R E S E A R C H A R T I C L E T h e S a f e t y o f In d u c e d S p u t u m C o l l e c t io n in In f a n t s u n d e r t h e a g e o f 1 8 m o n t h s . A B S T R A C T : The technique o f sputum induction im proves the y ie ld o f m icro bio logical investigations f o r organism s such as M yco b a cteriu m tuberculosis a n d P n eum ocystis carinii. The aim o f the study w as to d eterm in e the safety o f this m eth o d in children u nd er the age o f 18 m onths. H ea rt rate a n d oxygen sa tu ra tio n w ere m o n ito re d d u rin g the p ro c e d u r e a n d c o m p a re d w ith m easurem ents o btained during the conven tio nal m eth o d o f sputum collection in the sam e patients. Patients were also observed f o r other p ossible side effects. F o rty sam ples o f sputa were o b tain ed fr o m 20 patients. N o clinica l differences in h e a rt rate a n d oxygen saturation w ere fo u n d betw een the tw o m ethods. Overall, oxygen saturation m easurem ents below 80% were recorded in three p atients. Increa sed coughing a n d m ild ep istaxis d id o ccur m ore fr e q u e n tly during the spu tum induction m ethod. It w as co nclud ed th a t sp utu m induction is safe in sm all children, b u t a larger sam ple size needs to be studied. K E Y W O R D S: S P U T U M IN D U C T IO N , SAFETY, S ID E EFF E C TS, O X Y G E N SATU RATIO N , C H IL D R E N VAN W YK H, BSc Physiotherapy JACQUEMARD R 2; JOUBERT G 3 1 Department of Physiotherapy Universitas H ospital, Bloemfontein, Department of Paedia trics a n d Child Health, University of the O ra n g e Free State, Bloemfontein Department of Biostatistics, University of the O r a n g e Free State, Bloemfontein INTRODUCTION The usefulness o f induced sputa for the detection o f Mycobacterium tuberculosis and Pneumocystis carinii in adults and children has been dem onstrated in a num ber o f studies (Shata et al, 1996; Z ar et al, 2000; Valerie et al, 1989; Ognibene et al, 1989). Sputum induction was found to be better than gastric lavage for isolation o f m ycobacterium tuberculosis in infants and young chil dren. A lthough continuous m onitoring o f arterial oxygen saturation during sputum induction could not be done, sputum induction was reported to be well tolerated, even in children who w ere hypoxic or w ho had A cquired Im m une Deficiency Syndrom e (AIDS) (Z ar et al, 2000). The method entails the collection o f sputum after nebulisation with salbutamol, nebulisation with hyper tonic saline and chest p hysiotherap y consecutively. Side-effects reported in the literature include occasional nausea, vom iting (Shata et al, 1996; Ognibene et al, 1989), and dyspnoea (M iller et al, CORRESPONDENCE TO: H van Wyk PO Box 522, Parys 9585 Tel: (056) 811-3676 (h), (056) 811-2700 (w), Cell: 082 876-7163 1991). M ild epistaxis and wheezing can occur in infants (M iller et al, 1990). T hese studies were done on adults and children three years and older, and not on children under the age o f 18 m onths, in w hich case the therapist usu ally needs su c tio n in g to obtain sputa sam ples. No com parison between induced and conventional m ethods o f obtaining sputa could be found in the literature. Oxygen saturation and pulse were not m onitored in these studies, and no com parison regarding side-effects had been done. The aim o f this study was to deter m ine the safety o f sputum induction com pared to the conventional method of obtaining sputum specim en in paediatric patients under the age o f 18 months, as induced sputa sam ples (used to detect specific organisms) are often required by doctors in the hospital setting. No reference could be found in the literature about the freq u en cy o f u tilisa tio n o f sputum induction. METHODS T he pro tocol w as ap p ro v ed by the Ethics C om m ittee o f the Faculty o f Health Sciences, UFS (ETOVS 95/99). W ritten consent was obtained from the patient’s parents or guardian. A com parative study had been done. Two groups o f sam ples were collected, and the sam ple served as its own control. Paired t-tests and 95% confidence inter vals for differences in means were used for statistical analyses. The sam ples w ere o b tained from twenty consecutive patients under the age o f 18 m onths, ad m itted to the paediatric w ard o f U niversitas Hospital, Bloemfontein, South Africa, with clinical signs o f low er airw ay infection, during the period May to D ecem ber 1999. Each patient was exam ined and diagnosed by the same paediatrician. Exclusion crite ria fo r the study w ere patients with severe pneum onia adm itted to the Intensive Care U nits and patients with a low oxygen saturation (80%) or a high pulse rate (above 160 beats/m in). A qualified physiotherapist collected one induced, and one conventional specim en o f sputum from each patient as soon as possible after adm ission. The sputa were obtained on the same day, by means o f one m ethod in the m orning and the second m ethod in the afternoon. T he order o f the methods used was alternated daily. As precaution the procedure was perform ed at least tw o hours after the last feeding, to reduce oral contam ination and the risk o f vom iting. C are was taken to prevent a prolonged oxygen saturation level o f below 90%. Heart rate was also checked to no rm alise w ithin a few seconds after rising above the normal range. If norm alisation w ould not occur rapidly, 16 SA J o u r n a l o f Ph ysioth era p y 2001 V o l 57 No 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Table 1: O xygen saturation INDUCED N =20 Variable Mean Std Dev Minimum Maximum Median Prior to procedure 9 3 5 .1 8 3 1 0 0 9 3 . 0 After Salbutamol inhalation 9 6 . 2 5 .2 8 2 1 0 0 9 8 . 0 After Saline inhalation 9 6 .1 4 . 4 8 4 1 0 0 9 7 . 5 Minimum during procedure 8 8 . 5 4 . 7 7 6 9 7 8 8 . 5 After procedure 91 3 .8 8 3 9 7 9 0 . 0 CO N VENTIO N AL N =20 Prior to procedure 9 2 4 . 7 8 5 1 0 0 9 1 . 0 Minimum during procedure 8 7 . 3 6 .3 7 2 9 6 8 9 . 0 After procedure 8 8 . 6 6 7 2 9 6 8 8 . 0 the procedure was to be stopped and the patien t stabilised. T he p atient would, however, remain in the statistical analysis at the end o f the study. The norm al value o f oxygen saturation is above 90% . An oxygen saturation of 80% to 90% constitudes mild hypoxia with no danger for the patient. Norm al heart rate ranges from 100 to 160 bpm for this age group. Pulse and saturation readings w ere taken using a pulse- oxim eter (O hm eda Biox 3740) prior to the pro ced u re, after the salbutam o l inhalation, after the saline inhalation, directly after the suctioning, as well as 30 seconds after suctioning. The lowest oxygen saturation and highest pulse rate during each com ponent o f the proce dures (including chest physiotherapy) w ere recorded. F or induced sputum pro duction the patient was nebulised with 5m g Salbutam ol via je t nebuliser and face m ask (or head-box) for 10 m inutes, followed by 5ml o f hypertonic saline (5% ) over 10 m inutes. The acorn nebu liser was connected to a flow m eter (flow rate 4L/m in) at the oxygen point in the room. Follow ing nebulisation, chest physiotherapy w hich included percus sion and postural drainage (localised for each child’s specific condition), vibration, shaking as well as repeated stimulation o f the cough reflex as necessary was applied. No percussion (only postural drainage) would have been used on a patient suspected o f having TB, but none o f the patients included in the study presented w ith TB. The duration o f chest physiotherapy was about 10 m inutes for each patient. Oropharyngeal or naso p h ary n g eal su c tio n in g w as perform ed with a sterile mucus extractor im m ediately after productive coughing. The duration o f the w hole procedure was about 35 minutes. The conventional sputum was obtained by suctioning after the application of chest physiotherapy only. Physiotherapy and suctioning w ere perform ed in the sam e way as for the induced method. The duration o f the whole procedure was 15 m inutes for the conventional method. The patient was observed for possible a d v erse effects (ep istax is, vom iting, coughing) during the procedure and for 30 m inutes following the procedure. T he same physiotherapist obtained all the specim ens. A lterations in chest phy siotherapy techniques (postural drainage po sitio n s and percu ssio n localised for each child’s specific condition) were applied in the same way for induced and conventional sputa on a specific patient. The same saturation m onitor was used throughout the project. RESULTS Twenty patients were included in the study, 9 boys, and 11 girls. The ages ranged from three weeks to 16 m onths o f age with a median age o f seven months. No patient dropped out o f the study because o f prolonged decreased oxygen saturation o f increased heart rate during the procedures. M easurem ents o f oxygen saturation and heart rate before, during, and after the procedures are sum m arised in Tables 1 and 2. There was no difference in the mean values o f the lowest saturation level during the procedure irrespective o f the m ethod (p-value 0.184) or in the mean values o f the satu ratio n before the procedure (p-value 0.218). After the procedure the saturation level with the induced m ethod was higher than with the conventional method (p-value 0.028). The 95% confidence interval for this difference is 0.3 to 3.9 which is not considered clinically m eaningful. D uring the collection o f three o f the 40 specim ens, the oxygen saturation d ro p p ed to below 80% (76% , 72% and 73%). The oxygen saturation level dropped to 76% with percussion in one o f the subjects w hilst using the conven tional m ethod and in the sam e subject to 72% (also with percussion) during the induction method. In this child, who was three m onths old, the oxygen saturation level returned to above 80% within a few seconds in both methods. However, the saturation level returned to baseline (oxygen saturation level prior to pro cedure) w ithin one m inute after the p ro ced u re w hilst using the induced m ethod and one minute to baseline with the conventional method. In the second child, w ho was seven m onths old, the oxygen saturation level dropped to 73% with percussion during the conventional method. This low level o f saturation lasted only a few seconds before return ing to above 80%, and norm alisation to baseline took 4 m inutes. This child was SA J o u r n a l o f Physiotherapy 2001 V o l 57 No 3 17 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Table 2: Heart rate INDUCED N =20 Variable Mean Std Dev Minimum Maximum Median Prior to procedure 1 4 7 .6 1 4 .6 1 1 0 1 7 0 1 4 7 . 5 After Salbutamol inhalation 1 4 7 . 8 1 7 .2 1 2 0 1 7 8 1 4 6 . 5 After Saline inhalation 1 5 0 1 6 .9 1 1 6 1 8 0 1 4 8 . 0 Minimum during procedure 1 6 4 . 5 1 4 .1 1 4 0 1 8 5 1 7 0 . 0 After procedure 1 5 3 .1 1 9 1 2 5 1 8 0 1 6 0 . 0 CO N VENTIO N AL N =20 Prior to procedure 1 4 3 . 5 1 7 1 1 2 1 7 8 1 4 7 . 5 Minimum during procedure 1 5 6 .1 1 6 .5 1 3 0 1 8 9 1 6 0 . 0 After procedure 1 5 2 . 3 1 9 .9 101 1 8 2 1 5 7 . 0 Lowest Saturation Induced n=20 Conventional n=20 Percussion 6 1 3 Suction 1 0 5 Other 4 2 Table 3: Stage of lowest oxygen saturation crying, w hich could have an effect on the oxygen saturation level. T hese three children had saturation levels o f less than 90% before the procedure. In total, nine children (13 specim ens) had oxygen saturation levels below 90% prior to the procedure. D uring both the procedures, oxygen saturation rem ained above 80% in 10 o f these 13 specim ens. The stage o f the procedure during w hich the lo w est satu ra tio n level occurred was also recorded (see Table 3). D uring the induction pro cedure, the lowest saturation level occurred during suction in 10 o f the 20 patients in the sam ple, during percussion in six, and at other stages in four subjects. Using the conventional procedure, the lowest saturation level occurred during percus sion in 13 o f the 20 patients in the sam ple, during suction in five o f 20, and at other stages in two. T h ere w as no d ifferen ce in the m ean values o f the heart rate before (p-value = 0.126) or after the procedure (p-value = 0.865) irrespective o f the m ethod. The m ean peak heart rate during the procedure was slightly higher (p-value = 0.040) during the induced sputum procedure (165 beats/m in) as com pared to the conventional procedure (156 beats/min). The 95% confidence interval for this difference is 0.6 to 13.4. The highest recorded heart rate was 189/m in, and o ccu rred d u rin g the conventional procedure. No prolonged tachycardia occurred in any o f these cases. N one o f the children developed a bradycardia during the procedure. Saline inhalation caused increased coughing in twelve patients, but only m ild cou g h in g w ith less th an five coughs per episode. T he oxygen satura tion was not influenced dram atically by this coughing. Increased coughing was also caused by chest physiotherapy in b oth the in d u ced and co n v e n tio n al m ethods, but no severe coughing was noted. M ild epistaxis occurred in seven o f the 20 cases during the induced sputum m ethod and in four o f the 20 cases during the conventional m ethod, after suctioning. The sputa did not contain any blood. M ild vom iting occurred in one patient ju st after suctioning during the induction method. DISCUSSION N o clinically m eaningful differences in oxy g en satu ra tio n m easu rem en ts w ere found betw een the induced and the conventional m ethods o f obtaining sputum . O f note however, w as that the lowest saturation m easurem ent occurred m ore frequently with percussion during the c o n v e n tio n al m ethod than w ith the induced m ethod. It thus seem s that percussion is tolerated better during the induced sputum m ethod. A possib le explanation could be that bronchodila- tation after nebulisation with salbutamol increases the tolerance for percussion. T he mean peak heart rate was slightly h ig h e r d u rin g the sp u tu m in duction m ethod (165 beats/m in) than during the conventional m ethod (156 beats/m in). This is probably due to the nebulisation w ith salbutam ol. T hough statistically significant, this difference is too small to be o f clinical importance. A dverse effects such as increased coughing, mild epistaxis due to suctioning and vom iting do seem to occur m ore frequently during the induced sputum technique. T hese side effects however, are mild. T he vom iting in one o f the patients was probably triggered by the su c tio n in g and n o t by the spu tum induction. In view o f the possibility o f vom iting during suctioning, it is im por tant to w ait at least two hours after the last feed before collecting sputum. B radycardia caused by vagal stim ula tion could be expected during suctioning o f the pharynx, especially in the younger patients. This did not occur in any o f the patients. T he risk for bradycardia could increase if suctioning was prolonged. B ecause o f this theoretical risk o f brady- 18 SA J o u r n a l o f P hysiothera py 2001 V o l 57 No 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) cardia and the fact that the saturation levels dropped below 80% in three of the 40 sample collections, it seems wise to m onitor pulse and oxygen saturation during sputum collection in small chil dren, during both the conventional and the induction method. CONCLUSION Sputum induction is safe in children under 18 months o f age. No major dif ferences in oxygen saturation, heart rate or other side effects between the induction m ethod and the conventional method o f sputum collection were found. Clinical implications for physiotherapy The m ethod o f induced sputum can be used in children under the age o f 18 months w ithout com prom ising the patient’s safety. The induced m ethod o f collecting sputum specim en is m ore cost and time consum ing than the conventional method and therefore should be used only when a high yield for virological and bacterial investigations to detect specific organisms is required. Limitations and suggestions for further studies This study should be repeated with a larger sample size for more significant statistical analysis. The differences in yield should be com pared using the conventional and induced m ethods o f collecting sputum specimen. Investigation o f the effect o f age on m ethods o f sputum collection in chil dren under the age o f 18 months would be interesting. REFERENCES M i l l e r R F , K o c ja n G , B u c k la n d J e t al. 1991 S p u tu m In d u c tio n f o r th e D ia g n o s is o f P u lm o n a ry D is e a s e in H IV P o s itiv e P a tie n ts. Jo u rn a l o f I n fe c tio n 2 3 :5 -1 5 . M ille r R F, L e ig h T R , C o llin s JV, M itc h e ll D M . 1990 T e sts g iv in g a e tio lo g ic a l d ia g n o s is in p u lm o n a r y d is e a s e in p a tie n ts in f e c te d w ith th e H u m a n I m m u n o d e f ic ie n c y V iru s. T h o ra x 4 5 :6 2 - 6 5 . O g n ib e n e FP, G ill V J, P iz z o PA , K o v a c s JA , G o d w in C , S u ff e r d in i A F, S h e lh a m e r JH , P a r rillo JE , M a s u r H. 1989 In d u c e d sp u tu m to d ia g n o s e P n e u m o c y s tis c a rin ii p n e u m o n ia in im m u n o s u p p r e s s e d p e d ia tr ic p a tie n ts . T h e J o u r n a l o f P e d ia tr ic s S e p t: 4 3 0 -4 3 3 . S h a t a A M A , C o u l t e r J B S , P a r r y C M , C h i n g ’an i G , B r o a d h e a d R L , H a rt C A . 1996 S p u tu m i n d u c t i o n f o r t h e d i a g n o s is o f tu b e rc u lo sis . A rc h iv e s o f D ise a se s in C h ild h o o d 7 4 :5 3 5 - 5 3 7 . V a le rie L , G a r tn e r I, W e y m o u th L A , G o o d m a n C D . H o p e w e ll P C , H a d le y W K . 1 9 8 9 T h e u s e o f M u c o l y s e d I n d u c e d S p u tu m f o r th e I d e n tific a tio n o f P u lm o n a ry P a th o g e n s A s s o c i a t e d w ith I m m u n o d e f i c i e n c y V iru s In fe c tio n . A r c h iv e s o f P a th o lo g y L a b o ra to r y M e d ic in e 1 1 3 :4 8 8 -4 9 3 . Z a r H J, T a n n e n b a u m E , A p o lle s P, R o u x P, H a n s lo D , H u s se y G . 2 0 0 0 S p u tu m in d u c tio n f o r th e d ia g n o s is o f p u lm o n a r y tu b e r c u lo s is in in fa n ts a n d y o u n g c h ild r e n in a n u rb a n s e ttin g in S o u th A fric a . A r c h iv e s o f D is e a s e s in C h ild h o o d 8 2 :3 0 5 -3 0 8 . For the hottest work in the UK, taste what we have ' to offer Physi W id e s t c h o ic e o f L o cu m , P erm anent and Fixed-Term C o n tra c ts A d v ic e on: S ta te R egistration UK Visas and W o rk P erm its A c c o m m o d a tio n B a n k A c c o u n ts Top rates o f pay U K C P S M R e gistration Fees re im b u rse d FREE H oliday Pay Contact Bridget O ’Farrell BScOT in South Africa on (021) 423-3853 Fax: (021) 423-3855 E-mail: corinth@mweb.co.za nth i A e o i c a i London O ffice Toll F r e e 0 8 0 0 - 9 9 - 3 0 5 5 F ax: 0 9 4 4 2 0 8 2 0 7 6 8 9 4 E-M ail: p t@ c o rin th .c o .u k SA J o u r n a l o f P h y s io t h e r a p y 2001 V o l 57 No 3 19 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) mailto:corinth@mweb.co.za mailto:pt@corinth.co.uk