ORIGINAL CONTRIBUTION
body height; intubation, endotracheal
Length-Based EndotrachealTube and EmergencyEquipmentin Pediatrics From the Division of Emergency Medicine, Department of Surgery, University of Florida Health Science Center Jacksonville, Jacksonville, Florida;* Department of Emergency Medicine, Cleveland Memorial Hospital, Hickory, North Carolina;t Department of Pediatrics, University of North Carolina, Chapel Hill;¢ Department of Emergency Medicine, Mercy Children's Hospital, Kansas City, Missouri;§ Department of Anesthesia, Children's Hospital of Philadelphia;IIDepartments of Anesthesiology and Pediatrics, North Carolina Memorial Hospital, Chapel Hill;~ Department of Anesthesiology, North Carolina Baptist Hospital, Winston-Salem;** and Department of Emergency Medicine, Pittsburgh Children's Hospital, Pittsburgh, Pennsylvania.tt Received for publication May 23, 1990. Revision received November 6, 1991. Acceptedfor publication December 27, 1991. Presented at the Societyfor Academic Emergency Medicine Annual Meeting in Minneapolis,
Minnesota, May 1990.
14/900
Robert C Luten,MD* Robert L Wears, MD, FACEP* James Broselow, MDt Arno Zaritsky, MD$ Theodore M Barnett,MD§ Terry Lee, MDII Ann Bailey, MD~ Robert Vally, MD~ Robert Brown, MD** Bruce Rosenthal,MDtr
Hypothesis: Pediatric endotracheal (ET)tubes can be accurately selected based on body length using a specialized emergency tape. Population: Derivation set: Two hundred five children undergoing elective surgery. Validation set: Two hundred thirteen children undergoing elective surgery. Each child served as his or her own control. Methods: Derivation phase: Two hundred twenty-one children undergoing ET intubation for elective surgery had their body length and leak pressures measured. The 205 children who had leak pressures between 10 and 40 cm H20 constituted the derivation set. The body length for a given ET tube size was derived from the interquartile range of patient lengths in this derivation set. Sizes for other resuscitative equipment items were chosen by a panel of experts using a modified Delphi technique. This information was placed by length on a color-coded tape. Validation phase: The tape was validated by using it to select ET tube size in another group of 203 children undergoing elective surgey. Criteria for acceptable fit in this group included leak pressure as above and the anesthesiologists' decision to accept the tube size or to reintubate. In the validation phase, length-based ET tube selections were compared with age-based rules: (age + 16)/4, and (age + 18)/4. Results: The tape selected the appropriate ET tube size by leak pres-
sure criterion in 77% of the cases and was within +0.5 mm of the "correct" size 99% of the time. This was significantly better (P< .005) than two widely used age-based rules, which gave the correct initial size in only 47% and 9% of these cases, and were within +0.5 mm for 86% and 59%. The anesthesiologists chose to continue with the tape-sized tube rather than to reintubate in 89% of cases. Conclusion: A system for length-based selection of emergency equipment represents a significant adjunct to emergency physicians and paramedics who must deal with critically ill children. Length-based ET tube selection is clearly superior to age-based rules, which are difficult to remember and require accurate estimation of a patient's age. [Luten RC, Wears RL, Broselow J, Zaritsky A, Barnett TM, Lee T, Bailey A, Vally R, Brown R, Rosenthal B: Length-based endotracheal tube and emergency equipment selection in pediatrics. Ann EmergMedAugust 1992;21:900-904.]
ANNALS OF EMERGENCY MEDICINE
21:8
AUGUST1992
ENDOTRACHEAL TUBE
Luten el al
INTRODUCTION
Resuscitation or stabilization of acutely ill pediatric patients creates substantial cognitive demands on physicians and prohospital personnel; they must estimate body weight and recall or calculate equipment sizes and drug dosages in addition to the o r d i n a r y psychomotor demands of advanced life support. The Broselow Resuscitation Tape was developed to help resuscitators by enabling them to estimate dosages of resuscitation drugs from body length. The tape is based on the relationship between body length and weight and has been documented as an excellent method of r a p i d weight estimation. 1 It was recognized that this tape would be even more useful if it could als0 estimate the a p p r o p r i a t e equipment sizes needed in emergency management. Because endotracheal (ET) intubation is one of the most important maneuvers in pediatric advanced life support and because its success depends more than most procedures on choosing correctly sized equipment, we undertook a two-part study of lengthbased ET tube size selection. The first phase (derivation set) defined objective body length intervals relative to ET tube size; the validation phase determined the accuracy of a tape using those intervals in predicting ET size. As a separate p a r t of the study, the findings of a panel of experts in pediatric emergency medicine and critical care were used to define relevant equipment sizes by body length ranges by a modified Delphi technique. 2 This equipment information was subsequently printed on the tape at the appropriate length intervals. MATER
ALS
AND
METHODS
Recognized sources 3-8 of recommended sizes of pediatric equipment frequently u s e d in resuscitation were reviewed. These sources typically recommend equipment by patient age or weight. These equipment size recommendations were
converted to length-based equivalents by using the 50th percentile of length for weight or age as published by the National Center for Health Statistics data base for normal children. 9 Because there are seven sizes of ET tubes in the pediatric range (3.0-6.0 mm), the various sizes of the above items were assigned to the seven length zones that were determined in this study. These assignments were then validated by a panel of experts. In the modified Delphi technique, each expert's comments were circulated anonymously to the other panel members, who could then revise their recommendations if desired; this process continued until they reached a consensus. When discrepancies existed between sources or panel members, the size (length) most consistently recommended was used. The seven length zones for ET tubes were derived and then v a l i d a t e d i n separate phases. In the derivation phase, the lengths of 205 children (from four centers) requiring ET intubation for elective surgery were measured, along with the size of the ET tube that produced leak pressures > 10 and _ 6.5 ram, and one was excluded because a 2.5-mm tube was required; these groups were considered too small to enable rehable estimates, In the remaining 197 patients, end points for length intervals were set at the midpoint between the 75th percentile of body length for a given tube size and the 25th percentile of body length for the next larger size. In general, there was a clear division of body lengths between tube sizes; still, some overlap was noted to occur between 5.0- and 5.5-mm tubes and between 6.0- and 6.5-ram tubes, suggesting that biologic diversity would not allow complete accuracy in length-based ET tube sizing, at least in these ranges. These derived body length boundaries were used to develop a color-coded tape, with the a p p r o p r i ate ET tube and other equipment sizes printed in each color zone.
Table 1. Length~based equipment size recommendations Length (cm) Item ETtube size (ram) Lip-tip length (ram)* Laryngoscope Suction catheter St/let 0ral airway Sag-valve-mask 02 mask Vascular access catheter/butterfly Nasogastric tube Urinary catheter Chesttube Blood pressure cuff
58-70
70-85
85-95
95-107
107-124
124-138
138-155
3.0 10.5 1 Straight
3.5 12.0 1 Straight
4.0 13.5 2 Straight
8F 6F Infant/small child Infant Newborn
8-10 F 6F Smag child Child Pediatric
10 F 6F Child Child Pediatric
4.5 15.0 2 Straight or curved 10 F 6F Child Child Pediatric
5.0 16.5 2 Straight or curved 10 F 14F Child/small adult Child Adult
5.5 18.0 2-3 Straight or curved 1OF 14F Child/smalladult Child/adult Adult
6.0 19.5 3 Straight or curved 12 F 14F Mediumadult Adult Adult
22-24/23-25, intraosseoas 5-8 F 5-8 F 10-12 F Newborn, infant
20-22/23-25, intraosseous 8-10 F 8-10 F 16-20 F Infant, child
18-22/21-23, intraosseous 10 F 10 F 20-24 F Child
18-22/21-23, intraosseous 10-12 F 10-12 F 20-24 F Child
18-20/21-23 12-14 F 10-12 F 24-32 F Child
18-20/21-22 14-18 F 12 F 28-32 F Child/adult
16-20,18-21 18 F 12 F 32-40 F Adult
*Personal communication,Arno Zaritsky, MD, work in progress
AUGUST1992
21:8 ANNALS OF EMERGENCY MEDICINE
901/15
ENDOTRACHEAL TUBE Luten el al
In the validation phase, the tape was prospectively evaluated by using it to select ET tube size in 208 children (from three centers) requiring ET intubation for elective surgery. Five patients were larger than the tape could measure, leaving 203 patients for analysis. Two criteria for acceptable fit were used: 1) leak pressures _> l0 and < 40 c m n 2 0 , or 2) the anesthesiologists' decision to accept the tube size, whatever the leak pressure, or to reintubate. Performance was evaluated for each criterion separately. Anesthesiologists were free to choose a different ET tube size than that recommended by the tape; these cases were analyzed separately. If a patient's length fell on a boundary, the anesthesiologists chose one size or the other based on their judgment. The accuracy of ET tube sizes selected by the tape was also compared with the ET tube sizes recommended by two commonly used rules: size = (16 + age)/4, and size = (18 + age)/4. Contingency table methods (McNemar's test for p a i r e d data, Pearson's Z2 test for u n p a i r e d data, and log-linear models) and Kendall's x coefficient (for agreement in o r d e r e d categories) were used to analyze the results. Informed consent was o b t a i n e d .
RESULTS The body length intervals and equipment sizes that were derived in the first phase or determined by the expert panel are shown (Table 1). The median, 25th, and 75th percentiles of body length for each ET tube size in the derivation set are presented (Table 2). The resulting length zones were recomputed using the 152 patients who fit stricter criteria for Table 2. Median, 25th,"and 75th percentiles o f body length in the derivation set Percentiles of Body Length(cm) ET Tube Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0
25th
50th
75th
No.
50.5 60.5 71.75 90.0 94.5 108.5 125.0
52.0 64.0 75.75 92.5 100.0 115.75 133.5
55.0 68.0 79.25 96.0 105.0 122.0 140.0
13 32 45 25 31 29 22
Tabie 3. Cross-tabulation of ET tube size recommended by tape and size ultimately accepted by anesthesiologist Final ET Tube Size (ram) Tape Size (ram) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6,5
Total
6/902
3.0
3.5
4.0
4.5
5,0
5.5
6.0
6.5
16 2 0 0 0 0 0 0 1.8
O 19 3 0 0 0 0 0 22
0 O 31 2 0 O 0 0 33
0 O O 19 0 O 0 0 19
0 O O 0 13 2 0 9 15
0 O O 0 1 22 4 1 28
0 0 0 0 0 O 29 O 29
O O 0 0 0 0 1 2 3
Total 16 21 34 21 14 24 34 3 167
acceptable fit (20-30 cm H20); the zones did not change appreciably, suggesting that the length zones were stable. The anesthesiologists used the tape-recommended ET tube size in 167 (82.3%) of the vahdation phase patients. The ET tube size recommended by the tape and the tube size ultimately accepted by the anesthesiologist are compared (Table 3). The tube was correctly sized by leak pressure criterion in 74% of the patients who had pressures recorded (Table 4) and was within one tube size (+ 0.5 ram) of the "correct" size more than 99% of the time (Table 5). The tape was significantly more accurate (P < .005) than the two agebased rules, which gave the correct initial ET size in only 47% and 9% of these cases, and were within + 0.5 mm for 84% and 59%, respectively. The anesthesiologists chose to continue with the tape-sized tube r a t h e r than to reintubate in 89% of cases, even if the pressures were slightly out of range; agreement between the anesthesiologist and the tape was high (Kendall's z = .965, P < .0001). 1° The incidence of reintubation was not significantly different between patients in whom the tape size was used and patients for whom the Table 4. Leak pressures for patients receiving length-based ET tubes (14 patients did not have leak pressures recorded) Leak Pressure (cm H20) ETTube Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 Total (%)
< 10
10-40
> 40
Total
1 3 3 3 4 10 5 1 30 (19.6)
13 18 27 15 9 12 17 2 113 (73.9)
3 O 3 O 1 3 0 0 10 (6.5)
17 21 33 18 14 25 22 3 153
Table 5. Differences (tape size minus final tube size) in ET tube sizes in validation set Error (Tape size final tube size [mm]) -
Tape Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 Total (%)
-1.0
~).5
0.0
+0.5
Total
0 0 O 0 O O O 1 1 (0.6)
0 2 3 2 O 2 4 0 13 (7.8)
16 19 31 19 14 22 29 2 152 (91.0)
0 O O 0 O O 1 0 1 (0.6)
16 21 34 21 14 24 34 3 167
Table 6, Percentage of patients within leak pressure ranges for the 28 patients in whom tape size was not used and pressure was measured Size Selected Relative to Tape RecommendedSize Bigger (9) Smaller (19)
Leak Pressures (cm H20)
body height; intubation, endotracheal
Length-Based EndotrachealTube and EmergencyEquipmentin Pediatrics From the Division of Emergency Medicine, Department of Surgery, University of Florida Health Science Center Jacksonville, Jacksonville, Florida;* Department of Emergency Medicine, Cleveland Memorial Hospital, Hickory, North Carolina;t Department of Pediatrics, University of North Carolina, Chapel Hill;¢ Department of Emergency Medicine, Mercy Children's Hospital, Kansas City, Missouri;§ Department of Anesthesia, Children's Hospital of Philadelphia;IIDepartments of Anesthesiology and Pediatrics, North Carolina Memorial Hospital, Chapel Hill;~ Department of Anesthesiology, North Carolina Baptist Hospital, Winston-Salem;** and Department of Emergency Medicine, Pittsburgh Children's Hospital, Pittsburgh, Pennsylvania.tt Received for publication May 23, 1990. Revision received November 6, 1991. Acceptedfor publication December 27, 1991. Presented at the Societyfor Academic Emergency Medicine Annual Meeting in Minneapolis,
Minnesota, May 1990.
14/900
Robert C Luten,MD* Robert L Wears, MD, FACEP* James Broselow, MDt Arno Zaritsky, MD$ Theodore M Barnett,MD§ Terry Lee, MDII Ann Bailey, MD~ Robert Vally, MD~ Robert Brown, MD** Bruce Rosenthal,MDtr
Hypothesis: Pediatric endotracheal (ET)tubes can be accurately selected based on body length using a specialized emergency tape. Population: Derivation set: Two hundred five children undergoing elective surgery. Validation set: Two hundred thirteen children undergoing elective surgery. Each child served as his or her own control. Methods: Derivation phase: Two hundred twenty-one children undergoing ET intubation for elective surgery had their body length and leak pressures measured. The 205 children who had leak pressures between 10 and 40 cm H20 constituted the derivation set. The body length for a given ET tube size was derived from the interquartile range of patient lengths in this derivation set. Sizes for other resuscitative equipment items were chosen by a panel of experts using a modified Delphi technique. This information was placed by length on a color-coded tape. Validation phase: The tape was validated by using it to select ET tube size in another group of 203 children undergoing elective surgey. Criteria for acceptable fit in this group included leak pressure as above and the anesthesiologists' decision to accept the tube size or to reintubate. In the validation phase, length-based ET tube selections were compared with age-based rules: (age + 16)/4, and (age + 18)/4. Results: The tape selected the appropriate ET tube size by leak pres-
sure criterion in 77% of the cases and was within +0.5 mm of the "correct" size 99% of the time. This was significantly better (P< .005) than two widely used age-based rules, which gave the correct initial size in only 47% and 9% of these cases, and were within +0.5 mm for 86% and 59%. The anesthesiologists chose to continue with the tape-sized tube rather than to reintubate in 89% of cases. Conclusion: A system for length-based selection of emergency equipment represents a significant adjunct to emergency physicians and paramedics who must deal with critically ill children. Length-based ET tube selection is clearly superior to age-based rules, which are difficult to remember and require accurate estimation of a patient's age. [Luten RC, Wears RL, Broselow J, Zaritsky A, Barnett TM, Lee T, Bailey A, Vally R, Brown R, Rosenthal B: Length-based endotracheal tube and emergency equipment selection in pediatrics. Ann EmergMedAugust 1992;21:900-904.]
ANNALS OF EMERGENCY MEDICINE
21:8
AUGUST1992
ENDOTRACHEAL TUBE
Luten el al
INTRODUCTION
Resuscitation or stabilization of acutely ill pediatric patients creates substantial cognitive demands on physicians and prohospital personnel; they must estimate body weight and recall or calculate equipment sizes and drug dosages in addition to the o r d i n a r y psychomotor demands of advanced life support. The Broselow Resuscitation Tape was developed to help resuscitators by enabling them to estimate dosages of resuscitation drugs from body length. The tape is based on the relationship between body length and weight and has been documented as an excellent method of r a p i d weight estimation. 1 It was recognized that this tape would be even more useful if it could als0 estimate the a p p r o p r i a t e equipment sizes needed in emergency management. Because endotracheal (ET) intubation is one of the most important maneuvers in pediatric advanced life support and because its success depends more than most procedures on choosing correctly sized equipment, we undertook a two-part study of lengthbased ET tube size selection. The first phase (derivation set) defined objective body length intervals relative to ET tube size; the validation phase determined the accuracy of a tape using those intervals in predicting ET size. As a separate p a r t of the study, the findings of a panel of experts in pediatric emergency medicine and critical care were used to define relevant equipment sizes by body length ranges by a modified Delphi technique. 2 This equipment information was subsequently printed on the tape at the appropriate length intervals. MATER
ALS
AND
METHODS
Recognized sources 3-8 of recommended sizes of pediatric equipment frequently u s e d in resuscitation were reviewed. These sources typically recommend equipment by patient age or weight. These equipment size recommendations were
converted to length-based equivalents by using the 50th percentile of length for weight or age as published by the National Center for Health Statistics data base for normal children. 9 Because there are seven sizes of ET tubes in the pediatric range (3.0-6.0 mm), the various sizes of the above items were assigned to the seven length zones that were determined in this study. These assignments were then validated by a panel of experts. In the modified Delphi technique, each expert's comments were circulated anonymously to the other panel members, who could then revise their recommendations if desired; this process continued until they reached a consensus. When discrepancies existed between sources or panel members, the size (length) most consistently recommended was used. The seven length zones for ET tubes were derived and then v a l i d a t e d i n separate phases. In the derivation phase, the lengths of 205 children (from four centers) requiring ET intubation for elective surgery were measured, along with the size of the ET tube that produced leak pressures > 10 and _ 6.5 ram, and one was excluded because a 2.5-mm tube was required; these groups were considered too small to enable rehable estimates, In the remaining 197 patients, end points for length intervals were set at the midpoint between the 75th percentile of body length for a given tube size and the 25th percentile of body length for the next larger size. In general, there was a clear division of body lengths between tube sizes; still, some overlap was noted to occur between 5.0- and 5.5-mm tubes and between 6.0- and 6.5-ram tubes, suggesting that biologic diversity would not allow complete accuracy in length-based ET tube sizing, at least in these ranges. These derived body length boundaries were used to develop a color-coded tape, with the a p p r o p r i ate ET tube and other equipment sizes printed in each color zone.
Table 1. Length~based equipment size recommendations Length (cm) Item ETtube size (ram) Lip-tip length (ram)* Laryngoscope Suction catheter St/let 0ral airway Sag-valve-mask 02 mask Vascular access catheter/butterfly Nasogastric tube Urinary catheter Chesttube Blood pressure cuff
58-70
70-85
85-95
95-107
107-124
124-138
138-155
3.0 10.5 1 Straight
3.5 12.0 1 Straight
4.0 13.5 2 Straight
8F 6F Infant/small child Infant Newborn
8-10 F 6F Smag child Child Pediatric
10 F 6F Child Child Pediatric
4.5 15.0 2 Straight or curved 10 F 6F Child Child Pediatric
5.0 16.5 2 Straight or curved 10 F 14F Child/small adult Child Adult
5.5 18.0 2-3 Straight or curved 1OF 14F Child/smalladult Child/adult Adult
6.0 19.5 3 Straight or curved 12 F 14F Mediumadult Adult Adult
22-24/23-25, intraosseoas 5-8 F 5-8 F 10-12 F Newborn, infant
20-22/23-25, intraosseous 8-10 F 8-10 F 16-20 F Infant, child
18-22/21-23, intraosseous 10 F 10 F 20-24 F Child
18-22/21-23, intraosseous 10-12 F 10-12 F 20-24 F Child
18-20/21-23 12-14 F 10-12 F 24-32 F Child
18-20/21-22 14-18 F 12 F 28-32 F Child/adult
16-20,18-21 18 F 12 F 32-40 F Adult
*Personal communication,Arno Zaritsky, MD, work in progress
AUGUST1992
21:8 ANNALS OF EMERGENCY MEDICINE
901/15
ENDOTRACHEAL TUBE Luten el al
In the validation phase, the tape was prospectively evaluated by using it to select ET tube size in 208 children (from three centers) requiring ET intubation for elective surgery. Five patients were larger than the tape could measure, leaving 203 patients for analysis. Two criteria for acceptable fit were used: 1) leak pressures _> l0 and < 40 c m n 2 0 , or 2) the anesthesiologists' decision to accept the tube size, whatever the leak pressure, or to reintubate. Performance was evaluated for each criterion separately. Anesthesiologists were free to choose a different ET tube size than that recommended by the tape; these cases were analyzed separately. If a patient's length fell on a boundary, the anesthesiologists chose one size or the other based on their judgment. The accuracy of ET tube sizes selected by the tape was also compared with the ET tube sizes recommended by two commonly used rules: size = (16 + age)/4, and size = (18 + age)/4. Contingency table methods (McNemar's test for p a i r e d data, Pearson's Z2 test for u n p a i r e d data, and log-linear models) and Kendall's x coefficient (for agreement in o r d e r e d categories) were used to analyze the results. Informed consent was o b t a i n e d .
RESULTS The body length intervals and equipment sizes that were derived in the first phase or determined by the expert panel are shown (Table 1). The median, 25th, and 75th percentiles of body length for each ET tube size in the derivation set are presented (Table 2). The resulting length zones were recomputed using the 152 patients who fit stricter criteria for Table 2. Median, 25th,"and 75th percentiles o f body length in the derivation set Percentiles of Body Length(cm) ET Tube Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0
25th
50th
75th
No.
50.5 60.5 71.75 90.0 94.5 108.5 125.0
52.0 64.0 75.75 92.5 100.0 115.75 133.5
55.0 68.0 79.25 96.0 105.0 122.0 140.0
13 32 45 25 31 29 22
Tabie 3. Cross-tabulation of ET tube size recommended by tape and size ultimately accepted by anesthesiologist Final ET Tube Size (ram) Tape Size (ram) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6,5
Total
6/902
3.0
3.5
4.0
4.5
5,0
5.5
6.0
6.5
16 2 0 0 0 0 0 0 1.8
O 19 3 0 0 0 0 0 22
0 O 31 2 0 O 0 0 33
0 O O 19 0 O 0 0 19
0 O O 0 13 2 0 9 15
0 O O 0 1 22 4 1 28
0 0 0 0 0 O 29 O 29
O O 0 0 0 0 1 2 3
Total 16 21 34 21 14 24 34 3 167
acceptable fit (20-30 cm H20); the zones did not change appreciably, suggesting that the length zones were stable. The anesthesiologists used the tape-recommended ET tube size in 167 (82.3%) of the vahdation phase patients. The ET tube size recommended by the tape and the tube size ultimately accepted by the anesthesiologist are compared (Table 3). The tube was correctly sized by leak pressure criterion in 74% of the patients who had pressures recorded (Table 4) and was within one tube size (+ 0.5 ram) of the "correct" size more than 99% of the time (Table 5). The tape was significantly more accurate (P < .005) than the two agebased rules, which gave the correct initial ET size in only 47% and 9% of these cases, and were within + 0.5 mm for 84% and 59%, respectively. The anesthesiologists chose to continue with the tape-sized tube r a t h e r than to reintubate in 89% of cases, even if the pressures were slightly out of range; agreement between the anesthesiologist and the tape was high (Kendall's z = .965, P < .0001). 1° The incidence of reintubation was not significantly different between patients in whom the tape size was used and patients for whom the Table 4. Leak pressures for patients receiving length-based ET tubes (14 patients did not have leak pressures recorded) Leak Pressure (cm H20) ETTube Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 Total (%)
< 10
10-40
> 40
Total
1 3 3 3 4 10 5 1 30 (19.6)
13 18 27 15 9 12 17 2 113 (73.9)
3 O 3 O 1 3 0 0 10 (6.5)
17 21 33 18 14 25 22 3 153
Table 5. Differences (tape size minus final tube size) in ET tube sizes in validation set Error (Tape size final tube size [mm]) -
Tape Size (mm) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 Total (%)
-1.0
~).5
0.0
+0.5
Total
0 0 O 0 O O O 1 1 (0.6)
0 2 3 2 O 2 4 0 13 (7.8)
16 19 31 19 14 22 29 2 152 (91.0)
0 O O 0 O O 1 0 1 (0.6)
16 21 34 21 14 24 34 3 167
Table 6, Percentage of patients within leak pressure ranges for the 28 patients in whom tape size was not used and pressure was measured Size Selected Relative to Tape RecommendedSize Bigger (9) Smaller (19)
Leak Pressures (cm H20)
