ANESTHESIA AND ANALGESIA . . . Current Researches VOL.51, NO.5, SEPT.-OCT., 1975
602
The Surface Tension of Upper Airway Secretions in Patients With and Without Respiratory Disease THEODORE
H. STANLEY, M.D."
BASHIR A. ZIKRIA, M.D.t
The alveolar-arterial oxygen partial pressure (PAao2) difference and surface tension of upper airway secretions (UASST) were simultaneously measured in 33 intubated patients. Patients without respirabry disease had UASST and PAaoe gradients significantly lower than those with chronic obstructive lung disease. Patients in respiratory failure had UASST
and Paaoz gradients significantly higher than when they were out of failure. Correlation of UASST with PAaoz was good ( r = 0.81). These findings demonstrate that UASST closely correlate with the severity of pulmonary disease and suggest that their measurement may be a simple, clinically applicable method of assessing alveolar surfactant function.
I
Group Z.-Eight patients, followed for years in the pulmonary medicine clinic and known to have chronic obstructive pulmonary disease ( prerespiratory failure vital capacity lo0 percent increases in predicted residual volume and functional residual capacity, and hyperlucent lungs on radiologic examination), and were studied during and after respiratory failure.
been suggested that measurements of upper airway secretion surface tensions (UASST) may be a simple way of assessing alveolar surfactant activity.'-2 Recent work1 has confirmed that these secretions contain surfactant metabolites and possess significant surface activity. Patients in respiratory failure have decreased amounts of pulmonary surfactant.3 Those with chronic lung disease or a history of smoking also have less alveolar surfactant activity.4 T HAS
This study was conducted to measure the surface tensions of upper airway secretions in patients with and without chronic obstructive lung disease and in a group of the former during and after respiratory failure. These values were compared with simultaneously obtained alveolar-arterial oxygen partial pressure ( PAao,) gradients.
METHODS AND MATERIALS Thirty-three men patients were divided into four groups:
Group IZ.-Five patients who had had a recent massive cerebral hemorrhage but were without a history of smoking or pulmonary disease. Group ZIZ.-Ten preoperative patients with a long history of smoking cigarettes$
-
$All had a history of smoking 1.5 packages or more of cigarettes for 15 or more years and had been previously hospitalized for one or more episodes of bronchitis with or without respiratory failure. Eight of the 10 patients of this group had some preoperative pulmonary function testing and all these had results (vital capacity 70 percent of predicted increases in residual volume and functional residual capacity) consistent with chronic obstructive lung disease.
*Associate Professor of Anesthesiology and Assistant Research Professor of Surgery, University of Utah College of Medicine, Salt Lake City, Utah 84132. ?Assistant Professor, Department of Surgery, The Columbia-Presbyterian Medical Center, New York, New
York. Paper received: 12/17/74 Accepted for publication: 2/21/75
Surface Tension
. . . Stanley and Zikria
603
Patients in group I had second tracheobronchial secretion specimens and arterial blood gases similarly obtained when they were out of respiratory failure, off PEEP, Group ZV.-Ten preoperative patients and breathing spontaneously just prior to without a history of smoking or pulmonary extubation. disease. The tracheobronchial samples were anaPatients were considered to be in respira- lyzed on a standard Kimray pneumatic surtory failure if they could not maintain a factometer.5 Frozen samples were allowed Pao, above 60 torr despite concentrations to thaw and saline solution was added to of 0, >70 percent or if they had P ~ a o , each to give a final volume of 50 ml. The gradients >350 torr with an F’Io, of 1 de- solution was mixed by a magnetic stirrer spite 5 cm H,O positive end-expiratory pres- and filtered through cotton gauze into the sure (PEEP). All patients in the respira- Teflon trough of the surfactometer. After 60 tory failure group were also being subjected minutes of aging in a glass encasement, to to intermittent positive-pressure breathing allow the migration of surfactive materials (IPPB) with a Bennett MA-I volume-lim- to the surface, compression and expansion ited respirator at rates of 8 to 14 breaths/ cycles were begun. The surface film of each min and volumes of 12 to 18 ml/kg/breath sample was repeatedly compressed and reat the time of initial UASST and PAao, expanded until a stable replication of the hysteresis loops was obtained during a measurements. 2-hour period. The minimal surface tension Informed consent was obtained from the ( y min) , which is a sensitive index of surnext of kin in patients in groups I and I1 face activity in surfactant-containing soluand from the patients themselves at the pre- tions, was recorded for each sample. anesthetic visit in groups I11 and IV. PreArterial blood specimens were analyzed medication in groups I11 and IV included a for Pao, and Paco, immediately after colbarbiturate ( 1 to 2 mg/kg) and atropine or lection on a Radiometer micrometer acidscopolamine (0.05 to 0.1 mg/lO kg) 90 base analyzer calibrated with H,O that was minutes before induction of anesthesia and equilibrated with known concentrations of intubation. All patients were given 100 per- CO, (4.2 and 8 percent) and 0, (100, 50, cent 0, for 30 minutes, and at the end of and 20.9 percent) at 38c. PAO, was calthis time had an arterial blood sample drawn culated by the equation percutaneously from the radial artery for PAO,= PB- PACO, - PAH,O Pao, and Paco, analysis. Groups I11 and IV were then given 3 to 5 mg/kg of sodium where PB = barometric pressure thiopental, followed by 1.5 mg/kg of SUCPACO,= alveolar C 0 2 tension (obtained cinylcholine intravenously and were intuby measuring Paco, and assumbated. Patients in groups I and I1 were ing alveolar and arterial C 0 2 already intubated. tensions to be equal) Following blood sampling and in groups PAH,O= water vapor pressure 111and IV intubation, all patients had 5 ml of sterile saline solution injected endotraUASST Y minutes, ages, and differences cheally and were ventilated for an addition- (A) in PAO,and Pao, for each group were al 20 seconds. A sterile 16-Fr suction cath- recorded and the means and standard devieter was placed in the endotracheal tube and ations (S.D.) calculated. Student’s paired advanced to the orifices of the main-stem t-test was used to analyze the significance bronchi and the orifices of both bronchi and of the difference in group I values during the trachea were suctioned for 5 seconds. and after respiratory failure, and the unUsually, 0.5 to 1 ml of material was ob- paired t-test was used to analyze differences tained. These secretions were cdlected in between groups. Correlation of UASST Y 2 ml Lukens* specimen collectors. In 3 pa- min versus APAao, of all patients was obtients from whom less than 0.5 ml was ob- tained by scattergraph equation and corretained by the initial aspiration the process lation coefficient determination.6 was repeated. Sterile saline solution was added to each Lukens tube to make a total RESULTS volume of 2 ml and the sample was quickly Patient ages were similar (range of frozen, remaining frozen until analyzed. means, 50 to 56 2 S.D.). UASST 7 min and APAao, of all groups are recorded in *Pillkg Company, Fort Washington, Pennsylvania.
or preoperative pulmonary function testing findings consistent with chronic bronchitis and emphysema.
.
ANESTHESIA AND ANALGESIA . . Current Researches VOL.54, No. 5, SEPT.-OCT.,1975
604
TABLE 1 Upper Airway Secretion Tensions and and PAaoz Gradients in Group I Patients During and After Respiratory Failure (Means tS.D.) During respiratory failure
y
min (dyner/cm )
y min (dyner/cm)
PAaoz
(torr)
484
33
314
38
Mean
After respiratory failure
PAaoz
(torr)
33
357
31
188
36
419
32
220
34
408
31
186
38
485
34
339
35
390
50
174
37
437
32
224
35
411
32
210
35.8
424
S.D. 2 1 . 7
k41
31.9*
232*
rt1.2
2-57
*p
602
The Surface Tension of Upper Airway Secretions in Patients With and Without Respiratory Disease THEODORE
H. STANLEY, M.D."
BASHIR A. ZIKRIA, M.D.t
The alveolar-arterial oxygen partial pressure (PAao2) difference and surface tension of upper airway secretions (UASST) were simultaneously measured in 33 intubated patients. Patients without respirabry disease had UASST and PAaoe gradients significantly lower than those with chronic obstructive lung disease. Patients in respiratory failure had UASST
and Paaoz gradients significantly higher than when they were out of failure. Correlation of UASST with PAaoz was good ( r = 0.81). These findings demonstrate that UASST closely correlate with the severity of pulmonary disease and suggest that their measurement may be a simple, clinically applicable method of assessing alveolar surfactant function.
I
Group Z.-Eight patients, followed for years in the pulmonary medicine clinic and known to have chronic obstructive pulmonary disease ( prerespiratory failure vital capacity lo0 percent increases in predicted residual volume and functional residual capacity, and hyperlucent lungs on radiologic examination), and were studied during and after respiratory failure.
been suggested that measurements of upper airway secretion surface tensions (UASST) may be a simple way of assessing alveolar surfactant activity.'-2 Recent work1 has confirmed that these secretions contain surfactant metabolites and possess significant surface activity. Patients in respiratory failure have decreased amounts of pulmonary surfactant.3 Those with chronic lung disease or a history of smoking also have less alveolar surfactant activity.4 T HAS
This study was conducted to measure the surface tensions of upper airway secretions in patients with and without chronic obstructive lung disease and in a group of the former during and after respiratory failure. These values were compared with simultaneously obtained alveolar-arterial oxygen partial pressure ( PAao,) gradients.
METHODS AND MATERIALS Thirty-three men patients were divided into four groups:
Group IZ.-Five patients who had had a recent massive cerebral hemorrhage but were without a history of smoking or pulmonary disease. Group ZIZ.-Ten preoperative patients with a long history of smoking cigarettes$
-
$All had a history of smoking 1.5 packages or more of cigarettes for 15 or more years and had been previously hospitalized for one or more episodes of bronchitis with or without respiratory failure. Eight of the 10 patients of this group had some preoperative pulmonary function testing and all these had results (vital capacity 70 percent of predicted increases in residual volume and functional residual capacity) consistent with chronic obstructive lung disease.
*Associate Professor of Anesthesiology and Assistant Research Professor of Surgery, University of Utah College of Medicine, Salt Lake City, Utah 84132. ?Assistant Professor, Department of Surgery, The Columbia-Presbyterian Medical Center, New York, New
York. Paper received: 12/17/74 Accepted for publication: 2/21/75
Surface Tension
. . . Stanley and Zikria
603
Patients in group I had second tracheobronchial secretion specimens and arterial blood gases similarly obtained when they were out of respiratory failure, off PEEP, Group ZV.-Ten preoperative patients and breathing spontaneously just prior to without a history of smoking or pulmonary extubation. disease. The tracheobronchial samples were anaPatients were considered to be in respira- lyzed on a standard Kimray pneumatic surtory failure if they could not maintain a factometer.5 Frozen samples were allowed Pao, above 60 torr despite concentrations to thaw and saline solution was added to of 0, >70 percent or if they had P ~ a o , each to give a final volume of 50 ml. The gradients >350 torr with an F’Io, of 1 de- solution was mixed by a magnetic stirrer spite 5 cm H,O positive end-expiratory pres- and filtered through cotton gauze into the sure (PEEP). All patients in the respira- Teflon trough of the surfactometer. After 60 tory failure group were also being subjected minutes of aging in a glass encasement, to to intermittent positive-pressure breathing allow the migration of surfactive materials (IPPB) with a Bennett MA-I volume-lim- to the surface, compression and expansion ited respirator at rates of 8 to 14 breaths/ cycles were begun. The surface film of each min and volumes of 12 to 18 ml/kg/breath sample was repeatedly compressed and reat the time of initial UASST and PAao, expanded until a stable replication of the hysteresis loops was obtained during a measurements. 2-hour period. The minimal surface tension Informed consent was obtained from the ( y min) , which is a sensitive index of surnext of kin in patients in groups I and I1 face activity in surfactant-containing soluand from the patients themselves at the pre- tions, was recorded for each sample. anesthetic visit in groups I11 and IV. PreArterial blood specimens were analyzed medication in groups I11 and IV included a for Pao, and Paco, immediately after colbarbiturate ( 1 to 2 mg/kg) and atropine or lection on a Radiometer micrometer acidscopolamine (0.05 to 0.1 mg/lO kg) 90 base analyzer calibrated with H,O that was minutes before induction of anesthesia and equilibrated with known concentrations of intubation. All patients were given 100 per- CO, (4.2 and 8 percent) and 0, (100, 50, cent 0, for 30 minutes, and at the end of and 20.9 percent) at 38c. PAO, was calthis time had an arterial blood sample drawn culated by the equation percutaneously from the radial artery for PAO,= PB- PACO, - PAH,O Pao, and Paco, analysis. Groups I11 and IV were then given 3 to 5 mg/kg of sodium where PB = barometric pressure thiopental, followed by 1.5 mg/kg of SUCPACO,= alveolar C 0 2 tension (obtained cinylcholine intravenously and were intuby measuring Paco, and assumbated. Patients in groups I and I1 were ing alveolar and arterial C 0 2 already intubated. tensions to be equal) Following blood sampling and in groups PAH,O= water vapor pressure 111and IV intubation, all patients had 5 ml of sterile saline solution injected endotraUASST Y minutes, ages, and differences cheally and were ventilated for an addition- (A) in PAO,and Pao, for each group were al 20 seconds. A sterile 16-Fr suction cath- recorded and the means and standard devieter was placed in the endotracheal tube and ations (S.D.) calculated. Student’s paired advanced to the orifices of the main-stem t-test was used to analyze the significance bronchi and the orifices of both bronchi and of the difference in group I values during the trachea were suctioned for 5 seconds. and after respiratory failure, and the unUsually, 0.5 to 1 ml of material was ob- paired t-test was used to analyze differences tained. These secretions were cdlected in between groups. Correlation of UASST Y 2 ml Lukens* specimen collectors. In 3 pa- min versus APAao, of all patients was obtients from whom less than 0.5 ml was ob- tained by scattergraph equation and corretained by the initial aspiration the process lation coefficient determination.6 was repeated. Sterile saline solution was added to each Lukens tube to make a total RESULTS volume of 2 ml and the sample was quickly Patient ages were similar (range of frozen, remaining frozen until analyzed. means, 50 to 56 2 S.D.). UASST 7 min and APAao, of all groups are recorded in *Pillkg Company, Fort Washington, Pennsylvania.
or preoperative pulmonary function testing findings consistent with chronic bronchitis and emphysema.
.
ANESTHESIA AND ANALGESIA . . Current Researches VOL.54, No. 5, SEPT.-OCT.,1975
604
TABLE 1 Upper Airway Secretion Tensions and and PAaoz Gradients in Group I Patients During and After Respiratory Failure (Means tS.D.) During respiratory failure
y
min (dyner/cm )
y min (dyner/cm)
PAaoz
(torr)
484
33
314
38
Mean
After respiratory failure
PAaoz
(torr)
33
357
31
188
36
419
32
220
34
408
31
186
38
485
34
339
35
390
50
174
37
437
32
224
35
411
32
210
35.8
424
S.D. 2 1 . 7
k41
31.9*
232*
rt1.2
2-57
*p
