No evidence from trials about the optimum depth for catheter insertion when suctioning clear the endotracheal tube in babies in neonatal intensive care
Babies in neonatal intensive care often need mechanical ventilation to assist breathing. This involves inserting an endotracheal tube (ETT) down the baby's windpipe so that a machine ventilator can help the baby breathe. Lung secretions can build up in the tube and cause blockages. Buildup is minimized by suctioning the ETT clear with a catheter (small tube). One of the variations of technique possible for suctioning is depth of catheter insertion into the ETT. However, the review found no trials to show what depth of insertion of catheter into the endotracheal tube gains optimal clearance without damaging the baby's lungs.
The presence of the endotracheal tube causes soft tissue irritation and increased secretions due to suppression of normal ciliary action. In addition, the infant is unable to cough (Sturges 1979), which reduces the ability to clear secretions. The aim of endotracheal suctioning is to reduce the problems resulting from a build-up of secretions and, therefore, possible tube obstruction. Documented complications associated with endotracheal suctioning include hypoxaemia, bradycardia, tachycardia, atelectasis, pneumonia, fluctuations in blood pressure and intracranial pressure, localised trauma to the airway, sepsis, tube blockage, and tube dislodgement (Boothroyd 1996; Simbruner 1981; Gunderson 1986; Brodsky 1987; Durand 1989; Shorten 1991).
Protocols for maintaining patency of the endotracheal tube vary widely among institutions and are not, in general, based on sound evidence (Tolles 1990; Copnell 1995). Potentially harmful suctioning techniques such as frequent and deep suctioning, head turning, and multiple catheter passes have been questioned (Wrightson 1999). However, much of the practice of suctioning endotracheal tubes appears to be based on ritual rather than a physiological rationale or reliable evidence. Endotracheal tube suctioning remains a routine practice in the neonatal intensive care unit (Cameron 2000) with different practices across NICU's. Therefore, it is important that methods of suctioning the endotracheal tube that minimise complications are identified and implemented into practice.
Concern about the inadequate removal of secretions and subsequent tube blockage has increased the practice of deep suctioning. Although Darlow 1997 in a comparative study found that the removal of secretions using a dry shallow technique was adequate for obtaining samples of mucous for research, some research had shown that deep suction into the bronchial tree increases the mucous obtained on suction (Bailey 1988). Trauma to the lower airways may result from deep suctioning due to the suction catheter being passed into the airway beyond the tip of the endotracheal tube (Miller 1981; Brodsky 1987; Bailey 1988) and from repeated insult from suction catheters (Grylack 1984). Diligent attention to the length of the suction catheter in relation to the endotracheal tube may prevent this trauma. It has been speculated that bradycardia during endotracheal suctioning results from a vagal reflex initiated by stimulation of the airway mucosa that occurs when the catheter is passed beyond the tip of the endotracheal tube. Therefore, some authors have recommended the catheter be passed no farther than the tip of the ETT (Bailey 1988; Runton 1992; Harling 2000) and have provided guidelines for the length of the catheter to be inserted based on the size of the tube.
Subgroup analyses are planned on the basis of endotracheal tube size (with five subgroups ranging from 2mm to 4mm) and the duration of tube placement (with two subgroups, less than or equal to 48 hours or greater than 48 hours).
Primary
1. Tube removal (for suspected or actual blockage of the endotracheal tube)
2. Volume and consistency of secretions removed during suctioning procedure
(mucous plugs, tenacious, minimal, copious, thin)
3. Tracheal or bronchial damage (ulceration, inflammation and/or ciliary
damage)
Secondary
4. Level of oxygenation, absolute or percentage change after suctioning
(measured by transcutaneous oxygenation, saturation or arterial blood gas).
5. Heart rate, absolute or percentage change after suctioning (measured
on a cardio-respiratory monitor)
6. Atelectasis (lung collapse on chest x-ray)
7. Air leak (pneumothorax on chest x-ray)
To measure the effect of the different methods of suctioning the relative risk (RR), risk difference (RD), number needed to treat (NNT), or number needed to harm (NNH) and 95% confidence intervals (CI) were to be calculated for bivariate outcomes. The weighted mean difference (WMD) and its 95% CI was to be calculated for continuous outcomes. The fixed effect model was to be used in the meta-analysis if there was no heterogeneity among studies. Subgroup analyses were to be performed as proposed if data permitted.
No eligible studies comparing deep with shallow suction were found that met the criteria for inclusion in this review.
No studies were found that met the criteria for inclusion in this review
No studies were found that met the criteria for inclusion in this review
Research describing the potential negative effects of deep suctioning has been reported dating back to the 1960s (Thambiran 1966). Insertion of suction catheters to the end of the endo-tracheal tube has been recommended based on findings from electron microscopy in young rabbits where there was an increase in the area of tracheal necrosis and inflammation when deep suctioning was performed (Bailey 1988). A study comparing uncontrolled deep suctioning to controlled shallow suctioning in low birth weight infants suggested there was more severe tracheal pathology at autopsy in the infants who received deep suctioning (Brodsky 1987). However, these findings were not statistically significant, and this study used historical controls with several confounding factors. In a series of case reports where granulation tissue in the bronchi of premature infants was identified, the authors postulated that these findings were a response to repeated mechanical trauma of endo-tracheal tube suctioning (Miller 1981). The recommendations resulting from all of these findings were for modifications to the suction procedure to avoid the catheter tip extending beyond the tip of the endo-tracheal tube (Bailey 1988; Brodsky 1987; Miller 1981). Despite these recommendations from the 1980s the practice of deep suctioning continues in some NICU's (Tolles 1990; Copnell 1995). This may be a deliberate practice due to the belief that deep suctioning works better at removing secretions and helps maintain tube patency. However, we could not find any evidence from randomised trials to support or refute this practice.
The practice of suctioning the endo-tracheal tube of ventilated neonates and infants continues without adequate evidence on the various techniques used. There have been many protocols and guidelines published to assist caregivers in determining the most appropriate method for suctioning endo-tracheal tubes in neonates (Hodge 1991; Runton 1992; Knox, 1993; Young 1995; Wrightson 1999; Pollard 2001). However, surveys from practice indicate that protocols vary widely and are not, in general, based on sound evidence (Tolles 1990; Copnell 1995).
None
Bailey C, Kattwinkel J, Teja K, Buckley T. Shallow versus deep endotracheal suctioning in young rabbits: pathologic effects on the tracheobronchial wall. Pediatrics 1988;82:746-751.
Boothroyd AE, Murthey BV, Darbyshire A, Petros AJ. Endotracheal suctioning causes right upper lobe collapse in intubated children. Acta Paediatr 1996;85:1422-1425.
Brodsky L, Reidy M, Stanievich JF. The effects of suctioning techniques on the distal mucosa in intubated low birth weight infants. Int J Pediatr Otorhinolaryngol 1987;14:1-4.
Cameron J, Haines J. Management of Respiratory Disorders. In: Boxwell G, editor(s). Neonatal Intensive Care Nursing. London: Routledge, 2000:96-124.
Copnell B, Fergusson D. Endotracheal suctioning: time-worn ritual or timely intervention? Am J Crit Care 1995;4:100-105.
Darlow BA, Sluis KB, Inder TE, Winterbourn CC. Endotracheal suctioning of the neonate: comparison of two methods as a source of mucous material for research. Pediatr Pulmonol 1997;23:217-221.
Durand M, Sangha B, Cabal LA, Hoppenbrouwers T, Hodgman JE. Cardiopulmonary and intracranial pressure changes related to endotracheal suctioning in preterm infants. Crit Care Med 1989;17:506-510.
Grylack LJ, Anderson KD. Diagnosis and treatment of traumatic granuloma in tracheobronchial tree of newborn with history of chronic intubation. J Pediatr Surg 1984;19:200-201.
Gunderson LP, McPhee AJ, Donovan EF. Partially ventilated endotracheal suction. Use in newborns with respiratory distress syndrome. Am J Dis Child 1986;140:462-465.
Harling E. Diagnostic and Therapeutic Procedures. In: Boxwell G, editor(s). Neonatal Intensive Care Nursing. London: Routledge, 2000:285-314.
Hodge D. Endotracheal suctioning and the infant: a nursing care protocol to decrease complications. Neonatal Netw 1991;9:7-13.
Knox, AM. Performing endotracheal suction on children: a literature review and implications for nursing practice. Intensive Crit Care Nurs 1993;9:48-54.
Miller KE, Edwards DK, Hilton S, Collins D, Lynch F, Williams R. Acquired lobar emphysema in premature infants with bronchopulmonary dysplasia: An iatrogenic disease? Radiology 1981;138:589-592.
Pollard C. Endotracheal suction in the infant with an artificial airway. Nurs Crit Care 2001;6:76-82.
Runton N. Suctioning artificial airways in children: appropriate technique. Pediatr Nurs 1992;18:115-118.
Shorten DR, Byrne PJ, Jones RL. Infant responses to saline instillations and endotracheal suctioning. JOGNN 1991;20:464-469.
Simbruner G, Coradello H, Foder M, Havelec L, Lubec G, Pollak A. Effect of tracheal suction on oxygenation, circulation, and lung mechanics in newborn infants. Arch Dis Child 1981;56:326-330.
Sturges JM. Mucous secretions in the respiratory tract. Pediatr Clin North Am 1979;26:481-501.
Thambrian AK, Ripley SH. Observations on tracheal suction: an experimental study. Br J Anaesth 1966;38:459.
Tolles CL, Stone K. National survey of neonatal endotracheal suctioning procedures. Neonatal Netw 1990;9:7-14.
Wrightson DD. Suctioning smarter: answers to eight common questions about endotracheal suctioning in neonates. Neonatal Netw 1999;18:51-55.
Young J. To help or hinder: endotracheal suction and the intubated neonate. J Neonat Nurs 1995;1:23-28.
Ms Lynne Waterworth, RN
Registered Nurse
NSW Newborn and Pregnancy Emergency Transport Service
Western Sydney Area Health Service
AUSTRALIA
This review is published as a Cochrane review in The
Cochrane Library 2003, Issue 3, 2003 (see www.CochraneLibrary.net for information).
Cochrane reviews are regularly updated as new evidence emerges and
in response to comments and criticisms, and The Cochrane Library should be
consulted for the most recent version of the Review. |