System failure: Systemic inflammation following spinal cord injury

Spinal cord injury (SCI) affects hundreds of thousands of people in the United States, and while some effects of the injury are broadly recognized (deficits to locomotion, fine motor control, and quality of life), the systemic consequences of SCI are less well-known. The spinal cord regulates systemic immunological and visceral functions; this control is often disrupted by the injury, resulting in viscera including the gut, spleen, liver, bone marrow, and kidneys experiencing local tissue inflammation and physiological dysfunction. The extent of pathology depends on the injury level, severity, and time post-injury. In this review, we describe immunological and metabolic consequences of SCI across several organs. Since infection and metabolic disorders are primary reasons for reduced lifespan after SCI, it is imperative that research continues to focus on these deleterious aspects of SCI to improve life span and quality of life for individuals with SCI.

Public Awareness of Interventional Radiology: Population-Based Analysis of the Current State of and Pathways for Improvement

PURPOSE

To evaluate the awareness of interventional radiology (IR) among the public and identify methods for improvement.

MATERIALS AND METHODS

Participants (N = 1,000) were anonymously surveyed using Amazon's Mechanical Turk crowdsourcing platform about medical and IR-specific knowledge, preferred methods of acquisition of medical information, and suggestions for improving awareness of IR. The survey consisted of 69 questions, including both Likert Scale and free text questions.

RESULTS

Of the participants, 92% preferred undergoing a minimally invasive procedure over surgery. However, 39.8% recognized IR as a medical specialty, and less than 50% of these participants correctly identified IR as procedurally oriented. Of those who discussed or underwent an IR procedure (n = 113), most were also offered to undergo the procedure performed by a surgeon (n = 66). Furthermore, 71% (n = 20) of those who underwent the procedure performed by a surgeon reported that lack of awareness of IR played a role in their decision. Almost half of the respondents (n = 458) were interested in learning more about IR, particularly the diseases treated and procedures performed (42% and 37%, respectively). Short (<10-minute) educational videos and increased patient education by primary care providers (PCPs) were among the most suggested ways to improve awareness. Regarding the ambiguity of the name "interventional radiology," most respondents (n = 555) reported this to be true, and "minimally invasive radiologist" was the most preferred alternative (21.18%).

CONCLUSIONS

Lack of awareness of IR may underlie underutilization. When presented with the knowledge that IR improves patient outcomes, minimally invasive procedures by an interventional radiologist are more often desired by the public than surgical options. Educational videos and patient education by PCPs may increase awareness of IR.

Immune dysfunction after spinal cord injury - A review of autonomic and neuroendocrine mechanisms

Infections impair neurological outcome and increase mortality after spinal cord injury (SCI). Emerging data show that pathogens more easily infect individuals with SCI because SCI disrupts neural and humoral control of immune cells, culminating with the development of "SCI-induced immune deficiency syndrome" (SCI-IDS). Here, we review data that implicate autonomic dysfunction and impaired neuroendocrine signaling as key determinants of SCI-IDS. Although it is widely appreciated that mature leukocyte dysfunction is a canonical feature of SCI-IDS, new data indicate that SCI impairs the development and mobilization of immune cell precursors in bone marrow. Thus, this review will also explore how the post-injury acquisition of a "bone marrow failure syndrome" may be the earliest manifestation of SCI-IDS.

Placental gas exchange during amniotic carbon dioxide insufflation in sheep

OBJECTIVE

Insufflation of the amniotic cavity with carbon dioxide (CO₂ ) is used clinically to improve visibility during complex fetoscopic surgery. Insufflation with heated, humidified CO₂ has recently been shown to reduce fetal hypercapnia and acidosis in sheep, compared with use of cold and dry CO₂ , but the underlying mechanisms are unclear. The aim of this study was to investigate whether differences in placental CO₂ and oxygen (O₂ ) exchange during insufflation with heated and humidified vs cold and dry CO₂ could explain these findings.

METHODS

Thirteen fetal lambs at 105 days of gestation (term, 146 days) were exteriorized partially, via a midline laparotomy and hysterotomy, and instrumented with an umbilical artery catheter, an umbilical vein catheter and a common umbilical vein flow probe. Arterial and venous catheters and flow probes were also inserted into the maternal uterine circulation. Six ewes were insufflated with cold, dry CO₂ (22°C; 0-5% humidity) and seven with heated, humidified CO₂ (40°C; 95-100% humidity) at 15 mmHg for 180 min. Blood-flow recordings and paired arterial and venous blood gases were sampled from uterine and umbilical vessels. Rates of placental CO₂ and O₂ exchange were calculated.

RESULTS

After 180 min of insufflation, fetal survival was 33% (2/6) using cold, dry CO₂ and 71% (5/7) using heated, humidified CO₂ . By 120 min, fetuses insufflated with heated, humidified CO₂ had lower arterial CO₂ levels and higher arterial pH compared to those insufflated with cold, dry gas. Insufflation decreased significantly placental gas exchange in both groups, as measured by rates of both (i) fetal CO₂ clearance and O₂ uptake and (ii) maternal O₂ delivery and CO₂ uptake from the fetal compartment.

CONCLUSIONS

Lower arterial CO₂ and higher pH levels in fetuses insufflated with heated and humidified, compared to cold and dry, CO₂ could not be explained by differences in placental gas exchange. Instead, heated and humidified insufflation appeared to reduce fetal CO₂ absorption from the uterus, supporting its use in preference to cold, dry CO₂ . © 2019 International Society of Ultrasound in Obstetrics and Gynecology.

Antenatal sildenafil treatment improves neonatal pulmonary hemodynamics and gas exchange in lambs with diaphragmatic hernia

OBJECTIVES

Infants with congenital diaphragmatic hernia (CDH) are predisposed to pulmonary hypertension after birth, owing to lung hypoplasia that impairs fetal pulmonary vascular development. Antenatal sildenafil treatment attenuates abnormal pulmonary vascular and alveolar development in rabbit and rodent CDH models, but whether this translates to functional improvements after birth remains unknown. We aimed to evaluate the effect of antenatal sildenafil on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia (DH).

METHODS

DH was surgically induced at approximately 80 days' gestation in 16 lamb fetuses (term in lambs is approximately 147 days). From 105 days' gestation, ewes received either sildenafil (0.21 mg/kg/h intravenously) or saline infusion until delivery (n = 8 fetuses in each group). At approximately 138 days' gestation, all lambs were instrumented and then delivered via Cesarean section. The lambs were ventilated for 120 min with continuous recording of physiological (pulmonary and carotid artery blood flow and pressure; cerebral oxygenation) and ventilatory parameters, and regular assessment of arterial blood gas tensions. Only lambs that survived until delivery and with a confirmed diaphragmatic defect at postmortem examination were included in the analysis; these comprised six DH-sildenafil lambs and six DH-saline control lambs.

RESULTS

Lung-to-body-weight ratio (0.016 ± 0.001 vs 0.013 ± 0.001; P = 0.06) and dynamic lung compliance (0.8 ± 0.2 vs 0.7 ± 0.2 mL/cmH₂ O; P = 0.72) were similar in DH-sildenafil lambs and controls. Pulmonary vascular resistance decreased following lung aeration to a greater degree in DH-sildenafil lambs, and was 4-fold lower by 120 min after cord clamping than in controls (0.6 ± 0.1 vs 2.2 ± 0.6 mmHg/(mL/min); P = 0.002). Pulmonary arterial pressure was also lower (46 ± 2 vs 59 ± 2 mmHg; P = 0.048) and pulmonary blood flow higher (25 ± 3 vs 8 ± 2 mL/min/kg; P = 0.02) in DH-sildenafil than in DH-saline lambs at 120 min. Throughout the 120-min ventilation period, the partial pressure of arterial carbon dioxide tended to be lower in DH-sildenafil lambs than in controls (63 ± 8 vs 87 ± 8 mmHg; P = 0.057), and there was no significant difference in partial pressure of arterial oxygen between the two groups.

CONCLUSIONS

Sustained maternal antenatal sildenafil infusion reduced pulmonary arterial pressure and increased pulmonary blood flow in DH lambs for the first 120 min after birth. These findings of improved pulmonary vascular function are consistent with improved pulmonary vascular structure seen in two previous animal models. The data support the rationale for a clinical trial investigating the effect of antenatal sildenafil in reducing the risk of neonatal pulmonary hypertension in infants with CDH. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.