Ten Tips for Safer Suctioning

Wolters Kluwer Health, Inc.

Ten Tips for Safer SuctioningAuthor(s): Connie A. Glass and Mary Jo GrapSource: The American Journal of Nursing, Vol. 95, No. 5 (May, 1995), pp. 51-53Published by: Lippincott Williams & WilkinsStable URL: http://www.jstor.org/stable/3471211 .

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I f you work on a unit with patients receiving mechanical ventilation, chances are that you perform endotracheal suctioning several times a day. And when you do something so routinely, it's easy to lose sight of what can go wrong.

Suctioning to clear airway secretions is often necessary in a patient with an endotracheal or tracheostomy tube, but the procedure carries several risks. It removes oxygen from the airway, and so can result in hypoxemia and hypoxia. Suction- ing too long, at too high a pressure, or with too large a catheter can cause atelectasis. Other possible complications include bronchospasm, cardiac arrhythmias, hemodynamic al- terations (such as elevated mean arterial pressure), increased intracranial pressure, and airway trauma.

Consistent use of the best possible suctioning technique may help prevent these problems. However, we've found that nurses differ greatly in how they suction. In a study, we ob- served 100 nurses performing the procedure, with manual resuscitation bags (MRBs) used for oxygenation. What we found might surprise you: Volume delivered through the MRBs ranged from 66 to 1,656 mL, percentage of oxygen delivered from 24% to 97%, bag compression rates from 12 to 52 times per minute, and number of suction catheter passes from three to eight.

Much research has been done in recent years aimed at im- proving the practice of suctioning. Though controversies re- main, studies have answered many questions about endotracheal suctioning technique-how often to suction, whether to administer higher concentrations of oxygen (hyperoxygenation) and larger volumes (hyperinflation), how well MRBs (as compared to ventilators) preoxygenate patients, and how

Connie A. Glass is RN research coordinator on the Medical Respiratory Intensive Care Unit at the Medical College of Virginia Hospitals in Rich- mond. Mary Jo Grap is assistant professor at Virginia Commonwealth University School of Nursing, also in Richmond.

many passes to make with the catheter, among others. Here we'll look at the 10 key principles that have emerged from these studies and how you can apply them to make suctioning as safe and effective as it can be for your patients.

1 Suction only when necessary-not routinely. If you're like many nurses, you were taught to suction patients

Liroutinely, perhaps every two hours. But today there's a greater appreciation of the complications, such as airway trauma, that suctioning may cause. We also now understand that routine suctioning may actually stimulate production of airway secretions, possibly because of trauma to the airway.

Suctioning should be done only when the patient is cough- ing or experiencing respiratory distress, auscultation reveals rhonchi, ventilator airway pressures rise, or PaO2 or SpO2 suddenly drops. Some patients-need suctioning hourly or even more often, but others may need it only once every four hours or even less.

2 Administer extra oxygen to the patient before and after ; suctioning. Research has consistently shown that with- :

out hyperoxygenation (administration of oxygen at an FiO2 greater than what the patient has been receiving), endotracheal suctioning will result in hypoxemia. This has been demonstrated in animals, in healthy humans, and in humans with impaired lung function. There's no question about it: Hyperoxygenation before and after each catheter pass during suctioning is the standard.

Some newer ventilators (such as the Puritan Bennett 7200) have a mode that provides 100% oxygen for two minutes, then switches back to the previous FiO2 setting. Also, some ventilators can provide breaths equal to the patient's ventilat- ed volume with the push of a "manual breath" button. The 100% oxygen and manual ventilation modes can be used to- gether instead of an MRB and will deliver consistent FiO2.

AJN / May 1995 51



But it's important to keep in mind that the patient won't be breathing 100% oxygen as soon as you adjust the FiO2. It takes time-how long depends on the ventilator-to prime the ventilator tubing and deliver 100% oxygen to the patient. The Puritan Bennett 7200, for example, takes anywhere from 20 to 103 seconds to increase FiO2 to 100%, studies have shown. To be on the safe side, assume a washout period of two minutes, though this may require pushing the 100% oxygen button twice.

It's questionable whether MRBs are as effective as ventilators in hyperoxygenating patients. Several studies comparing SpO2 or PaO2 in ventilator- and MRB-hyperoxygenated patients haven't found differences. But these studies have used controlled conditions that guarantee 100% oxygen delivery from the MRS-conditions impossible to duplicate in clinical practice. In clinical tests with adult patients, MRBs with reser- voirs have generally failed to deliver 100% oxygen consistently. In fact, they've been found to give no more than 80%.

In clinical practice, the percentage of oxygen delivered by the MRB when a patient is taking a breath isn't measured. Oxygen concentration at this point may not even equal the baseline FiO2. If so, the patient is actually being hypo-oxy- genated with the MRB.

A few studies, some in patients with chronic obstructive pulmonary disease, have found hyperoxygenaiion with less than 100% oxygen (in one study, 20% above baseline FiO2) effective. But more information is needed before hyperoxygenation with FiO2 below 100% can be widely used in clinical practice.

Most studies of hyperoxygenation without larger breaths have used three breaths, but no research has been reported comparing the effectiveness of different numbers of breaths.

3 Use judgment and caution in giving larger breaths (hyperinflation) before and after suctioning. Your patient may or may not require hyperinflation (generally defined

as 150% of baseline ventilator tidal volume) in addition to hyperoxygenation before and after suctioning. In patients with normal lung function who are receiving mechanical ventilation for only a short time, such as those who have undergone coronary artery bypass grafting or other surgery, hyperoxygenation alone generally will prevent hypoxemia. In patients with abnormal lung function, such as from pulmonary disease, some studies have suggested hyperoxygenation is enough, while others indicate that both measures are necessary.

Hyperinflation isn't necessarily risk-free. It can cause eleva- tions in mean arterial pressure (MAP). So, before using it, assess the patient's response to hyperoxygenation alone by mon- itoring heart rate and SpO2. If, after hyperoxygenation, the patient's SpO2 remains stable during suctioning, hyperinflation is probably unnecessary (though it's important to keep in mind that, according to the oxyhemoglobin dissociation

curve, PaO2 must fall to 60 mmHg before much of a change will be seen in SpO2).

But if SaO2 drops despite hyperoxygenation, add hyperinflation and assess the SpO2 response and changes in MAP and heart rate. If hyperinflation raises MAP, you'll have to weigh that risk against the risk of a fall in SpO2 to determine the best course of action for the patient. Note your choice in the patient's documented care plan and communicate it to all care team members.

Research has demonstrated that for adults, it's virtualy impossible to give 150% of tidal volume with an MRB, especially given that the usual practice requires a one-handed bag compression technique to maintain the sterility of the other hand for suctioning. Instead, hyperinflation can be performed using the ventilator's sigh volume mode or through an increase in tidal volume.

Give no more than three hyperinflated breaths, one every five seconds, before and after each suction catheter pass. Stud- ies have shown that MAP becomes more elevated with each hyperinflation. The increase is related not to the volume of oxygen, but to how many times hyperinflation is repeated.

It's important to note that hyperinflation without hyperoxygenation won't reliably prevent hypoxemia. Also, keep in mind that a manual ventilation mode that delivers only the baseline FiO2 and tidal volume won't provide hyperoxygenation or hyperinflation. Indeed, one study has found that the tidal volume actually delivered using the manual ventilation option was less than the preset volume.

4 If you do use an MRB, take steps to maximize oxygen del//ery. There are reasons you may need to or prefer to use an MRB. The ventilators on your unit may not have

the special settings discussed earlier. Hospital procedure may prohibit you from changing ventilator settings. Or you may favor MRBs because of the tactile feedback they provide.

Under ideal conditions, MRBs can deliver 100% of tidal volume and an average FiO2 of 80%, which may be enough to hyperoxygenate some patients. In practice, however, oxygen delivery varies with the model of MRB, the bag's oxygen liter flow, the presence and capacity of an oxygen reservoir, the tidal volume delivered, and the bag compression rate.

To get the best possible performance from an MRB, make sure the reservoir is filly expanded. Set oxygen liter flow to 15 L/minute or higher; anything less will significantly reduce the bag's oxygen delivery.

Compress the bag at the same rate used for rescue breathing in cardiopulmonary resuscitation in adults-that is, one breath every five seconds. Nurses typically squeeze more fre- quently, but higher compression rates give the bag less time to refill with oxygen, resulting in less being delivered to the patient. The method of bag compression can also influence the volume of oxygen delivered to the patient. One-handed compression techniques have been shown to deliver lower vol-

52 AJN / May 1995

Saline has been shown to impair oxygenation.



umes than hand-to-forearm and two-handed techniques. To keep one hand sterile for suctioning, use the hand-to-forearm technique, especially if you have small hands.

5 Spare the saline. Many nurses believe that instilling saline solution into the endotracheal tube before suctioning loosens secretions and eases their removal. Some in-

stitutions even include saline lavage in their suctioning proto- cols. However, there are no research data to support this practice. At least one study has found that saline lavage doesn't im- prove patients' PaO2 during suctioning or increase the amount of secretions. It's been noted that saline and respiratory tract secretions don't mix in the test tube, so it's unlikely that they'll mix in a patient's airway to produce a mixture that can be suctioned out. What's more, there's no evidence that instilled saline moves beyond the main stem bronchus.

Some research suggests saline lavage may in fact harm patients. Saline has been shown to impair oxygenation. And it may increase the risk of infection, because bacteria dislodged during lavage can migrate to the lower airway.

6 t Use the smallest suction catheter that can do the job. Some authors have recommended using a catheter with an external diameter less than half the internal diameter

of the endotracheal tube. This allows air to enter the lungs while oxygen is being removed by suctioning, which helps to prevent excessive negative pressure and atelectasis. Endotra- cheal tubes used in adults generally range from 30 to 38 Fr (7 to 9 mm), suction catheters from 10 to 16 Fr (2 to 2.5 mm).

7 Make no more than three suction catheter passes. Or better yet, two, if possible. Limit the number of passes to those absolutely necessary. Most suctioning studies in

which the number of suction catheter passes made was reported have employed up to three while maintaining SaO2 or PaO2. The more passes, the greater the risk of trauma. And, when you employ hyperinflation, with more catheter passes comes escalating MAP. Keep each pass of the suction catheter to 10 seconds or less.

8 Limit suction pressures to 80 to 120 mmHg. Higher suc- ntion pressures increase the risk of atelectasis, hypoxemia,

. and trauma.

9 Don't count on intermittent suctioning to reduce airway trauma. Most of us have been taught to apply suc-

;?

tion pressure intermittently-typically by alternately placing the thumb over the catheter's control vent and taking it off-to reduce airway trauma. But at least one study has found that this practice is ineffective. Examining tracheal tis- sue samples, investigators saw ulceration, sometimes with necrosis, with both continuous and intermittent procedures. Apparently, suctioning is a very traumatic procedure no mat-

ter how you do it. Another common practice is to rotate the catheter while

withdrawing it to loosen secretions. But neither has this ma- neuver proved effective in research.

aWhen suctioning, monitor heart rate and rhythm, ( '| | arterial pressure, and SpO2. Monitor the patient for

arrhythmias, such as bradycardia or premature beats. If the patient shows these signs, a drop in blood pressure, or a decreased level of consciousness, stop suctioning and administer high FiO2 with the manual breath and 100% oxygen modes on the ventilator or, if that's not possible, with an MRB. Likewise, if you note any fall in SpO2 during suctioning, stop and hyperoxygenate the patient. Should SpO2 not return to normal, verify that the ventilator is in fact providing high FiO2. If it is, check for reduced perfusion at the pulse oximeter probe site. Also, assess the patient for mucous plug- ging, pneumothorax, and changes in lung function.

Don't rely on SpO2 alone to monitor oxygenation-note the PaO2 measurements as well. If they indicate hypoxemia subsequent to suctioning, you'll have to reduce suctioning fre- quency to the bare minimum, make sure that the patient is sufficiently preoxygenated, and look for the problems discussed above. O

AJN/May 1995 53

And it may increase the risk of infection....



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Ten Tips for Safer Suctioning