A study of the effect of nasal modes of ventilation on the incidence of gastro-oesophageal reflux in preterm neonates

Background

Nasal modes of respiratory support cause variable amounts of gastric dilatation which may increase gastro-oesophageal reflux (GER) in preterms. To compare the incidence of GER in nasally ventilated, preterm babies with controls (babies not on ventilation). Type of study: A prospective, observational comparative study.

Method

Twenty-three preterm babies of gestational age 28–36 weeks and weight ranging between 1,000 g and < 2,500 g on either nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure venti-lation (nIPPV) were assessed for GER. They were compared with controls not on ventilation some of who were test babies when off ventilation (subgroup A) and some were unrelated babies not on ventilator but matched for gestational age and weight with test babies (subgroup B). All babies were subjected to continuous, oesophageal pH monitoring with dual sensor (upper and lower oesophageal) catheters. Reflux index (RI) was calculated as the percentage of study time the lower oesophageal pH was < 4. Primary outcome was the RI in the test and controls groups. Secondary outcome was the temporal relation of the reflux with symptoms if any. Numerical data were shown as mean with standard deviation and statistical comparisons were done using the χ²-test, Fischer test, and t-test wherever applicable.

Results

The RI was higher in ventilated babies as compared to the control group, particularly in the subgroup A, where test babies formed their own controls. Grade IV reflux (7 cases) was seen only in the ventilated babies. There was no difference in the incidence of GER in babies on nCPAP as compared with nIPPV. Grade IV reflux could not be reliably predicted by RI alone. No definite temporal relation between episodes of reflux and symptoms could be determined in this study.

Conclusion

There is an increase in GER in preterms on nasal modes of ventilation. A combination of upper (pharyngeal) and lower oesophageal sensors are preferred to a single lower oesophageal sensor when assessing GER by oesophageal pHmetry in neonates.     

IVUS-guided evaluation and percutaneous intervention in an anomalous left main coronary artery

We report the case of a 42-year-old female with proven anterior ischemia and an anomalous origin of the left main coronary artery (ALMCA) who underwent successful percutaneous coronary intervention (PCI) with intravascular ultrasound (IVUS) guidance. Angiographic and IVUS images demonstrate features unique to the ALMCA. The epidemiology, pathophysiology, evaluation and management options, including technical considerations for percutaneous intervention, are discussed. The ALMCA from the right sinus of Valsalva represents one of the few potentially serious congenital coronary artery anomalies. These patients are often young, have atypical presentation and carry a risk of sudden death. In combination with unfamiliar anatomy and pathophysiology, they pose serious diagnostic and therapeutic challenges. We present our experience in a patient who underwent successful PCI with IVUS guidance, and discuss the anatomy, pathophysiology, evaluation and treatment options for the ALMCA.     

Anomalous circumflex artery: intravascular ultrasound imaging of dynamic compression and "two wire-two vessel" percutaneous intervention

An anomalous origin of the left circumflex is the most common congenital abnormality encountered in coronary angiography and it may selectively predispose to focal accelerated atherosclerotic disease. We report the case of a 54-year-old man who presented with non-ST elevation myocardial infarction and a characteristic retroaortic (proximal) culprit lesion in his anomalous circumflex artery. Intravascular ultrasound images illustrate the dynamic nature of the lumen compression. A "two wires-two vessel" angioplasty technique provided extra support and is recommended to facilitate successful anomalous circumflex percutaneous coronary interventions.     

In vitro biomechanical comparison of transpedicular versus translaminar C-2 screw fixation in C2-3 instrumentation

OBJECT: In instrumentation of the upper cervical spine, placement of pedicle screws into C-2 is generally safe, although there is the potential for injury to the vertebral arteries. Owing to this risk, translaminar screws into C-2 have been used. The aim of this study was to compare the stability of the in vitro cadaveric spine using C-2 laminar compared with C-2 pedicle screws in C2-3 instrumentation. METHODS: Eight fresh frozen human cadaveric cervical spines (C1-6) were potted at C1-2 and C5-6. Pure moments in increments of 0.3 Nm to a maximum of 1.5 Nm were applied in flexion, extension, right and left lateral bending, and right and left axial rotation. Each specimen was tested sequentially in three modes: 1) intact; 2) C2 pedicle screw-C3 lateral mass fixation; and 3) C2 laminar screw-C3 lateral mass fixation. The sequence of fixation testing was randomized. Motion was tracked with reflective markers attached to C-2 and C-3. RESULTS: Spinal levels with instrumentation showed significantly less motion than the intact spine in all directions and with all loads greater than 0.3 Nm (p < 0.05). Although there was no significant difference between C2 pedicle screw-C3 lateral mass fixation and C2 laminar screw-C3 lateral mass fixation, generally the former type of fixation was associated with less motion than the latter. CONCLUSIONS: When pedicle screws in C-2 are contraindicated or inappropriate, laminar screws in C-2 offer a safe and acceptable option for posterior instrumentation.     

Gene therapy and coronary artery bypass grafting: current perspectives

The early success of coronary artery bypass grafting (CABG) is limited by disappointing long-term patency rates of autologous saphenous vein grafts. Because current pharmacological interventions have only limited impact on vein graft patency rates, there remains a clear clinical need for effective agents to prevent failure of vein grafts in the long term. Gene therapy in vein grafts has great potential as gene delivery can be achieved ex vivo at the time of cardiac surgery, allowing transgene expression to occur rapidly post-grafting within the acute phase of vein graft remodelling. A variety of therapeutic strategies have been tested in a range of preclinical models, although to date, these have not advanced to Inhuman trials, except in the setting of adjunctive angiogenesis for improved revascularization (phase 1). Clinical translation is warranted to investigate the potential of gene therapy to improve CABG patency rates in the long term.