the dorsocranial region of the lung of SMRM compared to controls. CONCLUSION: Recruitment manoeuvres improved oxygenation, but SMRM was superior, with respect to hemodynamics and pulmonary inflammation, in ventilated sheep suffering from ARDS induced by lung lavage.

Neonatal hydrocolpos presenting as a rapidly progressive abdominal mass with inferior caval vein syndrome.

A 7-week-old infant was presented at the emergency department with an abdominal mass, unilateral swelling of the groin and suspicion of an inferior caval vein syndrome with bluish discolouration and oedema of the lower extremities. Abdominal imaging showed two large cysts and profound bilateral hydronephrosis. Following laparotomy, an extreme hydrocolpos and an overdistended urinary bladder were found. These findings turned out to be secondary to a transverse vaginal septum. She was treated surgically and was hospitalised for 2 weeks. Long-term follow-up showed normalisation of previously present hypercalciuria and hydronephrosis.A hydro(metro)colpos should be considered in the differential diagnosis of a female infant presenting with an abdominal mass, to apply the appropriate investigations and therapy.

Use and effectiveness of orthotics in hyperpronated dancers.

Hyperpronation is a common foot problem in dancers. The aim of this study was to investigate the usage and effectiveness of orthotics in the management of symptomatic hyperpronation among dancers. A prospective cohort study of all dancer-patients in the investigators' practice who were prescribed orthotics for new symptoms related to hyperpronation between July 2008 and January 2009 was conducted. In this group, the longitudinal medial arch angle of the foot was measured by the foot build registration system (FBRS), both barefoot and while wearing the orthotics. In addition, patients filled out questionnaires addressing perceived effectiveness of the orthotics for pain reduction and dance ability, among other items. A second retrospective study was conducted in order to obtain longitudinal data regarding dancers' compliance with, and subjective evaluation of, wearing orthotics over the preceding 6 years. Among participating dancers who met criteria for the prospective (N = 24) or retrospective (N = 81) aspects of the study (total N = 105), 67% wore orthotics at the time of follow-up. The average compliance in usage was 6.0 (± 1.5 ) days per week and 7.5 (± 3) hours per day. The average rate of satisfaction was 67.9 (± 26.5), average degree of relief in symptoms was 58.3 (± 28.3), and self-reported degree of improvement in dance ability was 45.7 (± 27.9) on a 100 mm Visual Analogue Scale (VAS). There was a significant decrease in pain from the day of orthotics prescription to follow-up (25.9%, or 18.9 mm decrease on the VAS, CI 6.6-30.9, p = 0.005) in the prospective group (N = 24). Orthotics were found to decrease the medial longitudinal arch angle significantly during static stance with the orthotic in place (CI 0.08-1.65, p = 0.03). It is concluded that the dancers in this study demonstrated a high rate of compliance in obtaining and wearing their orthotics and experienced a significant decrease in pain.

Hyperpronation in Dancers Incidence and Relation to Calcaneal Angle.

Hyperpronation is a common finding when examining the dancer-patient and is thought to be implicated in several dance-related injuries. Little is known about the incidence of hyperpronation-related symptoms in dancers. Additionally, there is no current easy method for estimating the degree of hyperpronation. This study was designed to investigate the incidence of symptoms related to foot hyperpronation in dancer-patients and to evaluate the potential correlation between the patient's calcaneal angle and severity of hyperpronation. A retrospective study of 2,427 dancers' charts over the past 6 years was undertaken to identify dancers who presented with musculoskeletal complaints or problems related to hyperpronation. Physical exam data and diagnoses were collected. Among 24 new dancer-patients presenting to clinic with hyperpronation-related symptoms, the calcaneal angle was measured and correlated with a clinical grading scale based on the Hübscher maneuver. Per chart review, the incidence of symptomatic hyperpronation resulting in prescription for orthotics was 30% (739 dancers out of 2,427). The most common related diagnosis was retropatellar chondropathy (10%). Clinical severity of hyperpronation was linearly related to the calcaneal angle (95% CI [1.25, 4.14], p = 0.0006; Pearson's r(2) = 0.97). The calcaneal angles among mild, moderate, and severe hyperpronators differed significantly (H = 13.45, p = 0.0012). It was concluded that measuring the calcaneal angle may be a useful adjunct to the Hübscher maneuver for grading the clinical severity of a dancer's hyperpronation. Healthcare providers working with dancers should be aware of the presence of hyperpronation, its relation to compensatory turnout techniques, and association with injuries in the foot, ankle, knee, hip, and low back. A standard, time-efficient method of measuring and grading hyperpronation is still needed.