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Inhalation injury with burns: A lethal combination
Thedoumaiofbnergency
Medcine.
Vol 6, pp 471-473.
1988
Printed in the USA
l
Copyright
L 1988 Pergamon
Press plc
INHALATION INJURY WITH BURNS: A LETHAL COMBINATION David L. Blinn,
MD,*
Harvey Slater,
MD,?
and I. William Goldfarb,
MD*
*Resident in General Surgery, The Western PennsylvanIa Hospital, Pittsburgh, PA: *Director, Burn/Trauma Center, :he Western Pennsylvania Hospital, Pittsburgh, PA; *Associate Director, Burn/Trauma Center, The Western Pennsylvania Hosuttal Reprint address: Harvey Slater, MD, 4815 Liberty Avenue, Suite #340. Pittsburgh. PA 15224
u! Abstract-Inhalation injury is known to add significant morbidity and mortality to patients with burns. Estimating the severity of inhalation injury is difficult, as signs of respiratory failure may occur hours or even days after the injury. We have reviewed 86 consecutive patients who were admitted to our Burn/Trauma Center with burns and evidence suggestive of smoke inhalation. Of these patients, 88% required endotracheal intubation. There was a 62% mortality. Admission chest x-rays studies, PAO,, and auscultation of the patient’s lungs were normal in 90% of the study group. These factors could not be used to predict respiratory failure or death. Patients with as little as 15% total body surface burns with mild smoke inhalation are at significant risk of respiratory failure and the need for ventilatory support.
that correlate with the need for respiratory support are an aid to the initial treating physician in making appropriate arrangements for patient treatment and monitoring or in making appropriate arrangements for patient referral.
MATERIALS
The records of all patients admitted to the Burn/Trauma Center from June of 1984 through June of 1986 were reviewed-a total of 400 charts. Patients who were not burned in a closed space, who had no evidence of smoke inhalation or respiratory distress, and who had a clinical course free of respiratory complications were not considered for this study. Eighty six patients who were felt to have suffered smoke inhalation on the basis of admission clinical findings or subsequent hospital course were identified, and these charts were carefully reviewed (Table 1). All patients were treated by the Director and Associate Director of the Burn/Trauma Center, and all patients were evaluated by one or both of these physicians at the time of admission. Bronchoscopic findings at the time of admission were recorded as mild, moderate, or severe and were performed by the Director or Associate Director of the Burn/Trauma Center. Mild bronchoscopic findings included patients with minimal erythema and edema. Moderate bronchoscopic findings included erythema and edema with occasional particles of soot. Severe bronchoscopic findings were denoted by marked coating of the tra-
c1 Keywords-blood gases; bronchoscopy; burns; inhalation mortality INTRODUCTION
Inhalation of smoke adds significant morbidity and mortality to patients with burns.‘-6 Shirani et al. found that the presence of smoke inhalation adds 20% to the risk of death to a typical burn patient.1-2 Of patients admitted to burn centers, 20% to 35% have a component of smoke inhalation, and most patients who die of burns have concomitant smoke inhalation.i-3 The physician in the emergency department or at the scene of a fire must decide upon local hospital admission or burn center referral. This decision will often be based solely upon clinical evaluation with minimal or no laboratory studies. Clinical parameters
___
AND METHODS
Original Contributions presents articles of interest to both academic and practicing JEM is coordinated by John A. Marx, MD, of Denver General Hospital.
RECEIVED: 3 August 1987; SECOND SUBMISSION RECEIVED: ACCEPTED: 4 December 1987 471
4 December 1987
physicians.
This section of
0736-4679188 t+%O + .OO
David L. Blinn, Harvey Slater, I. William Goldfarb
472
Table 2. Indications for Endotracheal (76 patients)
Table 1. General Data Number of Patients in study Survived Died Mean age and range Mean burn surface area and range Males Females Survivors: Mean age and range Mean burn surface area and range Percent intubated Nonsurvivors: Mean age and range Mean burn surface area and range Percent intubated
86 33 53 45 years (2-94) ;4.5o/a (O-100) 22 35.5 years (2-83) 20% (O-90) 76.0% 50.3 years (4-94) 62.6% (8-l 00) 96.0%
chea and mainstem bronchi with soot particles, as well as edema and ulceration. Facial burns were characterized as mild, moderate, and severe. A mild facial burn included patients with superficial second degree burns of the face without evidence of soot in the oropharynx and without singed nasal hair. Patients with moderate facial burns had deeper partial thickness burns to the face and singed nasal hair with minimal lip edema. Patients with severe facial burns were those with deep partial thickness injuries, facial and lip edema, singed nasal hair, and soot in the oropharynx and sputum. Chest x-ray studies upon admission were performed on 78 of the 86 patients (89%). The films were interpreted as being normal in 72 of the 78 cases by a Department of Radiology staff member. These radiographs were reviewed a second time by a hospital staff radiologist and one of the authors to determine retrospectively if there was, in fact, some indication of change due to smoke inhalation. Six patients had abnormal chest x-ray studies. The abnormal findings in these six patients were chronic changes that existed prior to the burn injury. The mean age of the patients with abnormal admission chest films was 72 years (Table 2). Fiberoptic bronchoscopy was performed on 69 of the 86 patients (80%) at the time of admission by the Director of Associate Director of the Burn/Trauma Center. Bronchoscopy was performed when it was felt that it would aid in the management of the patient. Some patients who had obvious severe facial burns and were already intubated at the time of admission were not bronchoscoped. Also, patients with minimal facial burns and minimal (< 15 %) total body surface burns were not bronchoscoped. Minimal bronchoscopic findings were noted in 45.5% of the survivors and in 1% of the nonsurvivors. Moderate bronchostopic findings were noted in 50% of the survivors and in 69% of the nonsurvivors. Severe bronchoscopic
Number of patients
Indication “Prophylactic” PAOa<60 PACOa150 Respiratory Supraglottic
lntubation
prior to transport mmHg mmHg rate >40 per minute obstruction
29 33 7 5 2
findings were present in 4.5% of the survivors and in 30% of the nonsurvivors. Chest auscultation was normal in 79 of the 86 patients (91%). Normal auscultation on admission was noted in 93% of the survivors and in 89% of the nonsurvivors. Moderate to severe facial burns were noted in 60 of the 86 patients (69.7%). Fifteen of the 33 survivors (45.4%) and 45 of the 53 nonsurvivors (85 %) had moderate to severe facial burns. Patients with as little as 15% total body surface area burns and mild inhalation injury required prolonged ventilatory support despite a normal chest xray study, normal auscultation, and normal PAO, at the time of admission. A review of patients with only cutaneous burns and no evidence of smoke inhalation who were admitted during the same time period revealed that early endotracheal intubation was not required for any patient with less than 35 % total body surface burn.
DISCUSSION The vast majority of the chest x-ray studies taken on admission were normal. This finding was in contrast to data published by Teisidor et al. in 1983.’ This study as well as others suggest that a classic perivascular fuzziness and peribronchial cuffing can be seen on admission chest x-ray studies of patients with severe inhalation injury.‘-6,* None of the patients in this study group had these findings (Table 2). Measurement of PAO, at the time of admission was not helpful in predicting final outcome or ultimate need for ventilatory support. The range and mean PAO, for survivors and for nonsurvivors was not statistically different. Firm conclusions cannot be drawn from this data as the administration of oxygen was not standardized prior to measurement of PAO, (Table 3). Sixty of the 86 patients (69.7%) had either moderate or severe facial burns. Fifteen of the 33 survivors (45.4%) had moderate to severe facial burns, and 45 of the 53 nonsurvivors (85%) had moderate to severe
Inhalation
Injury
Table 3. Parameters Outcome
473 Found not to Correlate
with Final
I. Chest x-ray studies on admission: 89% of all patients had chest x-ray studies on admission 92% of these were normal Il. Arterial PAO, on admission: mean PA02 for all was 155 mmHg mean PAO, of survivors was 147.5 mmHg mean PAO, of nonsurvivors was 159 mmHg Ill. Chest auscultation on admission: 91 Vo of all patients had clear lungs on admission 93% of survivors had clear lungs on admission 88.8% of nonsurvivors had clear lungs on admission
facial burns. Moderate to severe facial burns in our series were predictors of respiratory failure and death when combined with smoke inhalation and burns of other body areas. The severity of the bronchoscopic findings correlated well with the final outcome. Only one percent of the nonsurvivors had minimal bronchoscopic findings on admission. Further, only 4.5% of the survivors who underwent bronchoscopy were able to survive severe findings. Bronchoscopy remains an important tool for gauging the severity of inhalation injury. I-h.K Because 91% of all patients studied had clear lungs to auscultation on admission, we view chest auscultation as having little value in predicting final outcome or respiratory failure. This is in contrast to studies published in the literature.‘-4 It is difficult to draw firm conclusions about this group of patients based upon statistical significance. Many of the patients arrived at the burn center with endotracheal tubes in place. The indications for endotracheal intubation varied among the emergency physicians and the air ambulance physicians. Many patients underwent endotracheal intubation prior to
helicopter transfer for fear of respiratory compromise during flight, which could make endotracheal intubation difficult or even impossible. Most patients received oxygen during transport, although the exact flow rate could not be determined. Minimal smoke inhalation may markedly alter the course and outcome for many burn patients. The recognition of potential respiratory failure should be made early and appropriate supportive measures should be taken. The diagnosis of significant smoke inhalation with respiratory compromise should not await an abnormal chest x-ray study, abnormal physical findings, or abnormal arterial blood gases. When such patients are recognized, appropriate referral or plans for ventilatory support should be made. The patient should be placed in an upright position to maximize vital capacity. Humidified oxygen should be administered and pulmonary toilet procedures initiated. With early recognition and intervention, optimum results for this group of high risk patients may be obtained.
CONCLUSION In conclusion, the traditional means of diagnosing smoke inhalation injury are not valuable predictors of final outcome.l-63* Admission chest x-ray study, arterial PAO,, and chest auscultation are commonly used parameters in measuring the severity of the injury. These do not correlate with final outcome or with onset of respiratory failure. In this group of patients the only factors on admission that correlate with final outcome are age, total burn surface area, the severity of bronchoscopic findings, and the degree of facial burn.
REFERENCES 1. Peters TW: Inhalation injury caused by the products of combustion. &X4,4 1981; 125:249-252. 2. Peitzman B: Measurement of lung water in inhalation injury. Surgery 1981; 90:305-310. 3. Cahalane M: Early respiratory abnormalities from smoke inhalation. JAMA 1984; 251:771-773. 4. Nishimma N: Respiratory changes after major burn injury. CCM 1982; 10:25-28. 5. Shirani KZ, Pruitt BA Jr, Mason AD Jr: The influence of inha-
lation injury and pneumonia on burn mortality. ,Inn Surg 1987; 205:82-87.
6. Head JM: Inhalation injury in burns. Am JSurg
1980; 139:508-
512.
7. Teixidor HS: Smoke inhalation: radiologic manifestations. Rudial 1984; 149:383-387. 8. Guzzardi LJ: Inhalation of products of combustion. Ann Emerg Med 1983; 64~63-67.
Medcine.
Vol 6, pp 471-473.
1988
Printed in the USA
l
Copyright
L 1988 Pergamon
Press plc
INHALATION INJURY WITH BURNS: A LETHAL COMBINATION David L. Blinn,
MD,*
Harvey Slater,
MD,?
and I. William Goldfarb,
MD*
*Resident in General Surgery, The Western PennsylvanIa Hospital, Pittsburgh, PA: *Director, Burn/Trauma Center, :he Western Pennsylvania Hospital, Pittsburgh, PA; *Associate Director, Burn/Trauma Center, The Western Pennsylvania Hosuttal Reprint address: Harvey Slater, MD, 4815 Liberty Avenue, Suite #340. Pittsburgh. PA 15224
u! Abstract-Inhalation injury is known to add significant morbidity and mortality to patients with burns. Estimating the severity of inhalation injury is difficult, as signs of respiratory failure may occur hours or even days after the injury. We have reviewed 86 consecutive patients who were admitted to our Burn/Trauma Center with burns and evidence suggestive of smoke inhalation. Of these patients, 88% required endotracheal intubation. There was a 62% mortality. Admission chest x-rays studies, PAO,, and auscultation of the patient’s lungs were normal in 90% of the study group. These factors could not be used to predict respiratory failure or death. Patients with as little as 15% total body surface burns with mild smoke inhalation are at significant risk of respiratory failure and the need for ventilatory support.
that correlate with the need for respiratory support are an aid to the initial treating physician in making appropriate arrangements for patient treatment and monitoring or in making appropriate arrangements for patient referral.
MATERIALS
The records of all patients admitted to the Burn/Trauma Center from June of 1984 through June of 1986 were reviewed-a total of 400 charts. Patients who were not burned in a closed space, who had no evidence of smoke inhalation or respiratory distress, and who had a clinical course free of respiratory complications were not considered for this study. Eighty six patients who were felt to have suffered smoke inhalation on the basis of admission clinical findings or subsequent hospital course were identified, and these charts were carefully reviewed (Table 1). All patients were treated by the Director and Associate Director of the Burn/Trauma Center, and all patients were evaluated by one or both of these physicians at the time of admission. Bronchoscopic findings at the time of admission were recorded as mild, moderate, or severe and were performed by the Director or Associate Director of the Burn/Trauma Center. Mild bronchoscopic findings included patients with minimal erythema and edema. Moderate bronchoscopic findings included erythema and edema with occasional particles of soot. Severe bronchoscopic findings were denoted by marked coating of the tra-
c1 Keywords-blood gases; bronchoscopy; burns; inhalation mortality INTRODUCTION
Inhalation of smoke adds significant morbidity and mortality to patients with burns.‘-6 Shirani et al. found that the presence of smoke inhalation adds 20% to the risk of death to a typical burn patient.1-2 Of patients admitted to burn centers, 20% to 35% have a component of smoke inhalation, and most patients who die of burns have concomitant smoke inhalation.i-3 The physician in the emergency department or at the scene of a fire must decide upon local hospital admission or burn center referral. This decision will often be based solely upon clinical evaluation with minimal or no laboratory studies. Clinical parameters
___
AND METHODS
Original Contributions presents articles of interest to both academic and practicing JEM is coordinated by John A. Marx, MD, of Denver General Hospital.
RECEIVED: 3 August 1987; SECOND SUBMISSION RECEIVED: ACCEPTED: 4 December 1987 471
4 December 1987
physicians.
This section of
0736-4679188 t+%O + .OO
David L. Blinn, Harvey Slater, I. William Goldfarb
472
Table 2. Indications for Endotracheal (76 patients)
Table 1. General Data Number of Patients in study Survived Died Mean age and range Mean burn surface area and range Males Females Survivors: Mean age and range Mean burn surface area and range Percent intubated Nonsurvivors: Mean age and range Mean burn surface area and range Percent intubated
86 33 53 45 years (2-94) ;4.5o/a (O-100) 22 35.5 years (2-83) 20% (O-90) 76.0% 50.3 years (4-94) 62.6% (8-l 00) 96.0%
chea and mainstem bronchi with soot particles, as well as edema and ulceration. Facial burns were characterized as mild, moderate, and severe. A mild facial burn included patients with superficial second degree burns of the face without evidence of soot in the oropharynx and without singed nasal hair. Patients with moderate facial burns had deeper partial thickness burns to the face and singed nasal hair with minimal lip edema. Patients with severe facial burns were those with deep partial thickness injuries, facial and lip edema, singed nasal hair, and soot in the oropharynx and sputum. Chest x-ray studies upon admission were performed on 78 of the 86 patients (89%). The films were interpreted as being normal in 72 of the 78 cases by a Department of Radiology staff member. These radiographs were reviewed a second time by a hospital staff radiologist and one of the authors to determine retrospectively if there was, in fact, some indication of change due to smoke inhalation. Six patients had abnormal chest x-ray studies. The abnormal findings in these six patients were chronic changes that existed prior to the burn injury. The mean age of the patients with abnormal admission chest films was 72 years (Table 2). Fiberoptic bronchoscopy was performed on 69 of the 86 patients (80%) at the time of admission by the Director of Associate Director of the Burn/Trauma Center. Bronchoscopy was performed when it was felt that it would aid in the management of the patient. Some patients who had obvious severe facial burns and were already intubated at the time of admission were not bronchoscoped. Also, patients with minimal facial burns and minimal (< 15 %) total body surface burns were not bronchoscoped. Minimal bronchoscopic findings were noted in 45.5% of the survivors and in 1% of the nonsurvivors. Moderate bronchostopic findings were noted in 50% of the survivors and in 69% of the nonsurvivors. Severe bronchoscopic
Number of patients
Indication “Prophylactic” PAOa<60 PACOa150 Respiratory Supraglottic
lntubation
prior to transport mmHg mmHg rate >40 per minute obstruction
29 33 7 5 2
findings were present in 4.5% of the survivors and in 30% of the nonsurvivors. Chest auscultation was normal in 79 of the 86 patients (91%). Normal auscultation on admission was noted in 93% of the survivors and in 89% of the nonsurvivors. Moderate to severe facial burns were noted in 60 of the 86 patients (69.7%). Fifteen of the 33 survivors (45.4%) and 45 of the 53 nonsurvivors (85 %) had moderate to severe facial burns. Patients with as little as 15% total body surface area burns and mild inhalation injury required prolonged ventilatory support despite a normal chest xray study, normal auscultation, and normal PAO, at the time of admission. A review of patients with only cutaneous burns and no evidence of smoke inhalation who were admitted during the same time period revealed that early endotracheal intubation was not required for any patient with less than 35 % total body surface burn.
DISCUSSION The vast majority of the chest x-ray studies taken on admission were normal. This finding was in contrast to data published by Teisidor et al. in 1983.’ This study as well as others suggest that a classic perivascular fuzziness and peribronchial cuffing can be seen on admission chest x-ray studies of patients with severe inhalation injury.‘-6,* None of the patients in this study group had these findings (Table 2). Measurement of PAO, at the time of admission was not helpful in predicting final outcome or ultimate need for ventilatory support. The range and mean PAO, for survivors and for nonsurvivors was not statistically different. Firm conclusions cannot be drawn from this data as the administration of oxygen was not standardized prior to measurement of PAO, (Table 3). Sixty of the 86 patients (69.7%) had either moderate or severe facial burns. Fifteen of the 33 survivors (45.4%) had moderate to severe facial burns, and 45 of the 53 nonsurvivors (85%) had moderate to severe
Inhalation
Injury
Table 3. Parameters Outcome
473 Found not to Correlate
with Final
I. Chest x-ray studies on admission: 89% of all patients had chest x-ray studies on admission 92% of these were normal Il. Arterial PAO, on admission: mean PA02 for all was 155 mmHg mean PAO, of survivors was 147.5 mmHg mean PAO, of nonsurvivors was 159 mmHg Ill. Chest auscultation on admission: 91 Vo of all patients had clear lungs on admission 93% of survivors had clear lungs on admission 88.8% of nonsurvivors had clear lungs on admission
facial burns. Moderate to severe facial burns in our series were predictors of respiratory failure and death when combined with smoke inhalation and burns of other body areas. The severity of the bronchoscopic findings correlated well with the final outcome. Only one percent of the nonsurvivors had minimal bronchoscopic findings on admission. Further, only 4.5% of the survivors who underwent bronchoscopy were able to survive severe findings. Bronchoscopy remains an important tool for gauging the severity of inhalation injury. I-h.K Because 91% of all patients studied had clear lungs to auscultation on admission, we view chest auscultation as having little value in predicting final outcome or respiratory failure. This is in contrast to studies published in the literature.‘-4 It is difficult to draw firm conclusions about this group of patients based upon statistical significance. Many of the patients arrived at the burn center with endotracheal tubes in place. The indications for endotracheal intubation varied among the emergency physicians and the air ambulance physicians. Many patients underwent endotracheal intubation prior to
helicopter transfer for fear of respiratory compromise during flight, which could make endotracheal intubation difficult or even impossible. Most patients received oxygen during transport, although the exact flow rate could not be determined. Minimal smoke inhalation may markedly alter the course and outcome for many burn patients. The recognition of potential respiratory failure should be made early and appropriate supportive measures should be taken. The diagnosis of significant smoke inhalation with respiratory compromise should not await an abnormal chest x-ray study, abnormal physical findings, or abnormal arterial blood gases. When such patients are recognized, appropriate referral or plans for ventilatory support should be made. The patient should be placed in an upright position to maximize vital capacity. Humidified oxygen should be administered and pulmonary toilet procedures initiated. With early recognition and intervention, optimum results for this group of high risk patients may be obtained.
CONCLUSION In conclusion, the traditional means of diagnosing smoke inhalation injury are not valuable predictors of final outcome.l-63* Admission chest x-ray study, arterial PAO,, and chest auscultation are commonly used parameters in measuring the severity of the injury. These do not correlate with final outcome or with onset of respiratory failure. In this group of patients the only factors on admission that correlate with final outcome are age, total burn surface area, the severity of bronchoscopic findings, and the degree of facial burn.
REFERENCES 1. Peters TW: Inhalation injury caused by the products of combustion. &X4,4 1981; 125:249-252. 2. Peitzman B: Measurement of lung water in inhalation injury. Surgery 1981; 90:305-310. 3. Cahalane M: Early respiratory abnormalities from smoke inhalation. JAMA 1984; 251:771-773. 4. Nishimma N: Respiratory changes after major burn injury. CCM 1982; 10:25-28. 5. Shirani KZ, Pruitt BA Jr, Mason AD Jr: The influence of inha-
lation injury and pneumonia on burn mortality. ,Inn Surg 1987; 205:82-87.
6. Head JM: Inhalation injury in burns. Am JSurg
1980; 139:508-
512.
7. Teixidor HS: Smoke inhalation: radiologic manifestations. Rudial 1984; 149:383-387. 8. Guzzardi LJ: Inhalation of products of combustion. Ann Emerg Med 1983; 64~63-67.