Stories about: John Kheir

Monitoring mitochondria: Laser device tells whether oxygen is sufficient

Shining a laser-based device on a tissue or organ may someday allow doctors to assess whether it’s getting enough oxygen, a team reports today in the journal Science Translational Medicine.

Placed near the heart, the device can potentially predict life-threatening cardiac arrest in critically ill heart patients, according to tests in animal models. The technology was developed through a collaboration between Boston Children’s Hospital and device maker Pendar Technologies (Cambridge, Mass.).

“With current technologies, we cannot predict when a patient’s heart will stop,” says John Kheir, MD, of Boston Children’s Heart Center, who co-led the study. “We can examine heart function on the echocardiogram and measure blood pressure, but until the last second, the heart can compensate quite well for low oxygen conditions. Once cardiac arrest occurs, its consequences can be life-long, even when patients recover.”

In critically ill patients with compromised circulation or breathing, oxygen delivery is often impaired. The new device measures, in real time, whether enough oxygen is reaching the mitochondria, the organelles that provide cells with energy.

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Intravenous oxygen delivery edges toward the clinic

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Engineered microparticles that deliver oxygen straight to the bloodstream in emergency situations

Sudden oxygen deprivation can happen for many reasons, from choking to aspiration to cardiac arrest. In these emergency situations, rapid oxygen delivery can mean the difference between life and death. But what if the person cannot breathe?

In the summer of 2012, John Kheir, MD, of the Heart Center at Boston Children’s Hospital, published a study in Science Translational Medicine describing an alternative oxygen delivery system. Kheir used tiny, gas-filled microparticles with a thin outer layer of lipids (fatty molecules) that combined to form a liquid foam-like substance. Injected into the bloodstream, the particles rapidly dissolved and delivered oxygen gas directly to the red blood cells in animal models. But the bubbles were very unstable and not suitable for clinical use.

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“Could we have given her intravenous oxygen?” Breathing an idea to life

This syringe, containing particles of oxygen gas mixed with liquid, can potentially save the lives of patients unable to breathe — like the infant Kheir was unable to save early in his career.

John Kheir, MD, a physician in the Cardiac Intensive Care Unit at Boston Children’s Hospital, led a team that created tiny particles filled with oxygen gas, which, when mixed with liquid, could be injected directly into the blood. In an emergency, IV oxygen delivery could potentially buy clinicians time to start life-saving therapies. Kheir will recount his journey this evening at TEDMED, during the 5:30-7:30 p.m. session “Welcoming Death Into Life.” To preview his talk, we’re reprising his popular post from last year.

It was an ordinary Saturday night in the ICU at Boston Children’s, in the fall of 2006. One of my patients was a 9-month-old girl who was admitted with pneumonia, and was having trouble breathing. I had gone in to check on her just a few minutes before; although she was not feeling well, she reached out and touched my hand as I examined her. I assured her mother she was in the best possible place for her care.

Five minutes later, the code bell alarmed. Our team rushed into her room to the most horrific sight I have ever seen.

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