Comment
Thyroidectomy under local analgesia: the anatomical basis of cervical blocks We read with interest Professor Yerzingatsian's article (Annals, July 1989, vol 7, p207) on cervical local anaesthetic block for thyroid surgery. We are, however, concerned at his claim that 120 ml of 0.5% lignocaine with adrenaline 1:400 000 is "well within the safe dose" and his further claim that "local anaesthesia using dilute lignocaine is 'safe"'. The issue of maximum recommended doses (MRD) of local anaesthetics in general and lignocaine in particular is unresolved. If we accept that toxicity of local anaesthetics depends on plasma levels, we must accept that factors affecting plasma levels will also affect toxicity. These include dose injected, dilution, presence or absence of adrenaline and, most important, vascularity and site of injection. Professor Yerzingatsian's recommended dose, at 600 mg of lignocaine is higher than anything we have seen for any site and, whilst it may prove to be safe, 19 cases is far too small a series from which to draw conclusions. If such doses are to be used we suggest that this should be done with great caution, that the skills and equipment for resuscitation be immediately available (as they always should be) and that, ideally, plasma levels of lignocaine be measured. Such steps would ensure that a potentially excellent technique was placed on a sound basis-or not, as the case may be. R SINCLAIR FFARCS Senior Registrar JOHN S M ZORAB FFARCS Consultant Frenchay Hospital Bristol
A new technique of caecostomy using endotracheal tubes I recently read the article cited above (Annals, July 1989, vol 71, p211). I am writing to bring to your attention that I published a paper entitled 'Tube cecostomy using a wirewrapped endotracheal tube' in 1988 (1). I concur with the author's conclusion that this is a useful technique. However, I should like to urge that wire-wrapped endotracheal tubes be used as they can be bent to conform to the patient's body without kinking the tube. SAUL EISENSTAT MD FACS General and Vascular Surgeon Mountain View California, USA
Reference I Eisenstat S. Tube cecostomy using a wire-wrapped endotracheal tube. Surg Gynecol Obstet 1988;166:473-4.
Author's reply I was most interested to read of Dr Eisenstat's experience with endotracheal tubes for caecostomy drainage. I am pleased that he has also found them useful. Since my original paper I have used ordinary endotracheal tubes on two occasions without blockage. I therefore feel that it is the wide diameter of the tube which is valuable rather than any particular property of the wall. C J H INGOLDBY MChir FRCS Lecturer in Surgety St James's University Hospital Leeds
67
Fasting in children for day case surgery The above paper (Annals, July 1989, vol 71, p218) was read with interest, but I would like to bring to your attention an article by Stephen Ware and J P Osborne (1). In this study, on 57 children, the importance of perioperative hypoglycaemia was stressed. In this study not only were the blood sugars estimated but levels of growth hormone, insulin, as well as the duration of pre- and postoperative fasting were noted. It was noted that intravenous or oral fluid did not necessarily prevent a fall in blood sugar. The case that precipitated the study was a 13-month-old child who had a catastrophic fall in blood sugar levels after operation, resulting in coma and subsequent death. In perioperative hypoglycaemia in small children, the role of prolonged fasting was stressed. Prolonged periods of fasting were sometimes due to misinformation given to the child's parents for up to 24 h. During the collection of material for this study it was noted that sugar given orally or intravenously as a stat dose could have a dangerous rebound effect. Since this time it has been our policy to give small children a drink of milk 4 h before operation and recommence feeds as soon as possible after. J 0 N LAWSON FRCS Consultant Paediatric Surgeon Paediatric Urologist St Thomas' Hospital London
Reference I Ware S, Osborne JP. Postoperative hypoglycaemia in small children. Br Med J 1976;2:199-201.
Prolene plug repair for femoral hernia I read with interest the paper by Allan and Heddle (Annals, July 1989, vol 71, p220). The authors reported on seven out of a total of 25 femoral hernias. The authors conclude the paper by suggesting the use of a Prolene plug is safe for elective and emergency femoral hernia repair. I would like to make two points. 1. The use of the term incarcerated when referring to the status of a hernia is misleading and should be avoided. One takes the authors to mean by this term anything ranging from irreducibility to frank strangulation of the hernial sac contents. The term incarcerate is derived from the Latin word carcer meaning prison. Its use, as described by Bailey and Love should be specific to those hernias where "it is considered that the lumen of that portion of colon occupying a hernial sac is blocked with faeces". This must be a rare event with a femoral hernia. Less ambiguous terms pertaining to the status of a femoral hernia would have been more informative. 2. The nature of any fluid in the sac, the sac contents, and whether a resection was necessary, should have been stated in the emergency cases. Unfortuilately, the authors did not include such information so as to allow one to make a relative assessment of the risks of sepsis to the Prolene plug. I would suggest, therefore, that one should be guarded in recommending the technique of Prolene plug repair in all emergency femoral hernia surgery. ANDREW MASTERS FRCS FRCSEd Research Fellow
University College Hospital London
Thyroidectomy under local analgesia: the anatomical basis of cervical blocks We read with interest Professor Yerzingatsian's article (Annals, July 1989, vol 7, p207) on cervical local anaesthetic block for thyroid surgery. We are, however, concerned at his claim that 120 ml of 0.5% lignocaine with adrenaline 1:400 000 is "well within the safe dose" and his further claim that "local anaesthesia using dilute lignocaine is 'safe"'. The issue of maximum recommended doses (MRD) of local anaesthetics in general and lignocaine in particular is unresolved. If we accept that toxicity of local anaesthetics depends on plasma levels, we must accept that factors affecting plasma levels will also affect toxicity. These include dose injected, dilution, presence or absence of adrenaline and, most important, vascularity and site of injection. Professor Yerzingatsian's recommended dose, at 600 mg of lignocaine is higher than anything we have seen for any site and, whilst it may prove to be safe, 19 cases is far too small a series from which to draw conclusions. If such doses are to be used we suggest that this should be done with great caution, that the skills and equipment for resuscitation be immediately available (as they always should be) and that, ideally, plasma levels of lignocaine be measured. Such steps would ensure that a potentially excellent technique was placed on a sound basis-or not, as the case may be. R SINCLAIR FFARCS Senior Registrar JOHN S M ZORAB FFARCS Consultant Frenchay Hospital Bristol
A new technique of caecostomy using endotracheal tubes I recently read the article cited above (Annals, July 1989, vol 71, p211). I am writing to bring to your attention that I published a paper entitled 'Tube cecostomy using a wirewrapped endotracheal tube' in 1988 (1). I concur with the author's conclusion that this is a useful technique. However, I should like to urge that wire-wrapped endotracheal tubes be used as they can be bent to conform to the patient's body without kinking the tube. SAUL EISENSTAT MD FACS General and Vascular Surgeon Mountain View California, USA
Reference I Eisenstat S. Tube cecostomy using a wire-wrapped endotracheal tube. Surg Gynecol Obstet 1988;166:473-4.
Author's reply I was most interested to read of Dr Eisenstat's experience with endotracheal tubes for caecostomy drainage. I am pleased that he has also found them useful. Since my original paper I have used ordinary endotracheal tubes on two occasions without blockage. I therefore feel that it is the wide diameter of the tube which is valuable rather than any particular property of the wall. C J H INGOLDBY MChir FRCS Lecturer in Surgety St James's University Hospital Leeds
67
Fasting in children for day case surgery The above paper (Annals, July 1989, vol 71, p218) was read with interest, but I would like to bring to your attention an article by Stephen Ware and J P Osborne (1). In this study, on 57 children, the importance of perioperative hypoglycaemia was stressed. In this study not only were the blood sugars estimated but levels of growth hormone, insulin, as well as the duration of pre- and postoperative fasting were noted. It was noted that intravenous or oral fluid did not necessarily prevent a fall in blood sugar. The case that precipitated the study was a 13-month-old child who had a catastrophic fall in blood sugar levels after operation, resulting in coma and subsequent death. In perioperative hypoglycaemia in small children, the role of prolonged fasting was stressed. Prolonged periods of fasting were sometimes due to misinformation given to the child's parents for up to 24 h. During the collection of material for this study it was noted that sugar given orally or intravenously as a stat dose could have a dangerous rebound effect. Since this time it has been our policy to give small children a drink of milk 4 h before operation and recommence feeds as soon as possible after. J 0 N LAWSON FRCS Consultant Paediatric Surgeon Paediatric Urologist St Thomas' Hospital London
Reference I Ware S, Osborne JP. Postoperative hypoglycaemia in small children. Br Med J 1976;2:199-201.
Prolene plug repair for femoral hernia I read with interest the paper by Allan and Heddle (Annals, July 1989, vol 71, p220). The authors reported on seven out of a total of 25 femoral hernias. The authors conclude the paper by suggesting the use of a Prolene plug is safe for elective and emergency femoral hernia repair. I would like to make two points. 1. The use of the term incarcerated when referring to the status of a hernia is misleading and should be avoided. One takes the authors to mean by this term anything ranging from irreducibility to frank strangulation of the hernial sac contents. The term incarcerate is derived from the Latin word carcer meaning prison. Its use, as described by Bailey and Love should be specific to those hernias where "it is considered that the lumen of that portion of colon occupying a hernial sac is blocked with faeces". This must be a rare event with a femoral hernia. Less ambiguous terms pertaining to the status of a femoral hernia would have been more informative. 2. The nature of any fluid in the sac, the sac contents, and whether a resection was necessary, should have been stated in the emergency cases. Unfortuilately, the authors did not include such information so as to allow one to make a relative assessment of the risks of sepsis to the Prolene plug. I would suggest, therefore, that one should be guarded in recommending the technique of Prolene plug repair in all emergency femoral hernia surgery. ANDREW MASTERS FRCS FRCSEd Research Fellow
University College Hospital London
