Characterization of the acute pulse transit time response to obstructive apneas and hypopneas in preschool children with sleep-disordered breathing

Background

Surges in heart rate (HR) and blood pressure (BP) at apnea termination contribute to the hypertension seen in obstructive sleep apnea (OSA). Because childhood OSA prevalence peaks in the preschool years, we aimed to characterize the cardiovascular response to obstructive events in preschool-aged children.

Methods

Clinically referred children aged 3–5 years were grouped by obstructive apnea–hypopnea index (OAHI) into the following: primary snoring (PS) (OAHI ? 1 event/h [n = 21]), mild OSA (OAHI > 1– ? 5 [n = 32]), and moderate to severe (MS) OSA (OAHI > 5 [n = 28]). Beat-to-beat pulse transit time (PTT), an inverse continuous indicator of BP changes, and HR were averaged during the two halves (early and late) and during the peak after (post) each obstructive event and were expressed as percentage change from late- to post-event.

Results

We analyzed 422 events consisting of 55 apneas and 367 hypopneas. A significant post-event increase in HR and fall in PTT occurred in all severity groups (P < .05 for all). A greater response was associated with OSA, nonrapid eye movement sleep (NREM), cortical arousal, hypopneas, and oxygen desaturation (P < .05 for all).

Conclusions

Obstructive events elicit acute cardiovascular changes in preschool children. Such circulatory perturbations have been implicated in the development of hypertension, and our findings complement previous studies to suggest a cumulative impact of snoring on the cardiovascular system from childhood into adulthood.     

Ovarian vein thrombosis mimicking acute abdomen: a case report and literature review

Early diagnosis and active management of trans-anal rectal injuries is essential for a favorable outcome. Intraperitoneal free air (IFA) is usually diagnosed by an erect Chest X-ray. Point-of-care ultrasound has been recently used to detect IFA. We report a 45-year-old male who presented to the Emergency Department with lower abdominal peritonitis. Surgeon-performed portable point-of-care ultrasound as an extension of the abdominal examination revealed an inflamed omentum with hypoechoic stranding, thickened non compressible small bowel, and free fluid in the pelvis. A transverse abdominal section of the right upper quadrant showed free intraperitoneal air. Rectal examination revealed a longitudinal rectal tear. Laparotomy has confirmed the sonographic findings. There was a 12 cm intraperitoneal tear of the anterior wall of the rectum which was necrotic. This case clearly demonstrates that portable point-of-care ultrasound gives very useful detailed information even when performed by a non radiologist. Surgeons should be encouraged to use point-of-care ultrasound after appropriate training.     

A novel laparoscopic pulse oximeter device. An easy,efficient and cost- effective way of detecting arterial structures

The introduction of laparoscopy has revolutionized surgery. However, these new techniques have brought new problems into the surgical field. Due to the loss of depth and tactile sensation, time- consuming efforts must be made in order to identify normal anatomy and detect any aberrations. Even well experienced surgeons could face difficulties during demanding procedures, such as operations on inflammatory conditions. Therefore, there is still a strong need for developing additional tools to help mapping the anatomy. We designed a laparoscopic pulse oximeter device, which offers an easy, efficient and cost- effective way of using pulse oximetry in combination with a standard laparoscopic clamp in order to identify arterial structures.     

Cardiovascular control during sleep in infants: Implications for Sudden Infant Death Syndrome

In infants the cardiorespiratory system undergoes significant functional maturation after birth and these changes are sleep-state dependent. Given the immaturity of these systems it is not surprising that infants are at risk of cardiorespiratory instability, especially during sleep. A failure of cardiovascular control mechanisms in particular is believed to play a role in the final event of Sudden Infant Death Syndrome (SIDS). The “triple risk model” describes SIDS as an event that results from the intersection of three overlapping factors: (1) a vulnerable infant, (2) a critical development period in homeostatic control, and (3) an exogenous stressor. This review summarises normal development of cardiovascular control during sleep in infants and describes the association of impaired cardiovascular control with the three overlapping factors proposed to be involved in SIDS pathogenesis.     

Closure of a persistent sphincterotomy-related duodenal perforation by placement of a covered self-expandable metallic biliary stent

Retroperitoneal duodenal perforation as a result of endoscopic biliary sphincterotomy is a rare complication, but it is associated with a relatively high mortality risk, if left untreated. Recently, several endoscopic techniques have been described to close a variety of perforations. In this case report, we describe the closure of a persistent sphincterotomy-related duodenal perforation by using a covered self-expandable metallic biliary (CEMB) stent. A 61-year-old Greek woman underwent an endoscopic retrog...     

The development of autonomic cardiovascular control is altered by preterm birth

Objectives

Autonomic dysfunction, either sympathetic or parasympathetic, may explain the increased incidence of Sudden Infant Death Syndrome (SIDS) among preterm infants, as well as their subsequent heightened risk of hypertension in adulthood. As little is known about the development of autonomic function in preterm infants, we contrasted autonomic cardiovascular control across the first 6 months after term-corrected age (CA) in preterm and term infants.

Study design

Preterm (n = 25) and age matched term infants (n = 31) were studied at 2–4 weeks, 2–3 months and 5–6 months CA using daytime polysomnography. Blood pressure and heart rate were measured during quiet (QS) and active (AS) sleep. Autonomic control was assessed using spectral indices of blood pressure and heart rate variability (BPV and HRV) in ranges of low frequency (LF, reflecting sympathetic + parasympathetic activity), high frequency (HF, respiratory-mediated changes + parasympathetic activity), and LF/HF ratio (sympatho-vagal balance).

Results

In preterm infants, HF HRV increased, LF/HF HRV decreased and LF BPV decreased with age (p < 0.05); these changes were most evident in AS. Compared to term infants, preterm infants in QS exhibited lower LF, HF and total HRV at 5–6 months; higher HF BPV at all ages; and lower LF BPV at 2–4 weeks (p < 0.05).

Conclusions

With maturation, in preterm infants, parasympathetic modulation of the heart increases while sympathetic modulation of blood pressure decreases. Compared to term infants, preterm infants exhibit lesser parasympathetic modulation of the heart along with greater respiratory-mediated changes and lower sympathetic modulation of blood pressure. Impaired autonomic control in preterm infants may increase their risk of cardiovascular dysfunction later in life.     

The introduction of a simple maneuver to reduce the risk of postoperative bleeding after major hepatectomies

Background/Purpose  In major hepatectomies, postoperative increases in central venous pressure (CVP) may cause suture failure and massive bleeding. The aim of our study is to test the application of an intraoperative maneuver to reduce the risk of postoperative bleeding. Methods  Our study included 172 consecutive patients who had major liver resection with selective hepatic vascular exclusion and sharp transection of the liver parenchyma. An intraoperative maneuver (5 s occlusion of the hepatic vein) was applied in an alternating way, and the patients were assigned to two groups: Cohort A (n = 86), that was granted the maneuver, and Cohort B (n = 86), that was used as a control group. Results  In Cohort A, application of the maneuver was successful in demonstrating bleeders under low CVP levels. Cohort A had lower rate of massive bleeding requiring emergency reoperation (2.3 vs 5.8%, P = 0.049), less postoperative blood transfusions (13 vs 24%, P = 0.042), lower morbidity (20 vs 35%, P < 0.045) and shorter hospital stay compared to Cohort B. Conclusions  Hepatectomies conducted under low CVP are prone to postoperative hemorrhage which can be prevented if the final bleeding control is performed under high pressure in the hepatic veins. Application of our testing maneuver effectively unmasked previously undetectable bleeding veins.