Treat “201C;wrinkling” in the Abiomed Diaphragm as a Possible Sign of Hypovolemia

Treat “201C;wrinkling” in the Abiomed Diaphragm as a Possible Sign of Hypovolemia

Frank Rosemeier MD

Ventricular assist devices (VADs) are indicated for patients with ventricular failure on maximum pharmacological support in the post-cardiopulmonary bypass period, following an acute myocardial infarction, as bridge to transplantation, or destination therapy for permanent use. Most of these devices, which can be used in either an intracorporeal or extracorporeal position, are displacement pumps and assist the left ventricle. In a left VAD (LVAD) configuration, a device inflow cannula connects the left atrium or left ventricular apical region to the pump chamber. Blood returns to the ascending aorta via a device outflow cannula. For a right-sided VAD (RVAD), the inflow cannula is situated in the right atrium or right ventricle with the outflow cannula connected to the main pulmonary artery. These tubular cannulae are typically radiolucent and are not easily identifiable on a plain radio-graph.

The Abiomed assist device is most frequently used in an emergency for its ease of implantation, robustness of operation, and versatility as it can be configured as an LVAD, an RVAD, or BiVAD. It is simple to operate, inexpensive, and robust for transport purposes. It has the added advantage in that the pump section can be changed at the bedside in 1 minute. Drawbacks include a high re-exploration rate for hemorrhage. A clear plastic housing device that is placed below the level of the heart contains a pulsatile dual-chamber assembly in series. Filling of the upper chamber is via passive gravity drainage from the ventricle or atrium. Adjusting the height of the device relative to the patient’s heart level will control preload conditions. As the device is lowered, the flow into the upper chamber will increase, shortening diastolic filling time and increasing device output. The lower chamber performs the pumping action at a constant stroke volume of around 88 mL with an output limitation of 4 to 5 L/min. High systemic vascular resistance may increase the duration of the emptying of the lower chamber, prolonging systole with a possible decrease in output.

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Jul 1, 2016 | Posted by in ANESTHESIA | Comments Off on Treat “201C;wrinkling” in the Abiomed Diaphragm as a Possible Sign of Hypovolemia
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