Correspondence
reduce the incidence of conjunctival haemorrhage during subTenon’s block.
Diathermy does not reduce subconjunctival haemorrhage during sub-Tenon’s blocky
Table 1 Demographics and incidence of subconjunctival haemorrhage. Data are presented as mean (range) unless specified Sex Axial M/F length (mm)
Subconjunctival haemorrhage in infero-nasal quadrant (%)
Group (n)
Age (yr)
Standard (25) Diathermy (25)
72.87 11/14 22.89 48 (41–87) (20.86–25.58) 73.12 10/15 22.95 44 (47–87) (20.78–25.62)
Subconjunctival haemorrhage in other quadrants (%)
C. M. Kumar* S. Williamson Middlesbrough, UK *E-mail:
[email protected] 1 Guise PA. Sub-Tenon anesthesia. Anesthesiology 2003; 98: 964–8 2 Roman SJ, Chong Sit DA, Boureau CM, Auclin FX, Ullern MM. Sub-Tenon’s anaesthesia: an efficient and safe technique. Br J Ophthalmol 1997; 81: 673–6 3 Kumar CM, Dodds C. An anaesthetist evaluation of Greenbaum sub-Tenon’s block. Br J Anaesth 2001; 87: 631–3 4 Konstantatos A. Anticoagulation and cataract surgery: a review of the current literature. Anaesth Intensive Care 2001; 29: 11–18 5 Greenbaum S. Parabulbar anesthesia. Am J Ophthalmol 1992; 114: 776
doi:10.1093/bja/aei598
Pulmonary hypertension and sildenafil Editor—We read with interest the recent case report by Dr Ng and colleagues1 describing the use of oral sildenafil in the management of a patient with secondary pulmonary hypertension in a general adult intensive care unit. The authors quite rightly state that by and large the medical literature contains small observational studies and case reports of its use in patients with pulmonary hypertension. Nevertheless, we wish to point out that we have been using both oral and i.v. sildenafil in the cardiothoracic and adult intensive care units in St George’s Hospital for the past 3 yr and, indeed, have described encouraging results using oral therapy to treat perioperative pulmonary hypertensive crises in cardiac surgical patients.2 It has become an important treatment in our intensive care unit to address perioperative pulmonary hypertension in cardiac surgical patients. In addition, we have had encouraging experience with oral administration in the management of patients with pulmonary hypertension secondary to a variety of pulmonary conditions including chronic pulmonary thromboembolic disease.3 We have used doses of 25 mg to 50 mg three times daily and have not encountered problematic systemic hypotension to date. We agree with the authors that further studies are warranted to address the haemodynamic benefits of sildenafil in critically ill patients. It is hoped that ongoing multidisciplinary collaboration will help to achieve this. B. Madden A. Crerar-Gilbert London, UK E-mail:
[email protected] hotmail.com
gilbert_aj@
1 Ng J, Finney SJ, Shulman R, Bellinghan GJ, Singer M, Glynne PA. Treatment of pulmonary hypertension in the general adult intensive care unit: a role of oral Sildenafil? Br J Anaesth 2005; 94: 774–7 2 Madden BP, Sheth A, Ho TB, Park JE, Kanagasabay RR. Potential role for Sildenafil in the management of perioperative pulmonary hypertension and right ventricular dysfunction after cardiac surgery. Br J Anaesth 2004; 93: 155–6 3 Sheth A, Park JE, Ong YE, Ho TB, Madden BP. Early haemodynamic benefit of Sildenafil in patients with coexisting chronic thromboembolic pulmonary hypertension and left ventricular dysfunction. Vascul Pharmacol 2005; 42: 41–5
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doi:10.1093/bja/aei599 y
An abstract of this study was presented at the 13th World Congress of Anaesthesiologists, Paris, France, April 2004.
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Editor—The frequency of subconjunctival haemorrhage during posterior sub-Tenon’s block is 7–56%.1 2 This is usually confined to the area of dissection but can spread to other quadrants.2 The incidence is even higher with the use of an anterior sub-Tenon’s cannula.3 The damage to fine vessels inevitably severed during conjunctival dissection is the main cause of haemorrhage. It is not uncommon for elderly patients undergoing cataract surgery to receive anticoagulants and this may increase the incidence of haemorrhage.4 Cauterization of conjunctiva by a diathermy is recommended to reduce the incidence5 of subconjunctival haemorrhage but there are no scientific data to support this. Both ophthalmologists and anaesthetists are involved in the delivery of sub-Tenon’s block. Ophthalmic surgeons are trained to use diathermy instruments but anaesthetists may not feel comfortable in its use and for some it may be a daunting task. Further, addition of a diathermy will increase the overall cost, the complexity of the technique and morbidity if used by non-trained personnel. This prospective audit of 50 patients undergoing routine phaecoemulsification cataract surgery with lens implant was conducted to investigate if the use of a diathermy during sub-Tenon’s block reduces the incidence of subconjunctival haemorrhage. Informed consent was obtained from patients. Patients who had previous intraocular surgery, received anticoagulant, aspirin and nonsteroidal anti-inflammatory drugs were excluded. All patients received sub-Tenon’s block in the infero-nasal quadrant with a 25 mm long, blunt curved metal cannula.1 Lidocaine 2%, 4 ml with 1:200 000 epinephrine and hyaluronidase 10 IU ml1 were used in all cases. In the first consecutive 25 patients, the conjunctiva was cauterized using a disposable diathermy before the dissection. The remaining 25 patients received a standard sub-Tenon’s block without diathermy. Digital pressure was applied for 2 min. Six minutes after the sub-Tenon’s block, an independent observer, who was unaware of the use of diathermy, assessed the grade of subconjunctival haemorrhage using a scoring system (none, minor, moderate or severe). When anaesthesia was judged satisfactory, the patients were taken to the operating theatre. The operating ophthalmologist, who was not aware of diathermy use, also graded subconjunctival haemorrhage using the above scoring system before the start of surgery. Surgeons were also asked if subconjunctival haemorrhage interfered with surgery. The groups were comparable with respect to age, sex and axial length (Table 1). Subconjunctival haemorrhage was mainly confined to the infero-nasal quadrant. Minor to moderate subconjunctival haemorrhage occurred in 48% and 44%, and spread to other quadrants in 13% and 12%, in standard and diathermy groups, respectively. There was no case of severe haemorrhage. The incidence of subconjunctival haemorrhage noted by independent observers and operating surgeons was similar and did not impede surgery. Subconjunctival haemorrhage is inevitable in many patients during sub-Tenon’s block. The incidence of subconjunctival haemorrhage in our audit is similar to previously published studies. The use of disposable diathermy by the anaesthetist does not
