POSTGRAD. MED. J., (1966) 42, 360

SOME SPECIAL CONSIDERATIONS IN NEONATALANAESTHESIAA. B. BULL, F.F.A.R.C.S.

Professor of Anaesthetics, University of Cape TownRed Cross War Memorial Children's Hospital, Cape Townz.

STUDIES of mortality associated with anaesthesiaand surgery consistently indicate a considerablyhigher death-rate in which anaesthesia is, or maybe, contributory, during the first decade than inthe age-groups 10-60 years. In the geriatric agegroups, mortality is again high, approaching orequalling that found in the first decade. Steven-son, Reid and Hinton (1953), in la study of1,200 cardiac arrests during anaesthesia, re-ported 21 per cent of these as occurring in thefirst decade. West (1954), reported seven car-diac arrests in the 1-10 year age group out ofa total of 30. Beecher and Todd (1954) drewattention to the increased vulnerability of in-fants. Bergner (1955), found six out of 17 car-diac arrests to be in children under 10 yearsand Schull (1959), gives a figure of 25 per centfor the same age-group. Kok and Kitay (1960),showed a figure of 16 per cent of 300 cardiacarrests occurring in the 1-10 year age groupand Harrison (1965) found that whereas chilld-ren under 10 years represent 10 per cent of thesurgical population subjected to anaesthesia,they comprised 21 per cent of the deaths inWhich anaesthesia was a contributory cause.Accurate evaluation of these figures is difficult,as only too frequently no attempt is made toseparate causative factors into those due topatient disease, those due to surgical manage-ment and those due to anaesthetic management,and the background surgical population fromwhich they are taken is ill-defined. However,it would appear that ample justification existsfor the view that the surgical and anaestheticcare of small children is a imatter for specialconsideration. This view is strengthened bySmith (1954) in a detailled analysis of deathsoccurring in the individual years of the firstdecade. He found a 3.9 per cent operative andpost-operative mortality in the 0-1 year group,this figure being about four times that of anyother year in the first decade. Similarly, at theRed Cross War Memorial Children's Hospital,Cape Town, during 1963 and 1964, neon-atescomprised 1.8 per cent of deaths occurring dur-ing operation or in the post-operative period, asagainst 0.9 per cent mortality associated withsurgery in all children from 0-11 years of age.

Once again, the causes for this high mortality,compared with other age-groups, cannot beeasily or clearly separated 'into those due toanaesthetic factors and those due to surgicalfactors. Tihe operative care of infants, to givegreatest success, depends largely upon team-work, mutual appreciation of problems amongstmembers of the team and a degree of technicalskill above that required 'when dealing witholder age-groups. The application of methodsand knowledge derived from anaesthesia inadults or older children to neonates withoutmodification based on their speci,al requirementswill inevitably lead to complications and in-creased mortality. Pre-operation preparation,detailed anatomical and physiological dif-ferences, modified drug response, specialisedpathology of neonatal disorders and the des-cription of specialised techniques to deal withspecial conditions, and methods of monitoringduring anaesthesia will not be discussed.It is proposed here to deal only with three ofthe main considerations which irequire specialattention, other than the ordinary principles ofanaesthesia. These are:-

1. Pulmonary ventilation.2. The control of body temperature.3. Accurate assessment and replacement of

blood iloss during operation.Pulmonary VentilationThere are important differences in the res-

piratory physiology of neonates as comparedwith adults and older children. As one of theanaesthetist's functions is to maintain adequaterespiratory exchange, an appreciation is essen-tial. Whereas much has been written about res-piratory physiology in the adult, (both in thenormal and abnormal states, the same does nothold for neonates. This is due largely to thetechnical difficulties involved in making respira-tory 'measurements on these small patients.With regard to the medhanical aspects of breath-ing, one finds that the neonatal thorax presentsa combination of structural 'handicaps to ven-tilatory efficiency. The tihoracic cavity is small.The sternum, being pliable, provides an unstablebase for the rilbs. The ribs themselves, being

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horizontal, do not lend ithemselves to the"'bucket handle" movement which the thoracicrespiratory imuscles provide in the older childand adult. The intercosital muscles are poorlydeveloped and -the accessory muscles of littleassistance. Ventilatory volume change is broughtalbout largely by the diaphragm, and becauseof this, severe embarrassment to respiration canand does occur with abdominal distension fromany cause. This is important to bear in mindalso in such operations as repair of omphalo.cele and large umbilical herniae, where returnof viscera and too "tight" a repair may resuWltin respiratory distress. This will not be evidentduring the surgical procedure if controlledventilation is 'being used, and may only mani-fest itself in the post-operative period.The compliance of the thoracic cage is far

greater in infants, and this gives rise to 'thecharacteristic sternal and thoracic recession seenwith even mild degrees of respiratory dbstruc-tion during spontaneous respiration. This is fre-quently seen even when no organic obstructionis present, but when there is increased respira-tory demand, e.g., during crying, or during over-breathing in states of metabolic acidosis. It maybe taken as visible evidence of the diminishedrespiratory reserve of small infants, the pictureof this recession of the rib cage being medhanic-ally and physiologica;lly similar in effect to flailchest injury in adults. 'MdDonald i(1960) hasstated that in comparison with the adult, thenewborn has 'half the respiratory exchange sur-face iper unit lung weight and one third the res-piratory exchange surface per unit body weightas compared wit-h 'the adult. This is combinedwith a comparatively high metabolic rate, mak-ing a rapid respiratory frequency necessary tocompensate for these deficiencies. High respira-tory rate implies the frequent shifting of deadspace air as a concomitant. Nelson, Prod-Lom,Cherry, iLipsitz and Smith (1962), calcuilatingdead space from CO2 tensions in expired andalveolar air arrived at la 'figure of 4.4 ml. thisbeing some 30 per cent of tidal volume. Thispercentage is not far different from that foundin adults, but it is of importance to emphasise'the fact that in terms of absolute values, 5 ml.dead space in 'a neonate is comparable withabout 100 ml. in adults. Even a small increasein anatomical dead space volume such as thatwhich can be produced by poor choice ofanaesthetic circuit or apparatus, becomes verysiignilficant under these circuimstances and candecrease the already handicapped 'respiratoryreserves of these small patients. It may beargued that slight increase in dead 'space can

be compensated for 'by increase in ventilation,but this can on'ly be so, under most conditionsin anaesthetic practise, if fresh gas flow is in-creased proportionately to match the increasedtidal volume. 'Even this increase in ventilationmay not fully compensate for the added deadspace. Clappison and Hamilton (1956), showedthat increasing the dead space in normal un-medicated subjects led to increase in tidalvolume and rate which were not sufficient tocorrect end-expiratory CO2 tension. The prob-lem of apparatus dead space in paediatric anaes-thetic apparatus has been well summarised 'byVoss '(1963) in an assessment of the Magill,Potter and Cape Town gas circuits applied to'paediatric practice. The Cape Town system hasbeen found to be the most suitable for smallchildren and also has the virtue of extremesimplicity and versatility. This system, (Voss,1963), was evolved in 1954 'at the Red CrossWarMemorial Children's 'Hospital and is usedhere as standard apparatus for neonates andsmall 6hildren. It consists of a standard anglepiece with a tube of 6 mm. internal diametersoldered in the position shown in Fig. 1. A75 ml. soft latex bag with an open tail is fittedover the open limb of the angle piece. A similararrangement can be used for endotrachealanaesthesia and has 'been described by Rees(1950). These systems are, in effect, "T-piece"circuits and require fresh gas-flows of at leastdouble the minute volulme of the patient. Beingwithout valves they offer very little resistanceto respiratory flows.The widespread use of muscle relaxants and

controlled respiration necessitates some knowl-edge of the ventilatory requirements in termsof volume and pressures which may be toleratedby the infant and of the qualitative and quan-titative requirements in terms of gas exchange.The accurate assessment of adequate respiratoryexchange is not easy unless facilities for frequentblood-gas analysis or end expiratory 02 andCO2 measurements are available. In general,it may be stated, however, that if a patient with

FRESH GAS=4 -m

FIG. 1.-The Cape Town System.

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a normal haemoglobin value and normal circu-latory and respiratory system, ibreathing air,shows no sign of cyanosis, the blood carbondioxide tension is probably not increased. Underconditions of anaesthesia, 'however, decreasedventilation may occur in the presence of highinspired oxygen tenisions leading to the insidiousdevelopment of respiratory acidosis, which, ifsuperimposed upon possible pre-existing meta-bolic acidosis may lead to fatal decrease inarterial blood pH and become a factor in mor-tality. Conversely, overventilation over a longperiod of time can lead to marked lowering ofPco., and rise in pH accompanied by a risein cell potassium level and fall in extracellularpotassium. If facilities for gas analysis are notavailable, a reasonable estimate of ventilatoryrequirements may be made from the patient'ssize. Radiford (1955), have produced a mostuseful nomogram for this purpose from whichit is possible to estimate required respiratoryfrequency and tidal volume from body weight.From this it will be seen that tildal volume ofabout 15-20 ml. at a frequency of 30-40 perminute is about normal for the neonate. Theconstruction of the nomogram is based onthree major assumptions. Firstly, it assumesthat basal carbon dioxide production can bepredicted from body weight. Secondly, thatrespiratory dead space can be predicted frombody weight and is, in fact, about 1 ml. perpound. Thirdly, that optimal arterial Pco2 is40 mm. Hg. These assumptions must be bornein mind when referring to it. Measurement ofthese small tidal vollumes is, however, extremelydifficult, as most conventionall dry gas meterssuitable 'for operating theatre use show un-desira'ble inaccuracies at the smalil flow-ratesencountered with these small volumes. Nosimple satisfactory method has yet been devisedto overcome these difficulties, and in practice,the use of a monaural stethoscope strapped tothe 'patient's chest will at least give audibleindication of air entry. The nearest approadhto measured ventilation in neonates is prob-ably provided iby the use of a volume-cycledventilator. The use of automatic ventilators invery small children, however, has its own prob-lems, as most available models are designedand intended for use on adults. These problemshave been well discussed 'by Mushin, Maplesonand Lunn (1962). Automatic ventilators may,however, be used satisfactorily on neonates, evenfor long periods of time, provided they aresuitably adapted for this type of use. Smytheand Bull (1959) and Smythe (1963), describethe use of the Radcliffe respirator in the treat-

ment of tetanus neonatorum with IPPR andcurarization. For their satisfactory use, theessential thing to remember is that the unmodi-fied adult ventilator delivers a flow-rate duringinspiration which is too high. This has the effectof ensuring -turbulent flow in the airway system,thus relatively increasing resistance and inter-fering considerably with the t r i g g e r i n gmechanism of the ventilator. It also carries thedanger of overinflation, though this is not great.Rosen and Laurence (1965) give the pressure atwhich rupture of the neonate's lung occurs asbeing greater than 50 cm. H20. Most automaticventilators are provided with safety deviceswhich prevent this pressure being reached.The size and nature of the infant's respira-

tory tract makes it particularly vulnerable tomechanical obstruction. The large antero-pos-terior diameter of the head in relation to thatof the thorax makes kinking of the soft tracheaand dbstruction in the pharynx occur veryreadily unless hyper-extension of the neck ismaintained. The small diameter of the larynxand trachea, smallest at the level of the cricoidcartilage, allows little latitude for dimunitionof the lumen by secretions, oedeema or endo-tracheal tu,bes. Not often realised to the fullis the way in which badily chosen endotrachealtubes can increase airway resistance and causerespiratory obstruction instead of preventing it.This is due to the fact that under conditionsof flow operating in the respiratory tract, thecross section area of the tuibe or airway is themost important measurement determining flowresistance. Decrease in the diameter of theneonatal trachea with a 4 mm. diameter, suchas would arise from the passage of an endo-tracheal tufbe with wall thickness of 1 mm. willproduce a 75 per cent decrease in cross sectionarea. T'his is illustrated in Fig. 2 and appliesequally to obstruction arising from oedema dueto trauma or inflammatory processes.

Endotracheal tubes should, therefore, ibechosen with the largest possi'ble internal dia-meter. This, however, presents the problem ofkinking of the 'tube if the wall is excessivelythin. To 'provide both adequate lumen andfreedom from kinking, the Oxford pattern(Alsop, 1955) neonatal endotracheal tube ismost satisfactory. This tube has a tapered wall,but a constant lumen, providing rigidity of thesection where kinking is most likely, whereasthe end section Which lies in the larynx andtrachea 'has an extremely thin wall. In addition,the tube is moulded with a right angled curveto fit the curve of the oropharynx. Other tubeshaving a thin-walled section which fits the

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OBSTRUCTION CAUSED BY DIMINUTIONOF CROSS SECTION AREA.

rA-

C

0

0

2,c

4n

FIG. 2.-The upper curve is a plot of -rr' againsttracheal diameter. The lower curve represents('rr-1)2 against tracheal diameter. The verticaldistance between the curves at any diameterrepresents obstruction. The vertical distancebelow the lower curve at any value of diameterrepresents free lumen.

tarynx and trachea but with reinforced walilsproximally are obtainable in ruibber or in plas-tic and have been described by Cole 1(1954) andTunstall (1961). The 'funnel shape of the infantlarynx, with the narrowest position at the cri-coid ring allows an airtight fit ;between endo-tracheal tube and trachea, if the correct sizeof tulbe is chosen, making the use of cuffed en-dotracheal tubes unnecessary. Indeed, it is im-practical to attempt the use of cuffed tubesin small ibabies as the construction of such atulbe leaves a size of lumen which will lead toalmost total respiratory obstruction. Specifica-tions for endotracheal tube sizes have beendrawn up and 'published in the British Stan-dards Institution Specification B.S. 3487 of1962.As important as the choice of a tube with

an adequate lumen is the choice of an endo-tracheal tube adaptor which does not cause aconstriction in the anaesthetic system. Thelumen of the adaptor must be at least as greatas that of the tube.

The Control of Body TemperatureAccidental hypothermia occurring in the new-

born is a well-known occurrence. This has beenattrilbuted to immaturity of the heat-regulatingmechanism making the neonate ibehave like apoikilotherm, rather than a 'homeotherm, untilthermoregulatory controll develops with increas-ing maturity. It is likely, however, that thethermal instability of the newborn comparedto the adult is due mainly to physical charac-teristics affecting heat loss. The body-weightof the newborn infant is about 5 per cent ofthat of the adult, while its surface area, bycoimparison, amounts to approximately 15 percent. This high surface-area to body-mass ratio,and its curved body surfaces greatly facilitatesheat exchange between the infant and its en-vironment by conduction, convection and radia-tion. Insulation of 'body core provided by skinand subcutaneous fat is significantly less in thenewborn, too, again increasing heat exchangeby conduction. A further important factor inthe control of heat dissipation depends on thecirculation. Blood flow to the periphery playsa large ;part in the transfer of heat from thebody core to the surface, when heat iloss orgain takes place. This blood flow is, in turn,regulated by vasoconstriction and vasodilata-tion, both functions being well developed in theneonate. Heat production depends on the abilityto increase metabolic rate in response to cold,and the unanaesthetised neonate does, in fact,respond in this way. i(Bruk, 1961; Adams, Fuji-wara, Spears and Hodgman, 1964.)

During anaesthesia, a number of factors maycombine to render thermoregulation ineffiicient.Tissue metabolism depends upon adequate sup-plies of oxygen, glucose and other suitablesubstrates. Cross, Tizzard and TrythaHl (1958)have sholwn the effects of anoxia in this respect.Infants rendered hypoglycaemic through im-proper pre-operative preparation show a verymarked fall in body temperature during anaes-thesia. Drugs used in anaesthesia certainly playa part. The state of anaesthesia itself ajbclishesmuscular activity to a large extent, or evenentirely, so greatly diminishing a big source ofheat production. Many anaesthetic agents, not-ably halothane, ether and cyclopropane, producevasodilatation of the in-fant's surface area, largein relation to its body mass. Hypnotics, anal-gesics, neuromuscular and autonomic nervousblocking agents almost certainly all contrilbutetowards impairment of thermal perception andthe central control of heat production. Placedin conditions of low ambient temperature with

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which its deranged thermoregulatory mechan-isms and physical handicaps cannot copeadequately, the body temperature of the anaes-thetised infant will invariably fall un,lessadequate steps are taken to prevent this. Thetransfusion of cold blood can also play animportant part, as during major surgery a con-siderable percentage of the patient's -bloodvolume may need replacing. 'Major exposure ofthoracic or dbda minal viscera will also playa part in increasing the surface from which heatmay ibe lost.The degree to which body temperature may

fall, together with a statistical analysis of themain factors contributing to this fall has beenreported by Harrison, Bull and SRhmidt (1960).Farman (1962) stresses the importance of inad-vertent hypothermia in anaesthetised infantsas a contributing cause to mortality. On theother hand, the merits of cooling seriously illinfants under certain circumstances, have beenput forward by iMcCredie (1962). As far asanaesthetic management is concerned, however,most experienced paediatric anaesthetists agreethat fall of body temperature is undesirable.The main reason for this is that much of thedanger of cooling is believed to be due to a51tera-tion of the action of muscle relaxants, now analmost universal practice. Our experience hasshown that even without the use of musclerelaxants, cooling of neonates to temperaturesbelow 90°F not infrequently results in severerespiratory embarrassment in the post-operativeperiod. A likely explanation of this is thatthe hypothermic infant recovering from anaes-thesia and 'bringing its thermoregulatory mech-anisms fully into operation, may greatly increaseits oxygen consumption and respiratory de-mands to tan extent which it is unable to meetadequately, thus leading to a state of respiratoryinsufficiency.From the'point of view of practical manage-

ment, it should be assumed that the anaes-thetised neonate behaves very much like a poi-kilotherm. Ambient temperature and humiditywill have considerable influence on its bodytemperature. Hyperpyrexia in infants and child-ren during surgery has 'been described fre-quently, most notably iby Bigler and McQuiston(1951). In most instances, 'such descriptions con-cern conditions of high ambient temperaturein operating theatres wit'hout air conditioning.The use of atropine is a further factor underthese conditions as it prevents heat loss bysweating. Under modern operating theatre con-ditions, however, a fall in ibody temperature isthe rule and this requires active steps to prevent

the attainment of dangerously -low temperatures.In all cases of major or -prolonged surgery onneonates, some form of temperature monitoringis most desirable. The most convenient is oneof the many available electric thermometersavailable with either rectal or oesophageal ther-mocouple or thermistor leads. If ambient 'tem-perature is considerably below normal i,odytemperature, 'as 'much insulation of the patientas is commensurate with satisfactory surgicalaccess should 'be provided. This may ibe done'by the use of sterile gamgee tissue, and heatdissipation is further aided if plastic sheetingis incorporated in the draping, as this tendsto lessen heat 'loss due to evaporation of mois-ture. Active warming may have 'to be resortedto and this is ibest achieved by 'placing thepatient on a blanket in which plastic or rubbertubes are incorporated through which warmwater may ;be circulated. Several such blanketsare availaible commercially for this purpose. Itis essential, however, that 'the temperature ofthe circulating water Tbe controlled by a reliableand accurate 'thermostat, or burning of thepatient may result. Our experience is that acirculating water temperature of 102OF shouldnot be exceeded. A warm base such as this pro-vides a warm atmosphere beneath the drapesand is imost effective in maintaining body tem-perature at near normal levels. Prior to theavailability of such sophisticated circulatirog'water blankets, it was our practice to place thepatient on 'hot water bottles at 1020F. This isvery effective, too, as these provide a heatreservoir, effectively retarding temperature-dropfor most procedures of average duration. Cool-ing due to the administration of cold bloodis an important factor to be guarded against.,Donor blood is stored at temperatures ibetween40 and 10°C. Some 'method of warming itbefore it enters the patient is most desirableand this will be discussed more fully.Replacement of Blood Loss

Experience has shown that clinical assessmentof blood loss during surgery is a poor guide tothe quantity requiring replacement, almostalways leading to undertransfusion. In neonatalsurgery, where the margin for error in alll res-pects is small, accuracy of estimation of bloodloss and its replacement is of greatest import-ance. 'In the fit adult, a blood loss of 500 ml.is readily compensated -by normal physiologicalprocesses. This figure represents about 10 percent of expected normal blood volume. It hasbeen estimated tlhat the average normal bloodvolume in infants is in the order of 40 ml. per

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pound ibody weight. On this basis, it will beseen that in an infant weighing 7 lb. blood lossof 30 ml. will be equivalent to 500 ml. loss inthe adult. To those unaccustomed to workingwith infants, this is often difficuilt to appreciate,both as regards estimation of quantity lost dur-ing operation and with regard to realising thedegree of exsanguination which can take placein the pre-operative period if indiscriminatesampling for biochemical purposes is allowedto take iplace. Our experience is that a loss of10 per cent of 'blood volume in the otherwisefit infant is of relatively small significance. Anyquantity above this, however, must be replacedat the time it is lost. It is our practice to trans-late all blood loss into terms of percentage ofexpected normal volume, taking this at 40 ml.per lb. body weight.Almost any operation on the neonate may

cause 'blood Iloss sufficient to require replace-men't. Pretorius (1960) gives an analysis ofblood ioss in various types of operation onneonates and small children, and Davenportand Barr (1963) divide such blood loss intotwo groups. Our experience and that of othersmakes us 'firmly convinced that no infant shouldbe subjected to surgery unless cross-matchedblood is immediately available.Some means of measuring blood loss is

essential as specuilation by surgeon or anaesthe-tist is invarialbly grossly inaccurate. The meansof imeasuring the loss should be rapid, simpleand reasonably accurate and the limitations ofthe method chosen appreciated. Rickham (1954)has discussed the difficulties arising in suchmeasurements. Of the methods availalble forestimating blood loss, the colorimetric methoddescribed by Alsop, Emery and Zachery (1963)and the gravimetric method described by Pre-torius (1960) are the simplest and most prac-tical. The gravimetric method has the disad-vantage of requiring the use of dry swabs andof being subject to error due to evaporation onthe one hand and contamination with otherfluids on the other. Nevertheless, our experienceis that provided accurate standardisation ofswajbs is ensured and due care is taken in weigh-ing, the gravimetric method compares to withina 5 per cent limit with the colorimetric methodwhich is considerably more elaborate.When an amount of (blood requiring replace-

ment is lost, it should be replaced immediately,to prevent the changes in the fluid compart-ments of the body which follow haemorrhage.On occasion, blood loss may'be rapid, requiringrapid replacement. Such rapid replacement can-not be readily achieved via the small cannulae

or neediles required for the small veins one isdealing with unless provision is made for someform of pressure transfusion. A convenientmethod of overcoming this difficulty is to ad-minister blood from a syringe connected to thetransfusion system by a three-way tap. Thisalso makes for accuracy of administration ofthe small a'bsolute quantities involved. The dan-gers of over-transfusion must not be ignoredand once more a figure of 10 per cent in ex-cess of estimated normal blood volume shouldbe taken as the limit.The transfusion of a 'high percentage of nor-

mal iblood volume is not infrequently requiredand this brings with it the dangers of massivetransfusion. Citrate intoxication, hyperkalaemiaand disturbances of acid base balance due tothe unphysiological composition of stored bloodshould be watched for. Besseling, Bull, duPlessis and iMason (1965) have summarised thisproblem and drawn attention to the importantrole played 'by hypothermia in the genesis ofmassive transfusion collapse. The rapid replace-ment of a large proportion of the 'blood volumeby cold stored blood is a potent cause of hypo-thermia and in addition, may cause selectivecardiac hypothermia during rapid transfusionwhere the transfused blood forms a high propor-tion of venous return. Hypothermia may alsointerfere with citrate metabolism, renders theheart less able to withstand alterations in Ca/Kionic ratio and may interfere undesirably withacid base balance. Steps should, therefore, betaken to warm blood to near 'body temperatureunder conditions of rapid or massive trans-fusion. The warming of blood must, however,be undertaken with the greatest caution to avoiddamage to the red 'blood cells which will under-go rapid haemolysis at temperatures in excessof 400C. Warming may 'be carried out eitherby employing an extension of the intravenoustubing immersed in a reliably thermostattedwaterbath or by warming the whole blood con-tainer prior to use. The former method is mostsuitalble in paediatric transfusion ,as the abso-lute flow-rates through the transfusion systemare relatively slow and allow good heat exchangefrom the waterbath if approximately six feetof plastic tubing is used. It must again beemphasised, however, that under no circum-stances must any portion of the blood beallowed to exceed 400C at any time. Warmingof the whole container should only be done ifall the blood is to be used within a period ofan hour or two. Warm blood should be ad-ministered at once since incutbation of storedblood at near body temperature is deleterious

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to its post-transfusion survival. If warming thewhole container is the method chosen, againthe strictest control of temperatures is man-datory to avoid ihaemolysis. Waterbath warm-ing is slow and inefficient as the water tempera-ture must not exceed 400C. The method ofheating by radio frequency induction, describedby Besseling and others (1965) is most suitableand has notw been perfected to incorporate auto-matic temperature control.

Finally, it must be emphasised that the routeby which blood is to Tbe given must be reliable.It may be impossible or extremely difficult toreplace a dislodged needle or intravenous can-nula during operation, so a firmly fixed andreliable scalp vein or cutdown drip is essentialbefore surgery is alloiwed to commence.SummaryThe necessity for specialised anaesthetic care

of the newborn infant is outlined. The reasonsfor special attention to pulmonary ventilation,control of body temperature and the adequateassessment of blood loss and its replacementare discussed.

REFERENCESADAMS, F. H., FUJIWARA, T., SPEARS, R., andHODGMAN, J. (1964): Temperature Regulation inPremature Infants, Pediatrics, 33, 487.

ALSOP, A. F. (1955): Non-kinking EndotrachealTubes, Anaesthesia, 10, 401.

ALSOP, E., EMERY, J. L., and ZACHERY, R. B. '(1963):Measurement of Bloiod Loss during Opera,tion, Brit.med. J., i, 125.

BEECHER, H., and TODD, D. (1954): A Study ofDeaths associated with Anaesthesia and Surgery,Ann. Surg., 140, 2.

BERGNER, R. (1955): Cardiac Arrest. Some Aetio-logical Considerations, Anaesthesiology, 16, 177.

BESSELING, J. L., BULL, A. B., DU PLESSIS, J. M. E.,and MASON, I. M. (1965): The Rapid Warmingof Blood for Massive Transfusion by R.F. Induc-tion, S. Afr. med. J., 39, 137.

BIGLER, J. A., and McQuIsToN, W. 0. (1951): BodyTemperatures during Anaesthesia in Infants andChildren, J. Amer. med. Ass., 146, 551.

BRUK, K. (1961): Temperature Regulation in theNewborn Infant, Biol. Neonat., 3, 65.

CLAPPISON, G. B., and HAMILTON, W. K. (1956):Respiratory Adjustments to Increases in ExternalDeadspace, Anaesthesiology, 17, 643.

COLE, F. (1945): A New Endotracheal Tube forInfants, Anaesthesiology, 6, 87.

CROSS, K. W., TIZZARD, J. P. M., and TRYTHALL,D. A. H. i(1958): The Gaseous Metabolism of theNewborn Infant Breathing 15% Oxygen, Actapaediat. (Uppsala), 47, 217.

DAVENPORT, H. T., and BARR, M. N. (1963)': BloodLoss During Paediatric Operations, Canad. med.Ass. J., 89, 1309.

FARMAN, J. V. (1962): Heat Loss in Infants Under-going Surgery in Air Conditioned Theatres, Brit.J. Anaesth., 34, 543.

HARRISON, G. G., BULL, A. B., and SCHMIDT, H. J.(1960): Temperature Changes in Infants andChildren During General Anaesthesia, Brit. J.Anaesth., 32, 60.

HARRISON, G. G. (1965): Personal Communication.KOK, 0. V. S., and KITAY, C. (1960): Cardiac Arrest

Associated with Surgical Procedures, S. Afr. Med.J., 34, 229.

Mc. CREDIE, D. A. (1962): The Use of Hypothermiain Paediatric Emergencies, J. Paediat., 61, 653.

MCDONALD, I. H. (1960): Infant Physiology andAnaesthesia, Brit. J. Anaesth., 32, 22.

MUSHIN, W. W., MAPLESON, W. W., and LumN, J. N.(1962): Problems of Automatic Ventilation inInfants and Children, Brit. J. Anaesth., 34, 514.

NELSON, N. M., PROD'HOM, L. S., CHERRY, R. B.,LIPSITZ, P. J., and SMITH, C. A. (1962): Pulmon-ary Function in the Newborn Infant, Paediatrics,30, 963.

PRETORIUS, J. A. (1960): Blood Loss in PaediatricSurgery, Anaesthesia, 15, 4, 424.

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