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A new graph for insertion of umbilical artery catheters
Volume 96 Number 4
Auditory f u n c t i o n in N I C U
ment of auditory function in newborn infants revealed by auditory brain stem potential, Pediatrics 60:831, 1977. 6. Hecox K, and Galambos R: Brain stem auditory evoked responses in human infants and adults, Arch Otolaryngol 99:30, 1974. 7. Environmental Protection Agency: Report to the President
735
and congress on noise. (In compliance with Title IV of Public Law 91-604: The Clean Air Act Amendments of 1970.) U.S. Government Printing Office, February, 1972. Spector G, Pettit W, Davis G, Strauss M, and Rauchbach E: Fetal respiratory distress causing CNS and inner ear hemorrhage, Laryngoscope 88:764, 1978.
Brief clinical and laboratory observations A new graph for insertion of umbilical artery catheters W. Rosenfeld, M.D.,* d. Biagtan, M.D., H. Sehaeffer, M.D., H. Evans, M.D., S. Flicker, M.D., D. Salazar, M.D., and R. Jhaveri, M.D., Brooklyn, N.Y.
THE LENGTH of insertion for umbilical artery catheters has been based on the graphs tabulated by Dunn 1 for total body length and shoulder umbilical length. Despite frequent use, these graphs have not been critically evaluated and have several potential limitations. They are based on the anatomic landmarks of the pathologist (the diaphragm) rather than those of the clinician (vertebrae). The original study included only eight of 25 patients with TBL _< 40 cm (fiftieth percentile for patients weighing 1,200 gin); and used only postmortem patients. Using live patients and including a larger number of low-birth-weight neonates, we re-evaluated Dunn's graphs. In addition, new graphs for catheterization were calculated and their accuracy determined. METHODS
Eighty-two infants consecutively admitted to our Neonatal Intensive Care Unit requiring umbilical artery catheterization from July, 1978, to December, 1978, were initially included Seven were eliminated because of an abnormal number of ribs (five had 11 ribs, two had 13 ribs). Eighty-eight percent of the patients were premature ~ and 49% had TBL _< 40 cm. All catheterizations were performed by housestaff and fellows using a previously From the Departments of Pediatrics and Radiology, The Jewish Hospital and Medical Center of Brooklyn, The Downstate University School of Medicine. *Reprint address: Department of Pediatrics, Jewish Hospital and Medical Center of Brooklyn, 555 Prospect Place, Brooklyn, NY 11238.
0022-3476/80/040735 + 03500.30/0 9 1980 The C. V. Mosby Co.
described method? Standard polyvinyl arterial catheters (Argyle) were employed. Two clinicians performed the catheterization and independently measured TBL and SUL with a standard metric tape. Measurements differing by 0.5 cm or more were repeated until agreement was reached. All measurements were rechecked by one of the neonatologists. Abbreviations used TBL: total body length SUL: shoulder umbilical length The distance the catheter was to be inserted was calculated, using Dunn's graph for TBL and adding the length of the umbilical stump. The actual length of the inserted catheter was calculated by subtracting the distance from the abdominal wall to the first visible radiopaque marking on the catheter (5, 10, or 15 cm) or, if no markings were visible, from the end of the catheter (40.5 cm). The location of the catheter tip was determined by a radiograph of the chest and upper abdomen and verified by the neonatologists and radiologist. Catheters in improper position and catheters associated with complications such as blanching were changed or repositioned. As a result, 107 measurements were made in 75 patients. To determine if a new graph derived from this group of patients would result in more accurate catheter placements, new graphs for all catheters at T, in relation to TBL and SUL and the length of insertion were drawn. Both Dunn's graph and these new graphs for TBL and
736
Brief clinical and laboratory observations
The Journal of Pediatrics April 1980
RESULTS
2 2 84 20
18 CATHETER I 6 LENGTH {cm)
I4 m
12
9
iO 8 6 4 2 28
30
32 3 4
36 38 4 0 42 4 4 4 6 4 8 TOTAL BOOY LENGTH (cm)
,50 52
54
,56 58
Figure. Graph for catheter insertion to T~ using TBL. Location of 29 catheters and resulting regression line (m = 0.433, b = 4.4, r = 0.9549, P < 0.001).
Table. Comparison of accuracy and acceptability for Dunn's and new graphs
SUL (%)
Acceptability TBL (%)
65, (11/17) 71 (20/28)
76~ (81/107) 100~ (30/30)
A ccUracy TBL (%)
Dunn New graph TBL *P < tP < ~P <
76* (13/17) 93, (26/28)
] J
= Total body length; SUL: shoulder umbilical length. 0,25, 0.01. 0.05.
SUL were evaluated for catheters in an acceptable and accurate position. Catheters were considered acceptable if the tips were located at or between T~ and T~o or L~ and L~. Accuracy was evaluated by checking catheters one vertebra above or below the line described by the graph (T~, and T . for Dunn's graph and T~ and To for the new graphs). Catheter tips one vertebra above this line were accurate if they plotted out above the line described on the graph and inaccurate if they were plotted below. Similarly, catheters below the lines were accurate if they plotted below the line described by the graph and inaccurate if above. The use of the newly developed graph for Ts, using TBL measurements, was evaluated prospectively in a second group of 30 consecutive patients. The housestaff physicians were instructed to insert the catheter the exact distance predicted by this new graph. The length of the umbilical stump and that of the transected cord were added to the distance of insertion calculated by the graph (total length of catheter insertion = distance [from graph] for T8 + length of stump + length of transected cord).
In 75 patients and 107 catheter placements (55 in patients with TBL _< 40 cm), 81 catheters (76%) were in acceptable locations (71 at or between T6 and T10, 10 at or between L~ and L~) utilizing Dunn's graph for TBL. The remaining 26 (24%) catheters were positioned improperly (10 above "I"6, 15 below T10, and above L~, and one below Ls) (Table). Dunn's graph for TBL accurately predicted catheter position at T~ in 10 of 13 placements (77%) and at TH in 3 of 4 (75%), an overall accuracy of 76% (13 of 17). Dunn's graph for SUL demonstrated accurate prediction of catheter position at T9 in 8 of 13 placements (62%) and at T~ in 3 of 4 (75%) placements, an overall accuracy of 65% (Table). In 29 catheter placements at Ts, catheter length was plotted against TBL and a regression line calculated (m = 0.433, b = 4.4, r = 0.9549, P _< 0.001) (Figure). This graph 'led to accurate prediction of catheters positioned at T7 in all 15 placements (100%) and at T~ in 11 of 13 placements (85%), an overall accuracy rate of 93%. The accuracy with the new graph was not significantly different from that attained with Dunn's graph for TBL (X~ = 1.22, P < 0.25), but was significantly better than Dunn's graph for SUL (X~ = 3.935, P < 0.05). The SUL was plotted against the length of catheter insertion in 29 catheters at T~ (m = 1.09, b = 0.76, r = 0.904, P < 0.001). This graph led to accurate prediction of catheters positioned at T7 in 11 of 15 placements (73%)" and at To in 9 of 13 placements (69%), an overall accuracy of 71%. The accuracy of this new graph for SUL was not significantly different from Dunn's graphs for SUL or TBL. In comparison to our new graph for TBL, the graph for SUL did not reach significance (X~ = 3.043, P < 0.1). In 30 patients prospectively catheterized utilizing the new graph, the catheter tip was located at T7 in 11, T~ in 9, and T9 in 5, and between T~ and T~o in all 30. When compared to the original series of 107 catheterizations utilizing Dunn's graph for TBL, this new graph resulted in significantly more catheters in acceptable positions (X~ = 7.50, P < 0.01) (Table). DISCUSSION Optimal localization of umbilical artery catheters has been estimated by using anatomic relationships described by Dunn. 1 Despite the lack of critical evaluation of the accuracy of his data, most descriptions of catheter placement technique 4~ have been based on this work. Although mistakes in measurements for TBL, SUL, the umbilical stump, and length of insertion could account for some misplaced catheters, the present study demonstrated
Volume 96 Number 4
Brief clinical and laboratory observations
that use of TBL resulted in more accurate catheter placements than use of SUL, attaining statistical significance only when comparing our graph for TBL with Dunn's graph for SUL (Table). Utilizing this new graph for TBL, catheters were located in acceptable positions in each of 30 consecutive patients studied prospectively. Although each catheter was inserted the theoretically estimated distance, several did not rest exactly at T~ due to the wide natural variation between TBL and the distance the catheter must be inserted. This variation may also create a problem in attempting to place catheters at Txo. Although catheters above TI~ are in acceptable locatons, those that rest below TI0, will be at the origin of the major blood vessels. Therefore a margin of safety is gained by selecting Ts. This may be another benefit of its use.
737
REFERENCES 1. Dunn P: Localization of the umbilical catheter by post mortem measurement, Arch Dis Child 41:69, 1966. 2. BallardJ, Kazmaier K, and Driver M: A simplified assessment of gestational age, Pediatr Res 11:374, 1977. 3. Symansky M, and Fox H: Umbilical vessel catheterization: Indications, management, and evaluation of technique, J P~DIATR 80:820, 1972. 4. Kitterman J, Phibbs R, and Tooley W: Catheterization of umbilical vessels in newborn infants, Pediatr Clin North Am 17:895, 1970. 5. Fisher D, and Behrman R: Resuscitation of the newborn infant, umbilical vessel catheterization, Klaus MH, and Fanaroff AA, editors: Care of the high risk infant, Philadelphia, 1977,WB Saunders Company, pp 15-17. 6. Neal W, Reynolds J, and Jarvis C: Umbilical artery catheterization: Demonstration of arterial thrombosis by aortography, Pediatrics 50:6, 1972.
Inulin clearance in the premature infant receiving indomethacin Zack Catterton, M.D., Billy Sellers, Jr., M.D., and Bonnie Gray, A ugusta, Ga.
I N D OMETH AC I N has been utilized to achieve pharmacologic closure of the patent ductus arterious in premature infants. Frequently reported complications of lnd therapy are reduction of urine output and elevation of serum creatinine or blood urea nitrogen values. '~ This report documents the effect of Ind on the glomerular filtration rate of premature infants with a symptomatic PDA. Failure of serum creatinine and BUN concentrations to reflect changes in GFR in these infants is reported. PATIENTS
AND METHODS
The GFR was measured before and after Ind therapy in seven premature infants receiving Ind for treatment of a symptomatic PDA unresponsive to conservative medical management. Initial management consisted of fluid restriction ( < 130 ml/kg/24 hours), digitalization, and continuous distending airway pressure for pulmonary edema. An attempt to induce pharmacologic ductus closure with Ind was made when, after a minimum of 48 hours of medical management, the infants still displayed evidence of large left-to-right shunting that necessitated continuous distending airway pressure. The Ind was prepared by suspending the contents of a 25 mg capsule in normal saline as described by Heymann et al2 and was administered via orogastric tube. The Ind
0022-3476/80/040737 + 03500.30/0 9 1980 The C. V. Mosby Co.
(0.2 mg/kg) was administered initially and every 24 hours as needed to a maximum of 0.6 mg/kg. Daily BUN, serum creatinine, hematocrit, and, fluid intake and output values were recorded before and after each dose of Ind. Abbreviations used Ind: indomethacin PDA: patent ductus arteriosus GFR: glomerular filtration rate PGE: prostaglandin E BUN: blood urea nitrogen The GFR was measured prior to initiating Ind therapy, < 24 hours after administering the initial dose, and in three of the patients, two to ten days after completing a course of Ind. The GFR was determined by inulin clearance as previously reported? A bolus inject!on of 10% inulin (50 mg/kg) was infused over 30 seconds into a peripheral vein or umbilical vessel. Blood samples of 0.5 ml were collected at timed intervals over a two-hour period following injection of inulin. Inulin clearance was calculated according to the model of Sapirstein~ and expressed as ml/minute/1.73 m'-'. Blood pressure was measured at least hourly during each two-hour clearance
Auditory f u n c t i o n in N I C U
ment of auditory function in newborn infants revealed by auditory brain stem potential, Pediatrics 60:831, 1977. 6. Hecox K, and Galambos R: Brain stem auditory evoked responses in human infants and adults, Arch Otolaryngol 99:30, 1974. 7. Environmental Protection Agency: Report to the President
735
and congress on noise. (In compliance with Title IV of Public Law 91-604: The Clean Air Act Amendments of 1970.) U.S. Government Printing Office, February, 1972. Spector G, Pettit W, Davis G, Strauss M, and Rauchbach E: Fetal respiratory distress causing CNS and inner ear hemorrhage, Laryngoscope 88:764, 1978.
Brief clinical and laboratory observations A new graph for insertion of umbilical artery catheters W. Rosenfeld, M.D.,* d. Biagtan, M.D., H. Sehaeffer, M.D., H. Evans, M.D., S. Flicker, M.D., D. Salazar, M.D., and R. Jhaveri, M.D., Brooklyn, N.Y.
THE LENGTH of insertion for umbilical artery catheters has been based on the graphs tabulated by Dunn 1 for total body length and shoulder umbilical length. Despite frequent use, these graphs have not been critically evaluated and have several potential limitations. They are based on the anatomic landmarks of the pathologist (the diaphragm) rather than those of the clinician (vertebrae). The original study included only eight of 25 patients with TBL _< 40 cm (fiftieth percentile for patients weighing 1,200 gin); and used only postmortem patients. Using live patients and including a larger number of low-birth-weight neonates, we re-evaluated Dunn's graphs. In addition, new graphs for catheterization were calculated and their accuracy determined. METHODS
Eighty-two infants consecutively admitted to our Neonatal Intensive Care Unit requiring umbilical artery catheterization from July, 1978, to December, 1978, were initially included Seven were eliminated because of an abnormal number of ribs (five had 11 ribs, two had 13 ribs). Eighty-eight percent of the patients were premature ~ and 49% had TBL _< 40 cm. All catheterizations were performed by housestaff and fellows using a previously From the Departments of Pediatrics and Radiology, The Jewish Hospital and Medical Center of Brooklyn, The Downstate University School of Medicine. *Reprint address: Department of Pediatrics, Jewish Hospital and Medical Center of Brooklyn, 555 Prospect Place, Brooklyn, NY 11238.
0022-3476/80/040735 + 03500.30/0 9 1980 The C. V. Mosby Co.
described method? Standard polyvinyl arterial catheters (Argyle) were employed. Two clinicians performed the catheterization and independently measured TBL and SUL with a standard metric tape. Measurements differing by 0.5 cm or more were repeated until agreement was reached. All measurements were rechecked by one of the neonatologists. Abbreviations used TBL: total body length SUL: shoulder umbilical length The distance the catheter was to be inserted was calculated, using Dunn's graph for TBL and adding the length of the umbilical stump. The actual length of the inserted catheter was calculated by subtracting the distance from the abdominal wall to the first visible radiopaque marking on the catheter (5, 10, or 15 cm) or, if no markings were visible, from the end of the catheter (40.5 cm). The location of the catheter tip was determined by a radiograph of the chest and upper abdomen and verified by the neonatologists and radiologist. Catheters in improper position and catheters associated with complications such as blanching were changed or repositioned. As a result, 107 measurements were made in 75 patients. To determine if a new graph derived from this group of patients would result in more accurate catheter placements, new graphs for all catheters at T, in relation to TBL and SUL and the length of insertion were drawn. Both Dunn's graph and these new graphs for TBL and
736
Brief clinical and laboratory observations
The Journal of Pediatrics April 1980
RESULTS
2 2 84 20
18 CATHETER I 6 LENGTH {cm)
I4 m
12
9
iO 8 6 4 2 28
30
32 3 4
36 38 4 0 42 4 4 4 6 4 8 TOTAL BOOY LENGTH (cm)
,50 52
54
,56 58
Figure. Graph for catheter insertion to T~ using TBL. Location of 29 catheters and resulting regression line (m = 0.433, b = 4.4, r = 0.9549, P < 0.001).
Table. Comparison of accuracy and acceptability for Dunn's and new graphs
SUL (%)
Acceptability TBL (%)
65, (11/17) 71 (20/28)
76~ (81/107) 100~ (30/30)
A ccUracy TBL (%)
Dunn New graph TBL *P < tP < ~P <
76* (13/17) 93, (26/28)
] J
= Total body length; SUL: shoulder umbilical length. 0,25, 0.01. 0.05.
SUL were evaluated for catheters in an acceptable and accurate position. Catheters were considered acceptable if the tips were located at or between T~ and T~o or L~ and L~. Accuracy was evaluated by checking catheters one vertebra above or below the line described by the graph (T~, and T . for Dunn's graph and T~ and To for the new graphs). Catheter tips one vertebra above this line were accurate if they plotted out above the line described on the graph and inaccurate if they were plotted below. Similarly, catheters below the lines were accurate if they plotted below the line described by the graph and inaccurate if above. The use of the newly developed graph for Ts, using TBL measurements, was evaluated prospectively in a second group of 30 consecutive patients. The housestaff physicians were instructed to insert the catheter the exact distance predicted by this new graph. The length of the umbilical stump and that of the transected cord were added to the distance of insertion calculated by the graph (total length of catheter insertion = distance [from graph] for T8 + length of stump + length of transected cord).
In 75 patients and 107 catheter placements (55 in patients with TBL _< 40 cm), 81 catheters (76%) were in acceptable locations (71 at or between T6 and T10, 10 at or between L~ and L~) utilizing Dunn's graph for TBL. The remaining 26 (24%) catheters were positioned improperly (10 above "I"6, 15 below T10, and above L~, and one below Ls) (Table). Dunn's graph for TBL accurately predicted catheter position at T~ in 10 of 13 placements (77%) and at TH in 3 of 4 (75%), an overall accuracy of 76% (13 of 17). Dunn's graph for SUL demonstrated accurate prediction of catheter position at T9 in 8 of 13 placements (62%) and at T~ in 3 of 4 (75%) placements, an overall accuracy of 65% (Table). In 29 catheter placements at Ts, catheter length was plotted against TBL and a regression line calculated (m = 0.433, b = 4.4, r = 0.9549, P _< 0.001) (Figure). This graph 'led to accurate prediction of catheters positioned at T7 in all 15 placements (100%) and at T~ in 11 of 13 placements (85%), an overall accuracy rate of 93%. The accuracy with the new graph was not significantly different from that attained with Dunn's graph for TBL (X~ = 1.22, P < 0.25), but was significantly better than Dunn's graph for SUL (X~ = 3.935, P < 0.05). The SUL was plotted against the length of catheter insertion in 29 catheters at T~ (m = 1.09, b = 0.76, r = 0.904, P < 0.001). This graph led to accurate prediction of catheters positioned at T7 in 11 of 15 placements (73%)" and at To in 9 of 13 placements (69%), an overall accuracy of 71%. The accuracy of this new graph for SUL was not significantly different from Dunn's graphs for SUL or TBL. In comparison to our new graph for TBL, the graph for SUL did not reach significance (X~ = 3.043, P < 0.1). In 30 patients prospectively catheterized utilizing the new graph, the catheter tip was located at T7 in 11, T~ in 9, and T9 in 5, and between T~ and T~o in all 30. When compared to the original series of 107 catheterizations utilizing Dunn's graph for TBL, this new graph resulted in significantly more catheters in acceptable positions (X~ = 7.50, P < 0.01) (Table). DISCUSSION Optimal localization of umbilical artery catheters has been estimated by using anatomic relationships described by Dunn. 1 Despite the lack of critical evaluation of the accuracy of his data, most descriptions of catheter placement technique 4~ have been based on this work. Although mistakes in measurements for TBL, SUL, the umbilical stump, and length of insertion could account for some misplaced catheters, the present study demonstrated
Volume 96 Number 4
Brief clinical and laboratory observations
that use of TBL resulted in more accurate catheter placements than use of SUL, attaining statistical significance only when comparing our graph for TBL with Dunn's graph for SUL (Table). Utilizing this new graph for TBL, catheters were located in acceptable positions in each of 30 consecutive patients studied prospectively. Although each catheter was inserted the theoretically estimated distance, several did not rest exactly at T~ due to the wide natural variation between TBL and the distance the catheter must be inserted. This variation may also create a problem in attempting to place catheters at Txo. Although catheters above TI~ are in acceptable locatons, those that rest below TI0, will be at the origin of the major blood vessels. Therefore a margin of safety is gained by selecting Ts. This may be another benefit of its use.
737
REFERENCES 1. Dunn P: Localization of the umbilical catheter by post mortem measurement, Arch Dis Child 41:69, 1966. 2. BallardJ, Kazmaier K, and Driver M: A simplified assessment of gestational age, Pediatr Res 11:374, 1977. 3. Symansky M, and Fox H: Umbilical vessel catheterization: Indications, management, and evaluation of technique, J P~DIATR 80:820, 1972. 4. Kitterman J, Phibbs R, and Tooley W: Catheterization of umbilical vessels in newborn infants, Pediatr Clin North Am 17:895, 1970. 5. Fisher D, and Behrman R: Resuscitation of the newborn infant, umbilical vessel catheterization, Klaus MH, and Fanaroff AA, editors: Care of the high risk infant, Philadelphia, 1977,WB Saunders Company, pp 15-17. 6. Neal W, Reynolds J, and Jarvis C: Umbilical artery catheterization: Demonstration of arterial thrombosis by aortography, Pediatrics 50:6, 1972.
Inulin clearance in the premature infant receiving indomethacin Zack Catterton, M.D., Billy Sellers, Jr., M.D., and Bonnie Gray, A ugusta, Ga.
I N D OMETH AC I N has been utilized to achieve pharmacologic closure of the patent ductus arterious in premature infants. Frequently reported complications of lnd therapy are reduction of urine output and elevation of serum creatinine or blood urea nitrogen values. '~ This report documents the effect of Ind on the glomerular filtration rate of premature infants with a symptomatic PDA. Failure of serum creatinine and BUN concentrations to reflect changes in GFR in these infants is reported. PATIENTS
AND METHODS
The GFR was measured before and after Ind therapy in seven premature infants receiving Ind for treatment of a symptomatic PDA unresponsive to conservative medical management. Initial management consisted of fluid restriction ( < 130 ml/kg/24 hours), digitalization, and continuous distending airway pressure for pulmonary edema. An attempt to induce pharmacologic ductus closure with Ind was made when, after a minimum of 48 hours of medical management, the infants still displayed evidence of large left-to-right shunting that necessitated continuous distending airway pressure. The Ind was prepared by suspending the contents of a 25 mg capsule in normal saline as described by Heymann et al2 and was administered via orogastric tube. The Ind
0022-3476/80/040737 + 03500.30/0 9 1980 The C. V. Mosby Co.
(0.2 mg/kg) was administered initially and every 24 hours as needed to a maximum of 0.6 mg/kg. Daily BUN, serum creatinine, hematocrit, and, fluid intake and output values were recorded before and after each dose of Ind. Abbreviations used Ind: indomethacin PDA: patent ductus arteriosus GFR: glomerular filtration rate PGE: prostaglandin E BUN: blood urea nitrogen The GFR was measured prior to initiating Ind therapy, < 24 hours after administering the initial dose, and in three of the patients, two to ten days after completing a course of Ind. The GFR was determined by inulin clearance as previously reported? A bolus inject!on of 10% inulin (50 mg/kg) was infused over 30 seconds into a peripheral vein or umbilical vessel. Blood samples of 0.5 ml were collected at timed intervals over a two-hour period following injection of inulin. Inulin clearance was calculated according to the model of Sapirstein~ and expressed as ml/minute/1.73 m'-'. Blood pressure was measured at least hourly during each two-hour clearance