Rationale: Portopulmonary hypertension (PPHTN) occurs in 6% of liver transplant candidates. The pathogenesis of this complication of portal hypertension is poorly understood. Objectives: To identify genetic risk factors for PPHTN in patients with advanced liver disease. Methods: We performed a multicenter case-control study of patients with portal hypertension. Cases had a mean pulmonary artery pressure >25 mm Hg, pulmonary vascular resistance >240 dynes·s−1·cm−5, and pulmonary capillary wedge pressure ≤15 mm Hg. Controls had a right ventricular systolic pressure < 40 mm Hg (if estimated) and normal right-sided cardiac morphology by transthoracic echocardiography. We genotyped 1,079 common single nucleotide polymorphisms (SNPs) in 93 candidate genes in each patient. Measurements and Main Results: The study sample included 31 cases and 104 controls. Twenty-nine SNPs in 15 candidate genes were associated with the risk of PPHTN (P < 0.05). Multiple SNPs in the genes coding for estrogen receptor 1, aromatase, phosphodiesterase 5, angiopoietin 1, and calcium binding protein A4 were associated with the risk of PPHTN. The biological relevance of one of the aromatase SNPs was supported by an association with plasma estradiol levels. Conclusions: Genetic variation in estrogen signaling and cell growth regulators is associated with the risk of PPHTN. These biologic pathways may elucidate the mechanism for the development of PPHTN in certain patients with severe liver disease.

OBJECTIVE. The purpose of this work was to investigate whether using a muscle relaxant would improve intubation conditions in infants, thereby decreasing the incidence and duration of hypoxia and time and number of attempts needed to successfully complete the intubation procedure. PATIENTS/METHODS. This was a prospective, randomized, controlled, 2-center trial. Infants requiring nonemergent intubation were randomly assigned to receive atropine and fentanyl or atropine, fentanyl, and mivacurium before intubation. Incidence and duration of hypoxia were determined at oxygen saturation thresholds of ≤85%, ≤75%, ≤60%, and ≤40%. Videotape was reviewed to determine the time and number of intubation attempts and duration of action of mivacurium. RESULTS. Analysis of 41 infants showed that incidence of oxygen saturation ≤60% of any duration was significantly less in the mivacurium group (55% vs 24%). The incidence of saturation level of any duration ≤85%, 75%, and 40%; cumulative time ≥30 seconds; and time below the thresholds were not significantly different. Total procedure time (472 vs 144 seconds) and total laryngoscope time (148 vs 61 seconds) were shorter in the mivacurium group. Successful intubation was achieved in ≤2 attempts significantly more often in the mivacurium group (35% vs 71%). CONCLUSIONS. Premedication with atropine, fentanyl, and mivacurium compared with atropine and fentanyl without a muscle relaxant decreases the time and number of attempts needed to successfully intubate while significantly reducing the incidence of severe desaturation. Premedication including a short-acting muscle relaxant should be considered for all nonemergent intubations in the NICU.

Background & Aims Hepatopulmonary syndrome (HPS) affects 10%–30% of patients with cirrhosis and portal hypertension and significantly increases mortality. Studies in experimental models indicate that pulmonary angiogenesis contributes to the development of HPS, but pathogenesis in humans is poorly understood. We investigated genetic risk factors for HPS in patients with advanced liver disease. Methods We performed a multicenter case-control study of patients with cirrhosis being evaluated for liver transplantation. Cases had an alveolar-arterial oxygen gradient ≥ 15 mm Hg (or ≥20 mm Hg if age > 64 years) and contrast echocardiography with late appearance of microbubbles after venous injection of agitated saline (intrapulmonary vasodilatation); controls did not meet both criteria for case status. The study sample included 59 cases and 126 controls. We genotyped 1086 common single nucleotide polymorphisms (SNPs) in 94 candidate genes. Results Forty-two SNPs in 21 genes were significantly associated with HPS after adjustments for race and smoking. Eight genes had at least 2 SNPs associated with disease: CAV3, ENG, NOX4, ESR2, VWF, RUNX1, COL18A1, and TIE1. For example, rs237872 in CAV3 showed an odds ratio of 2.75 (95% confidence interval: 1.65–4.60, P = .0001) and rs4837192 in ENG showed an odds ratio of 0.35 (95% confidence interval: 0.14–0.89, P = .027). Furthermore, variation in CAV3 and RUNX1 was associated with HPS in gene-based analyses. Conclusions Polymorphisms in genes involved in the regulation of angiogenesis are associated with the risk of HPS. Further investigation of these biologic pathways might elucidate the mechanisms that mediate the development of HPS in certain patients with severe liver disease.

Background: The laryngeal mask airway (LMA) has been used in adult and pediatric populations for decades. While the familiarity of its use in the neonatal population is increasing, there are few data investigating this. Objective: The objective of this study was to determine the feasibility of LMA placement in neonates by investigating the time and number of attempts required for successful placement and physiologic stability during the placement of the device. Methods: This study is one component of a national, multicenter, randomized controlled trial investigating surfactant administration through an LMA in neonates. Videotape of LMA placement was reviewed to determine the total procedure time and the number of attempts required to successfully place the device. Heart rate and oxygen saturation (SaO₂) were analyzed as change from baseline, in order to examine physiologic stability during device placement. Results: Videotape and physiologic data were analyzed for 36 infants. Gestational age ranged from 29^3/7 to 35^4/7 weeks (mean 33 ± 1.7) with the birth weight ranging from 1,290 to 3,180 g (mean 2,006 ± 482). Average total procedure time was 88 s (±136) with 64% of the procedures successfully completed in <35 s. Successful placement was achieved on the first attempt in 69% of the cases. Compared to baseline, heart rate increased by an average of 1 bpm (±4.5) and SaO₂ decreased an average of 6% (±7). Conclusions: Successful placement was achieved in the majority of patients in <35 s and required only one attempt. Physiologic parameters were maintained close to baseline, measured by minimal fluctuation in heart rate and SaO₂ during the procedure. Placement of the LMA is feasible in neonates.