J. clin. Path. (1962), 15, 527 Laryngeal dysfunction and the pulmonary syndrome of the newborn G. R. OSBORN AND R. L. FLETT From the Departments of Pathology and Otorhinolaryngology, Derbyshire Royal Infirmary SYNOPSIS 'The pulmonary syndrome of the newborn' is a term used for a complex group of lesions. It has been found that in the important forms of this disorder lesions of the larynx are very common, probably constant, and are ulcers of pressure type occurring on the vocal folds and ventricular bands ('true' and 'false' cords). Abnormal closure of the larynx, especially spasm, must be the cause of the ulceration. Premature babies may breathe with alveolar ducts and with alveoli in different parts of the same lung. It is suggested that hyaline membrane forms because of the abuse of normal alveolar duct function in alveolar duct type respiration. Membrane formation is a secondary phenomenon. The lesions of the pulmonary syndrome of the newborn based on a cor- relation of laryngeal and pulmonary function are classified, and the correlation of function suggests that early treatment with an artificial larynx might prevent the development of the fatal lesions. Valvular mechanisms in the lungs responsible for obstructive emphysema and obstructive atelectasis have been described by Jackson and Jackson (1945) and by Osborn (1953). In the newborn the ball-valve type of obstruction appears to be the most significant (Fig. 1), but it has become clear that in an important group of cases no adequate demonstrable explanation can be found in the trachea and lungs. In these babies lesions are found in the larynx within a very short time of birth which enable us to understand the lung findings. Negus (1929, 1949) showed that the larynx was not evolved for speech but is a valve designed to keep water and other foreign substances out of the lungs; it is also necessary for fixation of the thorax, especially in arboreal animals (Figs. 2, 3, and 4). The most primitive form of larynx is muscular only but as it cannot withstand a water pressure of more than 4 mm. of mercury it is inefficient and higher animals have developed valves. Shaping the larynx like an inverted V (or Gothic arch) will cause it to close more tightly as pressure increases. The human larynx has two valves of this type. The lower is the subglottic region and the vocal folds. The upper, and the more important for the exclusion of water, is formed by the aryepiglottic folds which are in fact inlet valves. Between the two inlet valves there is a more efficient outlet valve, the ventricular bands or false cords. For running, the larynx reaches its Received for publication 14 April 1962. highest evolutionary stage in the horse and deer; for an arboreal existence, in lemurs and some monkeys. Because the human larynx is a regressive organ from the evolutionary viewpoint, we might expect it to be more efficient in the newborn than in later life. The newborn prove its efficiency by their ability to support their weight by holding with their hands, and by their ability to breathe and drink at the same time-a feat which would be dangerous if pos- sible in later life (Negus, 1961). The efficiency of the ventricular bands as outlet valves depends to a large extent on the saccules which are better de- veloped at birth than in children and adults (Fig. 8). If the foetus is partially asphyxiated before birth the larynx nearly always fails in its function of keeping everything except air out of the lungs (Fig. 5). Liquor amnii, blood, pus, mucus, nucleated and non-nucleated squames can all pass both the aryepiglottic and the vocal folds. Unlike a drowning person a foetus may obtain some oxygen through the umbilical cord and so be about half asphyxiated for a considerable period of time while it both inhales and swallows the content of the upper air passages (Osborn, 1958). If the newborn baby is to inhale air properly it is obvious that mucus, squames, and so on should not be-ahead of the first breath. The air inhaled with the first breath will only go as far as the alveolar ducts; to expand the alveoli it must be expired against resistance; while being forced out it will also be forced backwards into the alveoli (Negus, 527 copyright. on March 10, 2021 by guest. Protected by http://jcp.bmj.com/ J Clin Pathol: first published as 10.1136/jcp.15.6.527 on 1 November 1962. Downloaded from
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J. clin. Path. (1962), 15, 527
Laryngeal dysfunction and the pulmonarysyndrome of the newborn
G. R. OSBORN AND R. L. FLETT
From the Departments ofPathology and Otorhinolaryngology, Derbyshire Royal Infirmary
SYNOPSIS 'The pulmonary syndrome of the newborn' is a term used for a complex group of lesions.It has been found that in the important forms of this disorder lesions of the larynx are very common,probably constant, and are ulcers of pressure type occurring on the vocal folds and ventricularbands ('true' and 'false' cords). Abnormal closure of the larynx, especially spasm, must be thecause of the ulceration. Premature babies may breathe with alveolar ducts and with alveoli indifferent parts of the same lung. It is suggested that hyaline membrane forms because of the abuseof normal alveolar duct function in alveolar duct type respiration. Membrane formation is a
secondary phenomenon. The lesions of the pulmonary syndrome of the newborn based on a cor-relation of laryngeal and pulmonary function are classified, and the correlation of function suggeststhat early treatment with an artificial larynx might prevent the development of the fatal lesions.
Valvular mechanisms in the lungs responsible forobstructive emphysema and obstructive atelectasishave been described by Jackson and Jackson (1945)and by Osborn (1953). In the newborn the ball-valvetype of obstruction appears to be the most significant(Fig. 1), but it has become clear that in an importantgroup ofcases no adequate demonstrable explanationcan be found in the trachea and lungs. In thesebabies lesions are found in the larynx within a veryshort time of birth which enable us to understand thelung findings.Negus (1929, 1949) showed that the larynx was
not evolved for speech but is a valve designed tokeep water and other foreign substances out of thelungs; it is also necessary for fixation of the thorax,especially in arboreal animals (Figs. 2, 3, and 4).The most primitive form of larynx is muscular onlybut as it cannot withstand a water pressure of morethan 4 mm. of mercury it is inefficient and higheranimals have developed valves. Shaping the larynxlike an inverted V (or Gothic arch) will cause it toclose more tightly as pressure increases. The humanlarynx has two valves of this type. The lower is thesubglottic region and the vocal folds. The upper, andthe more important for the exclusion of water, isformed by the aryepiglottic folds which are in factinlet valves. Between the two inlet valves there is amore efficient outlet valve, the ventricular bands orfalse cords. For running, the larynx reaches itsReceived for publication 14 April 1962.
highest evolutionary stage in the horse and deer;for an arboreal existence, in lemurs and somemonkeys. Because the human larynx is a regressiveorgan from the evolutionary viewpoint, we mightexpect it to be more efficient in the newborn than inlater life. The newborn prove its efficiency by theirability to support their weight by holding with theirhands, and by their ability to breathe and drink at thesame time-a feat which would be dangerous if pos-sible in later life (Negus, 1961). The efficiency of theventricular bands as outlet valves depends to alarge extent on the saccules which are better de-veloped at birth than in children and adults (Fig. 8).
If the foetus is partially asphyxiated before birththe larynx nearly always fails in its function ofkeeping everything except air out of the lungs(Fig. 5). Liquor amnii, blood, pus, mucus, nucleatedand non-nucleated squames can all pass both thearyepiglottic and the vocal folds. Unlike a drowningperson a foetus may obtain some oxygen throughthe umbilical cord and so be about half asphyxiatedfor a considerable period of time while it both inhalesand swallows the content of the upper air passages(Osborn, 1958). If the newborn baby is to inhale airproperly it is obvious that mucus, squames, and soon should not be-ahead of the first breath. The airinhaled with the first breath will only go as far as thealveolar ducts; to expand the alveoli it must beexpired against resistance; while being forced out itwill also be forced backwards into the alveoli (Negus,
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FIG. 1. Lungs ofababy dying at birthfrom obstructiveemphysema caused bytenacious mucus in thetrachea which acted as aball valve allowing airinto the lungs butpreventing its returnthrough the glottis.So few breaths weretaken that theobstetrician thought thismight be a stillbirth.x 20.
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nG. 3
FIG. 2
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FIG. 2. Section from larynx of a boy of 7 years who wasdrowned. The superior fold (ventricular band orfalse cord),aided by the ventricle extending cranio-laterally, is anoutlet valve and hinders or prevents escape of air from thelungs. The inferior fold (vocal cord) is the lower of the twoinlet valves, and helps to prevent water entering the lungs,but its main function is hindering entry of air to permitfixation of the thorax in arboreal and other animals. Thestrong sphincter muscle can be seen in the inferior fold;the superior fold contains glands rather than musclefibres. x 15.
FIG. 3. Obstructive emphysema ('emphysema aquosum')in the lungs of the 7-year-old boy whose larynx is shownin Figure 2. x 20.
FIG. 4. Lungs of a newborn baby thought to have beendrowned as a result of being thrown into the sea. Obstruc-tive emphysema present. (Case of Dr. E. G. Evans ofBangor.) x 20.
FIG. 5. Head ofafoetus ofabout 25 weeks' development.The dark collection ofpus above the hard and soft palate isseen passing directly through the larynx into the trachea.This 'drowning in pus' is one of the forms of 'congenitalpneumonia'. x 5.
FIG. 6. Lungs ofa 27 cm.foetus (about 25 weeks) showingalveolar duct type respiration. The alveoli have not dif-ferentiated, hence although such a foetus may breathe airfor a short time it is not viable. x 20.
FIG. 5
FIG. 6
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Laryngeal dysfunction and the pulmonary syndrome of the newborn
FIG. 7. Ulceration of both vocal folds(cords) with a heavy inflammatory exudatein a baby dying of bronchopneumoniaat the age of 1 day. Note the normalsurface epithelium a short distancefrom the ulcers, the flattened epitheliumclose to the ulcers and its gradualdisappearance at the ulcer edge.This is characteristic of ulcers due topressure. x 30.
FIG. 8. Same case as in Figure 7 toshow ulceration of the ventricularbands (false cords). The histologicalfeatures of ulceration following pressureatrophy of the epithelium are again wellshown. There is very little inflammatoryexudate. The saccules of the ventriclesare shown anteriorly on either side andhelp to make the ventricular bandsmore efficient as exit valves at birth ascompared with later in life. x 11.
FIG. 9. Lungs of the baby whose larynxis shown in Figs. 7 and 8.Bronchopneumonic consolidation ispresent but most of the lungs isemphysematous. x 20.
FIG. 9
1929, and Fig. 24). Crying appears to be an importantmeans of forcing air out and backwards underpressure.The alveolar ducts and alveoli have very little
mechanical strength. Negus (1929) has shown experi-mentally that in a system like this, if there is a wideopening to the outside air, only the nearer of theweak-walled elements will expand and contract asair goes in and out, implying that if the normalvalvular action of the larynx fails at birth thealveolar ducts will balloon, the alveoli will notexpand, and the condition of hyaline membranewill follow.The stimulus to breathe is seen early in foetal
development. Respiratory efforts are functionallyquite useless until the alveolar ducts have differ-entiated at between 20 and 24 weeks' development.Alveolar duct respiration has been observed to keepa foetus of about 25 weeks' development alive in thelaboratory for an hour (Fig. 6). A foetus is not viableuntil its alveoli have differentiated sufficiently to beof functional use. In the transitional stage, betweenalveolar respiration being impossible, up to about 28
weeks, and easy at full term, the premature baby maybegin either the alveolar duct or the alveolar type ofrespiration. There is little doubt that in favourablecases the former can be replaced by the latter; alsothat in some babies both types of respiration occur,the alveolar duct type being more likely near thehilus and posteriorly. Ballooning of the alveolar ductscan cause the lungs to fill the chest cavity; if thishappens it is improbable that any form of treatmentwill change alveolar duct into alveolar type respira-tion. Although complete failure of laryngeal functionat birth cannot be demonstrated by the pathologist,it must be postulated that it does occur in somebabies, and it has in fact been observed by Jackson(1915) and by Professor H. C. McLaren (1961). Thelesions resulting from the opposite condition oflaryngeal spasm can be demonstrated histologically.
THE LARYNGEAL LESIONS
The sequence of lesions in the larynx, thought toresult from spasm, is the same as in the oesophagus,trachea, and urethra when a tube or catheter is left
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in contact with the mucosa (Osborn, 1958). The parttypically affected is the junction of the anterior andmiddle thirds of the vocal folds, that is, the middleof the mobile part of the vocal cord (Figs. 7, 10, 18,21, and 22), and is the part affected by 'singer'snodes' in later life. In the newborn the synonym'screamer's nodes' is more appropriate (Fig. 15).The analogy is one of position and not of histologicalstructure.The first stage is pressure atrophy (flattening) of
the stratified squamous epithelium of the vocalfold; the epithelium then disappears but the resultingulcer has compressed epithelium at its edges. In thesecond stage an inflammatory exudate, in whichpolymorphonuclear leucocytes predominate, de-velops and is a leucotaxine type of response due tothe products of epithelial breakdown. Local haemorr-hage may occur but it is usually slight or absent.Haemorrhage is frequent between the vocal cord andthe anterior part of the thyro-arytenoid muscle(Fig. 10); it is not uncommon in the foetus andshould be considered asphyxial in origin. In thethird stage the inflammatory exudate increases, andthe inflammation spreads into the ventricle and tothe ventricular bands ('false cords') (Fig. 8). Thelesion of the ventricular band is similar to that of thevocal fold but usually less severe; this difference isprobably structural in origin. The vocal fold is avalve with a strong sphincter muscle (Figs. 2 and 18)and the ventricular band a valve with many glandsand few muscle fibres. The inflammation has not beenobserved to extend towards the subglottic region.Finally bacteria lodge on the ulcerated parts. Thelesions of the vocal folds and ventricular bands arenot primarily bacterial in origin and infection istypically late, a fact of importance in the manage-ment of the newborn child with laryngeal ulceration.
PATHOGENESIS OF LARYNGEAL ULCERATION
Because the pathological lesions seen in the vocalfolds and ventricular bands are so very similar tothose in the oesophagus and urethra caused by anindwelling tube, it was at first concluded that theaetiology was the same, and the obvious explanationwas damage to the larynx by a mucus catheter. Astudy of the distance from the lips to the aryepi-glottic folds was therefore made at necropsy inbabies of various weights as it was thought that thesemeasurements would enable the mucus catheter tobe calibrated and so used more safely. Typical dis-tances were found to be 2-5 cm. in a 15-day femaleweighing 1 lb. 6 oz.; 4 cm. in a male of 10 hoursweighing 1 lb. 14 oz.; 5 cm. in a stillborn femaleweighing 4 lb. 6 oz.; and 4 5 cm. in a stillbornfemale weighing 6 lb. 12 oz. It is, however, very
difficult to be sure that this distance as measured atnecropsy represents the distance during life with anydegree of accuracy. Reliable case histories soon madeit clear that this conclusion was untenable. Some ofthe babies had not had a mucus catheter passed nordid there appear to be any possibility of mechanicaldamage to the larynx by the attendant. The onlytenable conclusion was that the damage resultedfrom the vocal folds being too tightly apposed intheir spasm. There is, however, one other possibilitywhich may be a factor in a few cases.
Jackson and Jackson (1937) wrote: 'Untoldthousands of infants have asphyxiated because ofbilateral abductor paralysis-the cyanosis beingattributed to a persistent foramen ovale or failure ofrespiration to start'. Cavanagh (1955) has describedvocal palsies in children. She had to perform 11tracheostomies on babies between the ages of a fewdays and 5 months because of vocal cord palsy andfive of these died. She considers the first six monthsof life the period of greatest hazard. Because therewas no obvious central cause of laryngeal paralysisin the present series of babies, the recurrent laryngealnerves were studied histologically. The recurrentnerves appeared normal, and abnormalities, whenpresent, took the form of small asphyxial haemor-rhages which did not appear to be causing pressureon the nerve fibres; these can have no clinicalsignificance. Practically all the births were easy andnatural so difficult labour was not the cause.
LUNG LESIONS IN BABIES WITH ULCERATEDVOCAL FOLDS
It was thought desirable to look at the problem fromtwo different angles. First, what are the lung lesionsfound in the presence of ulcerated vocal folds?Secondly, is there any lung condition which is notfound in the absence of ulcerated vocal folds?The lung lesions in the 32 babies with ulcerated
vocal folds are set out briefly in Table I. They areplaced in four main groups but the dividing linebetween the groups is not clear in some cases.The first group of babies numbers eight and are
diagnosed as cases of bronchopneumonia. Case 8had an operation for volvulus resulting from fibro-cystic disease of the pancreas. Case 4, the only babywith normal vocal cords, had an operation forexomphalos when an intratracheal tube passed foranaesthesia damaged the posterior part of thelarynx. Case 5 had an E. coli meningitis and umbilicalcord sepsis. Cases 6 and 7 had an infection of thevocal folds and other parts with Candida albicans.Case 2 is clearly a case of 'hyaline membrane withoutmembrane' (Figs. 10 and 11). The important lesionsare well shown in Case 1 (Figs. 7, 8, and 9).
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Interstitial Emphysema and Pneumothorax1 F 3 hr. 2,8562 F 6 hr. 3,500 +3 M 10 hr. 2,8004 F 13 hr. 2,4645 M 20 hr. 1,3446 F 53 hr. 7847 M 58 hr. 2,128 -
-1 ++
+-4++--X
Not studied microscopicallyI, ++
Not - +++-Not studied microscopically_±+++ 4+++ ++-
_ - - +4-++
The second group consists of 13 babies withhyaline membrane disease. Cases 1 and 13 are of theCaesarian section syndrome. In this series theamount of membrane in the alveolar ducts variesfrom a little to the large quantity shown by Case 11(Fig. 12). The variation in the quantity of membrane,and the finding of cases which have every feature ofthis disorder except membrane (Fig. 11), have ledto the conviction that the hyaline membrane is notthe cause of the disorder bearing its name but a
reaction to alveolar duct type respiration. Some ofthe babies with this disorder showed patches ofalveolar type respiration; the patches lack membraneand are apt to be emphysematous (Fig. 13). Balloon-ing of alveolar ducts is not emphysema and is one ofthe causes of interstitial emphysema (Fig. 23).The third group consists of four babies showing
emphysema. Case 3 (Fig. 14) is a severe examplewhich might be expected to progress to interstitialemphysema. Case 1 is a mild case in a baby dying at
3 hours; this may mean that the laryngeal mechanismis not as potent as a ball valve of mucus below thevocal folds (Fig. 1); against this is the fact that thenext group contains a baby also aged 3 hours whichhad progressed to pneumothorax.The fourth group is made up of seven babies with
interstitial emphysema and pneumothorax fallinginto two groups, one a complication of emphysema(alveolar type respiration), the other of balloonedalveolar ducts in membrane disease (alveolar ducttype respiration). The interstitial emphysema andpneumothorax compress the emphysematous alveoli,hence the emphysema appears less dramatic thanthat shown in Fig. 14. Figures 15, 16, 17, 18, and 19show typical lesions of the emphysematous form.When three of these babies had been found to havelaryngeal ulceration it was decided to examine thelarynx of two similar babies whose lungs had beenplaced in museum jars in 1957 and 1958. The secondof these died after three hours; the lungs are shown
Case Sex AgeNo.
Emphysema1 F2 M3 M4 M
3 hr. 1,3162 days 3,2203 days 2,4083 days 2,108
Hyaline membraneHyaline membrane
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FIG. 10. Ulceration ofboth vocal,folds in ababy dying at the age of28 hours from broncho-pneumonia. Theinflammatory exudateis just developing.Large haemorrhages ofasphyxial type arepresent in the anteriorpart of thyroarytenoidmuscle and nearbypart ofthe vocalfold.There is no evidencethat the ulcerated vocalfolds in babies followhaemorrhages, as'singer's nodes' do inlater life. The com-parison with singer'snodes is by location onlyas there is clearly noepithelial covering tothe lesion in the baby.x 30.
.' '; 9'
.. .-
.... .S ,C
4,,"!FIG. 11. Lungs of baby whosevocal folds are shown in Figure 12.Bronchopneumonic consolidationis present. Alveolar ducts areballooned. There is no hyalinemembrane or oedema norany emphysema except at theanterior margins of the lungs.A case of 'hyaline membrane
rFIG. 14. Severe obstructiveemphysema in the lungs of amale aged 3 days. x 20.
FIG. 15. Vocal folds of a babydying at the age of 6 hours frominterstitial emphysema andpneumothorax. The exudate onthe ulceratedjblds resembles'screamer's nodes'; unlike thelatter it lacks an epithelialcovering and is not primarilyhaemorrhagic. The section is at ahigher level on the right thanon the left, showing extension ofthe ulceration to the ventricularband. Note the saccule of theventricle near the anteriorpart of the right side. x 30.
FIG. 16. Interstitial emphysemain lung of baby whose laryngeallesion is illustrated in Fig. 15.x 3.
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FIG. 14
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FIG.~~~~~~17ihrmgiiaino h ugsilsrtdi iue1.Osrciv mhsm n nesiilepysemaarebothckar.x20.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~n
FIG. 18. Larynx of baby who died at the age of52 hours from interstitial emphysema and pneu-mothorax. Although the whole of the rima glottidiswill close when the vocalfolds are acting as an inletvalve the ulceration is characteristically at thejunction of the anterior and middle thirds. Thesphincteric muscle, which alone forms the mostprimitive larynx, is well shown; it is formed by thethyroarytenoid, cricoarytenoid, and interarytenoidmuscles. x 7.
FIG. 19. Obstructive emphysema and interstitial emphysema in the lungs ofthe baby whose vocal folds are shown in Figure 18. x 20.
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FIG. 20. Lungs of the baby whose vocal folds are illu-strated in Figure 21. These lungs with the larynx weremounted in a museum jar in 1957.
in Fig. 20 and the ulcerated vocal folds in Fig. 21.Figure 22 shows much more advanced inflammatorylesions in the vocal folds of the first baby who lived10 hours longer. Hence the five most dramaticexamples of interstitial emphysema and pneu-mothorax were complications of obstructive emphy-sema consequent on laryngeal spasm and ulceration.These five babies all weighed over 2,000 g. The twomuch smaller babies, Cases 5 and 6 in this group,have equal striking interstitial emphysema butmuch less emphysema of the mediastinum andpneumothorax (Fig. 23). Both of these small babieshad the characteristic ulceration of the vocal foldsand a typical hyaline membrane. Excessive balloon-ing in alveolar duct type respiration can thus produceinterstitial emphysema and pneumothorax also.The girl (Case 4) was treated with mouth-to-mouthartificial respiration; at that time this appeared anadequate explanation for the findings but this is theonly baby so treated. Mouth-to-mouth resuscitationwill raise bronchial pressure during inspiration andlower it during expiration; it is thus the opposite ofnormal laryngeal function, and so must be dangerousin most examples of the pulmonary syndrome of thenewborn.
Paediatricians are now familiar with these casesof pneumothorax. Case 7 in this group was diagnosed
...01
..4r,.W.:::e.
a
FIG. 21Ulceration ofboth vocalfoldsofa babydying at theage of3 hoursfrominterstitialemphysema andpneumothorax.Pressureatrophy of theepithelium isshown at theedges of theulcers. Theinflammatoryexudate hasnot had time todevelop to anyextent.x 30.
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Laryngeal dysfunction and the pulmonary syndrome of the newborn
FIG. 23
FIG. 22. Vocal folds of a baby dying at the ageof 13 hours from interstitial emphysema andpneumothorax. A heavy inflammatory exudate,in places gangrenous, has appeared. x 30.
FIG. 23. Lungs of a boy weighing 1,344 g. whodied at 20 hours. Hyaline membrane and inter-stitial emphysema. x 4.
FIG. 22
correctly during life, and air was drawn from theleft pleural cavity by a fine catheter passed throughan intercostal space. This treatment appears logicaluntil it is seen that it only affects the end of thecondition instead of the beginning. Some air isallowed to pass through the vocal folds but little ornone is allowed to make its way back past theventricular bands whose shape and efficiency issimilar to that of the aortic cusps. In this problemit would seem that the insertion of a small Magilltube is the method of choice (Reilly and Melville,1962) and not tracheostomy which would be toosevere on these bad-risk cases. Such a tube mayprove to be the best form of artificial larynx, for it5
will gently assist inspiration and oppose expiration.The tube will lie posteriorly in the interarytenoidspace (Fig. 18) where it may do some harm butwill not aggravate the pressure ulcers on the vocalfold and ventricular bands (Figs. 7 and 8). Thisdisorder in the newborn is not to be confusedwith acute tracheobronchitis and bronchiolitis inlater life, e.g., that seen in epidemics of influenza.Asphyxia developing in these primarily infectivecases may be treated by tracheostomy (Negus, 1952).
PULMONARY SYNDROME OF THE NEWBORN
Bound, Butler, and Spector (1956) used the term
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'pulmonary syndrome of the newborn' to cover thegroup of lung lesions which so often cause death innewborn babies most of which are otherwise normal.The pulmonary syndrome can be understood if it isregarded as one or more processes which arerelated to each other; also that although some lungsshow only alveolar type, or alveolar duct typerespiration, both types may be present in the samebaby. The five main causes of the pulmonarysyndrome of the newborn are: 1 Inhaled substances,especially squamesand mucus (obstructive atelectasisand obstructive emphysema); 2 effects of laryngealspasm in alveolar type respiration (obstructiveemphysema, interstitial emphysema, pneumothorax,and surgical emphysema of the mediastinum);3 effects of laryngeal dysfunction in alveolar ducttype respiration (ballooning of alveolar ducts,hyaline membrane formation, interstitial emphy-sema, and pneumothorax); 4 secondary lesions inthe lungs (oedema, asphyxial haemorrhages, massivehaemorrhage, and bronchopneumonia); 5 secondarylesions elsewhere (serous cavity effusions, especiallyperitoneal, retroperitoneal oedema, posterior media-stinal oedema, and haemorrhages, especially cere-bral).
In the third group 'laryngeal dysfunction' is theterm employed instead of laryngeal spasm. It was atfirst concluded that alveolar duct type respirationwas a consequence of laryngeal failure (paralysis orfailure to close for other reasons). The regularitywith which laryngeal lesions are found in this groupindicates that it too may be a consequence oflaryngeal spasm, the difference between the secondand third groups being the developmental state of thelungs and possibly later development of laryngealspasm in the second group after a period of normallaryngeal function. It is to be noted that the bron-chial and bronchiolar musculatures are synchronizedwith the larynx and all should be considered onefunctional unit; probably the larynx is more im-portant at birth and the bronchial musculature lateron. Pending direct observations by laryngoscopysoon after birth it should be concluded that alveolarduct type respiration in a baby mature enough tohave alveolar type respiration is a consequence oflaryngeal immobility; whether the immobility is inabduction (paralysis) or adduction (spasm) maymake little difference to the lungs. A larynx whichfails at birth may develop normal function or gointo spasm; nothing but normal function early onis of value. The likely cause of laryngeal spasm issome substance other than air passing, or attemptingto pass, the larynx, especially at the level of thearyepiglottic folds. A larynx which functions nor-mally at birth may go into spasm later.
Secondary lesions may modify the primary
L.O.BD
A
BEGINNING OF INSPIRATION
A
A
END OF INSPIRATION
BCL.C.
A
AR
EFFECTS OF LARYNGEAL SPASM
A
THEORETICAL EFFECT OF LARYNGEAL FAILURE
FIG. 24. A = alveolus. AE = emphysematous alveolus.AR = ruptured emphysematous alveolus. AD = alveolarduct. BD = bronchus dilated. BC = bronchus contracted.BDC = bronchus dilated or contracted. LO = larynxopen. LC = larynx contracted. LS = larynx in spasm.LF = laryngeal failure. Arrows indicate direction of airflow. Diagrammatic representation of respiratory move-ments (modifiedfrom Negus, 1929).
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Laryngeal dysfunction and the pulmonary syndrome of the newborn
appearances. Oedema and haemorrhage originate inalveoli and can cause the alveoli to expand and soreduce the amount of ballooning of the alveolarducts; haemorrhage can displace membrane fromalveolar ducts into bronchioles. Emphysema develop-ing after membrane is formed can displace it intoalveoli, but this is uncommon.
It is now 47 years since Chevalier Jackson (1915)noted the importance of laryngeal disorders in thenewborn. Jackson and Jackson (1942) thought thatthe laryngeal lesions were palsies due to difficultlabour, a conclusion not supported by this series.However, with the modifications indicated, there isno doubt that they were correct when they wrote'direct laryngoscopic examination is indicated inevery case of a newborn baby who fails to startrespiration promptly or whose colour is not good.In some instances the cause of the cyanosis will befound in the form of an accumulation of secretionsin the laryngopharynx, larynx, or trachea; in othercases a pulmonary atelectasis due to obstruction willbe found; in still other instances this condition ofbilateral laryngeal paralysis will be discovered as thesole factor in the impending asphyxia'.
CAESARIAN SECTION SYNDROME
This series includes two examples of the Caesariansection syndrome. Enough cases have been seen inthe past to justify the conclusion that this conditionis 'hyaline membrane disease', a term which shouldbe changed to 'alveolar duct type respiration'. The'Caesarian section syndrome' may be seen in pre-mature babies who are predisposed to alveolar ducttype respiration or in full-term babies in which it isotherwise rare and can have only a few causes.Laryngeal failure may be a consequence of theanaesthetic administered to the mother and laryngealspasm of the rapid delivery and clamping of thecord and the presence of substances other than air inthe region of the larynx.
It should be possible to abolish the Caesariansection syndrome by discovering the factors respons-ible for laryngeal dysfunction in a baby in whichnormal alveolar type respiration might be expectedand preventing their emergence. If the baby deliveredby Caesarian section is premature it may requireimmediate treatment with an artificial larynx afterthe airways have been cleared. The best form ofartificial larynx could well be the passage of a gentlestream of air into the trachea through a Magill tubewhich will lie in the posterior (interarytenoid) part
of the larynx. This treatment may only be requiredfor 10 minutes or so but it must be long enough foralveolar expansion to prevent ballooning of thealveolar ducts.
LUNG LESIONS WITHOUT, AND WITH,ULCERATION OF THE LARYNX
A variety of lung lesions, especially those dependenton congenital malformations and broncho-pneumonia, may occur without laryngeal ulcerationalthough laryngeal ulceration in the newborn mayoccasionally be secondary to infection.As our technical skill in the histological examina-
tion of the larynx has increased it has become clearthat ulceration of the vocal folds and ventricularbands is the rule in the pulmonary syndrome of thenewborn. It was first found in babies with emphy-sema and the correlation here is simple. It wasthought then that it would not be found in 'hyalinemembrane disease', but it is the rule in this disordertoo. Hence laryngeal dysfunction and ulceration arethe most important of the causes of the pulmonarysyndrome of the newborn.
We are grateful to Sir Victor Negus for his criticism ofthis paper and to Mrs. M. S. Costello and Mrs. V. M.Keen for their help in cutting the sections. We are alsograteful to the Clinical Research Committee of theSheffield Regional Hospital Board for financial assistance.The photographs were taken by Mr. J. S. Fayers,
clinical photographer to the Derbyshire Royal Infirmary.Finally we are indebted to the obstetricians, paediatricians,and midwives who supplied full case notes.
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Bound, J. P., Butler, N. R., and Spector, W. G. (1956). Brit. med. J.,2, 1191 and 1260.
Cavanagh, Florence (1955). J. Laryng., 69, 399.Jackson, C. (1915). Peroral Endoscopy and Laryngeal Surgery.
Laryngoscope Co., St. Louis.and Jackson, C. L. (1937). The Larynx and Its Diseases. Saunders,Philadelphia.
(1942). Diseases and Injuries of the Larynx. Macmillan,New York.
(1945). Diseases of the Nose, Throat, and Ear. Saunders,Philadelphia and London.
McLaren, H. C. (1961). Personal communication.Negus, V. E. (1929). The Mechanism of the Larynx. Heinemann,
London.(1949). The Comparative Anatomy and Physiology of the Larynx.Heinemann, London.
