cuffed oropharyngeal airway (copa) and pharyngeal tumours

Correspondence

Implementing PCA – theimportance of information andcontrol

I wish to comment on the report byChumbley et al. (Anaesthesia 1998; 53:216–21) which contributes to the debateconcerning the significance of control asa psychological mechanism underlyingthe efficacy of patient-controlled analge-sia (PCA) for the relief of postoperativepain.

The effectiveness of self-administeredanalgesia depends on a patient’s appro-priate response to the pain perceived.Psychological factors which influencethis response are increasingly betterunderstood and substantial evidencehas existed for some years that controlconfers positive effects on analgesiaself-administration and on recovery andconversely that noncontrol impacts nega-tively [1]. Psychological determinants ofcontrol in the context of illness, pain andrecovery are complex [2] but for mostpersonality types the potential for con-trol to confer positive benefits is closelylinked with the provision of information[3–5]. Similarly, with regard to post-operative pain relief in the clinicalsetting, the provision of information,instruction and continuing supervisionrepresents a major component contri-buting to improved analgesia, probablyof more importance than the analgesicmethod per se [5–8]. Chumbley andcolleagues’ findings are consistent withthis hypothesis showing the exercise ofcontrol, whether real or perceived, to belinked with the provision of informationand with more effective use of the PCApumps. Unfortunately, the majority oftheir patients received no pre-operative

instruction, did not know what to expectof the PCA pumps and were apparentlyneither reviewed nor coached duringtheir therapy – all widely regarded asprerequisites for successful implementa-tion of PCA. It is improbable thereforethat more than a minority of the patientsstudied had the capability for control andconsequently for a substantial proportionthe analgesic technique implementedcould not have been patient-controlledanalgesia. The inconsistencies found inthe perception and exercise of control bypatients are explicable by this alone, asare the generally mixed patient evalua-tions of treatment with the PCA pumps.Despite apparently recognising this intheir discussion, the authors make theassertion that ‘control is predominantly afeature of the professional’s view of PCArather than a reflection of the patient’sexperience’. This may apply to patientsusing PCA pumps in their hospital, butfor it to have any validity in respect ofPCA programmes implemented by painmanagement services elsewhere theirstudy would have to be carried out in apatient population where analgesia wasin fact patient controlled rather thanmerely patient administered.

The real value of the data presentedby Chumbley et al. is in the support itgives to the observation that the efficacyof an analgesic technique lies not intrin-sically in that technique but in thequality of its implementation [8].

M. R. GabrielczykDepartment of Anaesthesia, PainManagement & Intensive Therapy,Southend Hospital,Westcliff-on-Sea,Essex SS0 0RY

References1 Egan KJ. What does it mean to a

patient to be ‘‘in control’’. In: FerranteFM, Ostheimer GW, Cousins BG, eds.Patient Controlled Analgesia. Cambridge,MA: Blackwell Scientific Publications,1990; 17–26.

2 Skevington SM. Beliefs about controland causation affecting pain and illness.In: Skevington SM, ed. Psychology ofPain. Chichester: J Wiley & Sons,1995; 131–51.

3 Cromwell RL, Butterfield EC,Brayfield FM, Curry JJ. AcuteMyocardial Infarction: Reaction andRecovery. St Louis: Mosby, 1977.

4 Schorr D, Rodin J. Motivation tocontrol one’s environment inindividuals with obsessive-compulsive,depressive and normal personalitytraits. Journal of Personality and SocialPsychology 1984; 46: 1148–61.

5 Mahler HIM, Kulik JA. Preferencesfor health care involvement,perceived control and surgicalrecovery: a prospective study. SocialScience and Medicine 1990; 31:743–51.

6 Gould TH, Crosby DL, Harmer M,et al. Policy for controlling pain aftersurgery; effect of sequential changes inmanagement. British Medical Journal1992; 305: 1187–93.

7 Coleman SA, Booker-Milburn J.Audit of postoperative pain control.Influence of a dedicated acute painnurse. Anaesthesia 1996; 51: 1093–6.

8 Gabrielczyk MR, McGonagle C.Postoperative pain control; influence ofa dedicated acute pain nurse.Anaesthesia 1997; 52: 382–94.

Anaesthesia, 1998, 53, pages 1028–1037................................................................................................................................................................................................................................................

1028 Q 1998 Blackwell Science Ltd

All correspondence should be addressed to Professor M. Harmer, Department of Anaesthetics, University Hospital of Wales, Heath Park, Cardiff CF44XW, UK.

Letters (two copies) must be typewritten on one side of the paper only and double spaced with wide margins. Copy should be prepared in the usualstyle and format of the Correspondence section. Authors must follow the advice about references and other matters contained in the Notice toContributors to Anaesthesia printed at the back of each issue. The degree and diplomas of each author must be given in a covering letter personally signedby all the authors.

Correspondence presented in any other style or format may be the subject of considerable delay and may be returned to the author for revision. If theletter comments on a published article in Anaesthesia, please send three copies; otherwise two copies of your letter will suffice.

Any assessment of patient satisfaction isfraught with difficulties [1]. However,Chumbley and colleagues (Anaesthesia1998; 53: 216–21) have documentedsome interesting observations regardingpatient beliefs of PCA (patient-controlanalgesia) which highlight where PCApatient education can be focused. Theymention a previous study by two ofthe same authors to support their beliefthat patient control was consideredunimportant by patients [2] yet thispaper stated that 7/26 patients used thePCA in anticipation of movement, 7/26to reduce pain to an agreeable level and6/26 to control pain after waking. Inaddition, six of the 12 patients withnausea or vomiting attributed the PCAas the cause, suggesting patients coulduse the PCA to balance increasedanalgesia or the side-effects being experi-enced. These examples clearly identifypatient control as an important elementin their use of PCA despite it not beingverbalised without prompting.

In view of the well-recognised side-effects of morphine, it is no surprise thatsome patients, reported by Chumbley etal., only pressed the button when thepain was so bad that they could not cope.They also express surprise that othersmay be encouraging patients to the useof PCA. Ward nurses or medical staffoften advise pressing the button if thepatient is in pain as part of the patienteducation process. It would also not beunreasonable or unusual for patients tobe encouraged to use the PCA priorto mobilisation or physiotherapy. Theauthors believe their results ‘are incon-sistent with the notion that patients usePCA to achieve a pain-free state’. Myperception from talking to patients onacute pain rounds is that the vast majorityexpect to have at least some pain aftersurgery. Chumbley et al. also dismiss thepotential usefulness of PCA for assessinganalgesia consumption when testing effi-cacy of new analgesic regimens. Severalstudies have found this to be a useful tool[3, 4] and although not perfect may bebetter than the alternative or measuringnurse-administered analgesia.

Pain has been described as an ‘unplea-sant sensory and emotional experience’[5] implying that sensory analgesia is justone aspect of overall pain perception.

Coleman and Booker-Milburn suggestthat the advantages of PCA can benegated by failure to address deficienciesin knowledge of pain managementby both ward staff and patients [6]. Thelimitations of currently available analge-sics together with inadequate educationof ward nurses and medical staff regard-ing acute pain may be the main factorscontributing to inappropriate use of andconsequent suboptimal efficacy of PCArather than the technique itself.

A. M. CynaWomen & Children’s Hospital,North Adelaide, SA 5006,South Australia

References1 Whitty PM, Shaw IH, Goodwin DR.

Patient satisfaction with generalanaesthesia. Too difficult to measure?Anaesthesia 1996; 51: 327–32.

2 Taylor NM, Hall GM, Salmon Peter.Patients’ experiences of patient-controlled analgesia. Anaesthesia 1996;51: 525–8.

3 James MF, Heijke SA, Gordon PC.Intravenous tramadol versus epiduralmorphine for post thoracotomy relief:a placebo controlled double-blind trial.Anesthesia & Analgesia 1996; 83:87–91.

4 Rosenblatt WH, Cioffi AM, Sinatra R,Saberski LR, Silverman DG.Metoclopramide: an analgesic adjunctto patient-controlled analgesia.Anesthesia & Analgesia 1991; 73:553–5.

5 Merksey H, Albe-Fessard DG, BonicaJJ. Pain terms: a list with definitionsand notes on usage. Pain 1979; 6: 249.

6 Coleman SA, Brooker-Milburn J.Audit of postoperative pain control.Influence of a dedicated acute painnurse. Anaesthesia 1996; 512: 1093–6.

ReplyWe note with interest the commentsmade by both correspondents. Gabrielc-zyk has summarised the professional viewof patient-controlled analgesia (PCA),that the control the patient experienceswhilst using it improves analgesia, self-medication and recovery. Although weare aware of this view, our aim in thisand related studies has been to identify

the patient’s experience which we havefound to differ from the professionalview [1, 2]. Cyna implied that controlcan be achieved by the simple titration ofanalgesia against pain and side-effects. Toredefine control in this way trivialises theconcept. Indeed, in our present andprevious studies patients experiencedside-effects as restricting control [2, 3].It is likely that when patients describe afeeling of control, they are just describ-ing success in operating the machine.

We acknowledge that 43% patients inour study were not given pre-operativeinformation. The amount of pre-opera-tive information that patients receivedhad no significant effect on the amountof control they achieved (p� 0.19);however, those patients who achievedcomplete control did receive more infor-mation over time. The importance ofpre-operative information is unclear.Some authors have found that providingdetailed pre-anaesthetic information wasof little benefit compared with routineinformation [4]. This area warrants inten-sive investigation and is the focus of ourcurrent work. Nevertheless, althoughpre-operative information may producea feeling of control, it cannot influencethe side-effects associated with the drug.

It would appear that to preserve cur-rent views of the value of PCA, theconcept of control must be redefinedso as to be consistent with PCA andany remaining problems must be left to‘information’ and ‘education’ to solve.Clearly the appeal of this new techniquehas provided an alternative to under-standing and addressing the problemsthat have long been known to com-promise postoperative analgesia. Theplea for more education is simplistic;what is essential is more questioningand more analysis.

G. M. ChumbleyG. M. HallPeter SalmonSt. George’s Hospital MedicalSchool,London SW17 0RE, UK

References1 Peerbhoy D, Hall GM, Parker C,

Shenkin A, Salmon Peter. Patients’reactions to attempts to increase passive

Anaesthesia, 1998, 53, pages 1028–1037 Correspondence................................................................................................................................................................................................................................................

1029Q 1998 Blackwell Science Ltd

or active coping with surgery. SocialScience and Medicine (in press).

2 Taylor NM, Hall GM, Salmon Peter.Is patient-controlled analgesiacontrolled by the patient? Social Scienceand Medicine 1996; 43: 1137–43.

3 Taylor NM, Hall GM, Salmon Peter.Patients’ experiences of patient-controlled analgesia. Anaesthesia 1996;51: 525–8.

4 Elsass P, Eikard H, Junge J, Lykke J,Staun P, Feldt-Rasmussen M.Psychological effect of detailedpreanesthetic information. ActaAnaesthesiologica Scandinavica 1987; 31:579–83.

Oral transmucosal fentanyl

Oral transmucosal fentanyl has beenavailable in the USA for anaesthetic pre-medication since 1994. The commercialpreparation, Fentanyl Oralet whichconsists of a raspberry-flavoured, fenta-nyl-impregnated, sugar-matrix mountedon a stick, has provided anaesthetists withan opportunity to deliver anxiolysis andanalgesia to children safely and reliably bya readily acceptable route of administra-tion. Children are encouraged to suckand not bite or chew as 25% of the totaldose is absorbed ‘trans-buccally’. Thisaccounts for the early onset of centrallymediated anxiolytic and analgesic effectsseen within 15 min of administration.Of the remainder, which is swallowedwith saliva, only 25% escapes hepaticfirst-pass metabolism to become moreslowly available systemically [2].

The authors, wanting to evaluate theacceptability of this preparation to child-ren in the UK, manufactured units con-taining 200, 300 or 400 mg of fentanyland offered 15 healthy children, aged3–9 years, presenting for tonsillectomythe choice of having either midazolamsyrup or oral transmucosal fentanyl(15–20 mg.kgÿ1) [1] as part of their pre-medication. All but one child, whorefused it because it resembled a lollipop,chose the new preparation and con-sumption was, in all cases, completewithin 20 min. Twelve children pre-sented in an unsedated yet calm mannerand co-operated fully with venous can-nulation and induction of anaesthesia.

Despite prophylaxis with ondansetron(100 mg.kgÿ1) postoperative nauseaoccurred in three children, one ofwhom vomited. These incidences,though still appreciable, compare withprevious observations [1, 3].

Fentanyl Oralets are currently onlycommercially available in the USA,where sales approach 20 000 units eachyear, but the manufacturer is exploringthe feasibility of introducing them in theUK. We are encouraged by our provi-sional findings and would welcome theirintroduction in the U.K. for furtherevaluation.

D. ProsserM. AllmanRoyal Gwent Hospital,Newport, Gwent, UK

P. GrassbySt. Mary’s Hospital,Cardiff, UK

References1 Streisand JB, Stanley TH, Hague B,

van Vreeswijk H, Ho GH, Pace NL.Oral transmucosal fentanyl citratepremedication in children. Anesthesiaand Analgesia 1989; 69: 28–34.

2 Physicians’ Desktop Reference 1997;edn 51, Medical Economics FENTANYLORALET : 428–32.

3 Friesen RH, Carpenter E,Madigan CK, Lockhart CH. Oraltransmucosal fentanyl citrate for pre-anaesthetic medication of paediatriccardiac surgery patients. PaediatricAnaesthesia 1995; 5: 29–33.

Safety of fine-gauge, pencilpoint spinal needles

We read with interest and concern theletter to Anaesthesia (1997; 53: 411) byDrs Collier and Turner who have ‘ . . .virtually abandoned the use of a com-bined spinal epidural (CSE) techniquewith pencil point needles’, implying thatthese needles are unsafe. We suggest thattheir conclusion is unfounded and thatit is most likely their CSE techniquewhich is at fault.

Your correspondents referred to a letterby Turner and Shaw who observed para-esthesia in 6 out of 36 patients having

CSE anaesthesia for Caesarean section[1]. One of the six had a dysaesthesiasome 6 months after the procedure. Weassume that the CSE technique used wasthe ‘double-barrel’ method advocatedby Turner and Reifenberg, a methodwhich involves inserting a fine (25G)Whitacre needle via a short introducer,through the interspinous ligament, liga-mentum flavum and epidural space toreach the theca [2]. This technique ofspinal needle insertion is associated witha high incidence of needle deflection,misdirection and damage [3–6].

Undoubtedly the best way to mini-mise such damage is to avoid passingthe fine-gauge needle through thesetissues. In other words, insertion shouldbe through a Tuohy (or other similar,blunt) needle first sited in the epiduralspace. This is the basis of the needle-through-needle CSE method, which isarguably the most widely used CSEtechnique today. Almost all the studiescited in a recent comprehensive reviewof CSE used this needle-through-needlemethod [7], a technique which has beenused at Queen Charlotte’s Hospital inmore than 11 000 patients since 1991.Most of those blocks were administeredto obstetric and gynaecological patientsby trainees and to the best of our knowl-edge no problems involving damaged27G Whitacre needles have been encoun-tered. A recent audit of 1000 consecutiveCSEs performed at Queen Charlotte’sHospital indicates an incidence ofparaesthesia of 6% with one case of anassociated short-term dysaesthesia. Para-esthesia reported by a patient duringepidural and/or spinal or other regionalprocedure should always be recorded,accorded some concern and the patientfollowed-up postoperatively; but para-esthesia per se does not imply neuraldamage. Dysaesthesia, hypoaesthesia andsimilar sequelae can result from CSEwhere no paraesthesia is observed [8].

The significance of paraesthesiaeassociated with all lumbar puncture tech-niques has not been satisfactorily resolvedwith respect to spinal needle type orinsertion method used. But, as yourcorrespondents report, incidences ofparaesthesia of up to 27% have beenreported for needle-through-tissues tech-niques [3] and the extra depth of thecal

Correspondence Anaesthesia, 1998, 53, pages 1028–1037................................................................................................................................................................................................................................................


insertion of pencil-point needles doesrequire further investigation [2]. Yourcorrespondents’ anecdotes and an auditof 36 administrations are not a soundbasis to conclude that paraesthesiae axio-matically indicate neurotrauma due tothese needles.

We submit that the needle-through-needle CSE technique is emerging as amost important advance in anaestheticpractice and pain management. Like allregional anaesthetic procedures CSE isnot without unexpected hazards andthese and other aspects of all tech-niques of lumbar puncture requirefurther study.

J. A. CrowhurstF. PlaatQueen Charlotte’s & ChelseaHospital,London, UK

References1 Turner MA, Shaw M. Atraumatic

needles. Anaesthesia 1993; 48: 452.2 Turner MA, Reifenberg NA.

Combined spinal epidural anaesthesia.The single-space, double-barreltechnique. International Journal ofObstetric Anaesthesia 1995; 4: 158–60.

3 Hopkinson JM, Samaan AK, Russel IF,Birks RJS, Patrick MR. A comparativemulticentre trial of spinal needles forCaesarean section. Anaesthesia 1997;52: 1005–11.

4 Teh J. Breakage of Whitacre 27 gaugeneedle during performance of spinalanaesthesia for Caesarean section.Anaesthesia & Intensive Care 1997; 25:96.

5 Crowhurst JA. Fractured fine-gaugespinal needles. Anaesthesia & IntensiveCare 1997; 25: 317–8.

6 Hoskin MF. Spinal anaesthesia – thecurrent trend towards narrow gaugeatraumatic (pencil point) needles. Casereports and review. Anaesthesia &Intensive Care 1997; 26: 96–106.

7 Rawal N, Vanzundert A, HolmstromB, Crowhurst JA. Combined spinal–epidural (CSE) technique. RegionalAnesthesia 1997; 22: 406–23.

8 Paech MJ. Unexplained neurologicdeficit after uneventful combinedspinal and epidural anesthesia forCesarean delivery. Regional Anesthesia1997; 22: 479–82.

Another angle on LMA stability

Traction applied by the breathing systemfrom the head end of the table canmarkedly distort the shaft of a laryngealmask airway (LMA). Even if the tubingis supported to minimise the effects ofgravity, traction may still exist due to theelasticity of the tubing. In addition totying or taping the LMA into place,stability of the LMA can be achieved ifthe natural curve is maintained followinginsertion [1]. One method to achieve thisinvolves looping the inspiratory andexpiratory limbs of the breathing systemaround each side of the head to meet theLMA via an angle piece just infero-anterior to the chin [2]. This techniqueis obviously not suitable for co-axialbreathing systems or T-pieces and mayreduce surgical access to both sides ofthe head.

We would like to describe an effec-tive, yet simple, way of improving LMAstability. By attaching a second right-angle piece to the LMA (Fig. 1), it ispossible to adjust the position of thebreathing system in relation to the LMAso that the profile of the LMA prior toconnection is maintained. The tubingnow runs parallel to shaft of the LMA,and therefore traction is no longer

applied at right angles to the shaft ofthe LMA but tends to retain the devicein its natural position. This configura-tion can be used with any breathingsystem. It is particularly useful in eden-tulous patients in whom there is lesssupport for the LMA and may alsoreduce the pressure of the LMA againstthe upper incisors, possibly avoidingdamage to patients with poor denti-tion. The benefits of this techniquemust be weighed against the smalladditional deadspace and the presenceof an extra connection in the breathingsystem.

H. J. SkinnerJ. G. HardmanUniversity Department ofAnaesthesia,Queen’s Medical Centre and CityHospital,Nottingham NG7 2UH, UK

References1 Brimacombe JR, Brain AIJ,

BerryAM. The Laryngeal Mask AirwayInstruction Manual, 3rd edn. Intavent,1996.

2 Bignell S, Brimacombe J. LMAstability and fixation. Anaesthesia andIntensive Care 1994; 22: 746.



Figure 1 Ordinary traction by the breathing system does not distort the LMA. Bacterialfilter with gas sampling port removed for photograph.

Cuffed oropharyngeal airway(COPA) and pharyngealtumours

We read with interest the report byPigott et al. (Anaesthesia 1998; 53:480–3) describing the use of the cuffedoropharyngeal airway (COPA) as an aidto fibreoptic intubation. The patient,known to have a friable necrotictumour invading the tonsil, parapharyn-geal space, soft and hard palate and baseof tongue, was at risk of bleeding fromtrauma to the tumour surface. We weretherefore surprised that the COPA hadbeen used in these circumstances.

The authors state that insertion of alaryngeal mask airway could be trau-matic; we would suggest the COPAcould be as traumatic particularlybecause 45 ml of air was introduced toinflate the cuff. Also, introduction of thefibrescope between the COPA andpharyngeal wall may cause trauma as‘friction between the cuff and pharyn-geal wall stabilises the proximalbronchoscope to allow control of thedistal end’. The authors comment on themajor advantage of the COPA overother devices as being continuous freshgas flow and unhurried intubation.Many of these devices [1, 2] can, how-ever, be used with a facemask andbreathing system connector (Mainz uni-versal adaptor, Rusch UK or VBMendoscopy mask) in which a diaphragmis present that produces a seal around thefibrescope. The patient can breathespontaneously or by assisted ventilationfor a prolonged period with less dangerof trauma as no cuff is inflated. A furtheradvantage is that the fibrescope is direc-ted to the larynx unlike the COPAwhere orientation and positioning arealong one side of the oropharynx. Theauthors also commented on the optionsavailable for securing the airway inpatients with advanced oropharyngealtumours, but failed to mention trans-tracheal jet ventilation [3, 4] whichbypasses the upper airway and providesan alternative technique of ventilationduring fibreoptic intubation undergeneral anaesthesia with unhurriedconditions.

The COPA may have a role in airwaymanagement, but its role in the manage-ment of the difficult airway due to

necrotic tumours of the oropharynx isquestionable. Other devices are availablewhich allow spontaneous ventilation forprolonged periods, with less risk oftrauma to necrotic surfaces and provideimproved positioning of the fibrescopefor visualising the larynx.

A. PatelA. PearceGuy’s Hospital,London SE1 9RT, UK

References1 Ovassapian A. A new fiberoptic

intubating airway. Anesthesia andAnalgesia 1987; 66: S132.

2 Smith JE, Mackenzie AA, Scott-Knight VCE. Comparison of twomethods of fibrescope-guided trachealintubation. British Journal of Anaesthesia1991; 66: 546–50.

3 Baraka A. Transtracheal jet ventilationduring fiberoptic intubation undergeneral anesthesia. Anesthesia andAnalgesia 1986; 65: 1091–2.

4 Benumof JL, Scheller MS. Theimportance of transtracheal jetventilation in the management of thedifficult airway. Anesthesiology 1989;71: 769–78.

External or internal jugularcannulation?

I was interested by the report of Zaidaet al. of cerebral infarction followingcentral venous cannulation (Anaesthesia1998; 53: 186–91) because it is anopportunity to contrast internal jugularvein cannulation with the relativelyrisk-free external jugular approach.The patient described was a 65-year-old hypertensive, cigarette smoking,diabetic man with a very high risk ofcarotid artery disease and hence avoidingthe risk of arterial puncture would bedesirable. Blitt et al. [1] reported a 96%success rate of caval cannulation via theexternal route and stated that this mayunderestimate the success rate gainedwith experience. An earlier series of1537 external and 9973 internal jugularcannulations [2] yielded complicationrates of vein thrombosis and phlebitisof 1.74% and 2.2%, respectively, withthe external route, but compared to the

more serious complications of hydro-thorax, pneumothorax and arterialpuncture that occurred with internaljugular cannulation, these rates are notunfavourable. Isolated reports of hydro-thorax following external jugular cannu-lation can be found [3], but an exactincidence of this complication is notavailable.

Perhaps the authors would considerusing a 23 gauge needle when locatingthe internal jugular vein instead of the21 gauge needle described in theirreport. It is possible that arterial punc-ture by a small seeker needle has fewersequelae.

M. DuncanBeaumont Hospital,Dublin 9, Ireland

References1 Blitt CD, Wright WA, Petty WC.

Central venous catheterisation via theexternal jugular vein. Journal of theAmerican Medical Association 1974; 229:817.

2 Burri C, Krischak G. Techniques andcomplications of the administration oftotal parenteral nutrition. In: Manni C,Magalini SI, Scrascia E, et al., eds. TotalParenteral Alimentation. Amsterdam:Excerpta Medica, 1976; 306–15.

3 Ho CM, Lui PW. Bilateralhydrothorax caused by left externaljugular, venous perforation. Journal ofClinical Anaesthesia 1994; 6: 243.

Spinal flexion and CSF pressure

The paper by Dinsmore et al. (Anaesthe-sia 1998; 53: 431–4) shows that flexionof the spine decreases the capacity of thecerebrospinal fluid (CSF) space andincreases the CSF pressure. Figure 1 intheir paper shows an increase in CSFpressure with increasing flexion of thespine. However, in their summary andparagraph one of the discussion, theyerroneously state that the CSF pressureincreased from the fully flexed to theflexed position. This should read ‘theCSF pressure decreased from the fullyflexed to the flexed position’.

They found a mean increase of5.3 mmHg in CSF pressure whenpatients moved from the flexed to the



fully flexed position. The maximumincrease in CSF pressure they recordedwas 11 mmHg. With these results theyconclude that epidural puncture per-formed in a fully flexed position mayincrease the incidence of inadvertentdural puncture. However, when movingfrom lateral to the sitting position, themean CSF pressure increases by28 mmHg [1]. Yet with this greatlyincreased CSF pressure, there is no evi-dence that epidural puncture performedin the sitting position carries a greaterrisk of inadvertent dural puncture.

J. L. ShahCity Hospital NHS Trust,Birmingham, UK

Reference1 Loman J, Myerson A, Goldman D.

Effects of alterations in posture on thecerebrospinal fluid pressure. Archives ofNeurology and Psychiatry 1934; 33:1279–95.

A replyWe thank the Dr Shah for drawingattention to this error. The summaryshould have read: ‘There was a signifi-cant decrease in cerebrospinal fluid pres-sure on moving from the fully flexed tothe flexed position’. Regarding theirsecond point, the increased incidenceof inadvertent dural puncture. Perhapsthe message here is that any theoreticalincreased risk posed by different posi-tions is usually outweighed by the posi-tion in which the practitioner is mostexperienced.

J. DinsmoreAtkinson Morley’s Hospital,London SW20 0NE, UK

My ‘Y-can’ can’t

I recently encountered a problem oninserting a Y-CAN intravenous cannula(ref. YC23SY, lot 98 A 22, expires 20 0001, Sims Portex Limited, Colchester,Essex) into a large forearm vein as apreliminary to inducing anaesthesia. Arapid flashback of blood into the cham-ber was obtained on cannulation of thevein, the needle was withdrawn from thecannula but absolute resistance was met

on attempted injection through the one-way valve. Removal of the valve failedto produce the usual blood backflowup the ‘Y’ side channel and the resis-tance to injection remained absolute,even on removal of the cannula fromthe patient. Close scrutiny revealed thatthe Y-CAN was defective, with the sidechannel lumen obliterated for approxi-mately 1 mm where it joined the mainbody of the cannula. This was moreevident when the faulty Y-CAN(Figure) was compared with a functionalone.

Besides the cost implication of using asecond cannula, intravenous cannulationwith Y-CANS that can’t be injectedthrough does little to speed up busyoperating lists and even less to reassureanxious patients in the anaesthetic room.Other Y-CANS from the same lot thathave been used in our department havenot shared this defect.

A. L. GoldsmithSalisbury District Hospital,Salisbury SP2 8BJ, UK

A replyThank you for the opportunity to com-ment on the recent experience whichDr Goldsmith has brought to our atten-tion. The Y-Can has been available for18 years, during which time millions ofcannulae have been sold. We insist on

thorough quality inspections throughoutmanufacture and are disappointed thatthis product became available for use.Since we consider any such incident tobe unacceptable, we have revised ourmanufacturing and in-process qualityassurance procedures in order to mini-mise the likelihood of a recurrence ofblockage of the side-channel of thecatheter.

We would like to offer our sincereapologies to Dr Goldsmith for theinconvenience caused and thank him forbringing this incident to our attention.

S. ShervillInternational Product Manager,SIMS Portex Limited,Hythe, Kent CT21 6JL, UK

Unanticipated admissionfollowing day surgery

Unanticipated admission following daycase surgery is a useful marker for pre-dicting outcome following surgery andis an indicator of morbidity and mortal-ity [1]. The admission rate after ambu-latory surgery varies between 0.1% and5% [2]. Anaesthetic factors (nausea andvomiting, drowsiness, pain) play a signi-ficant role in the detainment as an in-patient following surgery [3, 4]. Withthe introduction of newer anaesthetic



agents, particularly propofol and sevo-flurane and improved pain managementtechniques, we wished to determinewhether anaesthesia was still a majorcontributing factor to patient admissionafter day surgery. To this end, in April1998 an audit was performed to deter-mine the incidence of and reasons foradmission as an in-patient following daysurgery. Reasons for admission wereclassified as either surgical, anaestheticor social.

The total number of cases performedat Rossendale General Hospital between1 April 1997 and 28 February 1998 was2520; 47.61% were ASA grade 1, 23.80%grade 2 and 23.57% grade 3. All ASA 3patients were over 70 years of age andhad three or more intercurrent illnesses(e.g. asthma, heart disease, hypertension,diabetes mellitus, cerebrovascular acci-dents, thyroid disease, epilepsy, connec-tive tissue disorders and renal disease).Of these patients, 758 were generalsurgical cases, 451 were urological, 235orthopaedic, 116 gynaecological, 115ENT and 131 medical cases. All medicalprocedures were performed under localanaesthesia and sedation. Twenty-sixpatients were detained as in-patientsand 21 sets of notes were available forreview. Of these patients, 12 were gen-eral surgical (1.6%) and 10 of these weredetained due to unanticipated extensivesurgery and two were admitted for socialreasons.

Three urological patients (0.7%) wereadmitted, one for pharyngeal bleedingfollowing trauma to an enlarged tonsilduring laryngeal mask airway insertion,while another developed ventricularectopics during the procedure and wasadmitted for 24-h ECG monitoring. Thethird underwent a procedure that tooklonger than anticipated. Three ortho-paedic patients (1.3%) were admitted,one due to leg weakness following anepidural injection for a prolapsed disc,one had a drain inserted during surgeryand the third for social reasons. OneENT patient (0.9%) was admitted forobservation following therapeutic endo-scopic procedures because of pre-existing illness. In total, 15 admissionswere for surgical reasons, three were foranaesthetic complications and three forsocial reasons.

This audit showed that the admissionrate following day case surgery was smalland that anaesthesia made little contri-bution. The need for admission due tosurgical or social factors may have beenpredictable and better adherence to therevised guidelines of the Royal Collegeof Surgeons of England [5] may havereduced the number of unexpectedadmissions further.

S. DeshpandeJ. WattsBurnley General Hospital,Burnley BB10 2PQ, UK

References1 Warner MA, Shields SE, Chute CG.

Major morbidity and mortality withinone month of ambulatory surgery andanaesthesia. Journal of American MedicalAssociation 1993; 270: 1437–41.

2 Meridy HW. Criteria for selection ofambulatory surgical patients andguidelines for anesthetic management.A retrospective study of 1,553 cases.Anesthesia and Analgesia 1982; 61:921–6.

3 Johnson CD, Jarrett PEM. Admissionto hospital after day surgery. Annals ofthe Royal College of Surgeons of England1990; 72: 225–8.

4 Gold BS, Kitz DS, Lecky JH, NeuhausJM. Unanticipated admission to thehospital following ambulatory surgery.Journal of American Medical Association1989; 262: 3008–10.

5 Royal College of Surgeons in England.Guidelines for Day Surgery. London:Revised Edition, March 1992.

Respiratory insufficiency inCharcot-Marie-Tooth disease

I congratulate Drs Reah, Lyons andWilson on their successful managementof a Caesarean section in a patient withhereditary motor and sensory neuro-pathy type I (HMSN I) or Charcot-Marie-Tooth disease (Anaesthesia 1998;53: 580–3). However, I would like tomake a point about respiratory insuffi-ciency in this disease. Although HMSNI predominantly affects distal nervesand therefore musculature, in severe,advanced disease, as in the patient

described, the diaphragm may also beinvolved [1]. Two years prior to preg-nancy, the patient complained of severeorthopnoea (in the absence of cardiacfailure) and this is highly indicative ofdiaphragmatic failure [2]. A decrease ofmore than 30% in forced vital capacitybetween the erect and lying position andparadoxical abdominal movement oninspiration would have supported thediagnosis although more sensitive testsfor diaphragmatic function such as mea-surement of transdiaphragmatic pressureare necessary for quantitative assessment.The presence of a gravid uterus and athoracic kyphosis would clearly furthercompromise respiratory function.

In summary, patients with severeHMSN I presenting for anaesthesiamust have diaphragmatic functionassessed carefully before planning anyintervention.

N. P. HirschThe National Hospital forNeurology and Neurosurgery,London WC1N 3BG, UK

References1 Hardie R, Harding AE, Hirsch NP,

Gelder C, Macrae AD, Thomas PK.Diaphragmatic weakness in hereditarymotor and sensory neuropathy. Journalof Neurology, Neurosurgery, and Psychiatry1990; 53: 348–50.

2 Newsom Davis J, Goldman M, Loh L,Casson M. Diaphragm function andalveolar hypoventilation. QuarterlyJournal of Medicine 1976; 45: 87–100.

The bearded airway

Maintaining an airway using a facemaskin patients who have beards can bedifficult. This is due to failure to achievean effective seal and in the difficulty ofperforming adequate chin lift, particu-larly if the beard growth is thick.

A simple solution to this problem is towrap cling film repeatedly around theface and head of the unconsciouspatient. Perforating a hole through thecling film at the mouth will then permitplacement of the face mask to achieve agood seal and establish easy assisted ven-tilation. We believe that this approach



has been life saving on at least oneoccasion, when an unconscious traumapatient, with an abundant growth offacial hair, presented to the casualtydepartment. Following difficulty in ade-quate placement of the face mask, thistechnique was employed. Assisted ven-tilation was then easily achieved and thepatient successfully oxygenated prior tothe establishment of a definitive airway.

As a result we recommend that nocasualty department should be without aroll of cling film.

C. VincentW. A. AmesQueen Victoria Hospital,East Grinstead RH19 3D2, UK

Critical incidents

The article by Findlay and colleagues(Anaesthesia 1998; 53: 595–7) was inter-esting, but there is perhaps more thatcould be made of their data.

The characteristics of a critical inci-dent [1] have been described as: itinvolved an error by a member of theanaesthetic team or a failure of the anaes-thetists’ equipment to function properly;it occurred at a time when the patientwas under the care of the anaesthetist; itwas described in clear detail by a personwho observed, or was involved, in theincident; it was clearly preventable.

By studying them we can hope todevelop strategies for their avoidance.To assist this, a scale of preventabilityhas been built into the Royal College ofAnaesthetists critical incident study, asfollows: (1) probably preventable withincurrent resource, e.g. failure to do pre-operative check; (2) probably prevent-able with reasonable extra resource, e.g.failure to detect oesophageal intubationwould be improved by having capno-graphs; (3) possibly preventable withcurrent resource, e.g. pneumothoraxinsertion might be prevented by betterteaching and supervision; (4) possiblypreventable with reasonable extraresource, e.g. problem arising becauseanaesthetist unwell might be prevented bymore cover; (5) not obviously prevent-able by any change in practice, e.g.electricity grid failure.

Cohen et al. [2] did indeed also find

that individuals reported only 30% ofincidents compared with reporting by athird party observer. Some of the reasonsfor this discrepancy have been explored[3], but in summary were: forgetfulnessby the anaesthetist; inadequate defini-tions of incidents; late showing of theoutcomes; fear of reporting; classifica-tion difficulties; need for direct ques-tioning of patients about outcomes. Thisflags up the major difficulty with criticalincident reporting – that thenumberscon-cerned, either as numerator or denomi-nator, are never likely to be accurate andcan only be taken as painting a mistypicture. The three oesophageal intuba-tions would surely have been detectedby capnography; its value in the anaes-thetic room is unquestionable and thetime is fast approaching when it will beconsidered negligent to induce anaes-thesia without its presence.

To appreciate the relative value ofmonitors, we need to know not justwhich monitor was the first to alert theanaesthetist to the presence of a criticalincident, but what feature of that signalwas valuable. There are several para-meters in each signal which often over-lap; for example, a bradycardia consequentupon inadequate atropinisation of ayoung man having a spinal anaestheticwould simultaneously show on the oxi-meter and ECG; this is well explored byWebb et al. [4]. What, for example, wasthe unique contribution made by theECG in the anaesthetic room; probablylittle. It would be surprising to hear thatits unique attributes, arrhythmia classifi-cation and ST segment analysis, werenoted in many incidents before the oxi-meter revealed the presence of anarrhythmia or any hypoxaemia.

The data the authors have collectedare surely most valuable, but perhaps itcould usefully be subjected to furtherexamination.

A. LackSalisbury SP5 4LXWiltshire, UK

References1 Cooper JB, Newbower RS, Long CD,

McPeek B. Preventable anesthesiamishaps: a study of human factors.Anesthesiology 1978; 49: 399–406.

2 Cohen MM, Duncan PG, Pope WD,

Wolkenstein C. A survey of 112,000anaesthetics at one teaching hospital(1975–83). Canadian Anaesthetists’Society Journal 1986; 33: 22–31.

3 Lack JA. Computerised measurementsin anaesthesia. In: Feldman SA, LeighJM, Spierdijk J, eds. Measurement inAnaesthesia. Leiden: Leiden UniversityPress, 1974.

4 Webb RK, van der Walt JH,Runciman WB, et al. The AustralianIncident Monitoring Study. Whichmonitor? An analysis of 2000 incidentreports. Anaesthesia & Intensive Care1993; 21: 529–42.

Use of suxamethonium in cordpatients – whether and when

The interesting paper by Hambly andMartin (Anaesthesia 1998; 53: 273–89)on patients with spinal cord lesions hastwo provocative statements regardinguse of suxamethonium and changes inplasma potassium: (1) ‘ . . . few woulddeny that elective use of suxametho-nium is safe after 9 months’. The state-ment refers to 9 months following a cordlesion; (2) ‘It would therefore be unfor-tunate to allow any spinal patient to dieof airway obstruction for fear of causinga hyperkalaemic arrest’. This statementrefers to the fact that all of the patientsdescribed in their bibliography who suf-fered hyperkalaemic arrest were success-fully resuscitated.

Cooperman [1] reported an increaseof 2 mmol.lÿ1 after suxamethonium in apatient as long as 7 years after onset andan increase > 4 mmol.lÿ1 in a patientwith progressive motor-related disease10 years after onset. This exaggeratedpotassium release is an upregulatoryphenomenon of nicotinic acetylcholinereceptors in skeletal muscle and pharma-codynamic resistance to nondepolarisingrelaxants is a paired aspect of this up-regulation [2]. If this receptor theory istrue, then a normal response to non-depolarising relaxants would indicate areturn to a normal potassium changeafter use of suxamethonium. I say thisbecause the resistance is due to extrareceptors at or around the endplate,while the agonist sensitivity of suxa-methonium is due to the cumulativeeffect of multiple receptors even far



beyond the endplate [2, 3]. Quantitativeevaluation of nondepolarising relaxantsin cord patients would perhaps be ofsome aid in this matter.

Deaths or neurological deficits afteruse of suxamethonium in these patientsare now seldom reported; in our countrythey do occur and they become legalcases. In the survival studies cited byHambly and Martin, most of the patientswere young and otherwise fit as regardstheir cardiovascular system. Youth andfitness may indeed play a role in survivalof acute hyperkalaemia, with or withoutcardiac arrest. In our studies of 89 youngand formerly fit burn patients threedecades ago, not one suffered a cardiacarrest, despite potassium levels to> 6 mmol.lÿ1 in 29 patients, and> 9 mmol.lÿ1 in two patients [4, 5].

Nonetheless, I do not believe that useof suxamethonium is generally appro-priate in patients with upper motorneurone lesions, as there are reasonablesubstitutes. This period of risk beginsabout 4 days following onset of thelesion [2]. Should suxamethonium beused in a patient in whom there mightbe a risk of hyperkalaemia, blood samplesshould be drawn before and after todocument any potassium changes.

G. A. GronertDepartment of Anesthesiology,UC Davis, USA

References1 Cooperman LH. Succinylcholine-

induced hyperkalemia inneuromuscular disease. Journal of theAmerican Medical Association 1970; 213:1867–71.

2 Martyn JAJ, White DA, Gronert GA,Jaffe RS, Ward JM. Up-and-downregulation of skeletal muscleacetylcholine receptors. Effects ofneuromuscular blockers. Anesthesiology1992; 76: 822–43.

3 Melton AT, Antognini JF, Gronert GA.Prolonged duration of succinylcholinein patients receiving anticonvulsants:evidence for mild upregulation ofacetylcholine receptors? CanadianJournal of Anaesthesia 1993; 40:939–42.

4 Schaner PJ, Brown RL, Kirksey TD,Gunther RC, Ritchey CR,

Gronert GA. Succinylcholine-inducedhyperkalemia in burned patients – I.Anesthesia and Analgesia 1969; 48:764–70.

5 Gronert GA, Dotin LN, Ritchey CR,Mason AD Jr. Succinylcholine-induced hyperkalemia in burnedpatients – II. Anesthesia and Analgesia1969; 48: 958–62.

An abnormal epiglottis but aneasy intubation

The Mallampatti test was devised as asimple bedside examination to predictthe likelihood of difficult intubation. Wewould like to report a case of unusualanatomy seen when performing thistest.

The on-call anaesthetist was requestedto provide anaesthesia for an otherwisehealthy 33-year-old woman requiringan urgent Caesarean section. A Mallam-patti test was performed as part of thepre-operative assessment and a 2-cmmass was immediately evident protrud-ing from the base of the tongue. Closerinspection revealed this to be thepatient’s epiglottis (Figure). The patientreceived a general anaesthetic for theoperation and was noted to be an extre-mely easy intubation. There were nointra- or postoperative complications.

In their paper describing what has

now come to be known as the Mallam-patti test, Mallampatti et al. [1] printedan illustration of a Mallampatti Class 1patient in whom the faucial pillars, softpalate and uvula are visible. The illustra-tion also shows a small part of theepiglottis seen at the base of thetongue, although no mention is madeof this in the text. We have been unableto find any case in the literature wherean epiglottis is visible on performing aMallampatti test, although there is a casereport of an elongated epiglottis with anunusual angle causing a difficult intuba-tion [2].

R. G. CraigRoyal London Hospital,London, UK

A. PatwardhanNewham General Hospital,London, UK

References1 Mallampatti SR, Gatt SP, Gugino LD,

et al. A clinical sign to predict difficulttracheal intubation: a prospective study.Canadian Anaesthetists’ Society Journal1985; 32: 429–34.

2 Hotchkiss RS, Hall JR, Braun IF,Schisler JQ. An abnormal epiglottis asa cause of difficult intubation: airwayassessment using magnetic resonanceimaging. Anesthesiology 1988; 68: 142–5.



Music and anaesthetists

Bully for Dr Zorab (Anaesthesia 1998;53: 613)! He is fortunate to have escapedthe plague of music during surgery for solong: in the mid-seventies, as a seniorregistrar in a London Teaching Hospital,I was unwillingly exposed to it in thecardiac theatre during the ‘bypass’ lists ofthe consultant surgeon. Rank had itsprivileges and thanks to his predilectionsI am still able to recall verbatim and witha ghastly accuracy the lyrics of all theearly works of Mr Neil Diamond. Evenafter a quarter of a century hearing thesongs again produces a catecholamineresponse in me that I was not able todemonstrate in his patients at the time[1]; they, of course, were mercifullyprotected by general anaesthesia!

To those colleagues without the moralauthority and cooperative colleaguesenjoyed by Dr Zorab, or unprepared toplay Dr Grumpy to protect their sanity,may I offer a strategem? It is simply tohum, whistle or sing along with the tapeat every list, enthusiastically and at adecibel level between ‘audible’ and ‘asser-tive’, with every expression of enjoymentof the tune. If possible, choose one ofthe subordinate harmonic lines such asthe viola part in a Brahms symphony orthe bass line of a pop standard. If theanaesthetist can contrive to be slightlyoff-key (should contrivance be neces-sary) the effect is mightily enhanced,especially if the surgeon has a musicalear, whilst the persistent inclusion of anincorrect word in one’s rendition ofSister’s favourite hit is similarly effective.

Two or three weeks is all it usuallytakes. ‘Qui desiderat pacem, praeparetbellum’.

I. HineCounty Hospital,Hereford HR1 2ER, UK

Reference1 Hine IP, Wood WG, Mainwaring-

Burton RW, Butler MJ, Irving MH,Booker B. The adrenergic response tosurgery involving cardiopulmonarybypass, as measured by plasma andurinary catecholamine levels. BritishJournal of Anaesthesia 1976; 48:355–63.



cuffed oropharyngeal airway (copa) and pharyngeal tumours

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