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Evaluation of Oxygen Therapy Devices by Arterial Oxygen Tensions
356
SHULMAN, SCHMIDT AND SADOVE
tween second and third complex is still shorter. On the basis of assumption of anomalous pathway the sinus impulse is conducted slowly through A-V node to the ventricles. This impulse returns in a retrograde direction via the anomalous pathway to the auricle. Due to longer time taken for the impulse to travel through the A-V node the auricle now responds and a retrograde depolarization wave is inscribed. This impulse once again returns to the A-V node only to find it refractory and no more impulse conduction takes place. If the degree of block could be prolonged and the refractory period of the normal path could be shortened it would then be responsive to the returning stimulus establishing a reversed reciprocal rhythm. In the mechanism of production of Wolff-Parkinson-White syndrome also, the theory of anomalous pathway was put forward by Holzmann and Scherf!" as well as Wolferth and Wood.!" The arrhythmia reported in this publication can also be explained on the basis of anomalous pathway. Recently Wolff'? has shown both patterns in the same tracing emphasizing such a mechanism of their production. We agree with Schamroth'" that the difference between reversed reciprocal rhythm and WolffParkinson- White pattern may be only of the presence of first degree A-V block in the former. Both the electrocardiographic phenomena can be explained on the basis of an anomalous pathway or extra bundle of Kent. 21 REFEREl"CES
1 KATZ, L. N., Al'o.'D PICK, A.: Clin ical electrocardiography, Part I, the arrhythmias, Lea & Febiger, Philadelphia, 1956, p . 623, figure 364. 2 WOLFERTH, C. C., A:-:D WOOD.: Amer. Heart ] ., 8:297, 1933. 3 SCHERF, D., A:"D COHE:-: J.: The atrioventricular node, Gmne and Stratton, New York, 1964. 4 SCHERF, D. : An experimental study of reciprocating rhythm, Arch . Intem. Med ., 67 :372 , 1941. 5 COD1:"G-ALTES, J., A:-:D PIJOAN DE BERISTAI:-:, C. : Short paroxysms of tachycardia due to reciprocating rhythm, Amer. Heart t.. 39:436, 1950. 6 ELDRIDGE, F. L.: Reciprocal beating of the atria, Amer. Hearl ] .,55:469, 1959 . 7 MI:-:ES, G. R.: On dynamic equilibrium in the heart, ] . Phuslol., 46:349 , 1913. 8 GALLAVARDI:-:, L., A:-m GRAVIER, L. : Bradycardia nodale permanent, Arch. mal. Coeur., 14:71 , 1921. 9 DRURY, A. N. : Paroxysmal tachycardia of A-V origin, exhibiting retrograde heartblock and reciprocal rhythm, Am er. Heart ] .,55:469, 1959. 10 DOCK, E .: The reciprocal rhythm. Report of a case in which auricular tachycardia with partial A-V dissocia-
tion and atrioventricular bradycardia were pre sent, Arch . Intern. Med., 41 :745 , 1928. 11 DECHERD, G., A:-:D Husxrx, A.: Studies of the properties of the A-V node. 1. Reciprocal rhythm, 11 drug effects on the A-V conduction, Texas Rep . Biol. Med ., 1:299, 1949 . 12 Bix, H.: Various mechanisms in reciprocal rhythm, Am er. Heart t.. 41 :488, 1951. 13 KIST1:-:, A. D., A:"D BRUCE, J. C. : Simultaneous esophageal and standard electrocard iographic leads in the study of cardiac arrhythmias, Amer. Heart ] ., 53:65, 1957. 14 LA:"CEXDORF, R., KATZ, L. N., AXD SIl\ION, A. J.: Reciprocal beating initiated by ventricular premature systoles, Brit. Heart J., 4 :3, 1944. 15 NAIl\I, M.: Paroxysmal auricular tachycardia due to reciprocal rhythm, Amer. Heart J., 29:398, 1945. 16 ZAKOPOULOS, K.: Double atrial stimulation with reciprocal rhythm, Amer. Heart J., 54 :291 , 1957. 17 HOLzl\IA:-::", M., A:'\D SCHERF, D.: Z. KUn. Med., 121: 404,1932. 18 \VOLFEIITH, C. C., AND \VOOD: Amer. Heart 1933.
t..
8:297,
19 WOLFF, L.: Anomalous atrioventricular conduction (Wolff-Parkinson-White syndrome), Circulation, 19:14, 1959. 20 SCHAl\II\OTH, L.: Reversed reciprocal tachycardia and its relationship to the Wolff-Parkinson-White syndrome, 57:507, 1960 . 21 KE:'\T, A. F . S.: Quart. ]. Exper. Physiol., 7:193, 1914.
Evaluation of Oxygen Therapy Devices by Arterial Oxygen Tensions* Mortoll Shulman, M.D., Gwen Schmidt, M.D ., and Max S. Sadove, M.D ., F.C.C.P.
Ten different oxygen administration devices were tested on volunteers in order to determine their relative efficiency in raising the arterial oxygen tension. The efficiency of any particular device was directly proportional to the oxygen flow into it. Those devices which utilized reservoir bags were the most effective. The nasal catheter and cannula techniques were also quite effective with the cannula appearing to be somewhat preferable because of its greater comfort, especially at high flow rates of oxygen. The importance of proper baffling in those mask type devices that did not utilize reservoir bags was demonstrated.
The relative effectiveness of oxygen administration devices has been studied previously.!'! The most comprehensive study was that of Kory and others" who compared eight different techniques. °From the Department of Anesthesiologv , University of lllinois Research and Educational Hospitals, Chicago, 1IIinois. .
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
357
EVALUATION OF OXYGEN THERAPY DEVICES
Their criteria of effectiveness were based on the measurements of oxygen concentrations in the gas , phase of samples from inspired air, nasopharyngeal air, and end-expired air. These methods are someI times difficult to interpret because the act of adI ministering the oxygen may lead to a substantial artifact in the measurements; also, a gas phase measurement gives us no information on the amount of oxygen present in the arterial blood. Since the whole purpose of oxygen therapy is to produce an adequate oxygen content of the arterial blood, it becomes apparent that this is the site where oxygen measurements should be made in order to determine the effectiveness of any particular method of oxygen administration. The recent widespread availability of oxygen electrodes has given us a convenient method of measuring blood oxygen tensions. Arterial oxygen tension is, in itself, a more sensitive technique than arterial oxygen content for assessing the effective-
ness of oxygen administration and thus this method gives us a convenient means for assessing the value of our therapy. Several reports have appeared recently on the use of this method to assess various oxygen therapy devices.P" The purpose of this study is to present a controlled comparison of the relative effectiveness of several of the more commonly used oxygen therapy devices. MATERIALS AND METHODS
Ten healthy volunteers, seven men and three women, between the ages of 20 and 30 were used. Each had a Teflon catheter inserted into a brachial artery and then remained in a semi-sitting position for the duration of the study. Each volunteer received oxygen by each of ten different methods. Oxygen flows of 5, 10, and 15 liters per minute were used with each device. Each volunteer was exposed to each combination of method and flow for at least ten minutes before blood was withdrawn from the catheter and measurements performed. In addition, blood was drawn while the volunteers were breathing room air both before the first administration of oxygen and at several intervals
Table I-Summary of arterial oxygen tensions achieved in each ten volunteers with previous oxygen flows of 5, 10, and 15 liters per minute, METHOD
Flow LIMin.
Vol. 1'\0. I
Vol. 1'\0. 2
Vol. No.3
Vol. 1':0. 4
Arterial Oxygen Tension, mm Hg . Vol. Vol. Vol. Vol. Vol. 1'\0. 5 1':0. 6 No.7 1':0. 8 No.9
Vol. 1':0. 10
Mean
Standard Deviation
Nasal Catheter
10 15
5
210 205 370
235 260 295
195 275 368
180 350 400
190 340 425
270 370 300
185 205 228
200 270 260
300 360
148 210 275
205 278 328
Nasal Cannula (Mouth Closed) Nasal Cannula (Mouth Open)
±35 ±61 ±65
5
10 15
210 250 275
200 295 395
195
220 270
155 270 320
175 320 315
270 360 450
215 258 350
168 186 188
250 270 300
155 250 310
199 267 317
±39 ±49 ±71
5 10 15
205 265 305
230
285
183 250 315
190 260 300
210 290 335
270 320 430
170 195 180
172 182 178
170 200 230
170 225 275
193 241 283
±31 ±44 ±75
5 10 15
155 200 220
165 165 170
190 265 310
135 215 180
230 345 400
270 315 490
145 144 158
230
205
250
185 180 185
128 145 155
180 220 251
±45 ±69 ±1l4
5
10 15
250 355 340
210 265
210
215 375 510
270
290
330 415
185 250 325
420 475
215 340 370
300 380 410
212 310 359
190 240 245
225 326 373
±36 ±60 ±81
Rebreathing 5 Mask, 10 Polyethylene 15
290 345 455
375 360 405
385 405 415
375 460
260
275 480 450
430 485 540
205 320 370
240 310 380
310 360 345
240 295 395
301
373 421
±73 ±65 ±56
Rebreathing Mask, Vinyl
5 10 15
295 425 525
320 400 430
350 365
390 495
455
435 460 480
225 350 410
250 335 480
290
397
335 370 400
355
270 315 340
316 387 428
±64 ±57 ±56
.5
200
260
195
180
180
250
143
210
212
±43
Face Mask Aerosol Mask
Face Tent
10
210
190
390
220
23.'5
240
372 285
395
175
165
200
330
220
325
425
290
15
225
440
230
5
235 310 395
295 455 435
215 370
405
295 375 395
200 300 335
380 385 500
210 385 400
240 260 420
390 400
280
360
225 245
305
304
262
±69 ±96
365 435
220
259 359 412
±57 ±55 ±42
Face Tent with Baffie
10
High Altitude Mask
10 15
5
455 545 550
595 630
550
415 415 575
455 570 57.')
360 435 515
465 490 600
265 365
570 600 590
390 510 500
295 375
570
422 496 553
±99 ±92 ±58
BLB Mask
5 10 15
380 515 560
425 605
460 610
420 585 605
420 515 545
350 505 480
525
605
395 505 480
525
580
400 480 460
270 435 495
404 528 541
±67 ±56 ±57
o
79
103
90
88
96
98
98
97
95
73
92
±9
Room Air
15
600
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
430
300
358
SHULMAN, SCHMIDT AND SADOV
pendence on facial contour and made the face ten almost as effective as a rebreathing mask. The importance of proper diffusion of the oxyge stream was also apparent in the difference betwee the face mask and the aerosol mask. Both of thes masks are almost identical in size and shape. Th main difference between the two is the diamete and position of the oxygen inlet. The inlet of th face mask is 4 mm in diameter and opens into th mask halfway up its surface so that the oxygen ca stream past the recipient's face via a jet effect. B contrast, the inlet of the aerosol mask is 18 mm i diameter and opens into the bottom of the mask This allows the oxygen to diffuse into the mask thu . increasing its efficiency. The nasal catheter produced slightly higher oxy gen tensions at each flow than did the nasal can ula, however, this difference was not considered t be significant (P < 0.05). Most volunteers com plained of severe discomfort when the flow of oxy gen through the nasal catheter exceeded 5 liter . per minute. Discomfort was never a problem wit the nasal cannula. The nasal cannula was slightl less efficient during mouth breathing, but this dif ference was not considered to be significant (P < 0.05). This finding was contrary to a previous re port. 10
during the course of the experiment. Arterial oxygen tensions (PaD .,) were measured with a Clark electrode. Th~ devices used to administer oxygen were the nasal catheter, the nasal cannula, a polyethylene face mask without a rebreathing bag, a polyethylene face mask with a rebreathing bag, a vinyl face mask with a rebreathing bag, an aerosol mask, a face tent, a face tent with a gas baffle inserted, a BLB mask (oronasal type), and a Puritan high altitude mask. RESULTS
Table 1 shows the arterial oxygen tensions achieved in each volunteer by each method. It can readily be seen that the tension produced by each device varied directly with the oxygen flow (Fig 1) . The highest arterial oxygen tensions were obtained by those methods which utilized a mask with a reservoir bag. The BLB mask and the Puritan high altitude mask were the most efficient of these devices (Le., they produced the highest arterial oxygen tensions). The differences between the two were not significant (P < 0.05 at all flows) ; however, many of the volunteers complained that the BLB mask was not comfortable to wear. The polyvinyl and polyethylene rebreathing masks were the next most efficient devices. Because of its greater flexibility, the polyvinyl mask can be more easily molded to the individual's facial contours; however, this factor apparently does not influence efficiency because there was no significant difference between the two masks (P < 0.05). The efficiency of the face tent depended markedly on each particular person's facial contour. If the person's face projected over the stream of oxygen, then the face tent was quite efficient, (e.g., volunteer No.2). If, however, the oxygen stream swept past the person's face without impinging on it, then the efficiency of this device was limited (e.g., volunteer No.7). The installation of a baffle which diffused the stream of oxygen and directed it towards the recipient's face eliminated this deARTERIAL OXYGEN TENSION
600
15 lite"
1m;.
10 lit.,,/min
Co:-.nfENT
The devices were evaluated by allowing eac subject to act as his own control ; thus a good eros comparison of each device could be obtained. Thos devices which utilized a reservoir bag for the oxy gen were the most efficient. The catheter tech niques, however, possess sufficient efficiency s that they might be considered adequate for routine use. This is especially true when one considers that a nasal catheter or cannula is more apt to remain in proper position than is a mask or a face tent. The nasal cannula may be even more effec-
~ /~ I,
II:
!5 lit.fl/mln
500
400
···
300
~
200
!I!
~
0
.II
s
.
"
Ji
i
~
~
100 o
;
;
1&
~
i
~ %
•
o i
.
~
..i
~
FIGURE 1. Effect of change in oxygen How on the mean arterial oxygen tension achieved by each method of administration.
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
359
INFECTIOUS MONONUCLEOSIS WITH PLEURAL EFFUSION
tive than the nasal catheter because the former is better tolerated at high flows. The importance of proper baffiing in those masks which do not utilize reservoir bags should not be underestimated. The aerosol mask and the face tent with baffle are both excellent means of giving the patient both effective aerosol therapy and oxygen therapy simultaneously. Although the findings of this type of study may be applied to clinical situations, one must be careful not to directly extrapolate data from a controlled study such as this to a clinical situation. If flow rates of less than 5 liters per minute are used with the masks, mechanical dead space problems may arise .' This is especially true with those masks that utilize rebreathing bags. It is worthy to note, in this regard, that the Puritan high altitude mask does not utilize a rebreathing bag but rather a reservoir bag that is connected to the mask via a one-way nonreb rea thing valve. This valve will automatically admit air to the mask if the oxygen flow is less than minute volume. Thus, dead space problems are minimized. Arterial oxygen tensions lower than those reported here could be anticipated at the lower rates in those patients with abnormally high minute volumes . This is because of the dilution of the delivered oxygen with the additional inspired air. Lower values would aso be anticipated in those patients with severe pulmonary ventilation perfusion disproportions. Nevertheless, the data presented here do indicate what one can expect from each device and how they compare with each other in effectiveness. R EFERENCES
2 3 4 5
6 7 8 9
BETIlu:"E, D .W ., A:"D COLLI:"S, J.~I. : The evaluation of oxygen masks, Anesthesia, 22:43, 1967. DOULTO:", E.P.. A:"D ADA~ls , T .\V.: Oxygen tents and nasal catheter, Brit. Med . I ., 1:567 (March 21) 1936. LO:"GOBAIIDI, A., EGHTEDAIII, A., A:-''O BUIIGEss, A.M.: Oxygen therapy on medical wards, I .A.M .A., 187:369 (Feb. 1) 1964. MILLEII, \V.F.: Oxygen therapy-eatheter, mask, hood, and tent, Anesthesiology, 23:445 , 1962 . KORY, R.C., BERG~IA:", J.C ., SWEET, R.D. A:"D S~IITH , J .R.: Comparative evalu ation of oxygen therapy techniques, I .A.M.A., 9:767 (March) 1962. GLUCK, ~I.C ., A:"D LUCHSI:"GER. P.C.: Arterial oxygen tension at different flow rate s of nasal oxygen , G. P., 34 ;99, (Oct.) 1966 . FLE:"LEY, D.C., HUTCHlSO:", D.C.S., A:"D DO:"ALD, K.W .: Behavior of apparatus for oxygen administration, Brit. Med . I ., 2:1081, 1963. CHER:"IAK, R.M., A:"() I-IAKI~IPOUI\ , K.: The rational use of oxygen in respiratory insufficiency, I .A .M.A., 199:178 (Jan . 16) 1967. ~fASSARO, D .J., KATZ, S. A:"D LucHsl:"GER, P.C.: Effect of various modes of oxygen administration on arterial gas values in patients with respiratory acid osis, Brit. Med. J., 2:627, 1962.
DIS. CHEST, VOL. 56 , NO.4, OCTOBER 1969
10
KIIAKU~I, V.D .: Oxygen therapy in management of the postoperative patient, Ohio Chern. Inhalation The r. Topics, 6:1 (August) 1960.
Reprint requests: Dr . Shulman, 840 South Wood Street, Chicago 60612
Infectious Mononucleosis with Pleural Effusion T. K. Sarkar, M.B.°
A 17-year-old boy was hospitalized for treatment of infectious mononucleosis. The clinical picture included atypical pneumonia complicated by pleural effusion. Follow-up chest roentgenogram showed pleural thickening on the affected side.
effusion occurring in the course of infecP leural tious mononucleosis is uncommon. The following case history may therefore be of interest. CASE REPORT
A 17-year-old youth was admitted to hospital on October 3, 1967, with a history of an influenza-like illness seven weeks previously, which was accompanied by left sided chest pain, pleuritic in nature. He was treated by his doctor with antibiotics while he continued to work as a clerk. Five weeks later, when recurrent chest pain cau sed him to visit the Casualty Department of another hospital, x-ray of the chest reveal ed patchy consolidation at the left base. Antibiotics were continued for a further two week s when, with increase of symptoms, he was admitted to the hospital and pla ced und er our care. His past history had been uneventful. He was, however, said to have had glandular fever at the age of 11 years and at 14 years of age he had been vaccinated with BCG . On examination his temperature was 101°F, pulse 100/ minute, respiration rate 22/minute. There was no finger clubbing. There were many firm discr ete glands palpable in both posterior triangles of the neck and in both axillae and groins . The liver and spleen were not palpable and abdominal examination was difficult because of the patient's inability to relax. The base of the left lung showed diminished movement, impaired percussion and diminished air entry. The cardiovascular system was normal except for a soft apical systolic murmur. Blood pressure was 120/70. The central nervous system was normal. Pyrexia continued after admission to hospital, varying from 99° to 103°F in spit e of ad ministration of intramuscular penicillin and later Ceporin. On the fourth day 100 ml of straw-colored fluid was aspirated from the left pleural space. On the tenth day aft er admission many petechiae appeared on the palate and the liver became palpable, two fingerbreaths below the costal margin. X-ray of the chest on admission showed an area of consolidation at the left hase with a small pleural effusion. The results of laboratory examination and tests were: Mantoux 1:1000 negative: erythrocyte sedimentation rate : 22 mm per hour (We stergren). Hemoglobin 15.0 gm /l00 ml. Lenkocyt e count 4,900 /mm:l ; neutrophils, 82 percent; lymphocytes , 14 percent: monocytes, 4 percent. Numerous atypical lymphocytes were seen in the film, Platelet connt 120,OOO/mma. Serum glutamic-oxalacetic tran samin ase was 180 nnits but other liver function tests were normal. Examination of throat swab, blood cult ures, "Formerly Registrar, Harlow Group of Hospitals, Essex, England.
SHULMAN, SCHMIDT AND SADOVE
tween second and third complex is still shorter. On the basis of assumption of anomalous pathway the sinus impulse is conducted slowly through A-V node to the ventricles. This impulse returns in a retrograde direction via the anomalous pathway to the auricle. Due to longer time taken for the impulse to travel through the A-V node the auricle now responds and a retrograde depolarization wave is inscribed. This impulse once again returns to the A-V node only to find it refractory and no more impulse conduction takes place. If the degree of block could be prolonged and the refractory period of the normal path could be shortened it would then be responsive to the returning stimulus establishing a reversed reciprocal rhythm. In the mechanism of production of Wolff-Parkinson-White syndrome also, the theory of anomalous pathway was put forward by Holzmann and Scherf!" as well as Wolferth and Wood.!" The arrhythmia reported in this publication can also be explained on the basis of anomalous pathway. Recently Wolff'? has shown both patterns in the same tracing emphasizing such a mechanism of their production. We agree with Schamroth'" that the difference between reversed reciprocal rhythm and WolffParkinson- White pattern may be only of the presence of first degree A-V block in the former. Both the electrocardiographic phenomena can be explained on the basis of an anomalous pathway or extra bundle of Kent. 21 REFEREl"CES
1 KATZ, L. N., Al'o.'D PICK, A.: Clin ical electrocardiography, Part I, the arrhythmias, Lea & Febiger, Philadelphia, 1956, p . 623, figure 364. 2 WOLFERTH, C. C., A:-:D WOOD.: Amer. Heart ] ., 8:297, 1933. 3 SCHERF, D., A:"D COHE:-: J.: The atrioventricular node, Gmne and Stratton, New York, 1964. 4 SCHERF, D. : An experimental study of reciprocating rhythm, Arch . Intem. Med ., 67 :372 , 1941. 5 COD1:"G-ALTES, J., A:-:D PIJOAN DE BERISTAI:-:, C. : Short paroxysms of tachycardia due to reciprocating rhythm, Amer. Heart t.. 39:436, 1950. 6 ELDRIDGE, F. L.: Reciprocal beating of the atria, Amer. Hearl ] .,55:469, 1959 . 7 MI:-:ES, G. R.: On dynamic equilibrium in the heart, ] . Phuslol., 46:349 , 1913. 8 GALLAVARDI:-:, L., A:-m GRAVIER, L. : Bradycardia nodale permanent, Arch. mal. Coeur., 14:71 , 1921. 9 DRURY, A. N. : Paroxysmal tachycardia of A-V origin, exhibiting retrograde heartblock and reciprocal rhythm, Am er. Heart ] .,55:469, 1959. 10 DOCK, E .: The reciprocal rhythm. Report of a case in which auricular tachycardia with partial A-V dissocia-
tion and atrioventricular bradycardia were pre sent, Arch . Intern. Med., 41 :745 , 1928. 11 DECHERD, G., A:-:D Husxrx, A.: Studies of the properties of the A-V node. 1. Reciprocal rhythm, 11 drug effects on the A-V conduction, Texas Rep . Biol. Med ., 1:299, 1949 . 12 Bix, H.: Various mechanisms in reciprocal rhythm, Am er. Heart t.. 41 :488, 1951. 13 KIST1:-:, A. D., A:"D BRUCE, J. C. : Simultaneous esophageal and standard electrocard iographic leads in the study of cardiac arrhythmias, Amer. Heart ] ., 53:65, 1957. 14 LA:"CEXDORF, R., KATZ, L. N., AXD SIl\ION, A. J.: Reciprocal beating initiated by ventricular premature systoles, Brit. Heart J., 4 :3, 1944. 15 NAIl\I, M.: Paroxysmal auricular tachycardia due to reciprocal rhythm, Amer. Heart J., 29:398, 1945. 16 ZAKOPOULOS, K.: Double atrial stimulation with reciprocal rhythm, Amer. Heart J., 54 :291 , 1957. 17 HOLzl\IA:-::", M., A:'\D SCHERF, D.: Z. KUn. Med., 121: 404,1932. 18 \VOLFEIITH, C. C., AND \VOOD: Amer. Heart 1933.
t..
8:297,
19 WOLFF, L.: Anomalous atrioventricular conduction (Wolff-Parkinson-White syndrome), Circulation, 19:14, 1959. 20 SCHAl\II\OTH, L.: Reversed reciprocal tachycardia and its relationship to the Wolff-Parkinson-White syndrome, 57:507, 1960 . 21 KE:'\T, A. F . S.: Quart. ]. Exper. Physiol., 7:193, 1914.
Evaluation of Oxygen Therapy Devices by Arterial Oxygen Tensions* Mortoll Shulman, M.D., Gwen Schmidt, M.D ., and Max S. Sadove, M.D ., F.C.C.P.
Ten different oxygen administration devices were tested on volunteers in order to determine their relative efficiency in raising the arterial oxygen tension. The efficiency of any particular device was directly proportional to the oxygen flow into it. Those devices which utilized reservoir bags were the most effective. The nasal catheter and cannula techniques were also quite effective with the cannula appearing to be somewhat preferable because of its greater comfort, especially at high flow rates of oxygen. The importance of proper baffling in those mask type devices that did not utilize reservoir bags was demonstrated.
The relative effectiveness of oxygen administration devices has been studied previously.!'! The most comprehensive study was that of Kory and others" who compared eight different techniques. °From the Department of Anesthesiologv , University of lllinois Research and Educational Hospitals, Chicago, 1IIinois. .
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
357
EVALUATION OF OXYGEN THERAPY DEVICES
Their criteria of effectiveness were based on the measurements of oxygen concentrations in the gas , phase of samples from inspired air, nasopharyngeal air, and end-expired air. These methods are someI times difficult to interpret because the act of adI ministering the oxygen may lead to a substantial artifact in the measurements; also, a gas phase measurement gives us no information on the amount of oxygen present in the arterial blood. Since the whole purpose of oxygen therapy is to produce an adequate oxygen content of the arterial blood, it becomes apparent that this is the site where oxygen measurements should be made in order to determine the effectiveness of any particular method of oxygen administration. The recent widespread availability of oxygen electrodes has given us a convenient method of measuring blood oxygen tensions. Arterial oxygen tension is, in itself, a more sensitive technique than arterial oxygen content for assessing the effective-
ness of oxygen administration and thus this method gives us a convenient means for assessing the value of our therapy. Several reports have appeared recently on the use of this method to assess various oxygen therapy devices.P" The purpose of this study is to present a controlled comparison of the relative effectiveness of several of the more commonly used oxygen therapy devices. MATERIALS AND METHODS
Ten healthy volunteers, seven men and three women, between the ages of 20 and 30 were used. Each had a Teflon catheter inserted into a brachial artery and then remained in a semi-sitting position for the duration of the study. Each volunteer received oxygen by each of ten different methods. Oxygen flows of 5, 10, and 15 liters per minute were used with each device. Each volunteer was exposed to each combination of method and flow for at least ten minutes before blood was withdrawn from the catheter and measurements performed. In addition, blood was drawn while the volunteers were breathing room air both before the first administration of oxygen and at several intervals
Table I-Summary of arterial oxygen tensions achieved in each ten volunteers with previous oxygen flows of 5, 10, and 15 liters per minute, METHOD
Flow LIMin.
Vol. 1'\0. I
Vol. 1'\0. 2
Vol. No.3
Vol. 1':0. 4
Arterial Oxygen Tension, mm Hg . Vol. Vol. Vol. Vol. Vol. 1'\0. 5 1':0. 6 No.7 1':0. 8 No.9
Vol. 1':0. 10
Mean
Standard Deviation
Nasal Catheter
10 15
5
210 205 370
235 260 295
195 275 368
180 350 400
190 340 425
270 370 300
185 205 228
200 270 260
300 360
148 210 275
205 278 328
Nasal Cannula (Mouth Closed) Nasal Cannula (Mouth Open)
±35 ±61 ±65
5
10 15
210 250 275
200 295 395
195
220 270
155 270 320
175 320 315
270 360 450
215 258 350
168 186 188
250 270 300
155 250 310
199 267 317
±39 ±49 ±71
5 10 15
205 265 305
230
285
183 250 315
190 260 300
210 290 335
270 320 430
170 195 180
172 182 178
170 200 230
170 225 275
193 241 283
±31 ±44 ±75
5 10 15
155 200 220
165 165 170
190 265 310
135 215 180
230 345 400
270 315 490
145 144 158
230
205
250
185 180 185
128 145 155
180 220 251
±45 ±69 ±1l4
5
10 15
250 355 340
210 265
210
215 375 510
270
290
330 415
185 250 325
420 475
215 340 370
300 380 410
212 310 359
190 240 245
225 326 373
±36 ±60 ±81
Rebreathing 5 Mask, 10 Polyethylene 15
290 345 455
375 360 405
385 405 415
375 460
260
275 480 450
430 485 540
205 320 370
240 310 380
310 360 345
240 295 395
301
373 421
±73 ±65 ±56
Rebreathing Mask, Vinyl
5 10 15
295 425 525
320 400 430
350 365
390 495
455
435 460 480
225 350 410
250 335 480
290
397
335 370 400
355
270 315 340
316 387 428
±64 ±57 ±56
.5
200
260
195
180
180
250
143
210
212
±43
Face Mask Aerosol Mask
Face Tent
10
210
190
390
220
23.'5
240
372 285
395
175
165
200
330
220
325
425
290
15
225
440
230
5
235 310 395
295 455 435
215 370
405
295 375 395
200 300 335
380 385 500
210 385 400
240 260 420
390 400
280
360
225 245
305
304
262
±69 ±96
365 435
220
259 359 412
±57 ±55 ±42
Face Tent with Baffie
10
High Altitude Mask
10 15
5
455 545 550
595 630
550
415 415 575
455 570 57.')
360 435 515
465 490 600
265 365
570 600 590
390 510 500
295 375
570
422 496 553
±99 ±92 ±58
BLB Mask
5 10 15
380 515 560
425 605
460 610
420 585 605
420 515 545
350 505 480
525
605
395 505 480
525
580
400 480 460
270 435 495
404 528 541
±67 ±56 ±57
o
79
103
90
88
96
98
98
97
95
73
92
±9
Room Air
15
600
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
430
300
358
SHULMAN, SCHMIDT AND SADOV
pendence on facial contour and made the face ten almost as effective as a rebreathing mask. The importance of proper diffusion of the oxyge stream was also apparent in the difference betwee the face mask and the aerosol mask. Both of thes masks are almost identical in size and shape. Th main difference between the two is the diamete and position of the oxygen inlet. The inlet of th face mask is 4 mm in diameter and opens into th mask halfway up its surface so that the oxygen ca stream past the recipient's face via a jet effect. B contrast, the inlet of the aerosol mask is 18 mm i diameter and opens into the bottom of the mask This allows the oxygen to diffuse into the mask thu . increasing its efficiency. The nasal catheter produced slightly higher oxy gen tensions at each flow than did the nasal can ula, however, this difference was not considered t be significant (P < 0.05). Most volunteers com plained of severe discomfort when the flow of oxy gen through the nasal catheter exceeded 5 liter . per minute. Discomfort was never a problem wit the nasal cannula. The nasal cannula was slightl less efficient during mouth breathing, but this dif ference was not considered to be significant (P < 0.05). This finding was contrary to a previous re port. 10
during the course of the experiment. Arterial oxygen tensions (PaD .,) were measured with a Clark electrode. Th~ devices used to administer oxygen were the nasal catheter, the nasal cannula, a polyethylene face mask without a rebreathing bag, a polyethylene face mask with a rebreathing bag, a vinyl face mask with a rebreathing bag, an aerosol mask, a face tent, a face tent with a gas baffle inserted, a BLB mask (oronasal type), and a Puritan high altitude mask. RESULTS
Table 1 shows the arterial oxygen tensions achieved in each volunteer by each method. It can readily be seen that the tension produced by each device varied directly with the oxygen flow (Fig 1) . The highest arterial oxygen tensions were obtained by those methods which utilized a mask with a reservoir bag. The BLB mask and the Puritan high altitude mask were the most efficient of these devices (Le., they produced the highest arterial oxygen tensions). The differences between the two were not significant (P < 0.05 at all flows) ; however, many of the volunteers complained that the BLB mask was not comfortable to wear. The polyvinyl and polyethylene rebreathing masks were the next most efficient devices. Because of its greater flexibility, the polyvinyl mask can be more easily molded to the individual's facial contours; however, this factor apparently does not influence efficiency because there was no significant difference between the two masks (P < 0.05). The efficiency of the face tent depended markedly on each particular person's facial contour. If the person's face projected over the stream of oxygen, then the face tent was quite efficient, (e.g., volunteer No.2). If, however, the oxygen stream swept past the person's face without impinging on it, then the efficiency of this device was limited (e.g., volunteer No.7). The installation of a baffle which diffused the stream of oxygen and directed it towards the recipient's face eliminated this deARTERIAL OXYGEN TENSION
600
15 lite"
1m;.
10 lit.,,/min
Co:-.nfENT
The devices were evaluated by allowing eac subject to act as his own control ; thus a good eros comparison of each device could be obtained. Thos devices which utilized a reservoir bag for the oxy gen were the most efficient. The catheter tech niques, however, possess sufficient efficiency s that they might be considered adequate for routine use. This is especially true when one considers that a nasal catheter or cannula is more apt to remain in proper position than is a mask or a face tent. The nasal cannula may be even more effec-
~ /~ I,
II:
!5 lit.fl/mln
500
400
···
300
~
200
!I!
~
0
.II
s
.
"
Ji
i
~
~
100 o
;
;
1&
~
i
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•
o i
.
~
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FIGURE 1. Effect of change in oxygen How on the mean arterial oxygen tension achieved by each method of administration.
DIS. CHEST, VOL. 56, NO.4, OCTOBER 1969
359
INFECTIOUS MONONUCLEOSIS WITH PLEURAL EFFUSION
tive than the nasal catheter because the former is better tolerated at high flows. The importance of proper baffiing in those masks which do not utilize reservoir bags should not be underestimated. The aerosol mask and the face tent with baffle are both excellent means of giving the patient both effective aerosol therapy and oxygen therapy simultaneously. Although the findings of this type of study may be applied to clinical situations, one must be careful not to directly extrapolate data from a controlled study such as this to a clinical situation. If flow rates of less than 5 liters per minute are used with the masks, mechanical dead space problems may arise .' This is especially true with those masks that utilize rebreathing bags. It is worthy to note, in this regard, that the Puritan high altitude mask does not utilize a rebreathing bag but rather a reservoir bag that is connected to the mask via a one-way nonreb rea thing valve. This valve will automatically admit air to the mask if the oxygen flow is less than minute volume. Thus, dead space problems are minimized. Arterial oxygen tensions lower than those reported here could be anticipated at the lower rates in those patients with abnormally high minute volumes . This is because of the dilution of the delivered oxygen with the additional inspired air. Lower values would aso be anticipated in those patients with severe pulmonary ventilation perfusion disproportions. Nevertheless, the data presented here do indicate what one can expect from each device and how they compare with each other in effectiveness. R EFERENCES
2 3 4 5
6 7 8 9
BETIlu:"E, D .W ., A:"D COLLI:"S, J.~I. : The evaluation of oxygen masks, Anesthesia, 22:43, 1967. DOULTO:", E.P.. A:"D ADA~ls , T .\V.: Oxygen tents and nasal catheter, Brit. Med . I ., 1:567 (March 21) 1936. LO:"GOBAIIDI, A., EGHTEDAIII, A., A:-''O BUIIGEss, A.M.: Oxygen therapy on medical wards, I .A.M .A., 187:369 (Feb. 1) 1964. MILLEII, \V.F.: Oxygen therapy-eatheter, mask, hood, and tent, Anesthesiology, 23:445 , 1962 . KORY, R.C., BERG~IA:", J.C ., SWEET, R.D. A:"D S~IITH , J .R.: Comparative evalu ation of oxygen therapy techniques, I .A.M.A., 9:767 (March) 1962. GLUCK, ~I.C ., A:"D LUCHSI:"GER. P.C.: Arterial oxygen tension at different flow rate s of nasal oxygen , G. P., 34 ;99, (Oct.) 1966 . FLE:"LEY, D.C., HUTCHlSO:", D.C.S., A:"D DO:"ALD, K.W .: Behavior of apparatus for oxygen administration, Brit. Med . I ., 2:1081, 1963. CHER:"IAK, R.M., A:"() I-IAKI~IPOUI\ , K.: The rational use of oxygen in respiratory insufficiency, I .A .M.A., 199:178 (Jan . 16) 1967. ~fASSARO, D .J., KATZ, S. A:"D LucHsl:"GER, P.C.: Effect of various modes of oxygen administration on arterial gas values in patients with respiratory acid osis, Brit. Med. J., 2:627, 1962.
DIS. CHEST, VOL. 56 , NO.4, OCTOBER 1969
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KIIAKU~I, V.D .: Oxygen therapy in management of the postoperative patient, Ohio Chern. Inhalation The r. Topics, 6:1 (August) 1960.
Reprint requests: Dr . Shulman, 840 South Wood Street, Chicago 60612
Infectious Mononucleosis with Pleural Effusion T. K. Sarkar, M.B.°
A 17-year-old boy was hospitalized for treatment of infectious mononucleosis. The clinical picture included atypical pneumonia complicated by pleural effusion. Follow-up chest roentgenogram showed pleural thickening on the affected side.
effusion occurring in the course of infecP leural tious mononucleosis is uncommon. The following case history may therefore be of interest. CASE REPORT
A 17-year-old youth was admitted to hospital on October 3, 1967, with a history of an influenza-like illness seven weeks previously, which was accompanied by left sided chest pain, pleuritic in nature. He was treated by his doctor with antibiotics while he continued to work as a clerk. Five weeks later, when recurrent chest pain cau sed him to visit the Casualty Department of another hospital, x-ray of the chest reveal ed patchy consolidation at the left base. Antibiotics were continued for a further two week s when, with increase of symptoms, he was admitted to the hospital and pla ced und er our care. His past history had been uneventful. He was, however, said to have had glandular fever at the age of 11 years and at 14 years of age he had been vaccinated with BCG . On examination his temperature was 101°F, pulse 100/ minute, respiration rate 22/minute. There was no finger clubbing. There were many firm discr ete glands palpable in both posterior triangles of the neck and in both axillae and groins . The liver and spleen were not palpable and abdominal examination was difficult because of the patient's inability to relax. The base of the left lung showed diminished movement, impaired percussion and diminished air entry. The cardiovascular system was normal except for a soft apical systolic murmur. Blood pressure was 120/70. The central nervous system was normal. Pyrexia continued after admission to hospital, varying from 99° to 103°F in spit e of ad ministration of intramuscular penicillin and later Ceporin. On the fourth day 100 ml of straw-colored fluid was aspirated from the left pleural space. On the tenth day aft er admission many petechiae appeared on the palate and the liver became palpable, two fingerbreaths below the costal margin. X-ray of the chest on admission showed an area of consolidation at the left hase with a small pleural effusion. The results of laboratory examination and tests were: Mantoux 1:1000 negative: erythrocyte sedimentation rate : 22 mm per hour (We stergren). Hemoglobin 15.0 gm /l00 ml. Lenkocyt e count 4,900 /mm:l ; neutrophils, 82 percent; lymphocytes , 14 percent: monocytes, 4 percent. Numerous atypical lymphocytes were seen in the film, Platelet connt 120,OOO/mma. Serum glutamic-oxalacetic tran samin ase was 180 nnits but other liver function tests were normal. Examination of throat swab, blood cult ures, "Formerly Registrar, Harlow Group of Hospitals, Essex, England.