The lecture on alternatives to mechanical ventilation was titled “Witchcraft and Wizardry,” but speaker Christopher Tainter, MD, started off by warning his virtual audience that he had neither to offer.
“I'm not a wizard, and you can do any of these things on your own. But maybe some of them will be new and seem like magic,” said Dr. Tainter, an emergency medicine and critical care specialist at the University of California, San Diego. As part of the 2021 Critical Care Congress, held online in February, he offered 10 tips for reducing need for mechanical ventilation, in descending order.
“This is a bit like choosing whether you want to manage your patient with respiratory failure the easy way or the hard way. In most cases, when you're contemplating mechanical ventilation, avoiding it is going to take more effort than just intubating, but that doesn't mean there isn't a benefit,” he said.
The suggested interventions may not all have been proven to significantly affect mortality risk, but staying off the ventilator can come with other important benefits such as lower risk of delirium or a shorter ICU stay, Dr. Tainter noted.
10. Augment diuresis. “We know that a positive fluid balance may be associated with increased lung injury,” said Dr. Tainter. One solution is to give hyperoncotic albumin. “I'm sure we've all done it and it definitely seems to work sometimes, especially for those with a low albumin level. But whether it's worth the cost, I can't say for sure, and our pharmacy doesn't always think so,” he added.
Other less expensive options include mannitol or hypertonic saline. Research has indicated benefits of the latter for heart failure patients, Dr. Tainter said, citing a 2014 publication in the International Journal of Cardiology. “This meta-analysis showed a mortality benefit and a shorter length of stay. In addition, they showed more effective diuresis with weight loss with hypertonic saline and an improvement in renal function.”
The effect of saline on chloride levels may help explain the improvement. “It turns out that both hyper- and hypochloremia are associated with diuretic resistance,” he said. “Perhaps treating hypochloremic patients with hypertonic saline sort of kills two birds with one stone...and maybe it makes sense to use hypertonic bicarb to treat hyperchloremic patients [based on] the same rationale.”
9. Optimize patient positioning. To illustrate this tip, Dr. Tainter showed a photo of a patient flat on his back in bed. “I don't know how many times I have been called in for acute respiratory failure, and I see this. Why does this seem to be our default position when somebody is in any kind of distress? This is just about the worst position possible for a patient who has trouble breathing,” he said.
He cited a retrospective study of 528 patients who underwent emergency endotracheal intubation. A complication occurred in 22.6% of patients intubated in the supine position, compared with 9.3% of those in the back-up, head-elevated position, according to results published by Anesthesia & Analgesia in April 2016.
“I've started doing pretty much all of my intubations in an upright or semi-upright position,” Dr. Tainter said. Semi-upright might be more appropriate than fully upright for patients with a large abdomen that might compromise movement of the diaphragm, he added.
This advice also applies to proning, an intervention that has come to prominence during the COVID-19 pandemic. When accomplished safely (e.g., without accidental extubation), spending some time on one's belly seems to hold benefit for a wide range of respiratory failure patients, from those on extracorporeal membrane oxygenation to those not yet requiring intubation, he said. “You don't have to be intubated to change position. We're doing the awake proning rotisserie dance pretty much routinely now with our COVID patients before they get intubated.”
8. Expand the lungs. The most easily available tool for executing this tip is the incentive spirometer. “I'm sure we've all seen these, usually by the window, out of reach from the patient,” said Dr. Tainter. Incentive spirometers don't have definitive evidence of benefit and require engagement by patients, he noted. “But they're pretty benign and I definitely encourage their use. If the patient can't or won't use the incentive spirometer, there are a variety of positive expiratory pressure devices available.”
7. Clear secretions. To follow this advice, physicians should seek assistance of respiratory therapists and their many available devices, which can help clear secretions using vibration, suction, or oscillation. The tools range from small handheld devices to much larger options. “Some of our hospital beds can perform vibratory percussive therapy, just like these beds we used to see in some cheap hotels,” said Dr. Tainter.
A less enjoyable option is the cough assist machine. “This can be pretty uncomfortable for the patient because it creates such violent changes in airway pressure. So sometimes it takes a little convincing, but it may still be better than an endotracheal tube,” he said. There are also drugs that can help, including anticholinergics, expectorants, and inhaled saline.
6. Support the airway. Dr. Tainter encouraged his audience to be creative in selection of a device to keep an unconscious patient's airway open. “Usually, we think about C collars making the airway more difficult to manage. But sometimes it can help support your chin in a straight position,” he said. Some cervical collars even include a mechanism to thrust the jaw forward and may be a helpful short-term solution to a drooping head.
5. Avoid starvation. “Nutrition is not the sexiest intervention on the list, but it might be the most easy to overlook,” said Dr. Tainter. “The consequences of starvation are not immediately apparent, while maybe some of the harms, like risk for aspiration, are.”
Patients in respiratory distress burn more calories than normal, which can lead to significant nutritional deficits if they don't get food. Most patients in respiratory failure can be fed through the stomach, he advised, citing 2016 guidelines from the Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition.
“But if you're really worried about aspiration, you can go for postpyloric, and we can use prokinetic agents to further decrease aspiration risk,” said Dr. Tainter. The top priority is to make sure patients get enough protein, up to 2 g/kg for most, he recommended. It's not generally necessary to put respiratory failure patients on a low-carb diet, but it is important to monitor their phosphate levels, he noted.
4. Use inhaled vasodilators. Beta-agonists are widely used in chronic obstructive pulmonary disease and asthma, but the evidence on them for some other breathing problems is conflicting and mixed, Dr. Tainter reported. In a meta-analysis of albuterol for acute respiratory distress syndrome, published in the World Journal of Emergency Medicine in 2015, ventilator-free days were increased with the drug, but so was mortality. “For acute lung injury, albuterol should probably be used selectively,” he said. “But if we start to look at patients with heart failure, we might see some benefit.” A small randomized trial of heart failure patients showed improved pulmonary vascular reserve with albuterol, according to results published by Circulation Research in 2018.
Pulmonary vasodilators may offer benefit in keeping patients off the ventilator, but long-term data are limited because they are generally used as rescue therapy, Dr. Tainter said. Inhaled milrinone and nitroglycerine are also being investigated for this, he added.
“If you're not familiar with these agents, it's probably worthwhile to ask for help. There are a few things to be aware of,” Dr. Tainter said. Those include that the drugs should be used as a bridge to another, rather than a treatment themselves, and that they may worsen pulmonary edema and cause some other side effects, albeit rarely.
3. Assist ventilation. That means with a bag valve mask. “I'd say that almost all the benefit from bag-valve-mask ventilation is from increasing the mean airway pressure. But increasing inspiratory pressure by squeezing the bag harder is not what we really want to do. This causes more lung injury and gastric insufflation,” said Dr. Tainter. The solution is a positive end-expiratory pressure valve, he suggested. Some masks also offer a pressure gauge to make it even easier to monitor the pressure provided. “And again, there's no reason to do this flat on their back. You can get a good mask seal from the front, especially if someone else is helping you,” he added.
2. Elicit cooperation. Avoiding mechanical ventilation requires help from the patient, too, but that can be hard to obtain. “How do you get your patient to cooperate with you when they feel like they're drowning? Historically, we've considered it a bad idea to sedate someone with difficulty breathing. But you can also think of this like procedural sedation and the procedure is breathing,” he said. Sedation can be an effective strategy for patients who could benefit from short-term noninvasive ventilation, but the patient should then be under close supervision, Dr. Tainter suggested.
1. Change altitude. This tip refers not to the variation in oxygen concentration by distance from sea level, but the variation in patient supervision by hospital floor. “I'm talking about moving the patient to a higher level of care,” Dr. Tainter said. He urged clinicians to identify and intervene on patients' potential need for mechanical ventilation earlier. “One of my all-time favorite quotes in medicine: An ounce of prevention is worth a pound of cure.”