University of Calgary

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Cumming School of Medicine Cumming School of Medicine Research amp Publications

2001-03

Ultrasound evaluation of the magnitude of

pneumothorax a new concept

Sargsyna Ashote E Hamilton Douglas R Nicolaou Saavas

Kirkpatrick Andrew W Campbell Mark R Billica Roger D

Dawson David Williams David R Melton Shannon L Beck

George

Southeaster Surgical Congress

Sargsyan AE Hamilton DR Nicolaou S Kirkpatrick AW Campbell MR Billica RD Dawson D

Williams DR Melton SL Beck G Forkheim K Dulchavsky SA Ultrasound evaluation of the

magnitude of pneumothorax a new concept Am Surg 200167(3)232-5

httphdlhandlenet188047408

journal article

Downloaded from PRISM httpsprismucalgaryca

Ultrasound Evaluation of the Magnitude of Pneumothorax A New Concept ASHOTE SARGSYAN MD DOUGLAS R HAMILTON MD PwD SAAVASNICOLAOUMDf ANDREW W KIRKPATRICK MDi MARK R CAMPBEU MD ROGER D BILLICA MD$ DAVID DAWSON MD$ DAVID R WILWAMS MD$ SHANNON L MELTON GEORGE BECK KEVIN FORKHEIM MDt SCOTT A DULCHAVSKY MD PnDtsect

From Wyle Laborafories Houstav~ Texas tVanca~~ver General Hospital Vancouver British Columbia Canada National Aeronautics and Space Adminisfration Space and Life Sciences Directorate Jahnson Space Center Houston Texas atld sectWayne State University Sclzool ofMedicilze Detroit Michigan

Pneumothorax is commonly seen in trauma patients the diagnosis is confirmed by radiography The use of ultrasound where radiographic capabilities are absent is being investigated by the National Aeronautics and Space Administration We investigated the ability of ultrasound to assess the magnitude of pneumothorax in a porcine model Sonography was perfonned on anes- thetized pigs in both ground-based laboratory (n = 5) and microgravity conditions (0 x g) aboard the KC-135aircraft during parabolic flight (n = 4) Aliquots of air (50-100 cm3) were introduced into the ohest to simulate pneumothorar Results were videorecorded and digitized for later interpretation Several distinct sonographic patterns of partial lung sliding were noted including the combination of a sliding zone with a stillzone and a segmented sliding zone These partial lung sliding patterns exclude massive pneumothorax manifested by a complete separation of the lung from the parietal pleura In 0 x g the sonographic picture is more diverse one x g differences between posterior and anterior aspects are diminished Modest pneumothorax can be inferred by the ultrasound sign of partial lung sliding This fiidinamp which increases the negative predic- tive value of thoracic ultrasound may be attributed to intermittent pleural contact small air spaces or alterations in pleural lubricant Further studies of these phenomena are warranted

P NEUMOTHORAX IS A COMMON clinical problem that amined the effects of weightlessness on these sono- may be spontaneous or iatrogenic or may follow graphic findings to ascertain the accuracy of ultra-

chest trauma The diagnosis of pneumothorax is sug- sound for the specialized application of determining gested by the history and clinical examination confir- the extent of pneumothorax during space flight mation requires chest roentgenography In settings where radiologic capabilities are not immediately Methods available ultrasound may provide information that can aid in the diagnos~s of pneumothomx Numerous sono- The procedures described herein conformed to the graphic signs have been described that are associated National Institutes of Health Guidelines for the Care of with pneumothorax however prior investigators have Laboratory Animals and were approved by the Na- suggested that ultrasound is inaccurate in the determi- tional Aeronautics and Space Administration (NASA) nation of the magnitude of the pneumothorax Johnson Space Center Institutional Review Board the

This study using a controlled animal model inves- University of British Columbia and University of tigates the utility of thoracic ultrasound imaging to Texas Medical Branch-Galveston Animal Care and determine the extent of pneumothorax We then ex- Use Committees

Initial ground studies were performed at the Animal Care Facility at the Jack Bell Animal Research Facility

Presented at the 43rd hnmal Meeting MidwcaSurg~calAYSO- at the University of British Columbia (Vancouver BC claoon Mnchac Ialand Michigan August 13-162000 Canada) to develop the model and verify the diagnos-

This study way supported by NASA Contract NAS9-09005 tic accuracy of ultrasound in this porcine model Adult Natlonal Aeronautics and Space AdrninistrdtiodTohnsoliSpace female Yorksh~re pigs (average weight 25 kg) were Center

Address correspondence and reprint requeslb to Scott A Dul- anesthetized with ketamine (10 mglkg) and xylazine (2 chavsky MD PhD Department of Surgery Detrod Reoe~vlng mglkg) and maintained with Pentobarbltal The anl- Hosp~ral 4201 St Antome Detroit MI 48201 mals were intubated and continuously ventilated with

No 3 ULTRASOUND NALUATlON OF PNEUMOMOFW MAGNITUDE Sargsyan et a 233

an Impact Ventilator (Model 754) (Impact Instrumen- tation West Caldwell NJ) with a tidal volume of 600 to 750 cm3 a positive end-expiratory premre of 5 cm HO and a rate of 12 to 16 per minute bIair on the anjmals chest and abdomen was removed with a de- pilatory agent and shaving A Foley catherer was in- serted into the bladder

Baseline ultrasonic scans of both hemithoraces were performed with a high-definition ultrasound machine and a hand-held ponabie ultrasound device Thoracic scaoswere done in a serial fashion in the anterior chest apex the mid-lateral chest and the posterior thoracic region Continuous scanning was done for approxi- mately 10 to 20 seconds in each area When possible the scanning plane was aligned parallel to the long axis of the body to maximize the possible range of motion The presence or absence of lung sliding (to-and-fro motion coincident with respiratian at the visceral- parietal interface) was then determined T h images were digitally recorded for later data analysis

Hardware

Two ultrasound imaging systems were investigated in this study The first device was an HDI-5000 (ATL Bothell WA) which is similar to the unit that will be part of the Human Research Facility in the US Laboratory Module on the International Space Station Images from this device were recorded and annotated for later analysis The transducer used for this appli- cafion was a broad-band 12-5-MHz linear probe A second portable uItrasound device the Sonosite 180 (Sonosite Inc Bothell WA) which is a 54-lb battery-powered unit equipped with a 5-2-MHz broad- band probe was used

Pnaumotharax Model

Baseline scans of both hemithoraces were per- formed before instnunentation to determine the pres- ence or absence of lung sliding or comet tail artifacts in all three thoracic portals A 16-F Cordis introducer was then inserted in the apex of the right chest through a small stab incision Care was taken to avoid intro- duction of air or lung injury during insertion the h-racic scans were repeated before instillation of air into the chest Aliquots of air were then serially imduced into the chest through the catheter followed by tho- racic ultrasound examinations in the anterior lateral and posterior portals Gradually increasing thoracic in- flation volumes were used starting at 10 cm3 and con- cluding with a total inflation volume of 1000 cm3 of air A chest tube was then inserted and connected to a Heimlich valve and the intratharacic pressure was in- creased by the addition of positive end-expiratory pressure and sigh ventilation The thoracic ultrasound examinations were then repeated before conclusion of

the protocol Each animal was eutbanized and necrop- sies were performed to verify catheter and chest tube placement and examine the lungs for evidence of iat- rogenic injury

The micrograwity phase of the study was done in conjunction wirh the University of Texas Medical Branch (UTMB)in Galveston TX and the NASA Johnson Space Center in Houston TXThe animals were prepared at an offsibe animal facility (UTMB-Galveston) before transport to Ellington Field for the flight Thezero gravity (0 x g) studies were performed onboard NASA KC-135 research aircraft during para- bolic flight profiles Each patabola consisted of two phases lasting approximately 2 minutes 30 to 40 sec-onds of 18 x g followed by approximately 15 to 20 seconds of transition fallowed by 20 to 25 seconds of 0x g flight followed by another transition period The animal life support moniroring equipment and ultra- sound equipment were secured in the aircraft floor before takeoff

Baseline ultraswnd evaluations were completed during level flight (I x g) and during parabolic flight (0 x g) before instrumentation The insufflation cath- eter was then inserted and the air insufflations were done as previously outlined during the initial zero- gravity transition to allow adequate time for air equili- bration and ultrmound evaluation during the period of zero gravity

Lung sliding was readily apparent in all lung fields before instrumentation in all of the animals Image quality was excellent with the HDI 5000 ultrasound machine with comet tail anifacts noted in a number of the animals The Sonosite 180 ultra~ound device pro- duced image quality of lesser resolution however lung sliding was also evident on the smaller built-in screen When the Sonosite 180 was connected to an external 15-inch monitor through its output channel excellent imagc qualiry was not~d

There was no evidence of pneumothorax after in- sertion of the insufflation catheter lung sliding was unchanged in all animals After insufflation of 150 cm3of air into the insufflation catheter an area of delineation of l ~ n g slidingnot sliding was identified in the anterior thoracic portal (Table 1) This finding of partial lung sliding consisted of visualization of lung sliding in a portion of the scanning window witb ad-jacent absence of sliding noted in the same window It is presumed that this occurs when the transducer is placed over an area where the visceral and parietal pleura are separated in the scanning window

~

$nrerfm LBteral Posterior

TABLE Resulrrf7om Thmaric Ultrasound Pc~fomred2 during PareboUc Fiighr on the NASA KC- I35 S4icrograviiy Reseun-h Facll~ly under Micmgmviry (0x g Condrlions

~ ~ 6 ampqumtly ~ a l 0~ frcjlq pmtttig ~

dhamptflUxWbi~~tcRest 01bm7rWii060UrS$poampnampyslyjor 01gii~samp~a affrIamp-c~nig$ieatiJ p u Y j ~ dieO6ampampeamp ~ ~ amp 8 $ ~ h e amp amp n o i a o f P-Q- is mamp on tha basisofh e ampampow CI~~$E~sfmmdefmactenisiephysicalfiadmgsandiamp cOampaaamp

~ ~~ e$t t3i~gtcby$w ~Wcr~~Xonalamp mA I ~ O ~ or modaamptepaewpthm isaampamp geampramply ampt life tEgeampampg adlslyliaampn$ ab u n tmapmul(brqamp- ampcbiroamptary col-lapseFwthrmrn~ahigh inampxofsua$~iond pea+ mpthbmx anamp imbilfty teORamp a raampb$rsph often mampaes dampampfjvamp~ br obixie~ofpaamp~ttcy anen$dnt pIrgamp~ampaampiampc pabilibili

ampvasblefn mamp$ lampampa1193ampsampm gampampf ampgampcant logis6im hhenges

atrasmd has p v e n diapeie aocuraq in nu-n~$application8 inmIvhg ~ampabdomen and en-wmities ISowe~eramp u pfampcgig~~I the h r ~ ~~~

h a hindwa 6eghpc0u6tic imppdWampampampntl~ u l b ~ m dmbean g~lggpstampito be a u e amp ~mamp~ io amp e y d u amp ~of pnampmampoha in paenafamp ulwwd-guidd lmg m vm-WrgtI meampelintensive unit ptamp2nts dmFre sptitamp hippaenfsMiamp g$mtratinampghes wm

lkTist ~epwamp~ amp eof n i ~ o ~ d diagnaamp ~eumoampox o c ~ ~in a ~etefinatyjoWd A pnemdtkmrax in a hem was dkgaosed ampwthozmi~ s e g the m d wsph- of

1~8g a qcaird a c f 4gtrawnie e d w -atirli6f iftfoamh sulggemdtg be paradozicd

~ampXQampS I~S ofampthe ampSe~e~ h amp l s aampahampfmej aspZeQFal $Eampgf marfm blung-campst wan inYerfgce Seamingis petfhrmedbetwee6 sib that are easilyidenfftdas r dens acoustic shadow The Ihngichest wall hiamp or pleural finemoyw a amp+aampamp sfiamptp-tion gy~ghfampampd Gith rqpiraatio~~Ultgsianigaphi~ sips wsOEked wii ~ ~ g g r nhave bed amp-~ D Ma d~GIucJ$thiabsampGeOY n6Wampg~fi~rig ampI amp gQit tail mifact$ wh +tsmptamphigmampl~smpfrom fjpampamptfetfe tampe ampdamplwnijfmampN

The $ampnampi$waf 3amp$amp0tl thl ampgnsi5fpnemampcq~c a$= be)wapampaleyifhthat of

Ultrasound Evaluation of the Magnitude of Pneumothorax A New Concept ASHOTE SARGSYAN MD DOUGLAS R HAMILTON MD PwD SAAVASNICOLAOUMDf ANDREW W KIRKPATRICK MDi MARK R CAMPBEU MD ROGER D BILLICA MD$ DAVID DAWSON MD$ DAVID R WILWAMS MD$ SHANNON L MELTON GEORGE BECK KEVIN FORKHEIM MDt SCOTT A DULCHAVSKY MD PnDtsect

From Wyle Laborafories Houstav~ Texas tVanca~~ver General Hospital Vancouver British Columbia Canada National Aeronautics and Space Adminisfration Space and Life Sciences Directorate Jahnson Space Center Houston Texas atld sectWayne State University Sclzool ofMedicilze Detroit Michigan

Pneumothorax is commonly seen in trauma patients the diagnosis is confirmed by radiography The use of ultrasound where radiographic capabilities are absent is being investigated by the National Aeronautics and Space Administration We investigated the ability of ultrasound to assess the magnitude of pneumothorax in a porcine model Sonography was perfonned on anes- thetized pigs in both ground-based laboratory (n = 5) and microgravity conditions (0 x g) aboard the KC-135aircraft during parabolic flight (n = 4) Aliquots of air (50-100 cm3) were introduced into the ohest to simulate pneumothorar Results were videorecorded and digitized for later interpretation Several distinct sonographic patterns of partial lung sliding were noted including the combination of a sliding zone with a stillzone and a segmented sliding zone These partial lung sliding patterns exclude massive pneumothorax manifested by a complete separation of the lung from the parietal pleura In 0 x g the sonographic picture is more diverse one x g differences between posterior and anterior aspects are diminished Modest pneumothorax can be inferred by the ultrasound sign of partial lung sliding This fiidinamp which increases the negative predic- tive value of thoracic ultrasound may be attributed to intermittent pleural contact small air spaces or alterations in pleural lubricant Further studies of these phenomena are warranted

P NEUMOTHORAX IS A COMMON clinical problem that amined the effects of weightlessness on these sono- may be spontaneous or iatrogenic or may follow graphic findings to ascertain the accuracy of ultra-

chest trauma The diagnosis of pneumothorax is sug- sound for the specialized application of determining gested by the history and clinical examination confir- the extent of pneumothorax during space flight mation requires chest roentgenography In settings where radiologic capabilities are not immediately Methods available ultrasound may provide information that can aid in the diagnos~s of pneumothomx Numerous sono- The procedures described herein conformed to the graphic signs have been described that are associated National Institutes of Health Guidelines for the Care of with pneumothorax however prior investigators have Laboratory Animals and were approved by the Na- suggested that ultrasound is inaccurate in the determi- tional Aeronautics and Space Administration (NASA) nation of the magnitude of the pneumothorax Johnson Space Center Institutional Review Board the

This study using a controlled animal model inves- University of British Columbia and University of tigates the utility of thoracic ultrasound imaging to Texas Medical Branch-Galveston Animal Care and determine the extent of pneumothorax We then ex- Use Committees

Initial ground studies were performed at the Animal Care Facility at the Jack Bell Animal Research Facility

Presented at the 43rd hnmal Meeting MidwcaSurg~calAYSO- at the University of British Columbia (Vancouver BC claoon Mnchac Ialand Michigan August 13-162000 Canada) to develop the model and verify the diagnos-

This study way supported by NASA Contract NAS9-09005 tic accuracy of ultrasound in this porcine model Adult Natlonal Aeronautics and Space AdrninistrdtiodTohnsoliSpace female Yorksh~re pigs (average weight 25 kg) were Center

Address correspondence and reprint requeslb to Scott A Dul- anesthetized with ketamine (10 mglkg) and xylazine (2 chavsky MD PhD Department of Surgery Detrod Reoe~vlng mglkg) and maintained with Pentobarbltal The anl- Hosp~ral 4201 St Antome Detroit MI 48201 mals were intubated and continuously ventilated with

No 3 ULTRASOUND NALUATlON OF PNEUMOMOFW MAGNITUDE Sargsyan et a 233

an Impact Ventilator (Model 754) (Impact Instrumen- tation West Caldwell NJ) with a tidal volume of 600 to 750 cm3 a positive end-expiratory premre of 5 cm HO and a rate of 12 to 16 per minute bIair on the anjmals chest and abdomen was removed with a de- pilatory agent and shaving A Foley catherer was in- serted into the bladder

Baseline ultrasonic scans of both hemithoraces were performed with a high-definition ultrasound machine and a hand-held ponabie ultrasound device Thoracic scaoswere done in a serial fashion in the anterior chest apex the mid-lateral chest and the posterior thoracic region Continuous scanning was done for approxi- mately 10 to 20 seconds in each area When possible the scanning plane was aligned parallel to the long axis of the body to maximize the possible range of motion The presence or absence of lung sliding (to-and-fro motion coincident with respiratian at the visceral- parietal interface) was then determined T h images were digitally recorded for later data analysis

Hardware

Two ultrasound imaging systems were investigated in this study The first device was an HDI-5000 (ATL Bothell WA) which is similar to the unit that will be part of the Human Research Facility in the US Laboratory Module on the International Space Station Images from this device were recorded and annotated for later analysis The transducer used for this appli- cafion was a broad-band 12-5-MHz linear probe A second portable uItrasound device the Sonosite 180 (Sonosite Inc Bothell WA) which is a 54-lb battery-powered unit equipped with a 5-2-MHz broad- band probe was used

Pnaumotharax Model

Baseline scans of both hemithoraces were per- formed before instnunentation to determine the pres- ence or absence of lung sliding or comet tail artifacts in all three thoracic portals A 16-F Cordis introducer was then inserted in the apex of the right chest through a small stab incision Care was taken to avoid intro- duction of air or lung injury during insertion the h-racic scans were repeated before instillation of air into the chest Aliquots of air were then serially imduced into the chest through the catheter followed by tho- racic ultrasound examinations in the anterior lateral and posterior portals Gradually increasing thoracic in- flation volumes were used starting at 10 cm3 and con- cluding with a total inflation volume of 1000 cm3 of air A chest tube was then inserted and connected to a Heimlich valve and the intratharacic pressure was in- creased by the addition of positive end-expiratory pressure and sigh ventilation The thoracic ultrasound examinations were then repeated before conclusion of

the protocol Each animal was eutbanized and necrop- sies were performed to verify catheter and chest tube placement and examine the lungs for evidence of iat- rogenic injury

The micrograwity phase of the study was done in conjunction wirh the University of Texas Medical Branch (UTMB)in Galveston TX and the NASA Johnson Space Center in Houston TXThe animals were prepared at an offsibe animal facility (UTMB-Galveston) before transport to Ellington Field for the flight Thezero gravity (0 x g) studies were performed onboard NASA KC-135 research aircraft during para- bolic flight profiles Each patabola consisted of two phases lasting approximately 2 minutes 30 to 40 sec-onds of 18 x g followed by approximately 15 to 20 seconds of transition fallowed by 20 to 25 seconds of 0x g flight followed by another transition period The animal life support moniroring equipment and ultra- sound equipment were secured in the aircraft floor before takeoff

Baseline ultraswnd evaluations were completed during level flight (I x g) and during parabolic flight (0 x g) before instrumentation The insufflation cath- eter was then inserted and the air insufflations were done as previously outlined during the initial zero- gravity transition to allow adequate time for air equili- bration and ultrmound evaluation during the period of zero gravity

Lung sliding was readily apparent in all lung fields before instrumentation in all of the animals Image quality was excellent with the HDI 5000 ultrasound machine with comet tail anifacts noted in a number of the animals The Sonosite 180 ultra~ound device pro- duced image quality of lesser resolution however lung sliding was also evident on the smaller built-in screen When the Sonosite 180 was connected to an external 15-inch monitor through its output channel excellent imagc qualiry was not~d

There was no evidence of pneumothorax after in- sertion of the insufflation catheter lung sliding was unchanged in all animals After insufflation of 150 cm3of air into the insufflation catheter an area of delineation of l ~ n g slidingnot sliding was identified in the anterior thoracic portal (Table 1) This finding of partial lung sliding consisted of visualization of lung sliding in a portion of the scanning window witb ad-jacent absence of sliding noted in the same window It is presumed that this occurs when the transducer is placed over an area where the visceral and parietal pleura are separated in the scanning window

~

$nrerfm LBteral Posterior

TABLE Resulrrf7om Thmaric Ultrasound Pc~fomred2 during PareboUc Fiighr on the NASA KC- I35 S4icrograviiy Reseun-h Facll~ly under Micmgmviry (0x g Condrlions

~ ~ 6 ampqumtly ~ a l 0~ frcjlq pmtttig ~

dhamptflUxWbi~~tcRest 01bm7rWii060UrS$poampnampyslyjor 01gii~samp~a affrIamp-c~nig$ieatiJ p u Y j ~ dieO6ampampeamp ~ ~ amp 8 $ ~ h e amp amp n o i a o f P-Q- is mamp on tha basisofh e ampampow CI~~$E~sfmmdefmactenisiephysicalfiadmgsandiamp cOampaaamp

~ ~~ e$t t3i~gtcby$w ~Wcr~~Xonalamp mA I ~ O ~ or modaamptepaewpthm isaampamp geampramply ampt life tEgeampampg adlslyliaampn$ ab u n tmapmul(brqamp- ampcbiroamptary col-lapseFwthrmrn~ahigh inampxofsua$~iond pea+ mpthbmx anamp imbilfty teORamp a raampb$rsph often mampaes dampampfjvamp~ br obixie~ofpaamp~ttcy anen$dnt pIrgamp~ampaampiampc pabilibili

ampvasblefn mamp$ lampampa1193ampsampm gampampf ampgampcant logis6im hhenges

atrasmd has p v e n diapeie aocuraq in nu-n~$application8 inmIvhg ~ampabdomen and en-wmities ISowe~eramp u pfampcgig~~I the h r ~ ~~~

h a hindwa 6eghpc0u6tic imppdWampampampntl~ u l b ~ m dmbean g~lggpstampito be a u e amp ~mamp~ io amp e y d u amp ~of pnampmampoha in paenafamp ulwwd-guidd lmg m vm-WrgtI meampelintensive unit ptamp2nts dmFre sptitamp hippaenfsMiamp g$mtratinampghes wm

lkTist ~epwamp~ amp eof n i ~ o ~ d diagnaamp ~eumoampox o c ~ ~in a ~etefinatyjoWd A pnemdtkmrax in a hem was dkgaosed ampwthozmi~ s e g the m d wsph- of

1~8g a qcaird a c f 4gtrawnie e d w -atirli6f iftfoamh sulggemdtg be paradozicd

~ampXQampS I~S ofampthe ampSe~e~ h amp l s aampahampfmej aspZeQFal $Eampgf marfm blung-campst wan inYerfgce Seamingis petfhrmedbetwee6 sib that are easilyidenfftdas r dens acoustic shadow The Ihngichest wall hiamp or pleural finemoyw a amp+aampamp sfiamptp-tion gy~ghfampampd Gith rqpiraatio~~Ultgsianigaphi~ sips wsOEked wii ~ ~ g g r nhave bed amp-~ D Ma d~GIucJ$thiabsampGeOY n6Wampg~fi~rig ampI amp gQit tail mifact$ wh +tsmptamphigmampl~smpfrom fjpampamptfetfe tampe ampdamplwnijfmampN

The $ampnampi$waf 3amp$amp0tl thl ampgnsi5fpnemampcq~c a$= be)wapampaleyifhthat of

No 3 ULTRASOUND NALUATlON OF PNEUMOMOFW MAGNITUDE Sargsyan et a 233

an Impact Ventilator (Model 754) (Impact Instrumen- tation West Caldwell NJ) with a tidal volume of 600 to 750 cm3 a positive end-expiratory premre of 5 cm HO and a rate of 12 to 16 per minute bIair on the anjmals chest and abdomen was removed with a de- pilatory agent and shaving A Foley catherer was in- serted into the bladder

Baseline ultrasonic scans of both hemithoraces were performed with a high-definition ultrasound machine and a hand-held ponabie ultrasound device Thoracic scaoswere done in a serial fashion in the anterior chest apex the mid-lateral chest and the posterior thoracic region Continuous scanning was done for approxi- mately 10 to 20 seconds in each area When possible the scanning plane was aligned parallel to the long axis of the body to maximize the possible range of motion The presence or absence of lung sliding (to-and-fro motion coincident with respiratian at the visceral- parietal interface) was then determined T h images were digitally recorded for later data analysis

Hardware

Two ultrasound imaging systems were investigated in this study The first device was an HDI-5000 (ATL Bothell WA) which is similar to the unit that will be part of the Human Research Facility in the US Laboratory Module on the International Space Station Images from this device were recorded and annotated for later analysis The transducer used for this appli- cafion was a broad-band 12-5-MHz linear probe A second portable uItrasound device the Sonosite 180 (Sonosite Inc Bothell WA) which is a 54-lb battery-powered unit equipped with a 5-2-MHz broad- band probe was used

Pnaumotharax Model

Baseline scans of both hemithoraces were per- formed before instnunentation to determine the pres- ence or absence of lung sliding or comet tail artifacts in all three thoracic portals A 16-F Cordis introducer was then inserted in the apex of the right chest through a small stab incision Care was taken to avoid intro- duction of air or lung injury during insertion the h-racic scans were repeated before instillation of air into the chest Aliquots of air were then serially imduced into the chest through the catheter followed by tho- racic ultrasound examinations in the anterior lateral and posterior portals Gradually increasing thoracic in- flation volumes were used starting at 10 cm3 and con- cluding with a total inflation volume of 1000 cm3 of air A chest tube was then inserted and connected to a Heimlich valve and the intratharacic pressure was in- creased by the addition of positive end-expiratory pressure and sigh ventilation The thoracic ultrasound examinations were then repeated before conclusion of

the protocol Each animal was eutbanized and necrop- sies were performed to verify catheter and chest tube placement and examine the lungs for evidence of iat- rogenic injury

The micrograwity phase of the study was done in conjunction wirh the University of Texas Medical Branch (UTMB)in Galveston TX and the NASA Johnson Space Center in Houston TXThe animals were prepared at an offsibe animal facility (UTMB-Galveston) before transport to Ellington Field for the flight Thezero gravity (0 x g) studies were performed onboard NASA KC-135 research aircraft during para- bolic flight profiles Each patabola consisted of two phases lasting approximately 2 minutes 30 to 40 sec-onds of 18 x g followed by approximately 15 to 20 seconds of transition fallowed by 20 to 25 seconds of 0x g flight followed by another transition period The animal life support moniroring equipment and ultra- sound equipment were secured in the aircraft floor before takeoff

Baseline ultraswnd evaluations were completed during level flight (I x g) and during parabolic flight (0 x g) before instrumentation The insufflation cath- eter was then inserted and the air insufflations were done as previously outlined during the initial zero- gravity transition to allow adequate time for air equili- bration and ultrmound evaluation during the period of zero gravity

Lung sliding was readily apparent in all lung fields before instrumentation in all of the animals Image quality was excellent with the HDI 5000 ultrasound machine with comet tail anifacts noted in a number of the animals The Sonosite 180 ultra~ound device pro- duced image quality of lesser resolution however lung sliding was also evident on the smaller built-in screen When the Sonosite 180 was connected to an external 15-inch monitor through its output channel excellent imagc qualiry was not~d

There was no evidence of pneumothorax after in- sertion of the insufflation catheter lung sliding was unchanged in all animals After insufflation of 150 cm3of air into the insufflation catheter an area of delineation of l ~ n g slidingnot sliding was identified in the anterior thoracic portal (Table 1) This finding of partial lung sliding consisted of visualization of lung sliding in a portion of the scanning window witb ad-jacent absence of sliding noted in the same window It is presumed that this occurs when the transducer is placed over an area where the visceral and parietal pleura are separated in the scanning window

~

$nrerfm LBteral Posterior

TABLE Resulrrf7om Thmaric Ultrasound Pc~fomred2 during PareboUc Fiighr on the NASA KC- I35 S4icrograviiy Reseun-h Facll~ly under Micmgmviry (0x g Condrlions

~ ~ 6 ampqumtly ~ a l 0~ frcjlq pmtttig ~

dhamptflUxWbi~~tcRest 01bm7rWii060UrS$poampnampyslyjor 01gii~samp~a affrIamp-c~nig$ieatiJ p u Y j ~ dieO6ampampeamp ~ ~ amp 8 $ ~ h e amp amp n o i a o f P-Q- is mamp on tha basisofh e ampampow CI~~$E~sfmmdefmactenisiephysicalfiadmgsandiamp cOampaaamp

~ ~~ e$t t3i~gtcby$w ~Wcr~~Xonalamp mA I ~ O ~ or modaamptepaewpthm isaampamp geampramply ampt life tEgeampampg adlslyliaampn$ ab u n tmapmul(brqamp- ampcbiroamptary col-lapseFwthrmrn~ahigh inampxofsua$~iond pea+ mpthbmx anamp imbilfty teORamp a raampb$rsph often mampaes dampampfjvamp~ br obixie~ofpaamp~ttcy anen$dnt pIrgamp~ampaampiampc pabilibili

ampvasblefn mamp$ lampampa1193ampsampm gampampf ampgampcant logis6im hhenges

atrasmd has p v e n diapeie aocuraq in nu-n~$application8 inmIvhg ~ampabdomen and en-wmities ISowe~eramp u pfampcgig~~I the h r ~ ~~~

h a hindwa 6eghpc0u6tic imppdWampampampntl~ u l b ~ m dmbean g~lggpstampito be a u e amp ~mamp~ io amp e y d u amp ~of pnampmampoha in paenafamp ulwwd-guidd lmg m vm-WrgtI meampelintensive unit ptamp2nts dmFre sptitamp hippaenfsMiamp g$mtratinampghes wm

lkTist ~epwamp~ amp eof n i ~ o ~ d diagnaamp ~eumoampox o c ~ ~in a ~etefinatyjoWd A pnemdtkmrax in a hem was dkgaosed ampwthozmi~ s e g the m d wsph- of

1~8g a qcaird a c f 4gtrawnie e d w -atirli6f iftfoamh sulggemdtg be paradozicd

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1~8g a qcaird a c f 4gtrawnie e d w -atirli6f iftfoamh sulggemdtg be paradozicd

~ampXQampS I~S ofampthe ampSe~e~ h amp l s aampahampfmej aspZeQFal $Eampgf marfm blung-campst wan inYerfgce Seamingis petfhrmedbetwee6 sib that are easilyidenfftdas r dens acoustic shadow The Ihngichest wall hiamp or pleural finemoyw a amp+aampamp sfiamptp-tion gy~ghfampampd Gith rqpiraatio~~Ultgsianigaphi~ sips wsOEked wii ~ ~ g g r nhave bed amp-~ D Ma d~GIucJ$thiabsampGeOY n6Wampg~fi~rig ampI amp gQit tail mifact$ wh +tsmptamphigmampl~smpfrom fjpampamptfetfe tampe ampdamplwnijfmampN

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No 3 ULTRASOUND EVALUATION OF PNEUMOMOW MAGNITUDE Sargsyan ef al 235

chest radiography The presence of lung sliding or comet tail signs reliily excludes pneumothorax h w - ever prior investigators have not been able to correlate ultrasound fmdings with the extent of pneumcthorax Sistrom et al blindly compared taped tharacic ultra- somd examinations of patients with variable-sized pneumothoraces and found limited correlation The di-agnostic sensitivity of ultrasound in this series was less than that of comparable reports suggesting that the accuracy of the examhation is reduced when images are sared for later miew on tape Furthermore the absence of a trained operator at the primaiy investiga- tion to allow repeat scanning or interpretation of subtle fmdings may affect the sensitivity of the examination

In this report partial lung sliding was initially evi- dent at very low insufflation volumes that would cor- relate with a clinically and possibly radiographically silent pneumothorax This finding has been recently reported in two patients who had a small pneumotho- rax detected on CT with a normal chest radiograph Although the complete absence of lung sliding is a reliable indicator of the presence Bfpneumothorax the addition of the partial lung sliding sign may improve the diagnostic sensitivity of the examination in the detection of small pneumothoraces

Thoracic ultrasound appears to be a u$eful test in the microgravity environment with some interesting dif- ferences from terrestrial applications Lung sliding is readily apparent in zero-gravity in normal lungs and is reliably absent in animals with pneumothom Tho- racic ultrasowmi appears to be more sensitive in a zero- gravity environment possibly because of more uniform distribution of the interpleural air in the absence of gfavity Furthermare all areas of the thorax were equally sensitive as the lung assumes a central peri- hilar position during pueumothonx in zero graviry This finding was confirmed in this investigation by visualization of the thoracic cavity by thosacoscopy as a secondary objective of this study (data not shown)

The absence of immediate chest roentgenography complicates the diagnosis of pneumothorax and can significantly impact treatment and outcome This is of particular importance in rural settings in military con- flicts and in aerospace medicjne where radiologic ca- pabilities are absent Injured patients with a possible pneumothorax in remote areas may receive thoracos- tomy tube placement without definitive diagnosis be- fore transport to a treatment center Astronauts aboard the International Space Station are at risk for pneumo-

thorax from hypobaric exposure during space walks and potential blunt injury Power and weight restric- tions prohibit the use of X-ray imaging aboard the Enternational Space Station The use of ultrasound may be of potential benefit for the diagnosis of pneumo- thorax in these settings and others facilitating appro- priate treatment before emergency transfer

Thoracic ultrasound appears to be apromising tech- nique for the exclusiou of pneumothorax in patienis in whom chest radiography is delayed or impossible Fa- miliarity gained by pedrnmance of thoracic ultrasound concomitant with abdominal evaluation in trauma pa- tients has led to the ability to detect an apicl pneu- mothorax with the identification of a partial lung slid- ing sign Theoretically recognition of the partial lung sliding sign may be used to diagnose partial or locu- lated pneurnothoraces that may not be identified by the strict application of complete absence of lung sliding as the only criterion for diagnosis of pneumothorax Verification of the usefilness of thoracic ultrasound requires randomized evaluation in trauma centers that should be explored during routine Focused Abdominal Sonography for Ttauma (FAST) analysis

REFERENCES

I Siavom CL Reiheld CTSpencer BoWallace KK Detec-tion and estimation of the volume of pneumothorax asing real-time ul~w~ographyAIR 19961663 17-21

2 Lichtenstein DA Mezrere Bidennan P Gepner A The comet tall An nluasound s~gnruling out prreurnothorax Intensrve Care Med 199925383-8

3 Dulchavsky SA Hamilton DR Diebel LN Sarsyan AE BiUca RDWiIIiams DR Thotacic ultrasound diagnods of pneo- mothorax Tmuma 19994197C-1

4 Lichtenstein DA Menu Y A bedsrde ulkaound sign mling out pneumothom in the critically ill Chest 19J51081345-8

5 Ramen NW Diagnostic ~Itrasound Biseases ofthe thopx Vet Clin North Am 1986249-66

6 Wmetck K Manski M Peters PE Hansen J Pneumotho-ran 8valuation by ultrmound-preliminary result8 J Thoracic Im-aging 19877768

7 Targhetta R Bouqeuis JM Balmes P Echography of pneu- mothorax Rev Ma1 Respzr 19907575-9 8 Targhenn JA Buougeois JMs Chavitgnem R Balmev PDi

agoosis of pneumothorax by ultrasound immediately after ultsa- sound immediately n h r uTtrawnically guided aspiration biopsy Chest 199~1018554

9 Schwan KWSargsyan AE Itarmlll)n DRDiabel LN Bil-lica RD Dawson DL Willlams DR Knkpatrick AW Dulchaysky SA Uladsonie diagnosis oF apical pneumotborex The pmia1 lung sliding sign I Clin Ulmsund tsubmitted)

DISCUSSION had to be present in the range of 1 to 250 cm7in a fairly DRRSPEPHQYSWTH (Wtchita KS) It would a p smallswine model before the technique was reliable Could

pear from your paper ha relatively large pneumothoraix you then surmise that this W i n laad to missed small pneu-

THE AMERICAN SURGEON M B P C ~2001

motho~t~~es Xnbte clinicalwhen used in the clinical sg setting many atients wfrh mwat ic p u ~ d h o r s x p ~ $ m t with s ~ u ~ e 6 u ~ a i r wid as vyefothe-sfFwteheiQiUi all know uibcutai~ampoiis air usually makes ulaasound ipp ing ef deeper $tmahtmdifficubif not impasible Row will this pmbkm amp+athe utihatian of this rechdiqm in the c h i d setting

Relatively hiampfrasuency bcoadband narlsducers were used in ~ amp l s t u i l ~ This was ppssible because of tfie 8maU animals i n y ~ v e dTfiest [cahsdueepmvi very good ~so1ution but p a r lnetration dbe to tilwsound attenua- tionWill rbeuse of low=-fquency uamducer~such as a 35~hfzhnsdheerrhatis uwampy used infhe evaluation of sn adult muma patiat kessea rhe acmrrwy of thb tech-nique~

mwolyat i~tmit~ e c e i v i d p j l h a s e ~ ~ v ee x w m e wi$hthe F i s ~ e a a min the m m a setting Can you corn-p m thedifficultyaf theFASTam witb this e m Is tbis more difficultndoampampe FAST Is there a leamingcunre that you went through beforeyou could pick up thissjiditg IWg Sign and paaid sfiding gnP

Igess a biiq question as far askASA is concmeded fsCrn~youaactuanyWamptronamwirb~dted experience M)do asttlampy

I tbinkbrraethas haveoffered us yetanether merhpd fw making a diagnosi6 oTpneiun~thm aod 1dd think mi6 wiU liav dlidicd irhplicamp not only ampI QUI rauma cen- EBrs but inQaee aS wen

Bassd d $our tnidal exprience Hiamp the wchniqae would you momamp ebat thisbeooms a gtandani wm-ponentef fie FAST examAndfinallydoyou think ws Vlll eyer becorn $rBcierit enough tg elimiaw Muti Chest X-ray frbn the e ~ ~ amp gof o pumapa$ampeuroampDK w m A m C amp mmfujiqUe

can -damptely ose small pnemofhwaees I Kinkit wilndss some7md war are allstfl$Lemirg about it

We have picked ups m d pn+umamp~raamps that werenf seen onchest X-ray but wendiscqyW l a k r ~ na Q scad obtain fpr same oerrewli One bf those me dm~ ~

achdty be down]m4eid fromthe Web We ha posamp it there i t wwwvghtraUmampsWhcOm re 3 queginampat subcutaneous emphysema will

prevent g ~ t t i n g h g w d f anychi~gdeper No testwwks i~ aU sityadons This is suppmted by the Smuybmok experk CRW with undet-k PASTem whish also repadd

soiographyis notuseful when there is subcwtanwus emphyiema almough thiq was uncommon

In ternbfpe msducei freqbegcy you samp fongges wiamp the transcfucer xiis uu question tbough that die 75-MFtz aansdueer givm ti bener image and it is easier w5 the hear transduoer to g6t it between fhe ribs S o if you have the ogpostunirJl to use the higher-fruenCy ansdurthXis nZnZlel)What W e would-ommend

ltte 1earningourve for diaptxiag a ccrmplete pmmo- ampats smep Far small pneumoibo~acesi ibinlc that the jury i s out and I ampfinkwe redly n d to do the clnical itudlies h~bnman patients befori ciiakgbg the s~tanclar PAST exWatiiori utmFbe hiq ye or to Nee W~ corn back ahd sayi yes Ktamp~ h o u qbe part of FAfl extun and weshoutif Bave bth the 35- and75-amp2 urn-ducers available Trainingasamponmto do this Ss qdre feasible with rt-

mote Ciampbn Tbat i s where you might discuS3 telepedi-cille x felesanqpphy Tamp m y te fible Mma lo earths orbit For gilytbing W e r ywmay g~ im imr-dinate t h e delays

FlatlyaI dodt think if will replaw chest X-ray ft is a camplembntary teohniqw I think its value is in its porn-bility Howamper p u ampetso Bvch in additional m a - tiai a cfjeqtXampyDRG w V ~~frty~ooodiLjDoes

NASApwsctaen its ~ ~ u ~ f o rpslmnary Mebs or hy- prinflafed lungs RR JMRampPATWCE No ndt at present alrhouampht

pneuorto58ceS a risk^ up mere beoaUS3 Of sojm of the h~perbaricobrk~eswith decbmpmBSion ptOC

mp4kBd for space walks

THE AMERICAN SURGEON M B P C ~2001

motho~t~~es Xnbte clinicalwhen used in the clinical sg setting many atients wfrh mwat ic p u ~ d h o r s x p ~ $ m t with s ~ u ~ e 6 u ~ a i r wid as vyefothe-sfFwteheiQiUi all know uibcutai~ampoiis air usually makes ulaasound ipp ing ef deeper $tmahtmdifficubif not impasible Row will this pmbkm amp+athe utihatian of this rechdiqm in the c h i d setting

Relatively hiampfrasuency bcoadband narlsducers were used in ~ amp l s t u i l ~ This was ppssible because of tfie 8maU animals i n y ~ v e dTfiest [cahsdueepmvi very good ~so1ution but p a r lnetration dbe to tilwsound attenua- tionWill rbeuse of low=-fquency uamducer~such as a 35~hfzhnsdheerrhatis uwampy used infhe evaluation of sn adult muma patiat kessea rhe acmrrwy of thb tech-nique~

mwolyat i~tmit~ e c e i v i d p j l h a s e ~ ~ v ee x w m e wi$hthe F i s ~ e a a min the m m a setting Can you corn-p m thedifficultyaf theFASTam witb this e m Is tbis more difficultndoampampe FAST Is there a leamingcunre that you went through beforeyou could pick up thissjiditg IWg Sign and paaid sfiding gnP

Igess a biiq question as far askASA is concmeded fsCrn~youaactuanyWamptronamwirb~dted experience M)do asttlampy

I tbinkbrraethas haveoffered us yetanether merhpd fw making a diagnosi6 oTpneiun~thm aod 1dd think mi6 wiU liav dlidicd irhplicamp not only ampI QUI rauma cen- EBrs but inQaee aS wen

Bassd d $our tnidal exprience Hiamp the wchniqae would you momamp ebat thisbeooms a gtandani wm-ponentef fie FAST examAndfinallydoyou think ws Vlll eyer becorn $rBcierit enough tg elimiaw Muti Chest X-ray frbn the e ~ ~ amp gof o pumapa$ampeuroampDK w m A m C amp mmfujiqUe

can -damptely ose small pnemofhwaees I Kinkit wilndss some7md war are allstfl$Lemirg about it

We have picked ups m d pn+umamp~raamps that werenf seen onchest X-ray but wendiscqyW l a k r ~ na Q scad obtain fpr same oerrewli One bf those me dm~ ~

achdty be down]m4eid fromthe Web We ha posamp it there i t wwwvghtraUmampsWhcOm re 3 queginampat subcutaneous emphysema will

prevent g ~ t t i n g h g w d f anychi~gdeper No testwwks i~ aU sityadons This is suppmted by the Smuybmok experk CRW with undet-k PASTem whish also repadd

soiographyis notuseful when there is subcwtanwus emphyiema almough thiq was uncommon

In ternbfpe msducei freqbegcy you samp fongges wiamp the transcfucer xiis uu question tbough that die 75-MFtz aansdueer givm ti bener image and it is easier w5 the hear transduoer to g6t it between fhe ribs S o if you have the ogpostunirJl to use the higher-fruenCy ansdurthXis nZnZlel)What W e would-ommend

ltte 1earningourve for diaptxiag a ccrmplete pmmo- ampats smep Far small pneumoibo~acesi ibinlc that the jury i s out and I ampfinkwe redly n d to do the clnical itudlies h~bnman patients befori ciiakgbg the s~tanclar PAST exWatiiori utmFbe hiq ye or to Nee W~ corn back ahd sayi yes Ktamp~ h o u qbe part of FAfl extun and weshoutif Bave bth the 35- and75-amp2 urn-ducers available Trainingasamponmto do this Ss qdre feasible with rt-

mote Ciampbn Tbat i s where you might discuS3 telepedi-cille x felesanqpphy Tamp m y te fible Mma lo earths orbit For gilytbing W e r ywmay g~ im imr-dinate t h e delays

FlatlyaI dodt think if will replaw chest X-ray ft is a camplembntary teohniqw I think its value is in its porn-bility Howamper p u ampetso Bvch in additional m a - tiai a cfjeqtXampyDRG w V ~~frty~ooodiLjDoes

NASApwsctaen its ~ ~ u ~ f o rpslmnary Mebs or hy- prinflafed lungs RR JMRampPATWCE No ndt at present alrhouampht

pneuorto58ceS a risk^ up mere beoaUS3 Of sojm of the h~perbaricobrk~eswith decbmpmBSion ptOC

mp4kBd for space walks