1 00:00:01,920 --> 00:00:04,320 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio. 2 00:00:06,320 --> 00:00:10,200 Speaker 1: Hey brain Stuff, Lauren Vogelbaum here. This episode is part 3 00:00:10,200 --> 00:00:13,560 Speaker 1: of our ongoing series surrounding the novel type of coronavirus 4 00:00:13,600 --> 00:00:17,040 Speaker 1: identified in twenty nineteen, which causes what's therefore being called 5 00:00:17,239 --> 00:00:21,000 Speaker 1: COVID nineteen. Because everything is a little less scary when 6 00:00:21,000 --> 00:00:24,880 Speaker 1: you understand it better. As the United States and the 7 00:00:24,920 --> 00:00:27,400 Speaker 1: rest of the world scrambled to cope with the COVID 8 00:00:27,480 --> 00:00:31,880 Speaker 1: nineteen pandemic, hospitals are faced with a critical shortage of ventilators, 9 00:00:31,920 --> 00:00:35,040 Speaker 1: the bedside devices that help patients who have difficulty breathing 10 00:00:35,040 --> 00:00:38,120 Speaker 1: on their own. So we wanted to talk today about 11 00:00:38,159 --> 00:00:42,440 Speaker 1: what ventilators are and how they work. U S hospitals 12 00:00:42,440 --> 00:00:45,440 Speaker 1: have about a hundred and sixty thousand ventilators, with another 13 00:00:45,520 --> 00:00:48,920 Speaker 1: twelve thousand, seven hundred available from the federal government's National 14 00:00:48,920 --> 00:00:52,960 Speaker 1: Strategic Stockpile, but it's feared that that will be nowhere 15 00:00:53,000 --> 00:00:55,120 Speaker 1: near enough to cope with all the people who could 16 00:00:55,120 --> 00:01:00,000 Speaker 1: become seriously ill from the virus. All of this has 17 00:01:00,000 --> 00:01:02,720 Speaker 1: suddenly focused attention on a piece of medical equipment that 18 00:01:02,800 --> 00:01:05,559 Speaker 1: most of us probably haven't given much thought to any 19 00:01:05,560 --> 00:01:09,119 Speaker 1: more than we think about breathing itself, but for someone 20 00:01:09,160 --> 00:01:12,280 Speaker 1: who can't get air into their lungs, the device, which 21 00:01:12,400 --> 00:01:15,720 Speaker 1: ranges in price from twenty to fifty dollars according to 22 00:01:15,720 --> 00:01:21,240 Speaker 1: The Washington Post, can be a lifesaver. Ventilators assist patients 23 00:01:21,280 --> 00:01:24,440 Speaker 1: who have a number of different conditions. We spoke by 24 00:01:24,440 --> 00:01:27,480 Speaker 1: an email with Dr Paul F. Courier, director of the 25 00:01:27,560 --> 00:01:30,520 Speaker 1: Respiratory Acute Care Unit for the Division of Pulmonary and 26 00:01:30,560 --> 00:01:35,160 Speaker 1: Critical Care at Massachusetts General Hospital. He said they can 27 00:01:35,200 --> 00:01:38,680 Speaker 1: be used to help people breathe during routine surgery under anesthesia, 28 00:01:39,120 --> 00:01:42,240 Speaker 1: or also when patients are sick and have difficulty breathing 29 00:01:42,280 --> 00:01:45,960 Speaker 1: due to their illness. A small proportion of people who 30 00:01:46,000 --> 00:01:50,120 Speaker 1: become infected with COVID nineteen may develop inflammation in their lungs. 31 00:01:50,800 --> 00:01:54,720 Speaker 1: Courier explained. An even smaller proportion of these patients can 32 00:01:54,760 --> 00:01:58,600 Speaker 1: develop respiratory failure, which is best treated with a ventilator. 33 00:02:00,000 --> 00:02:02,680 Speaker 1: But we also spoke by email with Kenneth Lutchen, dean 34 00:02:02,760 --> 00:02:05,520 Speaker 1: of the College of Engineering and a professor of biomedical 35 00:02:05,520 --> 00:02:09,720 Speaker 1: engineering at Boston University. He said, think of the lungs 36 00:02:09,760 --> 00:02:13,040 Speaker 1: as an elastic balloon. You can expand the balloon by 37 00:02:13,120 --> 00:02:16,640 Speaker 1: having the pressure at the opening mouth be greater than 38 00:02:16,680 --> 00:02:19,760 Speaker 1: the pressure on the other side of it. Normally, we 39 00:02:19,840 --> 00:02:23,200 Speaker 1: breathe by having our muscles expand the chest, which lowers 40 00:02:23,240 --> 00:02:26,000 Speaker 1: the pressure around the lungs inside the body, so that 41 00:02:26,040 --> 00:02:29,320 Speaker 1: the lungs expand. But if the lungs fill up with 42 00:02:29,400 --> 00:02:32,480 Speaker 1: fluid or become highly inflamed, both of which can happen 43 00:02:32,560 --> 00:02:36,360 Speaker 1: with novel coronavirus, then the negative pressures that occur with 44 00:02:36,520 --> 00:02:40,000 Speaker 1: normal breathing are not sufficient to expand the lungs enough, 45 00:02:40,320 --> 00:02:44,880 Speaker 1: and insufficient oxygen and carbon dioxide exchange will result. The 46 00:02:45,000 --> 00:02:49,240 Speaker 1: lucchen continued. The alternative is then to push air into 47 00:02:49,240 --> 00:02:52,720 Speaker 1: the lungs using a ventilator, which creates a positive pressure 48 00:02:52,760 --> 00:02:56,000 Speaker 1: at the mouth the inlet to the intubation tube large 49 00:02:56,080 --> 00:03:00,359 Speaker 1: enough to push enough fresh air in and out each breath. 50 00:03:01,160 --> 00:03:04,160 Speaker 1: Hopefully this can keep the blood, oxygen, and carbon dioxide 51 00:03:04,240 --> 00:03:07,480 Speaker 1: levels close to normal until the inflammation and fluid build 52 00:03:07,520 --> 00:03:10,360 Speaker 1: up subsides and the person can breathe on their own again. 53 00:03:11,560 --> 00:03:14,840 Speaker 1: A ventilator is a boxing mechanical device with a digital 54 00:03:14,840 --> 00:03:17,480 Speaker 1: display on top that typically sits on a cart next 55 00:03:17,480 --> 00:03:20,840 Speaker 1: to a patient's bed. As the National Heart Long and 56 00:03:20,960 --> 00:03:24,320 Speaker 1: Blood Institute website explains the patient is connected to the 57 00:03:24,360 --> 00:03:26,919 Speaker 1: device by a breathing tube that's inserted through their nose 58 00:03:27,000 --> 00:03:29,600 Speaker 1: or mouth down the throat, which is held in place 59 00:03:29,639 --> 00:03:31,960 Speaker 1: by tape or a strap that fits around the head. 60 00:03:32,840 --> 00:03:35,520 Speaker 1: The tube in the airway can cause some discomfort and 61 00:03:35,560 --> 00:03:39,080 Speaker 1: also affects the patient's ability to talk and eat. That's 62 00:03:39,120 --> 00:03:41,760 Speaker 1: why the care team may insert another tube into a 63 00:03:41,840 --> 00:03:44,960 Speaker 1: vein to feed the patient nutrients, or if the person 64 00:03:45,040 --> 00:03:47,120 Speaker 1: is going to be on a ventilator for a long time, 65 00:03:47,520 --> 00:03:50,080 Speaker 1: insert a feeding tube that goes directly into the stomach 66 00:03:50,160 --> 00:03:55,040 Speaker 1: or small intestine through a surgically created opening. Having a 67 00:03:55,120 --> 00:03:58,160 Speaker 1: tube down your throat isn't exactly pleasant, but it is 68 00:03:58,240 --> 00:04:03,000 Speaker 1: important electionics blamed Without intubation, Several things can threaten the 69 00:04:03,000 --> 00:04:06,120 Speaker 1: ability of the ventilator to do its job. Perhaps the 70 00:04:06,160 --> 00:04:09,000 Speaker 1: most important is that if the ventilator just blew into 71 00:04:09,000 --> 00:04:12,200 Speaker 1: the mouth, the delivered volume may not all go into 72 00:04:12,240 --> 00:04:14,520 Speaker 1: the lung. Some of it could leak out the nose, 73 00:04:14,560 --> 00:04:17,000 Speaker 1: which is connected to the mouth, or can end up 74 00:04:17,040 --> 00:04:19,880 Speaker 1: expanding the cheeks of the person rather than going into 75 00:04:19,880 --> 00:04:23,599 Speaker 1: the lung. To get all of this to work, hospitals 76 00:04:23,640 --> 00:04:28,400 Speaker 1: depend upon the expertise of highly trained professionals called respiratory therapists. 77 00:04:29,320 --> 00:04:32,040 Speaker 1: We also spoke via email with Timothy R. Myers, a 78 00:04:32,080 --> 00:04:35,640 Speaker 1: respiratory therapist and chief business officer of the American Association 79 00:04:35,720 --> 00:04:40,240 Speaker 1: for Respiratory Care. He said, the respiratory therapist determines the 80 00:04:40,279 --> 00:04:44,039 Speaker 1: appropriate settings to match the patient's respiratory needs based on 81 00:04:44,160 --> 00:04:48,720 Speaker 1: the underlying disease condition. From that point, they provide constant monitoring, 82 00:04:48,760 --> 00:04:51,719 Speaker 1: an assessment, and modify the setting as the patient's condition 83 00:04:51,839 --> 00:04:56,240 Speaker 1: improves or worsens. This would include non invasive monitoring and 84 00:04:56,400 --> 00:04:59,719 Speaker 1: measurements from blood analysis to look at oxygen and carbon 85 00:04:59,720 --> 00:05:04,440 Speaker 1: dio side levels. This requires a lot of careful management 86 00:05:04,600 --> 00:05:08,160 Speaker 1: because lungs are pretty complicated. While it's useful to think 87 00:05:08,160 --> 00:05:11,799 Speaker 1: of the lungs as a balloon for illustrative purposes, in reality, 88 00:05:11,960 --> 00:05:15,719 Speaker 1: Myers explained their quote more like a network of millions 89 00:05:15,720 --> 00:05:18,960 Speaker 1: of balloons that must transfer gases between the lungs and 90 00:05:19,080 --> 00:05:22,839 Speaker 1: the circulatory system. When the lungs are damaged or diseased, 91 00:05:23,160 --> 00:05:26,599 Speaker 1: each lung and the millions of balloons require gas entry 92 00:05:26,720 --> 00:05:30,520 Speaker 1: in and out differently than when they're healthy. Each patient 93 00:05:30,720 --> 00:05:34,880 Speaker 1: is unique. In recent years, there have been some advances 94 00:05:34,920 --> 00:05:38,760 Speaker 1: and how ventilators are used. Courier said research has shown 95 00:05:38,760 --> 00:05:43,000 Speaker 1: that using low breath size and low pressures improves outcomes. Also, 96 00:05:43,160 --> 00:05:46,480 Speaker 1: patients with severe respiratory failure may at times be turned 97 00:05:46,480 --> 00:05:49,080 Speaker 1: on their stomachs while on the ventilator, a process called 98 00:05:49,080 --> 00:05:53,120 Speaker 1: prone positioning, which can often improve their oxygen levels. Finally, 99 00:05:53,240 --> 00:05:56,360 Speaker 1: for some patients whose oxygen levels remain low despite being 100 00:05:56,360 --> 00:05:59,320 Speaker 1: on a ventilator, they may be able to receive extra 101 00:05:59,400 --> 00:06:05,039 Speaker 1: corpore membranous oxygenation. In some very specialized centers, this highly 102 00:06:05,080 --> 00:06:08,000 Speaker 1: intensive therapy can circulate the blood outside of the body 103 00:06:08,200 --> 00:06:13,480 Speaker 1: to provide additional oxygen. Luchen's research focuses on developing safer 104 00:06:13,520 --> 00:06:18,000 Speaker 1: mechanical ventilators, he said. Initially, the ventilator is working to 105 00:06:18,040 --> 00:06:21,560 Speaker 1: save a life by keeping proper oxygen and carbon dioxide levels, 106 00:06:22,080 --> 00:06:25,080 Speaker 1: but it does this by pushing air in and exposing 107 00:06:25,120 --> 00:06:29,080 Speaker 1: the lung to abnormal pressures, often larger pressures to help 108 00:06:29,120 --> 00:06:34,200 Speaker 1: expand a stiffer and or narrower lung. Also, a ventilator 109 00:06:34,279 --> 00:06:37,320 Speaker 1: is programmed to give the exact same breath every time, 110 00:06:37,720 --> 00:06:40,360 Speaker 1: where normal breathing varies a little from breath to breath 111 00:06:40,680 --> 00:06:44,200 Speaker 1: and we periodically take a big breath. He explained that 112 00:06:44,279 --> 00:06:47,880 Speaker 1: injuries can occur from those large, repetitive pressures, which could 113 00:06:47,920 --> 00:06:53,279 Speaker 1: eventually prevent the ventilator from providing enough gas exchange. That's 114 00:06:53,279 --> 00:06:57,200 Speaker 1: why Luchen is working with lead investigator Balisuki, a professor 115 00:06:57,240 --> 00:07:00,799 Speaker 1: of biomedical engineering at Boston University, on a concept called 116 00:07:00,920 --> 00:07:05,400 Speaker 1: variable ventilation, in which the ventilator delivers variable breaths similar 117 00:07:05,440 --> 00:07:09,520 Speaker 1: to a natural breathing pattern, to avoid repetitive abnormal pressures 118 00:07:09,720 --> 00:07:13,640 Speaker 1: in the same location when a person breathes. Trials and 119 00:07:13,680 --> 00:07:16,000 Speaker 1: animals have shown that this type of ventilation is less 120 00:07:16,000 --> 00:07:18,360 Speaker 1: likely to cause injuries, but it hasn't yet been tested 121 00:07:18,360 --> 00:07:23,440 Speaker 1: in humans. With the current shortage of ventilators, manufacturers are 122 00:07:23,600 --> 00:07:28,160 Speaker 1: ramping up production. Medtronic, one of the world's major ventilator makers, 123 00:07:28,440 --> 00:07:31,000 Speaker 1: is gearing up to double its output by adding shifts 124 00:07:31,040 --> 00:07:33,840 Speaker 1: to keep its Irish manufacturing plant running around the clock. 125 00:07:34,600 --> 00:07:38,720 Speaker 1: But manufacturers face a challenge in increasing production because ventilators 126 00:07:38,800 --> 00:07:46,320 Speaker 1: must be built with great care. Today's episode was written 127 00:07:46,360 --> 00:07:49,120 Speaker 1: by Patrick J. Tiger and produced by Tyler Klang. For 128 00:07:49,200 --> 00:07:51,040 Speaker 1: more on this and lots of other topics, visit how 129 00:07:51,040 --> 00:07:54,040 Speaker 1: stuff Works dot com. Brainstuff is production of I heart Radio. 130 00:07:54,200 --> 00:07:56,360 Speaker 1: For more podcasts for my heart Radio, visit the iHeart 131 00:07:56,400 --> 00:07:58,680 Speaker 1: Radio app, Apple Podcasts, or where ever you listen to 132 00:07:58,720 --> 00:08:08,480 Speaker 1: your favorite shows.