By Donna Wong / March 15, 2002
The last time six-year-old Rachel was in the hospital, a tracheotomy tube saved her life. This time, Rachel is back for laser surgery to eliminate the scars left by the tracheotomy tube and to enlarge her airway. Other children have experienced damage from saline instillation in endotracheal tubes, which can interfere with oxygen saturation and can even move harmful organisms from the tube into the child's lower airway. Are we doing enough to prevent unintended damage from inappropriate suction techniques and handling of equipment? How closely do we monitor for potential dangers?
A study by Kerr and associates (1991) substantiated these concerns. The study focused on endotracheal suctioning practices of nurses in a pediatric intensive care unit. The variables for the 24 patients, ages 2 weeks to 6 years, were as follows: oxygen delivery, glove technique, head position, type of suction, number of breaths and catheter insertions, secretion amount, and suctioning rationale. The reasons given for suctioning were as follows: q2 hour routine, congested lung sounds, mucus in tube, high ventilator pressure or alarm, and physician request. Practice differences included: catheter insertions (3-8 times), suction pressure application (3-13 seconds), and breath delivery (3-19). Despite the age range of the children, the study showed a striking variation in suctioning practices. Questions were raised concerning the large number of catheter insertions and breaths delivered and the potential dangers of current practice.
Appropriate use of the tracheotomy and endotracheal tubes can help patients avoid not only scarring, but also the reseeding of organisms into the lower airway from a colonized endotracheal tube. What improved techniques can nurses employ to prevent scarring and to minimize lower airway contamination, while maximizing oxygen saturation?
Giganti (1995) describes damage frequently done to children's airways from repeated intubation or inappropriate technique, reviewing procedure options that avoid tracheotomy, that decannulate, or that allow trach-dependent children to speak. But her focus is on trauma prevention, emphasizing correct tube selection, suctioning techniques, avoiding intubations when possible, and other safeguards.
Giganti emphasizes that careful assessment of each patient's suctioning needs is extremely important. The method used depends on the child's age, muscular and neurologic status, activity level, ability to cough, and the quantity and viscosity of secretions. Catheter diameter should be half that of the tracheal tube to minimize negative pressure that can cause atelectasis. The pressure should be limited to 60 to 100 mm Hg and in as little as a 5-second single pass. When suctioning premature infants, limit the Hg to 40 to 80 mm. Routine suctioning beyond the end of the endotracheal or tracheotomy tubes can damage the trachea and carina, especially by the "bumping off the carina" technique. The catheter should be withdrawn in a rotating motion to prevent adherence to tracheal tissue; suctioning should only be done during the withdrawal process. Finally, Giganti suggests that one always assess for hypoxia and heart rate changes during suctioning.
However, such meticulous techniques may not be enough. According to Hagler and Traver (1994), the use of a sterile technique does not rule out the possibility of organisms being repeatedly seeded into the lower airway from a colonized endotracheal tube. These tubes provide a surface for local bacteria to colonize and to form an adhesive polysaccharide glycocalyx layer. The glycocalyx layer in turn protects bacterial colonies from both natural and pharmacologic antibacterial agents. The effect of lower airway bacterial contamination is dependent on the immune status of the patient, bacterial virulence, and inoculum size.
It has been common practice for nurses and respiratory therapists to instill a bolus of normal saline into the endotracheal or tracheal tube prior to suctioning. This technique is now being questioned. It is believed that it may contribute to the problems of lower airway colonization and nosocomial pneumonia through repeated dislodgment of organisms from the tube's surface into the lower airway.
Hagler's research project was conducted to determine the extent to which normal saline irrigation and suction catheter insertion dislodge viable bacteria from the inner lumen of endotracheal tubes. The 10 patients in her study had been intubated for at least 48 hours. The process of suction catheter insertion and normal saline instillation was randomized, but both were performed on all endotracheal tubes. A 14F catheter was inserted through the universal adapter, and the entire length of the removed, vertical endotracheal tube was placed in a sterile specimen cup. A 5-cm length of the catheter was cut off into the cup. Suction was not applied. The remainder of the catheter was removed through the universal adapter end of the tube and discarded. A sterile specimen cup was held at the caudal end of the endotracheal tube to catch the flow of 5 mL of a prepackaged, newly opened single dose vial of sterile normal saline without additives. The entire amount was collected in the cup. After appropriate removal to the microbiology lab the specimens were plated.
The counts for dislodged viable bacteria were large enough to be reported clinically as 4+. These dislodged bacteria enter the lower airway repeatedly during frequent suctioning procedures. Since saline instillation is an optional step in the suctioning process, the risks and benefits should be evaluated for each patient. The major portion of saline instilled may not be recovered and may then travel to the lower airway along with the bacteria.
In another study, Ackerman (1993) focused on the use of a saline bolus prior to suctioning and its effect on oxygen saturation. Forty male patients, all over 40 years of age and in need of intensive care nursing and mechanical ventilation, were involved in the study. The patients were suctioned on a prn basis for 24 hours. A 5 mL saline bolus was given prior to every other suction procedure on each patient. Oximeters were used to determine oxygen saturation immediately before and after suctioning at 1 minute intervals for 5 minutes. The change scores for a saline and nonsaline suction episode were added together to determine the difference between a saline and nonsaline pair of suction episodes. The number indicated the mean change in oxygen saturation as a result of saline instillation for each patient. Then each patient's mean change scores were averaged to determine the group change in oxygen saturation as a result of saline instillation. Negative changes indicated that saline had an adverse effect on oxygen saturation; positive changes were beneficial.
At each 1 minute time period measured after suctioning when saline had been instilled, there was a negative effect on oxygen saturation. This negative effect increased at each interval. Since the purpose of suctioning is to clear the airway and improve gas exchange, the results of this study demonstrate that patients have better oxygenation after suctioning when a saline bolus is not used.
These studies focused on methods of suctioning and the positive and negative effects of saline boluses. It is necessary that the type and frequency of suctioning be determined on an individual basis using objective criteria. Diagnosis, medications in use, preventing airway trauma, and saline instillation policies and procedures are all to be taken into account prior to suctioning. Appropriate suctioning techniques performed by all nurses are of primary importance in order to return patients to their optimum level of physical health.
An internationally known writer, researcher, consultant, and lecturer in the field of pediatric nursing, Donna Wong, PhD, RN, PNP, CPN, FAAN, serves as a consultant for nurses and health care providers around the globe. She is an adjunct professor in the Department of Pediatrics at the University of Oklahoma College of Medicine-Tulsa; an adjunct professor at the University of Oklahoma College of Nursing; an adjunct professor and consultant at Oral Roberts University Anna Vaughn School of Nursing in Tulsa; and a nursing consultant at The Children's Hospital at Saint Francis and Texas Children's Hospital, Houston.
Ackerman MH: The effect of saline lavage prior to suctioning, Am J Crit Care 2(4):326-330, 1993.
Giganti AW: Lifesaving tubes, lifetime scars? MCN 20:192-197, 1995.
Hagler DA, Traver GA: Endotracheal saline and suction catheters: sources of lower airway contamination, Am J Crit Care 3(6):444-447, 1994.
Kerr M, Menzel L, Rudy E: (Abstract) Suctioning practices in the pediatric intensive care unit, Case Western Reserve University, Cleveland, OH, NTI Research Abstracts 20(3):300, 1991.