Intensive Care Med (1990) 16:95-99
IntensiveCare Medicine @ Springer-Verlag 1990
Effect of endotracheai suctioning on arterial blood gases in children E. Kerem, I. Yatsiv a n d K . J . G o i t e i n Pediatric Intensive Care Unit, Departments of Pediatrics and Pediatric Surgery, Hadassah University Hospital and Department of Pediatrics, Bikur Cholim Hospital, Jerusalem, Israel Received: 15 August 1988; accepted: 10 August 1989
Abstract. The occurrence o f hypoxia during endotracheal tube suctioning a n d its prevention was examined in 25 h e m o d y n a m i c a l l y stable and non-cyanosed pediatric patients. In each patient 4 suction and treatment protocols were studied: 1. pre- and post-suction arterial b l o o d gases (ABG) with no treatment (control). 2. A B G with pre-suction oxygenation. 3. A B G with presuction hyperinflation. 4. A B G with postsuction hyperinflation. With n o presuction treatment the PO2 and saturation fell significantly after suctioning f r o m control level o f 116.6+9.4 m m H g to 93 +9.3 m m H g post-suction and 97.2+0.4~ to 92.8+1.4070 ( p < 0 . 0 0 1 ) respectively. In 6 patients with low but adequate pre-suction PO2, hypoxic levels (PO2 < 6 0 m m H g ) were f o u n d post-suction. The significant fall in P O 2 was completely prevented by pre-suction oxygenation. Post-suction hyperinflation induced a rapid ret u r n o f the P O 2 to control levels. These results suggest t h a t severe hypoxia might occur during endotracheal suctioning and can be prevented by pre-oxygenation. We reco m m e n d 1 min oxygenation with FiO2 1.0 prior to suctioning procedures and intermittent hyperinflation with 100070 oxygen during repeated endotracheal suction passes to prevent hypoxia, especially in children in respiratory failure w h o already have low or borderline pre-suction P O 2.
Key words: Endotracheal suctioning gases -
Arterial b l o o d
Respiratory failure - H y p o x i a
Endotracheal tube (ETT) suctioning and p u l m o n a r y toilet are crucial in intubated patients t o maintain patent airway and ventilation. The interruption o f mechanical ventilation and oxygen supply by E T T suctioning (especially in patients w h o already have respiratory c o m p r o mises) might be harmful, causing cardiac arrhythmias a n d even death [ 1 - 9 ] . Physical d a m a g e to the tracheal m u c o s a might also be caused by the suction catheter with occurrence o f hemoptysis, b r o n c h o s p a s m and atelectasis [ 1 0 - 1 3 ] . In adults a n d in animal models several m e t h o d s
have been described to prevent or minimize the fall in PO2 during suctioning [ 1 4 - 2 8 ] . To the best o f o u r knowledge, no detailed and controlled study o f the effects o f suctioning o n arterial b l o o d gases (ABG) in the pediatric a g e group has b e e n previously reported [29]. There are n o clear-cut r e c o m m e n d a t i o n s for the optimal suctioning procedure in the pediatric literature and existing clinical guidelines are generalized and insufficient [30-31]. The present study investigated the effects o f suctioning o n A B G in children and the efficacy o f three therapeutic m e t h o d s to prevent the fall in P O 2 during and after E T T suctioning.
Patients and methods Twenty-five consecutive patients, admitted to a multidisciplinary Pediatric Intensive Care Unit (PICU), who required endotracheal intubation were included in this prospective study. Patients with cyanotic heart disease and patients who required an FiO2 greater than 0.6 were excluded from the study. Data was collected over a period when the patients were hemodynamically stable. All were receiving mechanical ventilation. Intermittent mandatory ventilation (IMV), FiO2, peak inspiratory pressure (PIP) and PEEP were all stable during the study period. All patients had an indwelling arterial catheter through which blood samples were drawn. Suction technique. The largest suction catheter, chosen according to
ETT size, was rapidly advanced to maximum length. Standard wall negative pressure was then applied and the catheter rapidly withdrawn. The whole procedure was stopwatch timed to last 8 s. Catheter size, negative pressure applied and time of suctioning were identical in all procedures, in the same patient, to prevent inter-test bias. Treatment protocol (a) Preoxygenation - The ventilator was set at FiO2 1.0 for 1 min prior to suctioning. All other ventilator settings remained unchanged (IMV, PEEP, PIP). (b) Hyperinflation - Five breaths over 10 s were administered at approximately twice the patient's tidal volume. The FiO2 was maintained at the pretest level. Blood sampling. All samples for blood gas analysis were rapidly drawn
from the indwelling arterial catheter. The samples were immediately put on ice and refrigerated until analysis at the end of each set of tests (see experimental protocol).
E. Kerem et al.: Effect of endotracheal suctioning
96
Experimental protocol
Data analysis
I.
Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS-X). Between group differences were analyzed by planned comparisons using Wilcoxon test for paired observations.
Control with no treatment: A. ABG taken at pre-test ventilator setting (control). B. Suction performed (as above). C. ABG drawn immediately at end of suctioning. D. Patient returned to ventilator at pre-test setting. E. ABG drawn at 5 and 10 min post suctioning. II. Preoxygenation: A. ABG drawn at pre-test ventilator setting (control). B. FiO 2 1.0 administered for 1 rain. C. ABG drawn prior to suctioning. D. Suction performed. E. ABG drawn. F. -Patient returned to ventilator at pre-test setting. G. ABG drawn at 5 and 10 min. III. Hyperinflation presuction: A. Pre-test ABG (control). B. Hyperinflation (as above). C. ABG drawn. D. Suction performed. E. ABG drawn. F. Patient returned to ventilator at pre-test setting. G. ABG drawn at 5 and 10 min. IV. Hyperinflation postsuction: A. Pre-test ABG (control). B. Suction performed. C. Hyperinflation (as above). D. ABG drawn. E. Patient returned to ventilator at pre-test setting. E ABG drawn at 5 and 10 min. Each test was consecutively performed on all patients, the sequence of tests randomly varied to insure lack of effect of one test on the others. At least 30 min elapsed between tests.
Results
N i n e t y s e v e n studies w e r e p e r f o r m e d o n 25 c o n s e c u t i v e a d m i s s i o n s t o a m u l t i d i s c i p l i n a r y P I C U . T h e r e were 15 m a l e s a n d 10 f e m a l e s . T h e y o u n g e s t p a t i e n t was 1 das o l d a n d t h e o l d e s t 10 years old. M e d i a n a g e was 197 days. E l e v e n p a t i e n t s h a d n o n - c y a n o t i c h e a r t disease, 7 c e n t r a l n e r v o u s s y s t e m d i s e a s e s ( h e a d t r a u m a , i n f e c t i o n ) , 5 respiratory failure (pneumonia, myopathy) and 2 had post-operative sepsis. T h e c h a n g e s in b l o o d gases w i t h d i f f e r e n t t r e a t m e n t m o d a l i t i e s are s u m m a r i z e d in Table 1. M e a n c o n t r o l P O 2 was l 1 6 . 6 + _ 9 . 4 m m H g ( m e a n + S t a n d a r d e r r o r o f m e a n [ S E M ] ) . A h i g h l y s i g n i f i c a n t fall in P O 2 t o 9 3 . 0 + 9 . 3 m m H g p o s t s u c t i o n ( / 9 < 0 . 0 0 1 ) was o b s e r v e d w h e n s u c t i o n was p e r f o r m e d w i t h n o p r e t r e a t m e n t . I n 6 (24~ patients, with an average pre-suction P O 2 o f 71.0 m m H g , h y p o x i a ( P O 2 < 60 m m H g ) o c c u r r e d d u r i n g s u c t i o n i n g ( m e a n = 53.4 m m H g ) . P O 2 r e t u r n e d to c o n t r o l levels 5 r a i n p o s t s u c t i o n . S a t u r a t i o n fell signific a n t l y f r o m 97.2 +0.4070 t o 92.8 + 1.4070 (p < 0.001) a n d ret u r n e d t o c o n t r o l level a f t e r 5 rain. P C O 2 d i d n o t c h a n g e significantly.
Table 1. Changes in blood gases with different treatment modalities
Treatment
Control
Pre-suction
Post-suction
5 min
10 rain
214.2-+ 14.1 p
IntensiveCare Medicine @ Springer-Verlag 1990
Effect of endotracheai suctioning on arterial blood gases in children E. Kerem, I. Yatsiv a n d K . J . G o i t e i n Pediatric Intensive Care Unit, Departments of Pediatrics and Pediatric Surgery, Hadassah University Hospital and Department of Pediatrics, Bikur Cholim Hospital, Jerusalem, Israel Received: 15 August 1988; accepted: 10 August 1989
Abstract. The occurrence o f hypoxia during endotracheal tube suctioning a n d its prevention was examined in 25 h e m o d y n a m i c a l l y stable and non-cyanosed pediatric patients. In each patient 4 suction and treatment protocols were studied: 1. pre- and post-suction arterial b l o o d gases (ABG) with no treatment (control). 2. A B G with pre-suction oxygenation. 3. A B G with presuction hyperinflation. 4. A B G with postsuction hyperinflation. With n o presuction treatment the PO2 and saturation fell significantly after suctioning f r o m control level o f 116.6+9.4 m m H g to 93 +9.3 m m H g post-suction and 97.2+0.4~ to 92.8+1.4070 ( p < 0 . 0 0 1 ) respectively. In 6 patients with low but adequate pre-suction PO2, hypoxic levels (PO2 < 6 0 m m H g ) were f o u n d post-suction. The significant fall in P O 2 was completely prevented by pre-suction oxygenation. Post-suction hyperinflation induced a rapid ret u r n o f the P O 2 to control levels. These results suggest t h a t severe hypoxia might occur during endotracheal suctioning and can be prevented by pre-oxygenation. We reco m m e n d 1 min oxygenation with FiO2 1.0 prior to suctioning procedures and intermittent hyperinflation with 100070 oxygen during repeated endotracheal suction passes to prevent hypoxia, especially in children in respiratory failure w h o already have low or borderline pre-suction P O 2.
Key words: Endotracheal suctioning gases -
Arterial b l o o d
Respiratory failure - H y p o x i a
Endotracheal tube (ETT) suctioning and p u l m o n a r y toilet are crucial in intubated patients t o maintain patent airway and ventilation. The interruption o f mechanical ventilation and oxygen supply by E T T suctioning (especially in patients w h o already have respiratory c o m p r o mises) might be harmful, causing cardiac arrhythmias a n d even death [ 1 - 9 ] . Physical d a m a g e to the tracheal m u c o s a might also be caused by the suction catheter with occurrence o f hemoptysis, b r o n c h o s p a s m and atelectasis [ 1 0 - 1 3 ] . In adults a n d in animal models several m e t h o d s
have been described to prevent or minimize the fall in PO2 during suctioning [ 1 4 - 2 8 ] . To the best o f o u r knowledge, no detailed and controlled study o f the effects o f suctioning o n arterial b l o o d gases (ABG) in the pediatric a g e group has b e e n previously reported [29]. There are n o clear-cut r e c o m m e n d a t i o n s for the optimal suctioning procedure in the pediatric literature and existing clinical guidelines are generalized and insufficient [30-31]. The present study investigated the effects o f suctioning o n A B G in children and the efficacy o f three therapeutic m e t h o d s to prevent the fall in P O 2 during and after E T T suctioning.
Patients and methods Twenty-five consecutive patients, admitted to a multidisciplinary Pediatric Intensive Care Unit (PICU), who required endotracheal intubation were included in this prospective study. Patients with cyanotic heart disease and patients who required an FiO2 greater than 0.6 were excluded from the study. Data was collected over a period when the patients were hemodynamically stable. All were receiving mechanical ventilation. Intermittent mandatory ventilation (IMV), FiO2, peak inspiratory pressure (PIP) and PEEP were all stable during the study period. All patients had an indwelling arterial catheter through which blood samples were drawn. Suction technique. The largest suction catheter, chosen according to
ETT size, was rapidly advanced to maximum length. Standard wall negative pressure was then applied and the catheter rapidly withdrawn. The whole procedure was stopwatch timed to last 8 s. Catheter size, negative pressure applied and time of suctioning were identical in all procedures, in the same patient, to prevent inter-test bias. Treatment protocol (a) Preoxygenation - The ventilator was set at FiO2 1.0 for 1 min prior to suctioning. All other ventilator settings remained unchanged (IMV, PEEP, PIP). (b) Hyperinflation - Five breaths over 10 s were administered at approximately twice the patient's tidal volume. The FiO2 was maintained at the pretest level. Blood sampling. All samples for blood gas analysis were rapidly drawn
from the indwelling arterial catheter. The samples were immediately put on ice and refrigerated until analysis at the end of each set of tests (see experimental protocol).
E. Kerem et al.: Effect of endotracheal suctioning
96
Experimental protocol
Data analysis
I.
Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS-X). Between group differences were analyzed by planned comparisons using Wilcoxon test for paired observations.
Control with no treatment: A. ABG taken at pre-test ventilator setting (control). B. Suction performed (as above). C. ABG drawn immediately at end of suctioning. D. Patient returned to ventilator at pre-test setting. E. ABG drawn at 5 and 10 min post suctioning. II. Preoxygenation: A. ABG drawn at pre-test ventilator setting (control). B. FiO 2 1.0 administered for 1 rain. C. ABG drawn prior to suctioning. D. Suction performed. E. ABG drawn. F. -Patient returned to ventilator at pre-test setting. G. ABG drawn at 5 and 10 min. III. Hyperinflation presuction: A. Pre-test ABG (control). B. Hyperinflation (as above). C. ABG drawn. D. Suction performed. E. ABG drawn. F. Patient returned to ventilator at pre-test setting. G. ABG drawn at 5 and 10 min. IV. Hyperinflation postsuction: A. Pre-test ABG (control). B. Suction performed. C. Hyperinflation (as above). D. ABG drawn. E. Patient returned to ventilator at pre-test setting. E ABG drawn at 5 and 10 min. Each test was consecutively performed on all patients, the sequence of tests randomly varied to insure lack of effect of one test on the others. At least 30 min elapsed between tests.
Results
N i n e t y s e v e n studies w e r e p e r f o r m e d o n 25 c o n s e c u t i v e a d m i s s i o n s t o a m u l t i d i s c i p l i n a r y P I C U . T h e r e were 15 m a l e s a n d 10 f e m a l e s . T h e y o u n g e s t p a t i e n t was 1 das o l d a n d t h e o l d e s t 10 years old. M e d i a n a g e was 197 days. E l e v e n p a t i e n t s h a d n o n - c y a n o t i c h e a r t disease, 7 c e n t r a l n e r v o u s s y s t e m d i s e a s e s ( h e a d t r a u m a , i n f e c t i o n ) , 5 respiratory failure (pneumonia, myopathy) and 2 had post-operative sepsis. T h e c h a n g e s in b l o o d gases w i t h d i f f e r e n t t r e a t m e n t m o d a l i t i e s are s u m m a r i z e d in Table 1. M e a n c o n t r o l P O 2 was l 1 6 . 6 + _ 9 . 4 m m H g ( m e a n + S t a n d a r d e r r o r o f m e a n [ S E M ] ) . A h i g h l y s i g n i f i c a n t fall in P O 2 t o 9 3 . 0 + 9 . 3 m m H g p o s t s u c t i o n ( / 9 < 0 . 0 0 1 ) was o b s e r v e d w h e n s u c t i o n was p e r f o r m e d w i t h n o p r e t r e a t m e n t . I n 6 (24~ patients, with an average pre-suction P O 2 o f 71.0 m m H g , h y p o x i a ( P O 2 < 60 m m H g ) o c c u r r e d d u r i n g s u c t i o n i n g ( m e a n = 53.4 m m H g ) . P O 2 r e t u r n e d to c o n t r o l levels 5 r a i n p o s t s u c t i o n . S a t u r a t i o n fell signific a n t l y f r o m 97.2 +0.4070 t o 92.8 + 1.4070 (p < 0.001) a n d ret u r n e d t o c o n t r o l level a f t e r 5 rain. P C O 2 d i d n o t c h a n g e significantly.
Table 1. Changes in blood gases with different treatment modalities
Treatment
Control
Pre-suction
Post-suction
5 min
10 rain
214.2-+ 14.1 p
