Surfactant impairs coagulation in-vitro: A risk factor for pulmonary hemorrhage?

The effect of natural surfactants on the development of postoperative intraabdominal adhesion

Background/aim

The development of postoperative adhesion after abdominal surgery is sometimes a severe problem. Our study investigates the effectiveness of exogenous surfactant application in preventing adhesion development in the experimental adhesion model.

Materials and methods

This randomized-controlled interventional study was carried out in the animal laboratory of Kahramanmaraş Sütçü İmam University between March 1 and March 31, 2020. An experimental intra-abdominal adhesion model was established in 24 adult female rats by cecal abrasion. Rats were randomly divided into four groups. Groups I, II, and III were taken intraperitoneally as beractant, poractant, and calfactant applied groups, respectively. Group IV was the control group. Relaparotomy was performed in all groups on the 15th postoperative day, and intra-abdominal adhesions were scored macroscopically according to the Canbaz scoring system. In addition, the cecal regions were evaluated microscopically and scored according to the Zühlke microscopic classification system. The scores of the groups were compared statistically.

Results

The Zühlke adhesion development score was significantly lower in the exogenous surfactant applied groups. In addition, when the surfactant-applied groups were compared among themselves, it was seen that the adhesion score in the beractant group was significantly better than the other surfactant types (p < 0.01).

Conclusion

Our study results showed that prophylactic intraperitoneal surfactant application significantly reduced postoperative adhesion development, particularly beractant.

Respiratory problems in preterm infants with pulmonary hemorrhage

AIM

Pulmonary hemorrhage is an important cause of morbidity and mortality in premature infants. There are few studies on pulmonary hemorrhage and associated morbidities observed in premature. The aim of this study was to investigate the possible relationship between pulmonary hemorrhage and respiratory problems in premature infants.

MATERIAL AND METHOD

Premature infants aged 25-32 weeks who were born between January 2014 and January 2018 in the neonatal intensive care unit were included to the study. Of these premature infants, 28 were patients diagnosed as pulmonary hemorrhage and 56 were control cases with the same demographic characteristics without pulmonary hemorrhage. From the medical records of infants; clinical course characteristics such as duration of ventilation, duration of oxygen supplementation, hospital stay were detailed. The data was analyzed statistically.

RESULTS

The duration of mechanical ventilation was significantly longer in the pulmonary bleeding group than in the control group (p: .001). There was a significant difference between the groups in terms of moderate and severe bronchopulmonary dysplasia (BPD) and the rate of BPD in the pulmonary hemorrhage group was higher than in the control group (17.2%-53.6%; p: .001). In addition, pulmonary hemorrhage group had significant patent ductus arteriosus (PDA) and preterm retinopathy (ROP) rate compared with control group.

DISCUSSION

This study implicated that, pulmonary hemorrhage is related with respiratory morbidities in preterm infants such as BPD and prolonged respiratory support. At the same time, the other morbidities such as ROP prolonged hospitalization are higher in infants with pulmonary hemorrhage.

CONCLUSION

In the follow-up of patients with pulmonary hemorrhage, defining respiratory problems and treatment and prophylaxis of comorbid conditions may be planned sooner.

Exploring prediction model and survival strategies for pulmonary hemorrhage in premature infants: a single-center, retrospective study

BACKGROUND

Pulmonary hemorrhage is a potentially fatal event especially for preterm infants, which can lead to serious complications and even death. Many risk factors have been associated with the development of massive pulmonary hemorrhage. However, there is still no effective strategy to prevent massive pulmonary hemorrhage. The purpose of this study is to explore prediction model and survival strategies for massive pulmonary hemorrhage in premature infants.

METHODS

In this retrospective study, we included all premature infants with birth weight <1,500 g who were hospitalized in our neonatal intensive care unit (NICU) between January 01 2010 and December 31 2019.

RESULTS

Of 599 preterm infants, 51 developed massive pulmonary hemorrhage. The logistic regression analysis showed that patent ductus arteriosus [odds ratio (OR) =11.4, 95% confidence interval (CI): 4.79-27.0, P<0.0001], coagulopathy (OR =6.56, 95% CI: 2.83-15.2, P<0.0001), and 10-minute Apgar Score (OR =0.52, 95% CI: 0.37-0.73, P=0.0001) were risk factors for massive pulmonary hemorrhage. Whether or not surfactant is used, the positive predictive value of combined patent ductus arteriosus and coagulopathy for predicting massive pulmonary hemorrhage was 68.9% and 70.4%, respectively. Of the 51 preterm infants with massive pulmonary hemorrhage, 25 died and 26 survived. The survivors group had higher positive end-expiratory pressure compared with the deceased group after the onset of massive pulmonary hemorrhage. After adjusting for potential risk factors, the multiple logistic regression analysis showed that higher positive end-expiratory pressure levels are closely related to survival.

CONCLUSIONS

Patent ductus arteriosus combined with coagulopathy has a high predictive value for massive pulmonary hemorrhage. Higher positive end-expiratory pressure levels may reduce mortality in massive pulmonary hemorrhage.

SHORT-TERM OUTCOME OF MASSIVE PULMONARY HEMORRHAGE IN PRETERM INFANTS IN TUZLA CANTON

Massive pulmonary hemorrhage (MPH) in neonates is a severe condition followed by many complications and associated with a high mortality rate. The aim of this study was to present the incidence, possible risk factors, and short-term outcome of neonatal MPH in Tuzla Canton. We retrospectively analyzed data on neonates with MPH from January 2015 to December 2017. On statistical analysis, standard methods of descriptive statistics were used. During the three-year study period, 16 neonates developed MPH, 5 (31.25%) male and 11 (68.75%) female. Their mean gestational age was 29.48±2.21 weeks and mean birth weight 1276.69±387.65 grams. Seven (43.75%) neonates survived and 9 (56.25%) died. Significant differences between the two outcome groups (survivors/died) were found in gestational age, birth weight, birth length, 5-minute Apgar score, and length of treatment at the Neonatal Intensive Care Unit. In Tuzla Canton, MPH occurred mainly in preterm neonates requiring mechanical ventilation, with the incidence of 1.91% of total premature births. The short-term outcome was uncertain, with a high mortality rate of 56.25%. Lower gestational age, lower birth weight, lower birth length and lower 5-minute Apgar score were confirmed as risk factors for poor short-term outcome.

Perinatal risk factors for pulmonary hemorrhage in extremely low-birth-weight infants

BACKGROUND

Pulmonary hemorrhage (PH) is a life-threatening respiratory complication of extremely low-birth-weight infants (ELBWIs). However, the risk factors for PH are controversial. Therefore, the purpose of this study was to analyze the perinatal risk factors and short-term outcomes of PH in ELBWIs.

METHODS

This was a retrospective cohort study of live born infants who had birth weights that were less than 1000 g, lived for at least 12 hours, and did not have major congenital anomalies. A logistic regression model was established to analyze the risk factors associated with PH.

RESULTS

There were 168 ELBWIs born during this period. A total of 160 infants were included, and 30 infants were diagnosed with PH. Risk factors including gestational age, small for gestational age, intubation in the delivery room, surfactant in the delivery room, repeated use of surfactant, higher FiO₂ during the first day, invasive ventilation during the first day and early onset sepsis (EOS) were associated with the occurrence of PH by univariate analysis. In the logistic regression model, EOS was found to be an independent risk factor for PH. The mortality and intraventricular hemorrhage rate of the group of ELBWIs with PH were significantly higher than those of the group of ELBWIs without PH. The rates of periventricular leukomalacia, moderate-to-severe bronchopulmonary dysplasia and severe retinopathy of prematurity, and the duration of the hospital stay were not significantly different between the PH and no-PH groups.

CONCLUSIONS

Although PH did not extend hospital stay or increase the risk of bronchopulmonary dysplasia, it increased the mortality and intraventricular hemorrhage rate in ELBWIs. EOS was the independent risk factor for PH in ELBWIs.

A Proposed Role of Surfactant in Platelet Function and Treatment of Pulmonary Hemorrhage in Preterm and Term Infants

BACKGROUND

We evaluated the effect of surfactant on platelet function as a potential contributing mechanism to the pathogenesis of pulmonary hemorrhage (PHEM) in term and preterm infants.

METHODS

Cord blood samples were collected from neonates following delivery. Complete blood count and platelet function were measured using a cone and platelet analyzer (CPA). Increasing surfactant concentrations were added to platelets in vitro, and the adhesion molecule P-selectin and the monoclonal antibody PAC-1 were evaluated following platelet activation by flow cytometry.

RESULTS

Forty-one infants (11 preterm and 30 term) were studied. CPA revealed a significant decrease in the average size of the aggregates and in platelet adhesion when surfactant was added. In term infants, the addition of surfactant to native platelets yielded an increased binding capacity of PAC-1 but did not affect P-selectin expression. In preterm infants, platelet activation with adenosine diphosphate in the presence of a high surfactant concentration (0.5 mg/mL) resulted in increased PAC-1 binding and no change in P-selectin expression.

CONCLUSIONS

The platelets of preterm infants are less active (hyporesponsive) than those of term infants, both in their native state as well as after stimulation with various agonists. Surfactant may play an important role in treating PHEM in preterm infants.

Surfactant Replacement Therapy Beyond Respiratory Distress Syndrome in Neonates

BACKGROUND

Surfactant replacement therapy is an established modality of treatment in preterm neonates with respiratory distress syndrome. In addition, there are various neonatal respiratory disorders which are characterized by surfactant deficiency in which surfactant therapy can be a feasible and safe option.

OBJECTIVE

To collate the literature on the use of surfactant replacement therapy in neonates beyond respiratory distress syndrome and examine the evidence and newer developments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, and EMBASE up to June 2015; and previous reviews, including cross-references, abstracts, and conference proceedings.

RESULTS

Evidence supports surfactant administration via bolus route in neonates with meconium aspiration syndrome, but additional robust evidence is required before its adoption in clinical practice. There is limited evidence to support surfactant therapy in neonates with pneumonia, pulmonary hemorrhage and bronchopulmonary dysplasia. Large multicenter randomized trials are needed to cement or refute the role of surfactant therapy in these disorders.

Deleterious mutation in the FYB gene is associated with congenital autosomal recessive small-platelet thrombocytopenia

BACKGROUND

The FYB gene encodes adhesion and degranulation-promoting adaptor protein (ADAP), a hematopoietic-specific protein involved in platelet activation, cell motility and proliferation, and integrin-mediated cell adhesion. No ADAP-related diseases have been described in humans, but ADAP-deficient mice have mild thrombocytopenia and increased rebleeding from tail wounds.

PATIENTS AND METHODS

We studied a previously reported family of five children from two consanguineous sibships of Arab Christian descent affected with a novel autosomal recessive bleeding disorder with small-platelet thrombocytopenia. Homozygosity mapping and exome sequencing were used to identify the genetic lesion causing the disease phenotype on chromosome 5. Bone-marrow morphology and platelet function were analyzed. Platelets were characterized by scanning electron microscopy.

RESULTS

We identified a homozygous deleterious nonsense mutation, c.393G>A, in FYB. A reduced percentage of mature megakaryocytes was found in the bone marrow. Patients' platelets showed increased basal expression of P-selectin and PAC-1, and reduced increments of activation markers after stimulation with ADP, as detected by flow cytometry; they also showed reduced pseudopodium formation and the presence of trapped platelets between the fibrin fibers after thrombin addition, as observed on scanning electron microscopy.

CONCLUSIONS

This is the first report of a disease caused by an FYB defect in humans, manifested by remarkable small-platelet thrombocytopenia and a significant bleeding tendency. The described phenotype shows ADAP to be important for normal platelet production, morphologic changes, and function. It is suggested that mutation analysis of this gene be included in the diagnosis of inherited thrombocytopenia.