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(6-35 years of age and 18-65 kg. body-weight) has shownthat a daily dosage 2-4 times that suggested by Dr. Currieis well tolerated and safe. Also a high total dosage hasbeen essential for the radical cure of bilharziasis with DHE

hydrochloride and resinate in Egypt.After a follow-up of nearly three months, we still prefer the

combined course of the DHE hydrochloride (i.m.) and DHEresinate, rather than injections or capsules alone. We havenoticed that the response of adults to treatment is usuallybetter than that of children and can be obtained on lower totaldosage. Most of the contraindications to using antimonialsdo not apply to DHE.We have so far had no experience with DHE hydrochloride

tablets.HASSAN HILMY SALEMProfessor of Tropical Medicine.

Faculty of Medicine,Alexandra.

GASTRIC HYPOTHERMIA

T. J. NOONAN.County Hospital, Cashel,Co. Tipperary, Ireland.

SIR,-Mr. Howe, in his otherwise objective letter ofJan. 11, was less than fair when he suggested that gastricfreezing should be put in quotation marks.

It has been shown that the intragastric temperature followsfairly closely the outflow temperature-the mucosal tempera-ture being somewhat below the latter. Wangensteen and hisassociates have for some time been carrying out experimentalwork on the open technique of gastric perfusion. This wouldhave " the theoretical advantage of contacting most, if not all,the parietal cells ".2The frequency of gastric erosions appears to vary a lot from

paper to paper. In the first 190 cases reported from theUniversity of Minnesota 3 there were 11 episodes of melasna.At present the workers there are using low-molecular-weightdextran to permit the use of lower temperatures without

inviting sludging in the vessels. This should reduce theincidence of such erosions.

The main issue is what the eventual outcome will be.

Wangensteen 2 has submitted 643 people to gastricfreezing without a death. About 90% of cases continueto have relief of pain. These figures would indicatethat the procedure may have far-reaching significance inthe treatment of intractable ulcers.

I am pleased that Mr. Howe regards gastric coolingas a valid technique. It has been overshadowed for toolong by the discussions on freezing.

DEATHS FROM TONSILLECTOMY

R. A. R. WALLACE.

SIR,-" It’s not what you do-but the way that youdo it!" In tonsillectomy, the way includes the properpreparation of the instrument-i.e., the blade of the

guillotine must be so blunt that it will not cut. I deprecatethe use of the word " blind " in Sir Denis Browne’sletter. 4 The patient’s head must be extended over theend of the table. The tonsils must be entirely and care-fully milked by an index finger through the fenestrumof the stoutly-built guillotine. When the tonsil is firmlyimprisoned by the closed 1/16 in. thick edge of the blade,it is slid (or pushed) downward (or sometimes plucked) offits bed. This tears and, by elastic recoil, secures all theblood-vessels which could cause bleeding.The adenoids also can be brought out entire in the " box

of a La Force adenotome, the blade of which, too, is blunted.Again no tags are left (as sometimes happens when a curetteis used) to swell up and ooze some days later. Finally, thetonsil beds and the lower part of the nasopharynx must be1. Wangensteen, O. H., Peter, E. T., Bernstein, E. F., Walder, A. I.,

Sosin, H., Madsen, A. J. Anns Surg. 1962, 156, 579.2. Wangensteen, O. H. Personal communication.3. Bernstein, E. F., Sosin, H., Madsen, A. J., McFee, A. S., Goodale, R. J.,

Allcock, E. A., Wangensteen, O. H. Univ. Minn. med. Bull. 1962,34, 108.

4. Browne, D. Lancet, 1963, ii, 1377.

viewed through the opened blades of a powerful sponge-forceps, or ovum-forceps, or (best of all) through a Collinspile-clamp. If any shreds or stumpy tags are seen, the clampis pushed home on to the tags. A jerk of the clamp will thenensure " elastic recoil " of the blood-vessels and a clean drysurface. Total time-45 seconds.The child must then be placed prone and kept flat on its

face for several days.The advantages of this method are: short anesthesia

(ethyl chloride); no blood inhaled; no chest trouble; andno catgut to slip off. When I operate for quinsy, or do anenucleation under local anxsthesia, I use the dissection

method, because the pull or jerk will cause pain beyondthe injected area. The ratio of my tonsil dissections to

guillotine removal is perhaps 1 to 10 in a total of about20,000 cases in nearly fifty years (with no deaths, nobleeding, and clean throats and nasopharynges).

Bishop’s Stortford,Herts.

CEREBRAL INJURY FOLLOWING CARDIACOPERATIONS

SIR,-Your suggestion (Jan. 11) that electroencephalo-graphic (E.E.G.) monitoring can help to warn the surgeonof impending hypoxia during hypothermia operations issupported by our observations. These also correct the im-pression given in early works on the subject that electricalbrain activity disappears below about 22°C. This mislead-ing statement has been repeated as recently as Jan. 18.At Bristol E.E.G.s have been recorded on patients undergoing

repair during hypothermia, cooled to temperatures as low as13°C by the Drew technique. In the early days of the pro-cedure the rather high incidence of complications actuallyfacilitated interpretation of the E.E.G. changes in these difficultand unfamiliar conditions. Now that the procedure is relativelyaccident-free, extreme conditions are rarely encountered andthe transition from physiological to pathological states is lessobvious. Clear signs of electrical activity of the brain can berecorded even at the lowest temperature reached during theoperation, provided that circulation is maintained. They dis-appear while the artificial circulation is interrupted-whichmay be as long as 60 minutes-and return shortly after therecommencement of circulation.Our early records of E.E.G. activity combined with observa-

tions of oxygen availability in the scalp tissues suggest that oneof the factors limiting the safety of protracted circulatory arrestat low temperatures might be the fall in blood CO2 duringartificial respiration. Accordingly CO2 was introduced into theanxsthetic gas mixture and adjusted to maintain a satisfactoryPc02 level. After this the patients have recovered more rapidlyand completely from the operation, and E.E.G. signs of cerebraldistress have been far less prominent and frequent. There areseveral plausible explanations for this, but cerebral vasodilata-tion and a shift to the right of the haemoglobin dissociationcurve are likely if not complete causes.With the PC02 maintained at a 40% level, the E.E.G. persists

up to 6 minutes after circulatory arrest at 13-14°C, and it canbe used as a sensitive indicator of cerebral hypoxia during allphases of cooling.

In our experience E.E.G. monitoring has providedessential information in hypothermia heart operations.Indeed a good case can be made for E.E.G. monitoringduring all heart operations, and we think that this willbecome routine procedure before very long.

Its value is not limited to the stages of cooling: one of thedangerous periods as regards cerebral hypoxia is before coolingcommences, when the surgeon is manipulating the heart inpreparation for cannulation. At this time an already inefficientheart is being further embarrassed in its function while thebrain is still at normal body temperature. Unless the surgeonis guided by the electroencephalographer and allows time forrecovery of the brain at the crucial stages of the manipulation,