968

Forum

drawal of one vaporizer and the addition of a syringe pump. The A M D PS6050 pump can be driven by 5 LR14 batteries ('C' cells) for approximately 100 hours, and is light, robust and easy to use. This method of anaesthesia is relatively simple and produces excellent operating conditions with minimal familiarity. The technique does need to be practised, but so does any other drawover method of anaesthesia. Most importantly, the drugs used caused minimal cardiorespiratory changes, although they were used in ASA 1 o r 2 patients in this study. Ketamine is more suitable than thiopentone in shocked or ill patients. Duration of recovery was longer than expected, as a result of several factors. It was difficult to anticipate the end of some operations and the infusion was not discontinued early enough; this problem is less likely to arise when the operation is for the delayed primary suture of a wound. The duration of recovery was determined by recovery staff who were unfamiliar with ketamine anaesthesia. Therefore, although the patients had awoken and were able to maintain their airway, they were not returned to the ward because they were deemed to be in a mildly dissociated state. Isoflurane concentrations were reduced earlier as we became more familiar with the technique and recovery became more rapid. The mean recovery times were not improved by one patient who remained unconscious for more than 60 minutes despite being given doxapram and naloxone intravenously. He was given flumazenil 0.2 mg and awoke immediately. The patients in group 1 recovered more rapidly on average than those in group 2 despite these problems, but the operations in group 1 were shorter. The new technique, using ketamine, midazolam and alfentanil intravenously and isoflurane by inhalation, proved to be at least as good as the well-tried technique employing the Triservice apparatus and conventional inhalation agents. The quality of anaesthesia was good, blood pressure remained stable, and the patients recovered in

comparable times. The benefit was that the tachypnoea due to trichloroethylene did not occur; tachypnoea can be relieved by administration of boluses of an opioid, but only at the expense of respiratory depression. We believe that this technique may be suitable in the field for patients with head injury. The amount of ketamine used is small and its effects on intra-ocular and intracranial pressures are modified by midazolam. Low concentrations of isoflurane do not cause an increase in cerebral blood flow provided that Pace? is normal.' We recommend this method as an acceptable means of anaesthetising a patient in a hazardous environment where sophisticated apparatus is not available and the patient can be allowed to breathe spontaneously.

References I . HOUGHTON IT. The Triservice anaesthetic apparatus. Anaesthesia 198 1; 36: 1094- 108. 2. INMANWHW, MUSHINWW. Jaundice after repeated exposure to halothane: a further analysis of reports to the Committee on Safety of Medicines. British Medical Journal 1978; 2: 1455-6. 3. KOCANM. The Triservice anaesthetist apparatus. Trial of isoflurane and enflurane as alternatives to halothane. Anaesthesia 1987; 4 2 1 1014. 4. TIGHESQM, PETHYBRIDGE RJ. A comparison of halothane and trichloroethylene with isoflurane. A study of drawover air anaesthesia with the Triservice anaesthetic apparatus. Anaesthesia 1987; 4 2 887-91. 5. RESTALLJ, TULLY AM, WARD PJ, KIDD AG. Total intravenous anaesthesia for military surgery. A technique using ketamine, midazolam and vecuronium. Anuesthesia 1988; 43: 46-9. 6. BORLANDCW, HEKBEKTP, PEKEIKAN H , THOKNTON JA, WILLIAMS N, THOKNTON JG. Evaluation of a new range of air drawover vaporizers. The 'PAC' series-laboratory and 'field' studies. Anaesthesia 1983; 38: 852-61. 7. EGEREl. Isoflurane: a review. Anesthesiology I98 I ;55: 559-76.

Anaesthesia, 1990, Volume 45, pages 968-97 1

Postoperative sore throat: topical hydrocortisone P.C. Stride, MB, ChB, FFARCS, Registrar, Department of Anaesthetics, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH.

Summary

Forty patients undergoing tracheal intubation and controlled ventilation of the lungsjor elective surgical procedures were studied. They were allocated randomly into one qf two groups. The tracheal tubes used for group A patients were lubricutrd bcffbre insertion with water-soluble I % hydrocortisone cream. Those,for group B patients were lubricated with KYjeIIy. The incidence of postoperative sore throat was found to be significantly greater in group A . Topical I % hydrocortisone cream is thercfiwe ineflective in the prevention qf' postoperative sore throat.

Key words Intubation. tracheal; complications.

Sore throat is a common complication of general anaesthesia. It may occur after mask anaesthesia, although tracheal intubation increases the incidence to a level as high as 90%.' Accepted 5 January 1990

Many factors contribute to this problem, but the association between sore throat and the area of contact between cuff and trachea has been clearly demonstrated.'-h This finding implies that irritation of the tracheal mucosa by the

Forum Table 1. Surgical procedures undertaken

Group A Group B (hydrocortisone) (KY jelly) Stripping of varicose veins Excision of breast lump Inguinal hernia repair Cholecystectomy Manual dilatation of the anus Percutaneous nephrolithotomy Arthroscopy Hip arthroplasty Excision of plantar spurs Abdominal hysterectomy Reversal of sterilisation Laparoscopy (dye tests)

( n = 20)

( n = 20)

4 I I

4 1

2 1 1

2 7

6

I I 2 2 3

I

tracheal tube cuff is an important aetiological factor in postoperative sore throat. Disappointing results obtained using topical local anaesthetic agents to prevent postoperative sore throat are therefore not surprising. Such agents may limit potential damage to the tracheal mucosa by suppressing coughing or bucking on the tube, but have no intrinsic anti-inflammatory action. Out of six s t u d i e ~ l . ~only . ~ - ~one9 ~ has shown a clear benefit, and in two studies’.3local anaesthetic agents were associated with an increased incidence of sore throat. The potential benefit of specific anti-inflammatory agents for the prevention of postoperative sore throat was suggested by an early study by Hamelberg.” Topical corticosteroids were used in this study in combination with local anaesthetic agents. The aim of the present study is to assess the effect of topical hydrocortisone 1 % on the incidence of sore throat after tracheal intubation for general anaesthesia.

Patients and methods

The study was conducted on 40 adult patients aged 18-74 years, ASA grades 1 or 2, and approval for the study was obtained from the local ethics committee. Patients selected were those about to undergo elective surgery for general, orthopaedic, gynaecological or urological procedures which would require tracheal intubation and controlled ventilation of the lungs. Patients undergoing surgery to the head and neck, or procedures that necessitated passage of a nasogastric tube were excluded. Informed consent was obtained from the patients, who were randomly allocated into one of two groups. The patients’ tracheal tubes were prepared before arrival in the anaesthetic room. Disposable PVC Portex ‘Theatre’ tubes were used for all patients (8.0 mm internal diameter for women and 9.0mm internal diameter for men). F o r group A patients 2-3 ml water-soluble 1YO hydrocortisone

cream was lightly smeared around the outside of the tube from the tip to 5 cm above the cuff. The same volume of ‘KY’ jelly was applied in the same way for group B patients. A standard anaesthetic technique was used. Oral temazepam (10-20 mg) and metoclopramide (10 mg) premedication was administered one hour before operation. A sleep dose of thiopentone was used for induction of anaesthesia and alcuronium (0.3 mg/kg) was given for neuromuscular block. The patients’ lungs were ventilated to normocapnia with 66% nitrous oxide and 33% oxygen supplemented with 1-2% enflurane. Papaveretum (0.1-0.3 mg/kg) was given for analgesia if required. Tracheal intubation was not attempted until 3 minutes after administration of the alcuronium. The cuff of the tracheal tube was inflated, after insertion to the minimum pressure required to prevent gas leak on positive pressure ventilation. This pressure was recorded, and further recordings were made at half-hourly intervals thereafter. The neuromuscular block was reversed with neostigmine and atropine on completion of the surgical procedure. The tracheal tubes were removed from the patients who were in the left lateral position once spontaneous ventilation had resumed, but before return of the cough reflex. The patients, who were unaware of which lubricant had been used, were all interviewed in a standard fashion on the day after surgery (1 6-24 hours after the procedure). They were asked directly if they had experienced any sore throat, if so, they were asked to grade it as mild, moderate, or severe. The Chi-squared test with Yates’ correction was used to compare the frequency of sore throat between the two groups.

Results

There were 20 patients in each group, with a comparable sex distribution of 1 1 men and 9 women in group A, and 12 men and 8 women in group B. The mean age of patients was 44.3 (SD 15.9) years in group A, and 42 (SD 15.5) years in group B. Table 1 lists the surgical procedures carried out. There is a comparable range of procedures between the two groups. Tracheal intubation was performed easily in all cases, and the duration of intubation averaged 53 minutes (SD 22.8) in group A and 54 minutes (SD 21.4) in group B. Eighteen out of the 20 patients in group A developed a sore throat compared with only 10 out of 20 in group B (Table 2). This difference is statistically significant (p < 0.01). Of the 28 patients who experienced symptoms, only five classed their sore throat as moderate or severe; three of these were in group A and two in group B. The influence of age, sex, duration of intubation and cuff pressure was also investigated (Table 3). There was no statistically significant association between thc incidence of sore throat and any of these factors.

Table 2. Incidence of postoperative sore throat None

Mild

Moderate

Severe

Total

2* (loo/,)

15 (75%)

I (5%)

2 (10%)

18* (90%)

lo* ( 5 0 % )

8 (40%)

I (5%)

1

(5%)

lo* ( 5 0 % )

Group A (hydrocortisone) ( n = 20)

Group B (KY jelly) ( n = 20)

*Chi-squared test significant at p 3.0 kPa < 3.0 kPa > 59 minutes < 59 minutes > 40 < 40 Male Female

Discussion

The idea of using a topical anti-inflammatory agent to prevent postoperative sore throat is not new. In 1958 Hamelberg studied the effect of applying lignocaine ointment that contained 1 % hydrocortisone to red rubber tubes before their insertion.” His results, a decrease in the incidence of sore throat from 35% to 26%, were encouraging, but not statistically significant. Details of the anaesthetic technique and agents which were used in this study were unfortunately not given. However, there was no indication that these were standardised or that suxamethonium was avoided. Capan’* has since demonstrated that sore throat is more frequent after the use of suxamethonium. He suggested that this may be a manifestation of suxamethonium myalgia. In addition, Hamelberg used an indirect questioning technique; he relied on the patients themselves volunteering symptoms related to the intubation. It is now appreciated that the incidence of sore throat varies with the method of q ~ e s t i o n i n g , ’ ~ ” and ~ ’ ~ the preferred method in recent studies has been to ask the patients directly if they have experienced any sore throat. The present study used this method, together with standardised anaesthesia and no suxamethonium, and has failed to confirm the encouraging results of Hamelberg. Indeed, the results show that the use of cream containing 1 YOhydrocortisone may actually increase the incidence of sore throat associated with tracheal intubation. The watersoluble hydrocortisone cream used contained chlorocresol, cetamacrogol emulsifying wax, liquid macrogol, white soft paraffin and liquid paraffin. None of these substances is particularly noted to be an irritant. However, it seems likely that one or more of them must have acted as such in this study. The overall incidence of sore throat in the study (70%) is high, especially when compared to the Hamelberg study. There are three factors which may have contributed to this. Firstly, a direct questioning technique is known to produce a higher incidence than an indirect technique.I4 Secondly, disposable PVC tubes were used in the present study, whereas red rubber tubes were used in the earlier study. The findings of other workers who compared tubes made from these two materials are inconclusive. Loeser,’ Shah,I5 and SpragueIh in their respective studies found that red rubber tubes were associated with a higher incidence of sore throat than PVC tubes, whereas JensenS found the reverse. It may be that the material used is unimportant. The differences found in the incidence of sore throat may merely reflect different designs (and hence area of contact between cuff and trachea) of the respective tubes. Thirdly, the work of LoeseP and Sprague” has suggested that even bland lubricating jelly may increase the incidence of sore throat. Such a lubricant was used in the control group in the present study. The finding that neither patient age, duration of intubation nor cuff pressure affect the incidence of sore throat supports the conclusions of previous ~tudies.’.~ However, as

No sore throat

26 14 17 23 18

22 19 21

Sore throat

19 9 14 14 13 15

(73%) (64%) (82%) (61%) (72%) (68%) 15 (79%) 13 (62%)

mucosal blood flow is compromised by lateral wall pressures exceeding 3 kPa,lR care should always be taken to limit cuff pressure to the ‘just seal’ level. In conclusion, hydrocortisone cream joins a long list of both bland and active lubricants that have been shown to be ineffective in the prevention of postoperative sore throat. The author suggests that lubrication of tracheal tubes for this purpose is no longer appropriate. Acknowledgments

The author thanks D r J. M. Watt and D r G. M. Cooper for their help with this study. References

I. LOESER EA, STANLEYTH, JORDAN W, MACHIN R. Postoperative sore throat: influence of tracheal tube lubrication versus cuff design. Canudian Anaesthetists’ Sociely Journal 1980; 27: 156-8. 2. LOESER EA, ORR DL, BENNETT GM, STANLEYTH. Endotracheal tube cuff design and postoperative sore throat. Anesthesiology 1976; 45: 684-7. A, DIAZA, STANLEY TH. PACENL. 3. LOESEREA, KAMINSKY The influence of endotracheal tube cuff design and cuff lubrication on postoperative sore throat. Anesthesiology 1983; 58: 376-9. 4. LOESER EA, BENNETTGM, ORRDL, STANLEY T H . Reduction of postoperative sore throat with new endotracheal tube CURS. Anesthesiology 1980; 5 2 257-9. 5. JENSENPJ, HOMMELCAARD P, S0NDERGAARD P, ERIKSON s. sore throat after operation: influence of tracheal intubation, intracuff pressure and type of cuff. British Journal of’ Anaesthesia 1982; 54: 453-457. 6. STOUT DM, BISHOP MJ, DWERSTECJF, CULLENBF. Correlation of endotracheal tube size with sore throat and hoarseness following general anesthesia. Anesthesiology 1987; 67: 419-21. 7. CONWAYCM, MILLERJS, SUGDENFLH. Sore throat after anaesthesia. British Journal of Anaesthesiu 1960; 32: 21 9-223. 8. HARTSELL CJ, STEPHEN CR. Incidence of sore throat following endotracheal intubation. Canadian Anar,s/he/ists’ Society Journal 1964; 11: 307-12. 9. LUNDLO, DAOSFG. Effects on postoperative sore throats of two analgesic agents and lubricants used with endotracheal tubes. Anesthesiology 1965; 2 6 681-3. 10. WINKEL E, KNUDSENJ. Effect on the incidence of postoperative sore throat of I percent cinchocaine jelly for endotracheal intubation. Anesthesia and Analgesia 1971; 5 0 92-4. 11. HAMELBERG W, WELCH CM, SIDDALLJ, JACOBYJ. Complications of endotracheal intubation. Journal of’ the American Medical Association 1958; 168: 1959-62. H. 12. CAPAN LM, BRUCE DL, PATEL KP, TURNDORF Succinylcholine-induced postoperative sore throat. Anesthesiology 1983; 5 9 202-6. 13. STENQVIST 0, NILSSON K. Postoperative sore throat related to tracheal tube cuff design. Canadian Anaesthetists’ Society Journal 1982; 2 9 384-6. 14. HARDINGCJ, MCVEYFK. Interview method affects incidence of postoperative sore throat. Anaesthesia 1987; 42: 1104-1 107.

Forum 15. SHAHMV, MAPLESON WW. Sore throat after intubation of the trachea. British Journal of Anaesthesia 1984; 5 6 1337-41. 16. SPRAGUENB, ARCHER PL. Magill versus Mallinckrodt tracheal tubes. A comparative study of postoperative sore throat. Anaesfhesia 1987; 4 2 306-1 I .

97 1

17. SPRAGUE NB, MOFFETT SP. Oral tracheal tubes: is lubrication necessary? Todays Anaestherist 1989; 4 140-2. 18. SEEGOBIN RD, VAN HAWELTGL. Endotracheal cuff pressure and tracheal mucosal blood flow: endoscopic study of four large volume cuffs. British Medical Journal 1984; 288: 9 6 5 4 .

Anaesthesia, 1990, Volume 45, pages 971-975 Isolated lung transplantation for pulmonary fibrosis

I. D. Conacher, MD, FFARCS, FRCPE, Consultant, J. Dark, FRCS, Senior Lecturer in Cardiothoracic Surgery, C. J. Hilton, FRCS, Consultant Cardiothoracic Surgeon, P. Corris, MRCP, Consultant Respiratory Physician, Regional Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne NE7 7DN.

Summary The peri-operative anaesthetic management of 1I patients with pulmonary jbrosis undergoing single-lung transplantation is presented. Intra-operative problems, the early postoperative phase of recovery and intensive care, and other incidents in which general anaesthesia was required f o r the management of complications, are featured. Results, both short- and long-term. are mentioned. Major intra-operative events that cause concern appear to be related to the severity of the presenting illness and the development of respiratory failure. Others have reported the development of intra-operative cardiac failure. All cases were successfully managed operatively using conventional one-lung anaesthesia, although resort to partial cardiopulmonary bypass may have been indicated in some. The indications and attitudes to utilising cardiopulmonary bypass in the evolution of techniques for facilitating single-lung transplantation are reviewed.

Key words Anaesthesia; thoracic. Surgery; lung transplantation.

Lung transplantation has been attempted for more than 20 years. Success, judged by recipients consistently leaving hospital symptomatically improved, has been slow to achieve in comparison to other transplants. There is a gradual accumulation of world experience of single-lung transplantation for emphysematous and pulmonary vascular disease, but current evidence is that best results are achieved in patients with pulmonary fibrosis.14 It is in these latter that both ventilation and perfusion favour the transplanted lung rather than the remaining, natural one. The necessary surgery and anaesthesia are complicated by the poor state of health of recipients initially and by the major physiological changes that occur peri-operatively and that are brought about by surgical events and manoeuvres that facilitate the implantation of an orthotopic lung. We report data and events related t o the perioperative and postoperative management of l l recipients of single-lung transplants for end-stage pulmonary fibrosis. Methods Patients. Details are shown in Table 1. There are six men and five women in the series; their ages a t time of operation ranged from 27 to 58 (mean 45.8) years. Nine were diagnosed as suffering from idiopathic pulmonary fibrosis or cryptogenic fibrosing alveolitis. One patient had eosinophilic granuloma and another obliterative bronchiolitis after a bone marrow transplant 8 years earlier.

Accepted 20 April 1990.

All patients were living a chair-bound existence before operation (mean Pao, breathing air 6.3 kPa) and required supplemental oxygen a t rest. Minimal exertion resulted in oxygen desaturation, and prognosis for survival was estimated to be less than a year. One was dependent on positive pressure ventilation and had a tracheostomy. Examples of pre-operative data from the first six patients are shown in Table 2. Recipients had mild t o moderate degrees of pulmonary hypertension, a degree of compromised right heart function, a restrictive ventilatory defect and marked impairment of diffusing capacity. Four were hypercarbic. Surgery. All patients underwent left-lung transplantation. The pneumonectomy was followed by insertion of the transplant which was anastomosed in the sequence pulmonary veins (on a cuff of donor left atrium), pulmonary artery, and b r o n ~ h u sThe . ~ bronchus anastomosis was then protected with a wrap of omentum. Anaesthesia. The anaesthetic technique was described p r e v i o ~ s l y .Six ~ . ~patients were sedated (midazolam, with o r without droperidol) while peripheral venous, central venous (antecubital fossa), and arterial access were secured under local anaesthesia. Central neck lines were inserted after induction of anaesthesia with the patients in the headdown position. These patients are capable of generating large negative intrathoracic pressures and there is a danger of air embolus when they are breathing spontaneously. Induction of anaesthesia was with a sleep dose of etomi-