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Minimal PEEP May Be “Best PEEP”
REFERENCES
2 3 4
5
Poe RH, Israel RH, Martin MG, et al. Utility of fiberoptic bronchoscopy in patients with hemoptysis and nonlocalizing chest roentgenogram. Chest 1988; 92:70-75 Vidal R, Ruiz J. dAumenta la tuberculosis en Espana? Med Clin (Barc) 1986; 86:845-47 \Vorld Health Organization. ~1agnitude of tuberculosis problem in the world. WHO Wkly Epidem Rec 1981; 50:17-20,33-36,4951,68-76 and 391-96 Grybowski S, Enarson D. Tuberculosis. In: Simmons DH, ed. Current pneumology, vol 7. Chicago: Year Book, 1987; 73-96 de Gracia J, Curull ~ Vidal R, et al. Diagnostic value of bronchoalveolar lavage in suspected pulmonary tuberculosis. Chest 1988; 329-32
To the Editor: The comments of deGracia and colleagues are appreciated. As cited in their correspondence, the experience with diagnosis of tuberculosis by bronchoscopy may be different in other countries in contrast to that of the US. Our experience with fiberoptic bronchoscopy in patients with hemoptysis and a nonlocalizing chest roentgenogram reflects the experience in Rochester, New York; fe\\' cases of tuberculosis were discovered. I In countries \\'here the prevalence of tuberculosis is greater, more cases would be found. We point out, however, that weight loss, cough, anenlia and persistent \\'heezing are additional indications for the procedure. These clinical features are not unusual in tuberculous disease and might have identified the two patients referred to by deGracia et al who did not nleet our other criteria. Robert H. Poe, ,\I.D., F.C.C.R, Associate Professor of Aledicine, Director, Pulrnonary Unit, Highland Hospital, Unit:ersity of Rochester School of Medicine and Dentistry, Rochester, NY
REFERENCE Poe RH, Israel RH, Marin ~fG, et al. Utility of fiberoptic bronchoscopy in patients \\'ith hemoptysis and a nonlocalizing chest roentgenogram. Chest 1988; 93:70-75
due to the selection of heterogenous patient groups, dangerous end points to give therapy (confirmed by the high incidence of complications), and inadequate hemodynamic monitoring and therapeutic interventions. Severe hypotension in 55 percent of the recruitive PEEP group indicates that ~ither this group was extremely sick or the therapy was harmful. In addition, some ofthe authors' statements deserve comments. 1) "PEEP hastens pulmonary recovery." This has not bee!1 proven. Pulmonary hypoxemia is secondary to infection, biochemical mediators, etc. PEEP-a mechanical device-is unlikely to reverse biochemical changes. Adequate level of PEEP should be used to lower FIo2 to a nontoxic range, while maintaining adequate oxygenation. 2) "Patients \~,ojth hypoxemia, due to atelectasis or unilateral lung This is erroneous. disease, must be treated with very high PEE~" Atelectasis may resolve faster with chest physiotherapy, postural drainage and bronchoscopy. Hyperexpansion of normal lung and increased pulmonary barotrauma is likely to occur in unilateral lung disease if high PEEP is used. If hypoxemia persists, high frequency ventilation or jet ventilation may be a preferred technique. 3) "Highest Pa02 is the best indicator of titrating PEE~' Suter et al 2 showed that the highest Pa02 is a poor, unreliable indicator for adjusting "best PEEP". Continual improvement in Pa0 2 and a decrease in intrapulmonary shunt will occur \\ith increasing PEEP beyond "best PEEP" at the cost of reduced cardiac output and O 2 deliver~ Various studies 3 have demonstrated that oxygen consunlption depends on 002 in the critically ill patient. Hence, the latter is more important than achieving very high Pa0 2 • 4) "Increased mortality in the recruitive PEEP group \\'as due to PEE~' This conclusion reminds us of a famous quote: "S·tatistics should be used as. the drunken man uses the lamp post, for the support, rather than illumination." The authors' data sho\\'s that inhospital mortality in both groups was statistically insignificant (19 vs 15). How can they blame recruitive PEEP for these deaths when autopsy revealed persistent sepsis? We agree with Civetta4 that this poorly-conducted study will be misinterpreted and that, until a well designed study proves that PEEP used \\isely is harmful or not beneficial in hypoxemic patients "ith ARDS, we \\ill continue to use it in order to bring Flo2 to a nontoxic level, while keeping in mind that normalization of oxygen delivery and tissue oxygen utilization are the important end points. Harakh \: Dedhia. M.D .. F.C.C.P.; Franklin Schiebel, M.D., and Luis Teba, AI.D., West Virginia University Health Sciences Center, Alorgantown
Erratum To the Editor:
On behalf of my coauthors I would like to point out two errors made in the Chest editorial office in our article "Significance of TWave Pseudonormalization during Exercise" (Chest 1988; 94:512) [September]. \Ve wish to point out that the upper and lower portions of Figure 1 (page 513) should be transposed and that reprint requests should be addressed to Dr. Oh at the Mayo Clinic, Rochester, Minnesota 55905. Carl J lAvie. AI.D., Rochester. Alinnesota
Minimal PEEP May Be "Best PEEP"
REFERENCES Carroll GC, Tuman KJ, Braverman B, et al. Minimal positive end-expiratory pressure (PEEP) may be "best PEEP". Chest 1988; 93:1020-25
2 Sutter PM, Fairley HB, Isenberg ~fD. Optimum end-expiratory airn'ay pressure in patients with acute pulmonary failure. N Engl J Med 1975; 292:284-89 3 Shapiro BA, Cane RD, Harrison RA. Positive end-expiratory pressure therapy in adults with special reference to acute lung injury: a review of the literature and suggested clinical correlations. Crit Care ~fed 1984; 12:127-41 4 Civetta JM. After quibbles and contrasts, concepts and caveats. Chest 1988; 93:897-98
To the Editor:
To the Editor:
We are dismayed by the article of Carroll et aI (Minimal Positive End-expiratory Pressure (PEEP) May Be "Best PEEP"', Chest 1988; 93: 1020-25). The authors are to be commended for their good intentions and hypothesis; however, they have failed in methodo~ogy
We are pleased that our paper stimulated Drs. Dedhia, Schiebel and Teba to comment on our study. However, we do take issue with their reading of our paper. First, they object to our alleged statement that "PEEP hastens
252
Communications to the Editor
2 3 4
5
Poe RH, Israel RH, Martin MG, et al. Utility of fiberoptic bronchoscopy in patients with hemoptysis and nonlocalizing chest roentgenogram. Chest 1988; 92:70-75 Vidal R, Ruiz J. dAumenta la tuberculosis en Espana? Med Clin (Barc) 1986; 86:845-47 \Vorld Health Organization. ~1agnitude of tuberculosis problem in the world. WHO Wkly Epidem Rec 1981; 50:17-20,33-36,4951,68-76 and 391-96 Grybowski S, Enarson D. Tuberculosis. In: Simmons DH, ed. Current pneumology, vol 7. Chicago: Year Book, 1987; 73-96 de Gracia J, Curull ~ Vidal R, et al. Diagnostic value of bronchoalveolar lavage in suspected pulmonary tuberculosis. Chest 1988; 329-32
To the Editor: The comments of deGracia and colleagues are appreciated. As cited in their correspondence, the experience with diagnosis of tuberculosis by bronchoscopy may be different in other countries in contrast to that of the US. Our experience with fiberoptic bronchoscopy in patients with hemoptysis and a nonlocalizing chest roentgenogram reflects the experience in Rochester, New York; fe\\' cases of tuberculosis were discovered. I In countries \\'here the prevalence of tuberculosis is greater, more cases would be found. We point out, however, that weight loss, cough, anenlia and persistent \\'heezing are additional indications for the procedure. These clinical features are not unusual in tuberculous disease and might have identified the two patients referred to by deGracia et al who did not nleet our other criteria. Robert H. Poe, ,\I.D., F.C.C.R, Associate Professor of Aledicine, Director, Pulrnonary Unit, Highland Hospital, Unit:ersity of Rochester School of Medicine and Dentistry, Rochester, NY
REFERENCE Poe RH, Israel RH, Marin ~fG, et al. Utility of fiberoptic bronchoscopy in patients \\'ith hemoptysis and a nonlocalizing chest roentgenogram. Chest 1988; 93:70-75
due to the selection of heterogenous patient groups, dangerous end points to give therapy (confirmed by the high incidence of complications), and inadequate hemodynamic monitoring and therapeutic interventions. Severe hypotension in 55 percent of the recruitive PEEP group indicates that ~ither this group was extremely sick or the therapy was harmful. In addition, some ofthe authors' statements deserve comments. 1) "PEEP hastens pulmonary recovery." This has not bee!1 proven. Pulmonary hypoxemia is secondary to infection, biochemical mediators, etc. PEEP-a mechanical device-is unlikely to reverse biochemical changes. Adequate level of PEEP should be used to lower FIo2 to a nontoxic range, while maintaining adequate oxygenation. 2) "Patients \~,ojth hypoxemia, due to atelectasis or unilateral lung This is erroneous. disease, must be treated with very high PEE~" Atelectasis may resolve faster with chest physiotherapy, postural drainage and bronchoscopy. Hyperexpansion of normal lung and increased pulmonary barotrauma is likely to occur in unilateral lung disease if high PEEP is used. If hypoxemia persists, high frequency ventilation or jet ventilation may be a preferred technique. 3) "Highest Pa02 is the best indicator of titrating PEE~' Suter et al 2 showed that the highest Pa02 is a poor, unreliable indicator for adjusting "best PEEP". Continual improvement in Pa0 2 and a decrease in intrapulmonary shunt will occur \\ith increasing PEEP beyond "best PEEP" at the cost of reduced cardiac output and O 2 deliver~ Various studies 3 have demonstrated that oxygen consunlption depends on 002 in the critically ill patient. Hence, the latter is more important than achieving very high Pa0 2 • 4) "Increased mortality in the recruitive PEEP group \\'as due to PEE~' This conclusion reminds us of a famous quote: "S·tatistics should be used as. the drunken man uses the lamp post, for the support, rather than illumination." The authors' data sho\\'s that inhospital mortality in both groups was statistically insignificant (19 vs 15). How can they blame recruitive PEEP for these deaths when autopsy revealed persistent sepsis? We agree with Civetta4 that this poorly-conducted study will be misinterpreted and that, until a well designed study proves that PEEP used \\isely is harmful or not beneficial in hypoxemic patients "ith ARDS, we \\ill continue to use it in order to bring Flo2 to a nontoxic level, while keeping in mind that normalization of oxygen delivery and tissue oxygen utilization are the important end points. Harakh \: Dedhia. M.D .. F.C.C.P.; Franklin Schiebel, M.D., and Luis Teba, AI.D., West Virginia University Health Sciences Center, Alorgantown
Erratum To the Editor:
On behalf of my coauthors I would like to point out two errors made in the Chest editorial office in our article "Significance of TWave Pseudonormalization during Exercise" (Chest 1988; 94:512) [September]. \Ve wish to point out that the upper and lower portions of Figure 1 (page 513) should be transposed and that reprint requests should be addressed to Dr. Oh at the Mayo Clinic, Rochester, Minnesota 55905. Carl J lAvie. AI.D., Rochester. Alinnesota
Minimal PEEP May Be "Best PEEP"
REFERENCES Carroll GC, Tuman KJ, Braverman B, et al. Minimal positive end-expiratory pressure (PEEP) may be "best PEEP". Chest 1988; 93:1020-25
2 Sutter PM, Fairley HB, Isenberg ~fD. Optimum end-expiratory airn'ay pressure in patients with acute pulmonary failure. N Engl J Med 1975; 292:284-89 3 Shapiro BA, Cane RD, Harrison RA. Positive end-expiratory pressure therapy in adults with special reference to acute lung injury: a review of the literature and suggested clinical correlations. Crit Care ~fed 1984; 12:127-41 4 Civetta JM. After quibbles and contrasts, concepts and caveats. Chest 1988; 93:897-98
To the Editor:
To the Editor:
We are dismayed by the article of Carroll et aI (Minimal Positive End-expiratory Pressure (PEEP) May Be "Best PEEP"', Chest 1988; 93: 1020-25). The authors are to be commended for their good intentions and hypothesis; however, they have failed in methodo~ogy
We are pleased that our paper stimulated Drs. Dedhia, Schiebel and Teba to comment on our study. However, we do take issue with their reading of our paper. First, they object to our alleged statement that "PEEP hastens
252
Communications to the Editor