CORRESPONDENCE
73
INSERTION OF NASOGASTRIC TUBES
C . VAN DER WEYDEN
Annandale, Australia REFERENCES
Saha, A. K. (1974). The insertion of nasogastric tubes in the anaesthetised patient. Anaesthesia, 29, 367. Seebacher, J., Nozik, D., and Mathieu, A. (1975). Inadvertent intracranial introduction of a nasogastric tube; a complication of severe maxillofacial trauma. Anesthesiology, 42, 100. Sweatman, A. J., Tomasello, P. A., Loughhead, M. G., Orr, M., and Datta, T. (1978). Misplacement of nasogastric tubes and oesophageal monitoring devices. Br. J. Anaesth., 50, 389. Sir,—Dr Sweatman and colleagues (1978) describe an elaborate method of insertion of a nasogastric tube. The following method is simpler, but applies to paralysed patients only. After negotiating the nasal cavity with a nasogastric tube, the whole larynx is elevated by gripping the thyroid cartilage between thumb and fingers and lifting. The nasogastric tube then slides down the oesophagus without hindrance. The procedure is easier in males because of their more prominent thyroid cartilage. Providing the gripping of the larynx is performed carefully, no harm should result. WILLIAM F. S. SELLERS Gloucester REFERENCE
Sweatman, A. J., Tomasello, P. A., Loughhead, M. G., Orr, M., and Datta, T. (1978). Misplacement of nasogastric tubes and oesophageal monitoring devices. Br. J. Anaesth., 50, 389. Sir,—Thank you for the opportunity to reply to Dr Sellers and Dr van der Weyden. We agree with Dr Sellers that forward movement of the larynx will allow a nasogastric tube to enter the oesophagus more easily. We prefer to achieve this by anterior displacement of the mandible rather than gripping and elevation of the larynx, which may be painful and compress the carotid arteries and carotid sinus. In reply to Dr van der Weyden, direct laryngoscopy is undoubtedly the best way to confirm the position of a nasogastric tube. However, in the situation we describe— multiple oesophageal intubations in anaesthesia for cardiac
surgery—as many as five tubes or devices may be taped in position so that the mouth and pharynx are too crowded to allow a direct view. In other situations, such as intensive care units, patients may not be paralysed and the nonmedical personnel to whom the task of inserting nasogastric tubes may be given are usually not trained to use the laryngoscope. The aim of our method was to provide a means of avoiding and detecting misplacement without the use of any extra equipment other than hands, eyes and ears. ALAN J. SWEATMAN PHILIP A. TOMASELLO MICHAEL G. LOUGHHEAD MALCOLM ORR TAPAN DATTA
Baltimore, U.S.A. ANAESTHESIA AND INFANT WEIGHT
Sir,—I found the recent article by Abouleish and colleagues (1978) provocative but erroneous. The authors examined the interesting hypothesis that the effects of maternal analgesia on the neonatal central nervous system might be sufficient to alter the change in weight that occurs after birth. They base this concept on the well-known properties of various agents used in obstetrics to influence many newborn behaviour patterns, including nutritive and non-nutritive sucking. They tested their hypothesis by performing a 2-year retrospective analysis of vaginal deliveries, randomly selected for type of anaesthesia. They assessed the change in weight of the infant, which reflects newborn fluid balance, and not necessarily the infant's ability to feed, suck or be other than minimally intact neurologically. Thus their study was marred from the outset. They excluded 50% or more of deliveries selected under each category. For example, we are not informed of the reasons for excluding 68 natural childbirth mothers from the study. In the analysis, they chose standard error of the mean (SEM) rather than standard deviation as a measure of central tendency. However, when SEM is converted to standard deviation (by multiplying the former by the square root of n), the enormous variance in weight and weight change within and between groups is evident. This leads to the conclusion that early, short-term neonatal weight is a useless measure of subtle changes in central neurological function which may be induced by drugs administered to the mother. Abouleish and his colleagues have merely demonstrated that infants who have access to fluid (the bottle) will gain weight after their acute fluid loss has occurred, while those with limited access to fluid (the prelactating breast) will not demonstrate an increase until fluid is available (lactation). Whether such differences are good or bad is, of course, unknown. In summary, their attempt to reassure us of the absence of neonatal effects from maternal drugs is inconclusive. JOHN W. SCANLON
Washington REFERENCE
Abouleish, E., Van der Donck, A., Meeuwis, H., and Taylor, E. (1978). Effect of anaesthesia for delivery on the weight of infants during the first 5 days of life. Br. J. Anaesth., 50, 569.
Downloaded from http://bja.oxfordjournals.org/ at University of California, San Diego on June 9, 2015
Sir,—The article by Dr Sweatman and colleagues (1978) reminded me of that facetious medical adage: "If all else fails, examine the patient." On separate occasions in their article they state that "if necessary" and "if there is doubt" direct laryngoscopy must be used. Surely any attempt at oesophageal intubation requires direct laryngoscopy. The cases of Saha (1974), Seebacher, Nozik and Mathieu (1975), case 1 (and, I suspect, case 2) of Sweatman and colleagues (1978) all had oesophageal devices passed blindly. In at least three of these patients, complications could have been avoided had the instrumentation been carried out under direct vision. If there is to be a message it is: "It is clearly desirable to pass the nasogastric tube (or any oesophageal device) under direct vision whatever technique is employed" (Saha, 1974).
73
INSERTION OF NASOGASTRIC TUBES
C . VAN DER WEYDEN
Annandale, Australia REFERENCES
Saha, A. K. (1974). The insertion of nasogastric tubes in the anaesthetised patient. Anaesthesia, 29, 367. Seebacher, J., Nozik, D., and Mathieu, A. (1975). Inadvertent intracranial introduction of a nasogastric tube; a complication of severe maxillofacial trauma. Anesthesiology, 42, 100. Sweatman, A. J., Tomasello, P. A., Loughhead, M. G., Orr, M., and Datta, T. (1978). Misplacement of nasogastric tubes and oesophageal monitoring devices. Br. J. Anaesth., 50, 389. Sir,—Dr Sweatman and colleagues (1978) describe an elaborate method of insertion of a nasogastric tube. The following method is simpler, but applies to paralysed patients only. After negotiating the nasal cavity with a nasogastric tube, the whole larynx is elevated by gripping the thyroid cartilage between thumb and fingers and lifting. The nasogastric tube then slides down the oesophagus without hindrance. The procedure is easier in males because of their more prominent thyroid cartilage. Providing the gripping of the larynx is performed carefully, no harm should result. WILLIAM F. S. SELLERS Gloucester REFERENCE
Sweatman, A. J., Tomasello, P. A., Loughhead, M. G., Orr, M., and Datta, T. (1978). Misplacement of nasogastric tubes and oesophageal monitoring devices. Br. J. Anaesth., 50, 389. Sir,—Thank you for the opportunity to reply to Dr Sellers and Dr van der Weyden. We agree with Dr Sellers that forward movement of the larynx will allow a nasogastric tube to enter the oesophagus more easily. We prefer to achieve this by anterior displacement of the mandible rather than gripping and elevation of the larynx, which may be painful and compress the carotid arteries and carotid sinus. In reply to Dr van der Weyden, direct laryngoscopy is undoubtedly the best way to confirm the position of a nasogastric tube. However, in the situation we describe— multiple oesophageal intubations in anaesthesia for cardiac
surgery—as many as five tubes or devices may be taped in position so that the mouth and pharynx are too crowded to allow a direct view. In other situations, such as intensive care units, patients may not be paralysed and the nonmedical personnel to whom the task of inserting nasogastric tubes may be given are usually not trained to use the laryngoscope. The aim of our method was to provide a means of avoiding and detecting misplacement without the use of any extra equipment other than hands, eyes and ears. ALAN J. SWEATMAN PHILIP A. TOMASELLO MICHAEL G. LOUGHHEAD MALCOLM ORR TAPAN DATTA
Baltimore, U.S.A. ANAESTHESIA AND INFANT WEIGHT
Sir,—I found the recent article by Abouleish and colleagues (1978) provocative but erroneous. The authors examined the interesting hypothesis that the effects of maternal analgesia on the neonatal central nervous system might be sufficient to alter the change in weight that occurs after birth. They base this concept on the well-known properties of various agents used in obstetrics to influence many newborn behaviour patterns, including nutritive and non-nutritive sucking. They tested their hypothesis by performing a 2-year retrospective analysis of vaginal deliveries, randomly selected for type of anaesthesia. They assessed the change in weight of the infant, which reflects newborn fluid balance, and not necessarily the infant's ability to feed, suck or be other than minimally intact neurologically. Thus their study was marred from the outset. They excluded 50% or more of deliveries selected under each category. For example, we are not informed of the reasons for excluding 68 natural childbirth mothers from the study. In the analysis, they chose standard error of the mean (SEM) rather than standard deviation as a measure of central tendency. However, when SEM is converted to standard deviation (by multiplying the former by the square root of n), the enormous variance in weight and weight change within and between groups is evident. This leads to the conclusion that early, short-term neonatal weight is a useless measure of subtle changes in central neurological function which may be induced by drugs administered to the mother. Abouleish and his colleagues have merely demonstrated that infants who have access to fluid (the bottle) will gain weight after their acute fluid loss has occurred, while those with limited access to fluid (the prelactating breast) will not demonstrate an increase until fluid is available (lactation). Whether such differences are good or bad is, of course, unknown. In summary, their attempt to reassure us of the absence of neonatal effects from maternal drugs is inconclusive. JOHN W. SCANLON
Washington REFERENCE
Abouleish, E., Van der Donck, A., Meeuwis, H., and Taylor, E. (1978). Effect of anaesthesia for delivery on the weight of infants during the first 5 days of life. Br. J. Anaesth., 50, 569.
Downloaded from http://bja.oxfordjournals.org/ at University of California, San Diego on June 9, 2015
Sir,—The article by Dr Sweatman and colleagues (1978) reminded me of that facetious medical adage: "If all else fails, examine the patient." On separate occasions in their article they state that "if necessary" and "if there is doubt" direct laryngoscopy must be used. Surely any attempt at oesophageal intubation requires direct laryngoscopy. The cases of Saha (1974), Seebacher, Nozik and Mathieu (1975), case 1 (and, I suspect, case 2) of Sweatman and colleagues (1978) all had oesophageal devices passed blindly. In at least three of these patients, complications could have been avoided had the instrumentation been carried out under direct vision. If there is to be a message it is: "It is clearly desirable to pass the nasogastric tube (or any oesophageal device) under direct vision whatever technique is employed" (Saha, 1974).
