Suctioning and Nursing Responsibilities
Endotracheal Suctioning
Endotracheal suctioning (ETS) is a common nursing intervention to remove mucus and debris from the tracheobronchial tree by the insertion of a suction catheter through the endotracheal tube and the application of vacuum during catheter withdrawal to aspirate tracheal secretions.
Endotracheal suctioning is usually performed every 1-2 hours or as needed to maintain airway patency and arterial oxygenation. There is insufficient research data to identify the most significant clinical indicators to determine the need for ETS.
However, clinicians report the following clinical cues: color, breath sounds, respiratory rate and pattern, coughing, presence of secretions in the tubing, saw-toothed flow-volume loops on the mechanical ventilator, and blood oxygen levels to indicate need.
Components of Suctioning
The ETS procedure has a number of components including: hyperoxygenation (increased inspired oxygen) which can be delivered either via the ventilator or manual resuscitation bag, hyperinflation (volume of inspired air above baseline tidal volume), open vs. closed ETS through an inline suction catheter to maintain mechanical ventilation, and post-oxygenation.
Associated variables include: saline instillation for the purpose of irrigation, suction catheter size, level of negative suction pressure, depth of suction catheter insertion, application of negative pressure either continuously or intermittently, duration of negative pressure application, and number of hyperoxygenation/hyperinflation suction sequences.
Despite almost 80 years of research, controversy continues regarding the most effective endotracheal suctioning procedure. While components of the endotracheal suctioning procedure have been well researched, the utilization of research findings has been variable in the clinical setting.
The components of the
endotracheal suctioning procedure have been developed to prevent the
complications associated with the procedure.
Research on Suctioning Procedure
The majority of research has been conducted to develop techniques to minimize the most common complication: hypoxemia.
Hypoxemia, which is the lowering of blood oxygen levels, may result from the disconnection of the patient from the ventilator during the procedure and/or due to the removal of oxygen from the respiratory tract during the application of vacuum. Researchers have documented other side effects which include:
(a) atelectasis
(b) bronchoconstriction and tracheal trauma
(c) alterations in arterial pressure (hypotension and hypertension)
(d) increased intracranial pressure
(e) cardiac arrhythmias
(f) cardiac arrest,
(g) death.
Atelectasis is due to the insertion of a suction catheter with an outer diameter that is too large for the inner diameter of the endotracheal tube, causing catheter impaction and the removal of respiratory gases from distal alveoli with the application of vacuum.
Bronchoconstriction and tracheal trauma are due to the catheter stimulating the
bronchial smooth muscle and inner lining of the trachea ( Czarnik , Stone,
Everhart, & Preusser , 1991; Turner & Loan, 2000).
Hyperoxygenation/hyperinflation is at component of the ETS procedure used to prevent hypoxemia. Hyperoxygenation is the administration of a fraction of inspired oxygen. (FO) greater than the patient's baseline FiOS, either prior to (pre-hyperoxygenation) or following (post-hyperoxygenation) suctioning.
Hyperinflation is defined as the delivery of a breath of inspired air greater than the patient's baseline tidal volume. Research has shown that patients who receive no form of hyperoxygenation/hyperinflation with ETS show a significant decline in arterial blood oxygen.
Critical Evaluation
A critical evaluation of their search examining the effect of hyperoxygenation/hyperinflation on suction-induced hypoxemia shows variability in the techniques and the results.
However, despite the conflicting findings, investigators have documented that three to four hyperoxygenation breaths at 100% oxygen and 135-150% of tidal volume has been effective in preventing suction-induced hypoxemia (Stone & Turner, 1989).
A recent survey indicated that the majority of critical care nurses use hyperoxygenation alone (n=55/60) (Paul-Allen & Ostrow, 2000).
Researchers
have documented that hyperinflation followed by ETS may cause both a decrease
or increase in mean arterial pressure and may be due to the number of hyperoxygenation/hyperinflation
suction sequences.
Hyperoxygenation/hyperinflation breaths can be delivered using either a manual resuscitation bag (MRB) or a ventilator. Investigators have inconsistently reported on the ability of different MRBS to deliver 100% oxygen.
Research has shown that consistency is improved when the MRB has a reservoir of 1,000-2,000 cc attached to an oxygen source at a flow rate of 15 L/min or flush and adequate time is allowed for refill from the reservoir.
Recent studies comparing the ventilator and the MRB, which have controlled important intervening variables, have concluded that hyperoxygenation/hyperinflation breaths delivered via the ventilator have resulted in elevated blood oxygen levels which are superior or equivalent to the MRB in preventing suction induced hypoxemia ,
Investigators have also determined that the MRB produces a greater increase in airway pressure, arterial pressure, and heart rate when compared to the ventilator.
Hence, the
ventilator is the preferred mode for delivering hyperoxygenation/hyperinflation
breaths (Stone, KS, 1990; Grap , Glass, Corley, & Parks, 1996).
Nursing Research on Suctioning
Closed ETS using an inline suction catheter permits uninterrupted ventilation, oxygenation, and positive end expiratory pressure during ETS. Without hyperoxygenation, blood oxygen levels decline more with open ETS than with closed. With hyperoxygenation, via the ventilator or MRB, the decline in blood oxygen levels is equal or less with closed ETS.
While saline instillation prior to ETS is common clinical practice, there is inconclusive research to support any physiological benefit and it may actually cause a decline in blood oxygen levels (Raymond, 1995).
The relationship between the outer diameter (OD) of the suction catheter and inner diameter (ID) of the endotracheal tube can be a significant factor in the development of atelectasis during ETS. Researchers recommend an OD/ID ratio of 1:2.
This can be achieved with a 14 Fr. catheter and an endotracheal tube of 7, 8, or 9 mm. Since the level of negative pressure or suction applied to the catheter influences the degree of tracheal trauma, negative airway pressure, secretion recovery, and hypoxemia, researchers recommend a suction pressure of 100-120 mm Hg.
The suction catheter should be advanced down the endotracheal tube without the application of vacuum until gentle resistance is met to reduce mechanical stimulation of the tracheal tissue that may cause bradycardia, premature atrial contractions, and increased intracranial pressure (Rudy, Turner, Baun , Stone, & Brucia , 1991; Kerr, ME, Rudy, Brucia , & Stone, 1993).
The catheter should be withdrawn a few centimeters prior to the application of vacuum to prevent catheter wedging, the vacuum can be applied either continuously or intermittently with no significant difference in tracheal trauma while withdrawing the catheter in a rotating motion ( Czarnik et al., 1991 ).
The duration of suction application should be no more than 10 seconds. The number of hyperoxygenation/hyperinflation suction sequences or catheter passes should be limited to no more than two per episode, as research data indicates that there is a cumulative increase in arterial pressure, heart rate, and intracranial pressure with each pass (Stone, KS, Bell, & Preusser , 1991; Rudy et al.).
If additional suction passes are needed, 5-10 minutes should elapse to allow for the patient's hemodynamic variables to return to baseline. The patient should be assessed for changes in blood pressure, heart rate, arrhythmias, and increased intracranial pressure and the patient's ability to tolerate the procedure should be documented.
The lungs
should be auscultated to assess airway clearance and the character of
secretions (amount, color, and viscosity) should be recorded following ETS.
Give your opinion if have any.