The oxygen supply in the Titanic sub is dwindling. Here's how to control and conserve your breath in emergencies, per an ER nurse.

• Controlled breathing is crucial in crisis situations, like being trapped on the missing Titanic sub.
• Taking fast, shallow breaths can worsen a panic response, says a former ER nurse.

Officials are racing against the clock to rescue the Titanic submersible that went missing Sunday, with limited resources to keep the five people on board alive.

But even with a shrinking supply of oxygen, holding your breath or breathing shallowly can actually worsen a panic response to a crisis, according to a healthcare professional.

Mindful breathing techniques can help your mind and body respond better to intense stress, said Micah Bedrosian, a former ER nurse who now works in integrative healthcare. He often uses breathwork and mindfulness techniques with patients.

"The way you breathe affects the way you think," he told Insider. "Controlling your breath in an emergency situation is very important to keep calm and regulate your nervous system. When we hold our breath, we create a stress response."

While specialized techniques may be best suited for specific situations like on a submarine, the principles are similar whether you're in a deep-sea crisis or on a crowded subway train.

Taking slow, deliberate breaths helps to stave off panic, balancing your nervous system to prevent an overwhelming fight-or-flight response, which can help you stay focused in a tough situation, according to Bedrosian.

It's particularly useful when you notice yourself holding your breath, or taking fast, shallow breaths. Common triggers that can disrupt your breathing beyond an all-out emergency include situations like a tense conversation, high-pressure meeting or presentation, or even something as simple as sending an email or scrolling social media, he said.

When this happens, Bedrosian recommends that you take a gentle breath in and a prolonged breath out to help bring about a relaxation response. He also suggests that you ground yourself by closing your eyes or setting a soft focus on something in your immediate environment.

Other experts recommend using box breathing, during which you inhale for four seconds, hold your breath for four seconds, exhale for four seconds, then hold another four seconds. Pay attention to the sensations of breathing, such as your belly rising and falling with each breath.

Calming your breathing can also help relax the people around you, and vice versa. This is known as "co-regulation," Bedrosian said. However, breathwork is a skill, and you can improve the potential benefits over time by working on it first in less-challenging situations.

"It can be more difficult to get into it when you find yourself reactive," he said. "The more you practice it, the more you can ease into it in moments of stress."