298 can be attached directly to the 15 mm connector of an endotracheal tube or an ETC. With a suction booster in place, the #2 lumen of the ETC becomes, in effect, an instantly available, perfectly positioned, high capacity suction catheter. Should regurgitation occur upon release o f cricoid pressure, the intubator can immediately clear the pharynx merely by placing the index finger over the suction-control opening of the suction booster. Once the pharynx is emptied, the index finger is lifted, releasing the suction, the ETC is passed into the esophagus, and the cuff and pharyngeal balloon are inflated. James P. Southwic . . . . . . Provo, Utah, USA

REPERENCE$ 1 CrosbyET, CooperRM, Douglas MJ, et al. The unanticipated difficult airway with recommendations for management. Can J Anaesth 1998; 45: 757-76. 2 Ruben H, Hansen E, MacNaughton FI. High capacity suction technique. A method of reducing the aspiration hazard during induction. Anaesthesia 1979; 34: 349-51.

The difficult airway and B U R P - a truly Canadian perspective To the Editor: I read with interest and admiration the recent Special Article on "The unanticipated difficult airway with recommendations for management", ! and the accompanied editorial. 2 The authors of the article should be congratulated for a thorough review of the subject and I agree with the editorial that the recommendations are concise, easy to follow, and in some ways, superior to the ASA algorithm. Having said that, I am somewhat puzzled at the omission of the distinctly Canadian contribution. I am referring to the fact that the "BURP manoeuvre" was introduced and the term coined by the late Dr. Richard KniU3 of London, Ontario whose power of observation was legendary. Yet, the original reference was not cited, and the reference quoted was that of Takahata et al. 4 whose work was based on the report by Knill. Moreover, the discussion overlooked an important point, which was likewise missed by Takahata et al., i.e. the BURP manoeuvre is far more likely to be successful when the laryngoscopist himself applies the pressure to deternfine the optimal direction and displacement of the larynx to obtain the best view. After determination of the optimal force and displacement,

CANADIAN JOURNAL OF ANESTHESIA

the laryngoscopist can then direct his or her assistant to reproduce the condition. This allows the laryngoscopist to delineate the "best" exposure that can be achieved and not simply accept what the assistant can provide as "optimal". This was implied but not spelled out as such in Knili's original publication. This is an important point, one which I have applied on more than one occasion to spare a patient the almost certain fate of a "crash" cricothyrotorny. On another issue, the algorithm did not outline for the readers the exact sequence leading to the decision box of "ventilation possible?" Many American anesthesiologists would routinely withhold muscle relaxants until they have ensured the ability to ventilate by mask. This, in my opinion, is a misguided approach, and should be reserved only for patients anticipated to be difficult to ventilate/intubate and not used on a routine basis. Since the algorithm is for the "unanticipated" difficult airway, I would assume "induction of general anesthesia" to include the administration of muscle relaxants. In the published paper, this is not entirely clear. Arthur M. Lam MD FRCPC Seattle, WA, USA REFERENCES

1 CrosbyET, CooperRM, Douglas MJ, et al. The unanticipated difficult airway with recommendations for management. Can J Anaesth 1998; 45: 757-76. 2 Finucane B. The difficult airway - a Canadian perspective (Editorial). Can J Anaesth 1998; 45: 713-8. 3 Knill RL. Difficult laryngoscopy made easy with a "BURP". Can J Anaesth 1993; 40: 279-82. 4 Takahata 0, Kubota M, Mamiya K, et al. The efficacy of the "BURP" maneuver during a difficult laryngoscopy. Anesth Analg 1997; 84: 419-21. REPLY: Dr. Southwick describes a technique which may be useful in reducing the likelihood or the severity of aspiration when releasing cricoid pressure during placement of a Combitube@ in an at-risk patient. Dr. Lain points out what might seem to be a surprising oversight for a group o~tensibly offering a Canadian perspective on airway management. In his description of the ~BURP -manoeuvre; Knill credited Wilson for his observation that anterior laryngeal pressure improved laryngoscopic view, reducing the incidence of Grade I I I and I V views from 9.2% to 1.6%.l Although Knill described both the rationale and methodfor application orB URP, it was Takahata who detailed the impact of the manoeuvre on the laryngoscopic view in 630 patients. Takahata noted a

CORRESPONDENCE

reduction in the incidence of Grade I I I and IVviews with the application of Knill's manoeuvre. In our attempt to meet the Journal's reasonable limitation on reference numbers for review articles no disrespect was intended Dr. Knill and we acknowledge his contribution. Dr Lain further points out the need for the laryngoscopist to make the determination of the optimal laryngeal manipulation rather than to rely on the assistantto do so. I agree and suggest that the assistant may be aided by having the laryngoscopist position their hand over that of the assistant and guide them to the optimal position. Minor changes in the position can then be achieved with simple, easily comprehensible commands. Finally, D r Lain is correct in his assumption that "induction of general anesthesia" in the algorithm would include, as a component part, the administration of a muscle relaxant. E.T. Crosby MD FRCPC Ottawa, Ontario

299

Total TNB consumed in the postoperative period averaged 4.4 + 2.0 mg. Nausea, sedation, and dysphoria were reported by 10 to 20% of patients. Pain in seven patients could not be adequately controlled following 3 mg TNB administered over 90 min and was treated with parenteral opioids. Previous research has demonstrated that TNB and acetaminophen + codeine (T3) were similarly effective in treating pain following musculoskeletal trauma. Given that TNB did not provide effective analgesia in 25% of patients in this case series it is unlikely that TNB offers sufficient advantage over T3 to justify its expense (CDN$ 80.77 vs CDN$ 11.94). Future research is required to identify a safe, effective, and inexpensive means of treating pain following ambulatory surgery. G.L. Bryson MD FKCPC I. Baker MD P.R. Bragg MD FRCPC Ottawa, Ontario

REFERENCES

1 WilsonME, Spiegelhalter D, RoberstonJA LesserP. Predicting difficult intubation. Br J Anaesth 1988; 61: 211-6.

2 Takahata O, Kubota M, Mamiya K, et al. The efficacy of the "BURP" maneuver during a difficult laryngoscopy. Anesth Analg 1997; 84: 419-21.

Patient-controlled transnasal butorphanol analgesia following outpatient surgery To the Editor: The increasing use of same-day discharge surgery has required that patients be discharged from hospital following more extensive surgical procedures. Butorphanol, a mixed opioid agonist-antagonist, has been shown to provide analgesia similar to parenterally administered narcotics. Rapid absorption and a minimum of respiratory depression suggest that transnasal butorphanol (TNB) may be a useful analgesic following ambulatory surgery. We conducted an open-label, observational study of TNB enrolling 28 ASA I-III patients undergoing a variety of ambulatory procedures at the Ottawa Hospital Civic Campus. Following written, informed, consent patients received a standardized general anesthetic including a prophylactic anti-emetic and a NSAID. Following discharge from the post-anesthesia care unit, patients were instructed to self administer a I m g spray of TNB every 30 min prn to control pain.

REFERENCES

1 GillisJC, Benfield P, Goa KL. Transnasal butorphanol. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in acute pain management. Drugs 1995; 50: 157-75. 2 Abboud TK, ZhuJ, GangollyJ~ et al. Transnasal butorphanol: a new method for pain relief in post-cesarean section pain. Acta Anaesthesiol Scand 1991; 35: 14-8. 3 KaUos T, Caruso FS. Respiratory effects of butorpahnoi and pethidine. Anaesthesia 1979; 34: 633-7. 4 WolfordR, Kahler J, Mishra P, Vasilenko P, DeYoung R. A prospective comparison of transnasal butorphanol and acetaminophen with codeine for the relief of acute musculoskeltal pain (Letter). Am J Emerg Med 1997; 15: 101-3.

Improved patient comfort after transsphenoidal surgery with a modified nasal packing To the Editor: At the completion o f transsphenoidal pituitary surgery, petroleum jelly or bacitracin-impregnated gauze rolls are packed into the patient's nostrils to prevent bleeding and infection. This precludes patients from breathing through their nose in the immediate postoperative period. According to the nurses in our postanesthesia care unit and the surgeons at our institution, the inability to breathe nasal-