Ultrasound Guided Lumbar Puncture and Remote Guidance for Potential In-Flight Evaluation of VIIP/SANS

Abstract

INTRODUCTION: Changes of visual function/neuro-opthalmic structures during spaceflight have been described as visual impairment and intracranial pressure syndrome (VIIP)/spaceflight-associated neuro-ocular syndrome (SANS). Although theories are suggested, the mechanism is unknown. Only indirect measurements of intracranial pressure (ICP) have been performed in spaceflight. Direct determination of in-flight ICP is crucial to understanding VIIP. Current “gold standard” is lumbar puncture (LP). The only direct evaluation has occurred with postflight LP. In-flight measurements would allow correlation of opening pressures/possible contributing factors. The only imaging modality on the International Space Station (ISS) is ultrasound. With appropriate methodology, remotely guided ultrasound-guided lumbar puncture (USGLP) may allow safe performance in flight. Therefore, we sought to develop a novel ultrasound approach for definitive placement of an LP needle, and to show this can be achieved with remote guidance by those without training.METHODS: Literature review and round-table discussions with multiple medical fields was performed. Volunteers were scanned with ultrasound for optimizing technique. A cadaver was used to perform this technique by a radiologist, then taught to volunteers not experienced in image guided procedures, and finally was repeated multiple times by volunteers with simulated remote guidance.RESULTS: Optimal visualization was in the fetal and seated lordotic positions. Technical success was achieved by the radiologist in all attempts and achieved in 9 of 11 attempts by the trainees.DISCUSSION: Given ultrasound experience at NASA and the ability to educate non-image-guided trained personnel, these could make this technique feasible and aid in direct in-flight measurements to further research VIIP.Lerner DJ, Chima RS, Patel K, Parmet AJ. Ultrasound guided lumbar puncture and remote guidance for potential in-flight evaluation of VIIP. Aerosp Med Hum Perform. 2019; 90(1):58–62.

Spaceflight associated neuro-ocular syndrome (SANS) and the neuro-ophthalmologic effects of microgravity: a review and an update

“…Renewed interest in the role of ICP [60][61][62][63][64][65][66][67][68][69] in SANS has led to discussion about the feasibility of performing a lumbar puncture in space despite the obvious logistical and operational challenges to an in-flight invasive procedure. [70][71][72] Non-invasive assessment of ICP have not been reliably validated on earth but ultrasound is available on the ISS and the possibility of ultrasonographic metrics (e.g., optic nerve sheath diameter, CSF in the sheath) remain an area of continued research. Likewise terrestrial head down studies with and without hypercapnia have demonstrated increased retinal nerve fiber layer on OCT and might still prove to be a suitable terrestrial analog to test hypotheses and potential countermeasures to SANS.…”

New Challenges for Critical Care by using Point of Care Ultrasound

“…POCUS is also used as a method of clinical evaluation in space flights. Astronauts are trained in POCUS and receive health care by medical professionals from the spaceport through complex systems of telecommunications [5].…”

<p>Spaceflight Associated Neuro-Ocular Syndrome (SANS): A Systematic Review and Future Directions</p>

“…They found the SVOne (Smart Vision Labs; New York, New York, USA) device was easy to use, could obtain measurements quickly and had excellent intersession reproducibility. Another study by Lerner et al 13 reported on ultrasound guided LP technique with remote guidance for possible inflight performance of LP. The found the technique was successful 9 of 11 times and could be performed in both the fetal and seated lordotic positions.…”