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Comparative study of closed-chest compression, open-chest manual compression, and direct mechanical ventricular assistance
2 groups using the 2-tailed Student t test (a = .05). Comparable types of infecting organisms were cultured as revealed by multin o m i a l c h i - s q u a r e analysis w i t h c o r r e c t i o n for c o n t i n u i t y (~ = .05). When comparing the 2 regimens, the ceftriaxone group cure rate (18/20 = 90%) was not significantly different from that of the TMS-treated control group (13/13 = 100%), using the 2tailed Student t test {~ = .05). Type II error at the 50% level equals .13.
0
Lymphadenitis: Natural History and Response to Percutaneous Aspiration
G Fleisher, MD, FACEP, J Grosflam; S Selbst, MD; S Ludwig, MD / Emergency Department, The Children's Hospital of Philadelphia, PhiLadelphia Children frequently seek treatment in the emergency department (ED) for enlarged lymph nodes, often the result of a bacterial infection. While the etiologic agents of lymphadenitis in childhood have been defined clearly, optimal treatment remains uncertain. We studied lymphadenitis in children seen in an ED to determine the course of patients with fluctuant and nonfluctuant infections and to assess the roles of antibiotics, percutaneous needle aspiration (PNA), and surgical drainage as forms of therapy. During a 9-month period, all children who were diagnosed as having localized lymph node enlargement were contacted and followed by the investigators, who reviewed daily computer listings from the ED by diagnosis. The protocol called for administration of antistaphylococcal antibiotics to every patient with lymphadenitis, and for PNA of fluctuant lesions; surgical drainage was reserved for treatment failures. Forty-two children were diagnosed as having enlarged nodes, due in 32 cases to bacterial lymphadenitis. Thirty of the 32 (94%) were followed until their lesions resolved; at diagnosis, 26 had nonfluctuant and 4 had fluctuant infections. These 30 patients ranged in age from 3 mo to 17 yr; children with fluctuant nodes were younger (P < .05, t test). Subsequently fluctuanee developed in 4 of 26 lymph nodes that initially were firm to palpation. All 8 children with fluctuant lesions resolved their infections following PNA and antibiotic therapy, and 25 of 26 with initially nonfluctuant infections were cured with antibiotic therapy alone or accompanied by PNA (4 cases) when fluctuance developed. S t a p h y l o c o c c u s a u r e u s , the only pathogen isolated, was recovered from 5 infected nodes. We r e c o m m e n d antistaphylococcal antibiotics plus P N A for the treatment of lymphadenitis whenever abscess formation is detected clinically. Surgical drainage or excision should be reserved for persistent infections.
1
Hemodynamic Effects of Rate During Open-Chest Resuscitation
RL Bartlett, MD; NJ Stewart, MD; J) Raymond, MD; GL Anstadt, DVM; SD Martin, EMT / Department of Emergency Medicine, Richland Memorial Hospital, Columbia, SC Prolonged CPR using closed-chest compression (CCC) is associated with poor survival rates and neurological outcomes. The magnitude and distribution of blood flow to vital organs during CCC are inadequate after 5 to 10 rain. There is a growing body of evidence to support the use of open-chest manual compression of the heart (OCMC) for potentially salvageable patients who do not respond to standard ACLS. Del Guercio and others have reported several patients who, after failing CCC, were resuscitated successfully using OCMC. Although O C M C was first demonstrated to be an effective method of resuscitation in 1898, few studies have addressed the technical aspects of its use. Confusion still exists regarding the appropriate rate of compression. With little experimental support, it has been assumed generally that a rate of compression of 60 or less will produce the best results. Objections to the use of faster rates cite the need for an adequate ventricular filling time between compressions. This study was designed to evaluate the hemodynamic effects of compression rate during OCMC. Ventricular fibrillation was induced in 5 dogs.
13:5 May 1984
They initially were given 10 min of CCC at 60/rain, followed by 10 rain of OCMC at 60 and then 10 min of O C M C at 90. CCC produced a cardiac index (CI) of 886 {20% of pre-arrest value [PAV]), with a mean arterial pressure (MAP) of 25 m m Hg (22% of PAV). O C M C at 60 produced a CI of 1,698 (39% of PAV) with a MAP of 53 m m Hg [47% of PAV) (P < .01 and .0005, respectively, when compared to CCC). O C M C at 90 increased the CI to 2,018 [46% of PAV) and the MAP to 67 m m Hg (59% of PAV). These increases in CI and MAP with OCMC at 90 were both significant (P < .05) whcn compared to OCMC at 60. Calculation of the stroke index (SI) during O C M C at 60 and 90 revealed a decrease from 28 to 22 mL/compression. Increasing the compression rate during O C M C does decrease the SI (P < .05). However, the net effect of an increase in rate is an increase in MAP and CI. Blood flows and pressures can be improved substantially by using OCMC. Use of compression rates faster than 60/min will produce additional hemodynamic improvements.
2
Comparison of Open.Chest Cardiac Massage Techniques in Dogs
.WM Barnett, MD; JK Alifinoff, MD; PM Paris, MD; RD Stewart, MD; P Safar, MD / Affiliated Residency in Emergency Medicine, Resuscitation Research Center, and Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh; and Center for Emergency Medicine, Pittsburgh Manual compression of the heart during open-chest cardiac massage (OCPR) has been shown to be superior to closed-chest compression. This study sought to determine, in a canine model, the optimal hand position for manual compression of the heart. Twelve dogs were anesthetized with ketamine and orally intubated, and a n e s t h e s i a was m a i n t a i n e d w i t h n i t r o u s oxide, halothane, and pancuronium. Cannulae were placed to monitor diastolic (DBP) and systolic (SBP) blood pressures, intracranial pressure (ICP), and common carotid blood flow (CCBF). Control values were obtained under light general anesthesia and ventricular fibrillation was then induced. External CPR (ECPR) was performed with a mechanical compressor before opening the chest and pericardium through the left fifth interspace. A randomized sequence of 3 hand positions was used for OCPR, as follows: T e c h n i q u e A - - One-handed technique with thumb on left ventricle, fingers over the right ventricle, and apex in palm; T e c h n i q u e B - - Two-handed t e c h n i q u e w i t h right ventricle cupped in left hand and fingers of right hand over left ventricle; and T e c h n i q u e C - - One-handed technique with fingers of right hand over left ventricle and heart against sternum. Each was done at a rate of 60 compressions per minute with the operator blind to results during performance. All 3 techniques produced significantly greater {P < .05) DBP and CCBF when compared with ECPR. All 3 also produced significantly lower (P < .05} ICP when compared with ECPR. DBP, SBP, CCBF, and cerebral perfusion pressures were similar for techniques B and C and all were significantly greater (P < .05} than those achieved with technique A. These data suggest that techniques B and C may produce greater cardiac and cerebral blood flow during OCPR.
3
Comparative Study of Closed.Chest Compression, Open-Chest Manual Compression, and Direct Mechanical Ventricular Assistance
RL Bartlett, MD, NJ Stewart, MD; JI Raymond, MD; GL Anstadt, DVM; SD Martin, EMT / Department of Emergency Medicine, Richland Memorial Hospital, Columbia, SC Current cardiac arrest studies indicate that closed-chest c o m pression (CCC) does not provide adequate coronary and cerebral perfusion for more than 5 to 10 rain. Ditchey demonstrated coronary blood flow to be less than 1% of pre-arrest values during CCC. Cerebral perfusion studies suggest that CCC cannot reliably supply a cortical blood flow at more than 10% of normal values after the first 10 rain of resuscitation. A case control study
Annals of EmergencyMedicine
397/133
UAEM ABSTRACTS 14TH ANNUAL MEETING
was designed to evaluate 3 different methods of circulatory support: standard CCC, opep-chest m a n u a l c o m p r e s s i o n (OCMC), and direct mechanical ventricular assistance (DMVA). DMVA is a m e t h o d of open-chest circulatory support using a glass assistor cup that fits over the heart and alternately compresses and expands the ventricles to provide systole and diastole. The systolic duration, rate of compression, and force of assistor compression can be controlled by the m a i n drive system. Ventricular fibrillation was induced in 15 dogs. They initially were given 10 rain of CCC using a T h u m p e r TM. At the end of this period [hey were divided into 3 groups for c o n t i n u e d resuscitation. Group I received 10 m i n of O C M C at 6 0 / m i n followed by 10 rain at 90/min. DMVA was then applied for similar periods at rates of 60 and 90. In Group II, DMVA preceded OCMC. The experimental design was otherwise the same as in Group I. The data from this group were used to determine w h e t h e r the order in w h i c h O C M C or DMVA was applied had any significant effects. Group IlI continued to receive CCC at 6 0 / m i n for an additional 40 min. The total arrest time for all 3 groups was 50 min. Analysis of Groups I and II showed no significant difference in the order of application of O C M C and DMVA. CCC produced a cardiac index (CI) of 780 (19% of normal) w i t h a m e a n arterial pressure (MAP) of 26 m m Hg (23% of normal). Compared to CCC, b o t h forms of open-chest resuscitation produced higher values for all indices. O C M C at 60/ rain m a i n t a i n e d a CI of 2,069 (52% of normal) w i t h a MAP of 50 m m Hg (45% of normal). DMVA at the same rate produced a CI of 2,780 (70% of normal) w i t h a MAP of 72 m m Hg (65% of normal}. These represent significant increases w h e n compared to O C M C at 60 (P < .005 for CI and < .0005 for MAP). Changing from standard CCC to DMVA at 90/rain produced the greatest h e m o d y n a m i c i m p r o v e m e n t s : diastolic pressure increased by 380%; MAP, by 250%; and CI, by 340%. With DMVA at 90, the systolic pressure, stroke index, and CI could not be statistically distinguished from case-controlled pre-arrest values. This study indicates that DMVA is capable of long-term circulatory support during ventricular fibrillation.
4
Prolonged Cardiac Arrest and Resuscitation in Dogs h Cardiac Resuscitability and Net Perfusion Pressures with CPR Versus IAC.CPR
0 Hayes, MD; J Omans, MD; BC White, MD; AT Evans, DVM; RJ Indrieri, DVM; LD Aronson, MD; L Fox; T Hoehner / Departments of Emergency Medicine, Ingham and Sparrow Hospital, Lansing, MI; Department of Emergency Medicine, Butterworth Hospital, Grand Rapids, MI; and Section of Emergency Medicine, College of Human Medicine and College of Veterinary Medicine, Michigan State University, East Lansing Sixteen mongrel dogs weighing b e t w e e n 20 and 25 kg were anesthetized w i t h k e t a m i n e (7 mg/kg) IV followed by halothane (1% to 2% mixture w i t h oxygen). The animals were intubated and a central venous (CV) line was inserted by right venisection. The left femoral artery was catheterized. Both central venous and arterial catheters were c o n n e c t e d to pressure transducers attached to an EPM-BR8 fast photoreeorder, w h i c h was standardized before each experiment. All animals were ECG-monitored. Cardiac arrest was induced by CV injection of 0.5 mEq/kg KC1 after pre-arrest ABGs were drawn. After 15 m i n of cardiac arrest, 8 animals were resuscitated w i t h m a n u a l front-to-back CPR and 8 animals were resuscitated w i t h interposed abdominal compression (IAC) CPR. All animals were secured in a V-trough to prev e n t m o t i o n . For IAC-CPR a folded blood p r e s s u r e cuff was placed on the mid-abdomen and compressed manually to 100 m m Hg pressure b e t w e e n chest compressions. C h e s t c o m p r e s s i o n rates were maintained at 80/rain in both groups, and 100% Oz was delivered by manual bag ventilation every sixth chest compression. All animals were given NaHCO3 (3 mEq/kg IV) and epinephrine (20 i~g/kg IV) via the CV line at the beginning of resuscitation, and had a c o n t i n u o u s e p i n e p h r i n e infusion (3 ~g/kg/ rain] during artificial perfusion. S i m u l t a n e o u s arterial and CV
134/398
pressure recordings were taken at 5, 10, and 20 rain of resuscitation. ABGs were drawn at 10 rain resuscitation time. All animals were countershocked once at 3 ws/kg after 6 rain resuscitation, and every 2 m i n thereafter until defibrillated. There were no significant differences detected between CPR and IAC-CPR in net systolic and diastolic perfusion pressures, required n u m b e r of s h o c k s to defibrillate (CPR, 3.9 _+ 1.9; IAC-CPR, 3.5 ± .9), n u m b e r of animals resuscitated (CPR, 6; IAC-CPR, 5), time to spontaneous perfusion (CPR, 17.9 -+ 7.1 rain; IAC-CPR, 20.7 ± 7.2 min), or blood gases after 10 m i n resuscitation {CPR: pH, 7.51 ± .13; PCO2, 21.12 -+ 6.5; PO2, 318 ± 79; HCO3-, 18.4 _+ 6.0; and IAC-CPR: pH, 7.49 -+ .10; PCO2, 27.0 ± 4.8; PO2, 180 -+ 82; HCO3, 22.2 _+ 3.7). These data indicate that IAC-CPR does not improve cardiac resuscitability after a 15-rain cardiac arrest.
5
Cardiopulmonary Bypass for Resuscitation After Prolonged Cardiac Arrest in Dogs
R Cantadore, MD; P Vaagenes, MD; P Safar, MD; W Stezoski / Resuscitation Research Center and Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh and Presbyterian-University Hospital, Pittsburgh With standard CPR (SCPR), restoration of spontaneous circulation (ROSe) may not be achieved after long cardiac arrest (CA) times. Cardiopulmonary bypass (CPB) permits control of perfusion pressure, flow, oxygenation, temperature, blood composition, and administration of drugs that may benefit the brain b u t depress the cardiovascular system (CVS). A study was performed in dogs to determine w h e t h e r CPB can reverse n o r m o t h e r m i c CA of 20 m i n v e n t r i c u l a r fibrillation (VF) better t h a n can SCPR. Group I {n = 9) was resuscitated w i t h SCPR; Group II In = 6), with CPB w i t h blood priming (CPB-B); and Group III (n = 7), with CPB w i t h plasma substitute priming (Dextran 40/lactated Ringer's 1:1) (CPB-P). Preparation was w i t h light halothane-NzO. After 20 m i n VF, R o s e was achieved by SCPR w i t h drugs and c o u n t e r s h o c k ; in the CPB groups CPB was c o n t i n u e d for 2 h w i t h o u t countershock, and t h e n R O S e was accomplished. A pediatric bubble-oxygenator, w i t h one pump and priming volume of 1,000 mL was used, with a flow of 80 to 100 mL/kg/min. Cardiac o u t p u t (CO) was m e a s u r e d (by t h e r m o d i l u t i o n ) , and arteriovenous Oz difference and 0 2 utilization coefficient (Ca-vOz) were calculated. Sacrifice was at 4 h. SCPR achieved R o s e w i t h i n 5 m i n in 7 of 9 dogs (5 countershocks); all 7 survived 4 h but with severe dysrhythmias. CPB was feasible for 2 h and was followed by R o s e with one countershock; there were no dysrhythmias post ROSC. There were no differences in return times for spontaneous breathing, pupillary light reflexes, or EEG activity. CO decreased to 50% of control at 1 to 4 h post ROSC in the SCPR and CPB-B groups. In the CPB-P group, CO was normalized post CA, but 0 2 utilization coefficient was worse, both as the result of h e m o d i l u t i o n (hematocrit, 15%). ROSC is feasible after 20 m i n CA (VF) using CPB or CPR; CPB, however, stabilizes the CVS early post arrest and facilitates ROSC as compared to SCPR. CPB should be explored further for emergency resuscitation after prolonged CA.
6
Cardiovascular Resuscitability of Dogs After Up to 90 Minutes Cold Water Drowning Using Cardiopulmonary Bypass
S Tisherman; C Chabal; W Clougherty; P Safar, MD; J Lewis, MD; W Stezoski / Resuscitation Research Center and Departments of Anesthesiology/Critical Care Medicine and Medicine, University of Pittsburgh and Presbyterian-University Hospital, Pittsburgh Anecdotal h u m a n case reports include recoveries after cold water drowning of up to 40 rain. A t t e m p t s at restoration of spontaneous circulation (ROSe) in cases of cold water drowning by standard external CPR often fail to rewarm and restart the heart. This feasibility study was designed to determine the longest period of asphyxial cardiac arrest u n d e r h y p o t h e r m i a from w h i c h
Annals of Emergency Medicine
13:5 May 1984
0
Lymphadenitis: Natural History and Response to Percutaneous Aspiration
G Fleisher, MD, FACEP, J Grosflam; S Selbst, MD; S Ludwig, MD / Emergency Department, The Children's Hospital of Philadelphia, PhiLadelphia Children frequently seek treatment in the emergency department (ED) for enlarged lymph nodes, often the result of a bacterial infection. While the etiologic agents of lymphadenitis in childhood have been defined clearly, optimal treatment remains uncertain. We studied lymphadenitis in children seen in an ED to determine the course of patients with fluctuant and nonfluctuant infections and to assess the roles of antibiotics, percutaneous needle aspiration (PNA), and surgical drainage as forms of therapy. During a 9-month period, all children who were diagnosed as having localized lymph node enlargement were contacted and followed by the investigators, who reviewed daily computer listings from the ED by diagnosis. The protocol called for administration of antistaphylococcal antibiotics to every patient with lymphadenitis, and for PNA of fluctuant lesions; surgical drainage was reserved for treatment failures. Forty-two children were diagnosed as having enlarged nodes, due in 32 cases to bacterial lymphadenitis. Thirty of the 32 (94%) were followed until their lesions resolved; at diagnosis, 26 had nonfluctuant and 4 had fluctuant infections. These 30 patients ranged in age from 3 mo to 17 yr; children with fluctuant nodes were younger (P < .05, t test). Subsequently fluctuanee developed in 4 of 26 lymph nodes that initially were firm to palpation. All 8 children with fluctuant lesions resolved their infections following PNA and antibiotic therapy, and 25 of 26 with initially nonfluctuant infections were cured with antibiotic therapy alone or accompanied by PNA (4 cases) when fluctuance developed. S t a p h y l o c o c c u s a u r e u s , the only pathogen isolated, was recovered from 5 infected nodes. We r e c o m m e n d antistaphylococcal antibiotics plus P N A for the treatment of lymphadenitis whenever abscess formation is detected clinically. Surgical drainage or excision should be reserved for persistent infections.
1
Hemodynamic Effects of Rate During Open-Chest Resuscitation
RL Bartlett, MD; NJ Stewart, MD; J) Raymond, MD; GL Anstadt, DVM; SD Martin, EMT / Department of Emergency Medicine, Richland Memorial Hospital, Columbia, SC Prolonged CPR using closed-chest compression (CCC) is associated with poor survival rates and neurological outcomes. The magnitude and distribution of blood flow to vital organs during CCC are inadequate after 5 to 10 rain. There is a growing body of evidence to support the use of open-chest manual compression of the heart (OCMC) for potentially salvageable patients who do not respond to standard ACLS. Del Guercio and others have reported several patients who, after failing CCC, were resuscitated successfully using OCMC. Although O C M C was first demonstrated to be an effective method of resuscitation in 1898, few studies have addressed the technical aspects of its use. Confusion still exists regarding the appropriate rate of compression. With little experimental support, it has been assumed generally that a rate of compression of 60 or less will produce the best results. Objections to the use of faster rates cite the need for an adequate ventricular filling time between compressions. This study was designed to evaluate the hemodynamic effects of compression rate during OCMC. Ventricular fibrillation was induced in 5 dogs.
13:5 May 1984
They initially were given 10 min of CCC at 60/rain, followed by 10 rain of OCMC at 60 and then 10 min of O C M C at 90. CCC produced a cardiac index (CI) of 886 {20% of pre-arrest value [PAV]), with a mean arterial pressure (MAP) of 25 m m Hg (22% of PAV). O C M C at 60 produced a CI of 1,698 (39% of PAV) with a MAP of 53 m m Hg [47% of PAV) (P < .01 and .0005, respectively, when compared to CCC). O C M C at 90 increased the CI to 2,018 [46% of PAV) and the MAP to 67 m m Hg (59% of PAV). These increases in CI and MAP with OCMC at 90 were both significant (P < .05) whcn compared to OCMC at 60. Calculation of the stroke index (SI) during O C M C at 60 and 90 revealed a decrease from 28 to 22 mL/compression. Increasing the compression rate during O C M C does decrease the SI (P < .05). However, the net effect of an increase in rate is an increase in MAP and CI. Blood flows and pressures can be improved substantially by using OCMC. Use of compression rates faster than 60/min will produce additional hemodynamic improvements.
2
Comparison of Open.Chest Cardiac Massage Techniques in Dogs
.WM Barnett, MD; JK Alifinoff, MD; PM Paris, MD; RD Stewart, MD; P Safar, MD / Affiliated Residency in Emergency Medicine, Resuscitation Research Center, and Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh; and Center for Emergency Medicine, Pittsburgh Manual compression of the heart during open-chest cardiac massage (OCPR) has been shown to be superior to closed-chest compression. This study sought to determine, in a canine model, the optimal hand position for manual compression of the heart. Twelve dogs were anesthetized with ketamine and orally intubated, and a n e s t h e s i a was m a i n t a i n e d w i t h n i t r o u s oxide, halothane, and pancuronium. Cannulae were placed to monitor diastolic (DBP) and systolic (SBP) blood pressures, intracranial pressure (ICP), and common carotid blood flow (CCBF). Control values were obtained under light general anesthesia and ventricular fibrillation was then induced. External CPR (ECPR) was performed with a mechanical compressor before opening the chest and pericardium through the left fifth interspace. A randomized sequence of 3 hand positions was used for OCPR, as follows: T e c h n i q u e A - - One-handed technique with thumb on left ventricle, fingers over the right ventricle, and apex in palm; T e c h n i q u e B - - Two-handed t e c h n i q u e w i t h right ventricle cupped in left hand and fingers of right hand over left ventricle; and T e c h n i q u e C - - One-handed technique with fingers of right hand over left ventricle and heart against sternum. Each was done at a rate of 60 compressions per minute with the operator blind to results during performance. All 3 techniques produced significantly greater {P < .05) DBP and CCBF when compared with ECPR. All 3 also produced significantly lower (P < .05} ICP when compared with ECPR. DBP, SBP, CCBF, and cerebral perfusion pressures were similar for techniques B and C and all were significantly greater (P < .05} than those achieved with technique A. These data suggest that techniques B and C may produce greater cardiac and cerebral blood flow during OCPR.
3
Comparative Study of Closed.Chest Compression, Open-Chest Manual Compression, and Direct Mechanical Ventricular Assistance
RL Bartlett, MD, NJ Stewart, MD; JI Raymond, MD; GL Anstadt, DVM; SD Martin, EMT / Department of Emergency Medicine, Richland Memorial Hospital, Columbia, SC Current cardiac arrest studies indicate that closed-chest c o m pression (CCC) does not provide adequate coronary and cerebral perfusion for more than 5 to 10 rain. Ditchey demonstrated coronary blood flow to be less than 1% of pre-arrest values during CCC. Cerebral perfusion studies suggest that CCC cannot reliably supply a cortical blood flow at more than 10% of normal values after the first 10 rain of resuscitation. A case control study
Annals of EmergencyMedicine
397/133
UAEM ABSTRACTS 14TH ANNUAL MEETING
was designed to evaluate 3 different methods of circulatory support: standard CCC, opep-chest m a n u a l c o m p r e s s i o n (OCMC), and direct mechanical ventricular assistance (DMVA). DMVA is a m e t h o d of open-chest circulatory support using a glass assistor cup that fits over the heart and alternately compresses and expands the ventricles to provide systole and diastole. The systolic duration, rate of compression, and force of assistor compression can be controlled by the m a i n drive system. Ventricular fibrillation was induced in 15 dogs. They initially were given 10 rain of CCC using a T h u m p e r TM. At the end of this period [hey were divided into 3 groups for c o n t i n u e d resuscitation. Group I received 10 m i n of O C M C at 6 0 / m i n followed by 10 rain at 90/min. DMVA was then applied for similar periods at rates of 60 and 90. In Group II, DMVA preceded OCMC. The experimental design was otherwise the same as in Group I. The data from this group were used to determine w h e t h e r the order in w h i c h O C M C or DMVA was applied had any significant effects. Group IlI continued to receive CCC at 6 0 / m i n for an additional 40 min. The total arrest time for all 3 groups was 50 min. Analysis of Groups I and II showed no significant difference in the order of application of O C M C and DMVA. CCC produced a cardiac index (CI) of 780 (19% of normal) w i t h a m e a n arterial pressure (MAP) of 26 m m Hg (23% of normal). Compared to CCC, b o t h forms of open-chest resuscitation produced higher values for all indices. O C M C at 60/ rain m a i n t a i n e d a CI of 2,069 (52% of normal) w i t h a MAP of 50 m m Hg (45% of normal). DMVA at the same rate produced a CI of 2,780 (70% of normal) w i t h a MAP of 72 m m Hg (65% of normal}. These represent significant increases w h e n compared to O C M C at 60 (P < .005 for CI and < .0005 for MAP). Changing from standard CCC to DMVA at 90/rain produced the greatest h e m o d y n a m i c i m p r o v e m e n t s : diastolic pressure increased by 380%; MAP, by 250%; and CI, by 340%. With DMVA at 90, the systolic pressure, stroke index, and CI could not be statistically distinguished from case-controlled pre-arrest values. This study indicates that DMVA is capable of long-term circulatory support during ventricular fibrillation.
4
Prolonged Cardiac Arrest and Resuscitation in Dogs h Cardiac Resuscitability and Net Perfusion Pressures with CPR Versus IAC.CPR
0 Hayes, MD; J Omans, MD; BC White, MD; AT Evans, DVM; RJ Indrieri, DVM; LD Aronson, MD; L Fox; T Hoehner / Departments of Emergency Medicine, Ingham and Sparrow Hospital, Lansing, MI; Department of Emergency Medicine, Butterworth Hospital, Grand Rapids, MI; and Section of Emergency Medicine, College of Human Medicine and College of Veterinary Medicine, Michigan State University, East Lansing Sixteen mongrel dogs weighing b e t w e e n 20 and 25 kg were anesthetized w i t h k e t a m i n e (7 mg/kg) IV followed by halothane (1% to 2% mixture w i t h oxygen). The animals were intubated and a central venous (CV) line was inserted by right venisection. The left femoral artery was catheterized. Both central venous and arterial catheters were c o n n e c t e d to pressure transducers attached to an EPM-BR8 fast photoreeorder, w h i c h was standardized before each experiment. All animals were ECG-monitored. Cardiac arrest was induced by CV injection of 0.5 mEq/kg KC1 after pre-arrest ABGs were drawn. After 15 m i n of cardiac arrest, 8 animals were resuscitated w i t h m a n u a l front-to-back CPR and 8 animals were resuscitated w i t h interposed abdominal compression (IAC) CPR. All animals were secured in a V-trough to prev e n t m o t i o n . For IAC-CPR a folded blood p r e s s u r e cuff was placed on the mid-abdomen and compressed manually to 100 m m Hg pressure b e t w e e n chest compressions. C h e s t c o m p r e s s i o n rates were maintained at 80/rain in both groups, and 100% Oz was delivered by manual bag ventilation every sixth chest compression. All animals were given NaHCO3 (3 mEq/kg IV) and epinephrine (20 i~g/kg IV) via the CV line at the beginning of resuscitation, and had a c o n t i n u o u s e p i n e p h r i n e infusion (3 ~g/kg/ rain] during artificial perfusion. S i m u l t a n e o u s arterial and CV
134/398
pressure recordings were taken at 5, 10, and 20 rain of resuscitation. ABGs were drawn at 10 rain resuscitation time. All animals were countershocked once at 3 ws/kg after 6 rain resuscitation, and every 2 m i n thereafter until defibrillated. There were no significant differences detected between CPR and IAC-CPR in net systolic and diastolic perfusion pressures, required n u m b e r of s h o c k s to defibrillate (CPR, 3.9 _+ 1.9; IAC-CPR, 3.5 ± .9), n u m b e r of animals resuscitated (CPR, 6; IAC-CPR, 5), time to spontaneous perfusion (CPR, 17.9 -+ 7.1 rain; IAC-CPR, 20.7 ± 7.2 min), or blood gases after 10 m i n resuscitation {CPR: pH, 7.51 ± .13; PCO2, 21.12 -+ 6.5; PO2, 318 ± 79; HCO3-, 18.4 _+ 6.0; and IAC-CPR: pH, 7.49 -+ .10; PCO2, 27.0 ± 4.8; PO2, 180 -+ 82; HCO3, 22.2 _+ 3.7). These data indicate that IAC-CPR does not improve cardiac resuscitability after a 15-rain cardiac arrest.
5
Cardiopulmonary Bypass for Resuscitation After Prolonged Cardiac Arrest in Dogs
R Cantadore, MD; P Vaagenes, MD; P Safar, MD; W Stezoski / Resuscitation Research Center and Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh and Presbyterian-University Hospital, Pittsburgh With standard CPR (SCPR), restoration of spontaneous circulation (ROSe) may not be achieved after long cardiac arrest (CA) times. Cardiopulmonary bypass (CPB) permits control of perfusion pressure, flow, oxygenation, temperature, blood composition, and administration of drugs that may benefit the brain b u t depress the cardiovascular system (CVS). A study was performed in dogs to determine w h e t h e r CPB can reverse n o r m o t h e r m i c CA of 20 m i n v e n t r i c u l a r fibrillation (VF) better t h a n can SCPR. Group I {n = 9) was resuscitated w i t h SCPR; Group II In = 6), with CPB w i t h blood priming (CPB-B); and Group III (n = 7), with CPB w i t h plasma substitute priming (Dextran 40/lactated Ringer's 1:1) (CPB-P). Preparation was w i t h light halothane-NzO. After 20 m i n VF, R o s e was achieved by SCPR w i t h drugs and c o u n t e r s h o c k ; in the CPB groups CPB was c o n t i n u e d for 2 h w i t h o u t countershock, and t h e n R O S e was accomplished. A pediatric bubble-oxygenator, w i t h one pump and priming volume of 1,000 mL was used, with a flow of 80 to 100 mL/kg/min. Cardiac o u t p u t (CO) was m e a s u r e d (by t h e r m o d i l u t i o n ) , and arteriovenous Oz difference and 0 2 utilization coefficient (Ca-vOz) were calculated. Sacrifice was at 4 h. SCPR achieved R o s e w i t h i n 5 m i n in 7 of 9 dogs (5 countershocks); all 7 survived 4 h but with severe dysrhythmias. CPB was feasible for 2 h and was followed by R o s e with one countershock; there were no dysrhythmias post ROSC. There were no differences in return times for spontaneous breathing, pupillary light reflexes, or EEG activity. CO decreased to 50% of control at 1 to 4 h post ROSC in the SCPR and CPB-B groups. In the CPB-P group, CO was normalized post CA, but 0 2 utilization coefficient was worse, both as the result of h e m o d i l u t i o n (hematocrit, 15%). ROSC is feasible after 20 m i n CA (VF) using CPB or CPR; CPB, however, stabilizes the CVS early post arrest and facilitates ROSC as compared to SCPR. CPB should be explored further for emergency resuscitation after prolonged CA.
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Cardiovascular Resuscitability of Dogs After Up to 90 Minutes Cold Water Drowning Using Cardiopulmonary Bypass
S Tisherman; C Chabal; W Clougherty; P Safar, MD; J Lewis, MD; W Stezoski / Resuscitation Research Center and Departments of Anesthesiology/Critical Care Medicine and Medicine, University of Pittsburgh and Presbyterian-University Hospital, Pittsburgh Anecdotal h u m a n case reports include recoveries after cold water drowning of up to 40 rain. A t t e m p t s at restoration of spontaneous circulation (ROSe) in cases of cold water drowning by standard external CPR often fail to rewarm and restart the heart. This feasibility study was designed to determine the longest period of asphyxial cardiac arrest u n d e r h y p o t h e r m i a from w h i c h
Annals of Emergency Medicine
13:5 May 1984