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SBA Answers and Explanations
Published in Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury, SBAs for the MRCS Part A, 2018
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury
The levator palpebrae superioris is the exception to the earlier. It elevates the eyelid but has a dual innervation from both the occulomotor nerve and sympathetic fibres. The latter innervate a small smooth muscle portion of the levator muscle known as Muller’s muscle. The clinical significance of this dual innervation is that a 3rd cranial nerve (occulomotor) palsy, or sympathetic interruption (Horner’s syndrome), may result in a droopy eyelid (ptosis). To distinguish the two, it is essential to lift up the eyelid and inspect the pupil to see if it is enlarged (mydriasis, in an occulomotor nerve palsy) or constricted (miosis, in a Horner’s syndrome). Furthermore, in an occulomotor palsy the eyeball points downwards and outwards from the unopposed action of superior oblique and lateral rectus, supplied by the 4th and 6th cranial nerves. Horner’s syndrome is associated with hemifacial anhidrosis (absent sweating of the ipsilateral face), flushing symptoms (the so-called Harlequin syndrome or effect) and enophthalmos (a sunken eyeball), in addition to ptosis and miosis.
Percutaneous treatment of cardiogenic shock after myocardial infarction
Published in Ever D. Grech, Practical Interventional Cardiology, 2017
Jayan Parameshwar, Stephen Pettit, Alain Vuylsteke
Cannulation complications are frequent particularly with prolonged use (>7 days) and include venous thrombosis and distal limb ischaemia. Patients with severe peripheral vascular disease are not suitable for peripheral V-A ECMO. Thromboembolic events may occur in the circuit or the patient. Haemorrhage is an important complication, around the cannula and retroperitoneally. The ‘Harlequin syndrome’ is a recognised complication of peripheral V-A ECMO; deoxygenated blood from the LV supplies the upper body and limbs (including the coronary circulation) whilst oxygenated blood via the ECMO circuit supplies the lower body and limbs with competing flow in the aorta.
Hot Flushes
Published in Tony Hollingworth, Differential Diagnosis in Obstetrics and Gynaecology: An A-Z, 2015
Harlequin syndrome – hemifacial flushing and sweating with or without warmth and anhidrosis of the contralateral limbs. It may be associated with lung cancer and Pancoast syndrome, which is an apical tumour affecting the adjacent anatomical structures and can cause a Horner’s syndrome.
Research progress of portable extracorporeal membrane oxygenation
Published in Expert Review of Medical Devices, 2023
Yuansen Chen, Duo Li, Ziquan Liu, Yanqing Liu, Haojun Fan, Shike Hou
There are still many areas of improvement in ECMO, such as management of ECMO complications and anticoagulation strategies, which need to be investigated in clinical trials. An important concern during V-A ECMO operation is the harlequin syndrome. The collision between ECMO output and cardiac pumped blood will form a watershed that can cause differential hypoxia in the upper and lower body, affecting the oxygen supply to the heart and brain. Several studies have been conducted in recent years to address this problem. There is no standard method of determining its location, Carlo et al. developed an effective method of treating clown syndrome by adding an auxiliary centrifugal pump to the venous line to form a pumping device to control arteriovenous blood flow [53,54]. The influence can be reduced by improving the catheter position, and the oxygenation of patients’ upper limbs can be improved by switching the drainage position to the superior vena cava [55,56]. Meanwhile, the establishment of veno- arteriovenous (V-AV) ECMO, with oxygenated blood flowing to the femoral and internal carotid arteries respectively, may helped to improve this matter [57]. A clinical practice guideline also suggests that a change to central cannulation or switch to V-AV ECMO may be considered for harlequin syndrome where conservative measures have failed [8]. Also, to avoid the risk of thrombosis that may result from the use of external clamps to regulate flow in V-AV ECMO, Carlo et al. developed an effective method of treating harlequin syndrome by adding an auxiliary centrifugal pump to the venous line to form a pumping device to control arteriovenous blood flow [58]. Clinical studies can identify and improve the problems during ECMO operation and help to promote the use of ECMO.
Ross Syndrome
Published in Neuro-Ophthalmology, 2020
Manikanta Damagatla, Pratyusha Ganne, Rakesh Upparakadiyala, Prabhakaran N
The first case of Ross syndrome was described by Ross in 1958.2 Ever since there have been only a handful of cases reported worldwide. Some believe this to be a combination of two separate syndromes namely Harlequin syndrome and Holmes-Adie syndrome.3 Recent evidence suggests a decrease in sudomotor, vasomotor and pilomotor innervation in the skin of patients with Ross syndrome.4–6 Hence, there is a lack of sweating and cutaneous vasoregulation leading to heat intolerance. The iodine-starch test helps to demarcate areas of intact sweating and anhidrotic areas. Areas of intact sweating stain positive.7 Our patient showed no staining on the left side of her back and had patchy staining on the right side of her back (Figure 2). Tonic pupil results from damage to the ciliary ganglion or postganglionic parasympathetic nerve fibres.8 The exact cause of areflexia has not been found. Some postulate damage to the dorsal roots, sensory ganglia or the afferent fibres in the spinal cord.9,10 Tonic pupil may be present unilaterally or bilaterally and areflexia may be generalised. The tonic pupil shows a hypersensitivity response to dilute pilocarpine drops and this may be performed to confirm the diagnosis of postganglionic parasympathetic denervation hypersensitivity.11 The exact pathogenesis of the autonomic ganglion damage is uncertain but it is postulated that there is a congenital lack of factors that promote the survival of these neurons leading to their apoptosis. Some studies have suggested an autoimmune basis for the disease with some patients testing positive for different antibodies like anti-nuclear (ANA), SSA, SSB and anti-thyroid antibodies.12,13 Nolano et al. showed that this condition is progressive but benign.6
Comparison of mechanical cardiopulmonary support strategies during lung transplantation
Published in Expert Review of Medical Devices, 2020
Noah Weingarten, Dean Schraufnagel, Gilman Plitt, Anthony Zaki, Kamal S. Ayyat, Haytham Elgharably
VA ECMO’s effects depend on whether cannulas are inserted peripherally or centrally. In peripheral cannulation, the venous cannula is placed in a peripheral vein and advanced into the inferior vena cava or right atrium. Blood is returned to a peripheral artery, such as the femoral artery, and flows retrograde to the aorta allowing oxygenated blood to perfuse the heart and brain. Risks include distal limb ischemia and differential oxygenation of upper and lower body. Limb ischemia is experienced by 12–25% of patients with femoral artery cannulation, though its risk can be reduced with the placement of a distal perfusion cannula – typically a 6 to 8 Fr cannula placed percutaneously in the superficial femoral artery and connected to the main arterial cannula’s side port with extension tubing and an intervening stopcock. The distal perfusion cannula facilitates perfusion to the distal limb [44–46]. Limb ischemia may also be prevented with central cannulation, whereby venous blood is drained from the right atrium and returned to the ascending aorta. Differential upper body hypoxemia, known as Harlequin syndrome, is at risk of occurring in the setting of respiratory failure and peripheral cannulation. It occurs when poorly oxygenated blood pumped by the left heart perfuses aortic arch branches and coronary arteries, while blood oxygenated by the ECMO circuit primarily perfuses the lower extremities. It is diagnosed with the finding of hypoxic oxygen saturations on arterial blood gas from the right radial artery. This potentially fatal condition may be treated by several adjustments to the ECMO circuit including the addition of a venous inflow cannula to the upper extremity [47]. Central cannulation enables the placement of larger cannulas that permit higher flow rates. One study comparing rates of deep vein thromboses and peripheral wound complications such as groin infections among 103 patients undergoing double LT for pulmonary hypertension found lower rates in central relative to peripheral cannulation [46]. This study did not find increased rates of bleeding, infection or re-operation between these two groups, which have each been cited as risks of central cannulation [43,46].