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