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Topical negative pressure in the treatment of pressure ulcers
LETTERS I I Topical negative pressure in the treatment o f pressure ulcers
To the Editor: We read with interest the CME article on pressure ulcers by Kanj et al (J Am Acad Dermatol 1998;38:517-36). We were surprised, however, not to see mention of negative pressure therapy. This technique, otherwise known as vacuum-assisted closure or the vacuum sealing technique, has been described by Argenta and Morykwas 1 and Fleischmann et al. 2 Argenta had described his clinical experience of negative pressure therapy in 300 patients with a variety of wounds including pressure ulcers. Mullner, Mrkonjic, and Vecsei 3 have reported a clinical trial of negative pressure giving good results in pressure sores. The technique involves placing foam into a wound and applying subatmospheric pressure. The foam allows the vacuum to be evenly applied throughout the wound. Negative pressure increases blood flow around the ulcer and may reduce bacterial counts. 4 With the use of a pig model and comparing continuous negative pressure of 125 m m Hg to treatm e n t with saline-soaked gauze, wounds treated with negative pressure showed an increase in granulation tissue of 63.3% + 26.15%, rising to 103.4% -+ 35.3% when intermittent pressure was used (125 m m Hg; 5 minutes on, 2 minutes off.) 4 We accept that no randomized controlled trials have been published to date. The negative pressure technique is in widespread use in plastic surgery units in the United Kingdom, and we have recently gained s o m e experience in our Dermatology unit. Initial results have been very encouraging, and we believe further evaluation of this method is warranted. Susan Mary Cooper, MRCPUK,MRCGP Elspeth Young FRCP Dermatology Unit Amersham Hospital Amersham Buckinghamshire United Kingdom HP5 0JD REFERENCES I. Argenta LC, Morykwas MJ. Vacuum assisted closure: a new method of wound control and treatment: clinical experience. Ann Plast Surg 1997;38:563-76. 2. Fleischmann W, Strecker W, Bombelli M, Kinzl L. Vakuumversiegelung zur Behandtung des Hautweichteilschadens bei offenen Frakturen. Unfallchirug 1993;96:488-92. 3. Mullner T, Mrkonjic L, Kwasny O, Vecsei V. The use of negative pressure to promote the healing of tissue defects:a clinical trial using the vacuum sealing technique. Br J Plast Surg 1997;50: 194-9.
280
AUGUST, PART 1, 1999
4. Morykwas M J, Argenta LC, Shelton Brown El, McGuirt W. Vacuum assisted closure:a new method for wound control and treatment: animal studies and basic foundation. Ann Plast Surg
1997;38:553-62.
A case o f l i d o c a i n e a b s o r p t i o n from topical administration o f 40% l i d o c a i n e cream
To the Editor.. The use of topical anesthetic agents (eutectic mixture of local anesthetics [EMLA] and lidocaine topical cream) to alleviate pain from laser p r o c e d u r e s has b e c o m e standard practice. 1-3 Application of these agents under occlusion to skin from which the e p i d e r m i s has b e e n r e m o v e d enhances their absorption. The following case illustrates potential problems with this procedure. A 30-year-old white female social worker in g o o d health requested t r e a t m e n t for stretch marks and striae about the breasts and a b d o m e n , which had b e e n p r o m i n e n t since a pregnancy 7 years earlier. On examination p r o m i n e n t h y p o p i g m e n t e d striae were n o t e d about the umbilicus and inferiorly on both breasts. The estimated portion of body surface of the striae was 4% or 200 cm 2. The patient underwent erbium:YAG laser (ConBio Erbium/2.4; C o n t i n u u m Biomedical, Dublin, Calif) resurfacing. No intralesional anesthetic was administered. After the initial two passes, 40% lidocaine in acid mantle base cream was applied in a thin coating to the lased areas and then occluded with plastic wrap. After 15 minutes, sufficient anesthesia was achieved to allow 4 additional passes. At the completion of the case, the patient requested that m o r e lidocaine cream be applied to relieve the burning and pain. Five grams of 40% lidocaine was reapplied and a Telfa dressing was secured with Micropore tape. Postoperatively the patient reported dizziness and headache; she was given orange juice for p r e s u m e d hypoglycemia. She had stated that she had worked all night and had not eaten or slept within the last 24hour period. After monitoring her closely for 30 to 45 minutes, she was discharged, feeling better with normal vital signs. On the way h o m e the patient developed further light-headedness, increasing dizziness, and confusion. She was transported by ambulance to the emergency department, and she was admitted for observation. The initial diagnosis by the e m e r g e n c y d e p a r t m e n t staff was drug overdose. She was hydrated and observed. The attending physician was contacted, and the diagnosis of lidocaine toxicity was suspected. At this time the dressJ AM ACAD DERMATOL
To the Editor: We read with interest the CME article on pressure ulcers by Kanj et al (J Am Acad Dermatol 1998;38:517-36). We were surprised, however, not to see mention of negative pressure therapy. This technique, otherwise known as vacuum-assisted closure or the vacuum sealing technique, has been described by Argenta and Morykwas 1 and Fleischmann et al. 2 Argenta had described his clinical experience of negative pressure therapy in 300 patients with a variety of wounds including pressure ulcers. Mullner, Mrkonjic, and Vecsei 3 have reported a clinical trial of negative pressure giving good results in pressure sores. The technique involves placing foam into a wound and applying subatmospheric pressure. The foam allows the vacuum to be evenly applied throughout the wound. Negative pressure increases blood flow around the ulcer and may reduce bacterial counts. 4 With the use of a pig model and comparing continuous negative pressure of 125 m m Hg to treatm e n t with saline-soaked gauze, wounds treated with negative pressure showed an increase in granulation tissue of 63.3% + 26.15%, rising to 103.4% -+ 35.3% when intermittent pressure was used (125 m m Hg; 5 minutes on, 2 minutes off.) 4 We accept that no randomized controlled trials have been published to date. The negative pressure technique is in widespread use in plastic surgery units in the United Kingdom, and we have recently gained s o m e experience in our Dermatology unit. Initial results have been very encouraging, and we believe further evaluation of this method is warranted. Susan Mary Cooper, MRCPUK,MRCGP Elspeth Young FRCP Dermatology Unit Amersham Hospital Amersham Buckinghamshire United Kingdom HP5 0JD REFERENCES I. Argenta LC, Morykwas MJ. Vacuum assisted closure: a new method of wound control and treatment: clinical experience. Ann Plast Surg 1997;38:563-76. 2. Fleischmann W, Strecker W, Bombelli M, Kinzl L. Vakuumversiegelung zur Behandtung des Hautweichteilschadens bei offenen Frakturen. Unfallchirug 1993;96:488-92. 3. Mullner T, Mrkonjic L, Kwasny O, Vecsei V. The use of negative pressure to promote the healing of tissue defects:a clinical trial using the vacuum sealing technique. Br J Plast Surg 1997;50: 194-9.
280
AUGUST, PART 1, 1999
4. Morykwas M J, Argenta LC, Shelton Brown El, McGuirt W. Vacuum assisted closure:a new method for wound control and treatment: animal studies and basic foundation. Ann Plast Surg
1997;38:553-62.
A case o f l i d o c a i n e a b s o r p t i o n from topical administration o f 40% l i d o c a i n e cream
To the Editor.. The use of topical anesthetic agents (eutectic mixture of local anesthetics [EMLA] and lidocaine topical cream) to alleviate pain from laser p r o c e d u r e s has b e c o m e standard practice. 1-3 Application of these agents under occlusion to skin from which the e p i d e r m i s has b e e n r e m o v e d enhances their absorption. The following case illustrates potential problems with this procedure. A 30-year-old white female social worker in g o o d health requested t r e a t m e n t for stretch marks and striae about the breasts and a b d o m e n , which had b e e n p r o m i n e n t since a pregnancy 7 years earlier. On examination p r o m i n e n t h y p o p i g m e n t e d striae were n o t e d about the umbilicus and inferiorly on both breasts. The estimated portion of body surface of the striae was 4% or 200 cm 2. The patient underwent erbium:YAG laser (ConBio Erbium/2.4; C o n t i n u u m Biomedical, Dublin, Calif) resurfacing. No intralesional anesthetic was administered. After the initial two passes, 40% lidocaine in acid mantle base cream was applied in a thin coating to the lased areas and then occluded with plastic wrap. After 15 minutes, sufficient anesthesia was achieved to allow 4 additional passes. At the completion of the case, the patient requested that m o r e lidocaine cream be applied to relieve the burning and pain. Five grams of 40% lidocaine was reapplied and a Telfa dressing was secured with Micropore tape. Postoperatively the patient reported dizziness and headache; she was given orange juice for p r e s u m e d hypoglycemia. She had stated that she had worked all night and had not eaten or slept within the last 24hour period. After monitoring her closely for 30 to 45 minutes, she was discharged, feeling better with normal vital signs. On the way h o m e the patient developed further light-headedness, increasing dizziness, and confusion. She was transported by ambulance to the emergency department, and she was admitted for observation. The initial diagnosis by the e m e r g e n c y d e p a r t m e n t staff was drug overdose. She was hydrated and observed. The attending physician was contacted, and the diagnosis of lidocaine toxicity was suspected. At this time the dressJ AM ACAD DERMATOL