Usefulness of central venous oxygen saturation monitoring during cardiopulmonary resuscitation. A comparative case study with end-tidal carbon dioxide monitoring

The usefulness of continuous monitoring of central venous oxygen saturation (ScvO2) in comparison with the capnogram during cardiopulmonary resuscitation (CPR) was demonstrated in a cardiac arrest patient. ScvO2 and end-tidal carbon dioxide (ETCO2) decreased following cessation of chest compression or increased during recovery of systemic circulation. During the complete stasis of systemic circulation, when defibrillation was done, ScvO2 did not change, while ETCO2 gradually decreased. However the larger decrease in ScvO2 temporally occurred when chest compression was resumed. And also the ScvO2 monitoring had great advantage to detecting peripheral tissue oxygenation. ScvO2 seems to be no less accurate and reliable monitoring than the capnogram during CPR procedures. Since the capnogram is non-invasively and easily used in cardiac arrest patients, ScvO2 monitoring combined with the capnogram is a more preferable method for assessing the efficacy of ongoing CPR.     

Adenosine deaminase in differential diagnosis of peripheral lymph node tuberculosis

Improved hemodynamics and blood flow have been reported in patients with IABPs who experience cardiopulmonary arrest and require CPR. The following research questions, however, remain unanswered: Is there a more effective method of using IABP to prevent cardiac arrest and the need for CPR? Is the timing of balloon inflation and deflation the same for patients undergoing CPR as it is for patients who do not require CPR? Would earlier or later inflation or deflation further enhance cerebral or systemic blood flow? What are the most effective ways for healthcare staff to maintain competency skills in CPR in patients with IABPs?     

Antiproliferative therapy with 5-fluorouracil in erbium:YAG laser sclerostomy ab externo

In the United States debate continues about the necessity of ventilation during CPR because of fear of contracting infectious diseases. Three questions will be considered in this article. First, is ventilation necessary for the treatment of cardiac arrest? Second, is mouth-to-mouth ventilation any better than no ventilation at all? Third, are other techniques of ventilation as effective or more effective than mouth-to-mouth ventilation during basic life support CPR? Although research is still inconclusive with regard to the need for ventilation during CPR, recent findings have clarified the effect of ventilation during low blood flow states and how ventilation influences resuscitation. Ventilation affects oxygenation, carbon dioxide elimination, and pH during times of low rates of blood flow. Ventilation may be unnecessary during the first few minutes of CPR. Under conditions of prolonged, untreated cardiac arrest, ventilation during CPR affects return of spontaneous circulation. Isolated hypoxemia and hypercarbia independently have adverse effects on survival of cardiac arrest. Because ventilation with exhaled gas contains as much as 4% CO2 and less oxygen than air, it may have adverse effects during CPR. Spontaneous gasping may provide sufficient ventilation during CPR. Chest compression alone provides some pulmonary ventilation and gas exchange. Active chest compression-decompression may improve gas exchange better than does standard chest compression. Other forms of manual ventilation may also have a role in CPR.     

Effect of the no-flow interval and hypothermia on cerebral blood flow and metabolism during cardiopulmonary resuscitation in dogs

BACKGROUND and PURPOSE: We sought (1) to determine the effect of brief periods of no flow on the subsequent forebrain blood flow during cardiopulmonary resuscitation (CPR) and (2) to test the hypothesis that hypothermia prevents the impact of the no-flow duration on cerebral blood flow (CBF) during CPR. METHODS: No-flow intervals of 1.5, 3, and 6 minutes before CPR at brain temperatures of 28 degreesC and 38 degreesC were compared in 6 groups of anesthetized dogs. Microsphere-determined CBF and metabolism were measured before and during vest CPR adjusted to maintain cerebral perfusion pressure at 25 mm Hg. RESULTS: Increasing the no-flow interval from 1.5 to 6 minutes at 38 degreesC decreased the CBF (18. 6+/-3.6 to 6.1+/-1.7 mL/100 g per minute) and the cerebral metabolic rate (2.1+/-0.3 to 0.7+/-0.2 mL/100 g per minute) during CPR. Cooling to 28 degreesC before and during the arrest eliminated the detrimental effects of increasing the no-flow interval on CBF (16. 8+/-1.0 to 14.8+/-1.9 mL/100 g per minute) and cerebral metabolic rate (1.1+/-0.1 to 1.3+/-0.1 mL/100 g per minute). Unlike the forebrain, 6 minutes of preceding cardiac arrest did not affect brain stem blood flow during CPR. CONCLUSIONS: Increasing the no-flow interval to 6 minutes in normothermic animals decreases the supratentorial blood flow and cerebral metabolic rate during CPR at a cerebral perfusion pressure of 25 mm Hg. Cooling to 28 degreesC eliminates the detrimental impact of the 6-minute no-flow interval on the reflow produced during CPR. The brain-protective effects of hypothermia include improving reflow during CPR after cardiac arrest. The effect of hypothermia and the impact of short durations of no flow on reperfusion indicate that increasing viscosity and reflex vasoconstriction are unlikely causes of the "no-reflow" phenomenon.     

Syncope in bradycardic cardiac arrhythmias

Bradyarrhythmias, depending on the patient population, are the cause of syncope in 3 to 10%. Marked bradycardia or asystole can be due to impaired function of the sinus node (sinus node syndrome) or high-grade AV-conduction block as well as carotid sinus syndrome and pathologic vasodepressor reactions. In particular, in the presence of high-grade AV-block, the diagnosis of bradyarrhythmia-induced syncope can frequently be established on the basis of a standard ECG. One of the most common causes of syncope is functional impairment of the sinus node, in particular, an inadequate permanent sinus bradycardia, sinus node arrest or SA-block and paroxysmal atrial tachycardia alternating with atrial bradycardia. The method of choice for detecting suspected paroxysmal arrthythmias is ambulatory ECG monitoring but interpretation may be encumbered by the absence of concomitant symptoms during the registration. Frequently, the use of non-invasive methods alone, such as detailed history, ambulatory ECG and ECG exercise testing, will not render confirmatory findings to document the cause of syncope, that is, > 3 s pause in sinus rhythm or high-grade AV-block. In this situation, the question arises which patients should undergo electrophysiologic examination. Several studies have shown that in patients with a pathologic resting ECG (first degree AV-block, bundle branch block, inadequate sinus bradycardia) and cardiac disease, electrophysiologic studies will document a cause of syncope in more than 30%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Marfan's syndrome and surgical repair of ascending aortic aneurysms

Marfan's syndrome is an inherited, degenerative connective tissue disorder that affects many body systems (eg, skeletal, ocular, cardiovascular, cutaneous, pulmonary, abdominal, neurologic). The cause of Marfan's syndrome is unknown, but recent genetic studies have linked this disorder to chromosome 15q15-q21.3. The characteristics associated with Marfan's syndrome require a multidisciplinary approach to patient care. This article discusses one serious complication of Marfan's syndrome-aortic root dilatation- and composite graft repairs of ascending aortic aneurysms. Physicians and nurses must be more aware of Marfan's syndrome so that life-threatening medical conditions can be evaluated and followed by health care providers.     

Interaction of the Na(+)-Ca2+ exchanger with small molecules on cell Ca2+ signaling

BACKGROUND: Evaluation of outcome after CPR in severe hypothermic patients. DESIGN: Perspective study from October 1995 to April 1996. SETTING: First aid team of Italian Red Cross, Busto Arsizio (Varese), Italy. METHODS: A population of 22 patients in cardiac arrest in which CPR was performed immediately after rescue team's arrival is studied. ECG, core temperature, SpO2 and MAP were monitored whereas vital parameters were present during Basic Life Support. Outcome after CPR was evaluated with GOS scale. RESULTS: It has been observed that severe hypothermia and time of cardiac arrest impact on the clinical outcome after CPR. The high mortality rate after CPR with BLS standard is worsened by a core temperature < or = 33 degrees C. CONCLUSIONS: Severe hypothermia seems to have a dangerous effect upon outcome after cardiopulmonary resuscitation; heating systems for body temperature could prevent this situation improving CPR results.     

Effect of selective aortic arch perfusion on median frequency and peak amplitude of ventricular fibrillation in a canine model

STUDY OBJECTIVE: To determine whether the computer-derived measures of median frequency or peak amplitude of ventricular fibrillation (VF), obtained by fast Fourier transform of the VF waveform, change during selective aortic arch perfusion in a canine model of cardiac arrest. METHODS: Eight mongrel dogs (including 4 control animals) were sedated, intubated, catheterized, and instrumented to record the electrocardiogram (digitally at 100 Hz, filtered with a finite impulse response filter at 2 Hz), right atrial pressure, and aortic pressure during resuscitation in a model of VF-induced cardiac arrest. After 10 minutes of VF-induced arrest, cardiopulmonary resuscitation (CPR) with a mechanical chest compression device was initiated. Beginning 2 minutes later, the 4 study animals received, every 2 minutes, 45 seconds of selective aortic arch perfusion (SAAP) with autologous blood infusions under high pressure. Defibrillation was attempted after 3 minutes of CPR and every minute thereafter. Both study and control groups received standard-dose epinephrine (.01 mg/kg) every 3 minutes by means of an intraaortic catheter. The median frequency, peak amplitude, and coronary perfusion pressure (CPP) during the 5-second period just before defibrillation were obtained with the use of computer algorithms. RESULTS: All SAAP animals and 1 control animal were resuscitated. Baseline measures of median frequency (8.4 +/- 1.5 versus 6.6 +/- 1.0 Hz) and peak amplitude (.18 +/- .05 versus .36 +/- .13 mV) were not different between the SAAP and control groups, respectively, at the start of CRP. SAAP infusion resulted in significant increases in the SAAP group compared with the control group: median frequency, 9.6 +/- .4 versus 7.3 +/- 1.4 Hz; peak amplitude, .74 +/- .21 versus .39 +/- .15 mV; and CPP, 40.5 +/- 7.1 versus 18.0 +/- 15.0 mm Hg, respectively. Median frequency correlated with CPP (r2 = .67). Peak amplitude did not correlate with CPP (r2 = .06). CONCLUSION: Median frequency and peak amplitude increase with SAAP during cardiac arrest in a canine model. This method of resuscitation was reliable in allowing restoration of a stable perfusing rhythm after defibrillation. Changes in measures of peak amplitude and median frequency may reflect interventions that enhance the likelihood of successful defibrillation and may thereby offer a noninvasive means of monitoring interventions during cardiac arrest.     

New trends in ECG Holter monitoring

The authors review contemporary possibilities of Holter ECG monitoring. In the first group of patients they emphasize possibilities and the yield of long-term ambulatory ECG monitoring by means of an apparatus started by the patient. The second group of patients was examined by Holter monitoring, using an oesophageal lead. It is a method hitherto not used in the Czech Republic, which if properly indicated, improves the non-invasive diagnosis of cardiac arrhythmias.     

Interposed abdominal compression in mechanical cardiopulmonary resuscitation. Description of a clinical case

Among the different techniques proposed to integrate the standard cardiopulmonary resuscitation (sCPR) protocol, mechanical CPR (mCPR) and interposed abdominal compression (IAC) were found to be particularly effective for the simplicity of the procedure and the significant results obtained. A case of a 54-year old male with cardiogenic shock following viral infection, in which prolonged mechanical cardiopulmonary resuscitation with interposed abdominal compression was performed, is presented. Five hours after admission in the ICU, the patient's condition worsened with subsequent cardiac arrest with pulseless electrical activity (PEA). Mechanical CPR was promptly started, subsequently associated with IAC and prolonged for 1 hour and 20 minutes. Although the patient survived for only eight hours following cardiac arrest, prolonged IAC-mCPR allowed to start extra corporeal circulation (CPP). The patient was then transferred to the cardiosurgical operating theatre for ventricular assistance by centrifugal pump (VAP). Cardiovascular data obtained from patients monitoring did not shown any cardiac lesions or adverse effects as observed by autoptic examination and suggest the reliability of this mechanical method, which allows a better performance when compared to standard CPR. In prolonged resuscitations a few contraindications to both mCPR and IAC suggest the application of the associated techniques at all times in cardiac arrest, combining the benefits of both procedures.     

Paraplegia in a patient with Marfan's syndrome as a result of a thoraco-abdominal aortic aneurysm repair

Marfan's syndrome is a hereditary disorder involving a deficit in connective tissue collagen. Physical findings include musculoskeletal, ocular, and cardiovascular abnormalities. A 29-year-old man with a history of Marfan's syndrome was admitted to the hospital with back and chest pain secondary to a dissecting aortic aneurysm. He later underwent surgical aortic bypass graft surgery. Postoperatively, he was paraplegic. Our impression was anterior spinal artery syndrome due to prolonged cross-clamping of the aorta during surgical repair. This paper shows the risk of paralysis resulting from surgical repair of an aortic aneurysm as a poorly documented complication of Marfan's syndrome.     

Aortic root dilatation in Marfan's syndrome: a contribution from obstructive sleep apnea?

We report two cases of Marfan's syndrome with coexistent obstructive sleep apnea (OSA) in which treatment with nasal continuous positive airway pressure was associated with attenuation of aortic root dilatation, a serious complication of the syndrome. We speculate that coexistent OSA promotes progressive aortic dilatation in some patients with Marfan's syndrome.     

Acute aortic dissection complicated with acute myocardial infarction--a case report of successful operation for the case of DOA

A 61-year-old woman who suddenly manifested chest and back pain was admitted after the diagnosis of acute type A dissection complicated with acute inferior myocardial infarction at another hospital. While being transported to our hospital by ambulance, her ECG repeatedly demonstrated ventricular fibrillation of cardiac arrest. She was in the state of dead on arrival (DOA) when arrived at our hospital. ECG demonstrated complete A-V block and cardiac arrest alternately. However, soon after right ventricular pacing was done, her blood pressure increased and she recovered consciousness. We therefore performed an emergency operation. We performed reconstruction of the ascending aorta and right coronary bypass grafting, since she had aortic dissection and conus brach avulsion. The postoperative course was uneventful.     

Substrate specificity of human prolyl-4-hydroxylase

BACKGROUND: The mechanism responsible for the forward blood flow associated with external chest compression is still controversial. Evidence for both blood flow caused by direct cardiac compression and blood flow generated by a general increase in intrathoracic pressure has been found in experimental as well as clinical studies. No data are available concerning the mechanism causing forward blood flow in hypothermic patients undergoing cardiopulmonary resuscitation. Therefore, echocardiographic findings during external chest compression in seven hypothermic arrest victims are reported. METHODS: All transesophageal echocardiographic studies performed at the Anaesthesia department between 1994 and 1997 were reviewed and seven hypothermic patients with transesophageal echocardiography performed during cardiopulmonary resuscitation were identified. RESULTS: An open mitral valve or a circumferential reduction in aortic diameter during the compression phase was found in four of seven patients, indicating that primarily an increase in intrathoracic pressure (thoracic pump mechanism) generated forward blood flow. In three patients, mitral valve closure during external chest compression indicated that direct cardiac compression (cardiac pump mechanism) contributed to forward blood flow. Two patients studied during active compression-decompression cardiopulmonary resuscitation demonstrated enhanced right ventricular filling and aortic valve opening during active decompression of the thorax. CONCLUSIONS: In contrast to normothermic arrest victims, an open mitral valve during external chest compression is a common finding during hypothermia, indicating that thoracic pump mechanism is important for forward blood flow during cardiopulmonary resuscitation in hypothermic arrest victims. Aortic valve opening in two hypothermic arrest victims suggests forward blood flow also during active decompression of the thorax with the Cardiopump.     

Rupture of a dissecting aneurysm into the superior vena cava in Marfan's syndrome

Aneurysmal dilatation of the aorta with subsequent dissection or rupture occurs frequently in patients with Marfan's syndrome. These complications are among the major causes of death. We report the case of a 51-year-old man with annulo-aortic ectasia in Marfan's syndrome. Acute aortic dissection and rupture into the superior vena cava occurred 8 years after aortic valve replacement. The preoperative diagnosis was made by right heart catheterization and computed tomography. A markedly increased left-to-right shunt occurred with rapid enlargement of the fistula due to the fragility of the aortic wall characteristic of Marfan's syndrome. Postmortem examination demonstrated severe medial necrosis with rupture of the aortic wall into the superior vena cava which was adherent to the suture line of the aortotomy from the previous surgery. Type A aortic dissection with severe congestive heart failure strongly suggested rupture into the pulmonary circulation.     

Visceral, hematologic and bacteriologic changes and neurologic outcome after cardiac arrest in dogs. The visceral post-resuscitation syndrome

We studied the post-resuscitation syndrome in 42 healthy dogs after normothermic ventricular fibrillation cardiac arrest (no blood flow) of 7.5, 10, or 12.5 min duration, reversed by standard external cardiopulmonary resuscitation (CPR) (< or = 10 min) and followed by controlled ventilation to 20 h and intensive care to 72 h. We reported previously, in the same dogs, no difference in resuscitability, mortality, or neurologic outcome between the three insult groups. There was no pulmonary dysfunction, but post-arrest cardiovascular failure, of greater severity in the 12.5 min arrest group. This report concerns renal, hematologic, hepatic and bacteriologic changes. Renal function recovered within 1 h after arrest, without permanent dysfunction. Clotting derangements at 1-24 h postarrest reflect transient disseminated intravascular coagulation with hypocoagulability, more severe after longer arrests, which resolved by 24 h after arrest. Hepatic dysfunction was transient but more severe in the animals that did not recover consciousness and correlated with neurologic dysfunction, but not with brain histologic damage. Bacteremia was present in all animals postarrest. We conclude that in the previously healthy organism after cardiac arrest of 7.5-12.5 min no flow, visceral and hematologic changes, although transient, can retard neurologic recovery.     

Aortic compliance measured by non-invasive Doppler ultrasound: application of a personal computer based MkII system and its repeatability

A non-invasive pulse-wave-velocity Doppler ultrasound technique for the assessment of aortic compliance is described. A computational approach for correcting for the effect of non-chronic changes in blood pressure is considered and applied to compliance measurements performed on an age-select cohort of 70 normotensive, normal healthy volunteers. In order to permit the wider availability of the pulse-wave-velocity Doppler ultrasound technique, the authors have developed a MkII system based on a standard 80486/33 MHz IBM compatible WINDOWS based personal computer; real-time spectral analysis being achieved using a relatively inexpensive but fast analogue to digital signal processing card. An overview of the new apparatus is provided and verification work to compare the repeatability of the MkI and MkII systems is described. Medical disorders such as atherosclerosis, diabetes mellitus, familial hypercholesterolaemia, growth hormone deficiency, and Ehlers-Danlos and Marfan's syndromes have all been shown to affect arterial wall compliance. We suggest that the in vivo clinical measurement of blood pressure corrected aortic distensibility using the MkII system may be a useful, reproducible, non-invasive tool for assessing such patients' susceptibility to atheromatous arterial disease as well as for monitoring their response to therapeutic interventions. Measurements in the aorta may be especially pertinent since the natural history of fatty streaks there tends to parallel that in the coronary vasculature thereby potentially affording a convenient surrogate estimate of coronary heart disease.     

Predictors of outcome from critical illness. Shock and cardiopulmonary resuscitation

Many of our patients in ICUs suffer from shock, be it due to sepsis, trauma, arrest, or other causes. These patients continue to have a very high mortality rate in spite of very labor intensive and expensive treatment. The ability to identify patients who are likely to succumb to their illness is of utmost importance. Of the multitude of scoring systems published, the APACHE seems to accurately stratify shock patients according to severity of illness. However, these systems tend to be more useful for stratifying risk groups of patients than assessing the risk of death. Hemodynamic data can specifically assess the severity of the shock state in an individual patient. Those who maintain a relatively low cardiac index (< 4.5 L/m/M2) and oxygen delivery (< 15 mL/m/kg or 600 mL/m/M2) have persistent tissue hypoperfusion. Arterial lactate concentrations reflect the severity of this perfusion defect and correlate with outcome. Therefore, by restoring tissue perfusion, we can clearly improve mortality. CPP, although not generally obtainable during cardiac arrest, is the major physiologic determinant of outcome from CPR. ETCO2 monitoring during cardiac arrest in humans correlates with resuscitability, however, provides a rapid noninvasive monitor of cardiac output, and therefore has secured its role as an invaluable tool for assessing the effectiveness of CPR. An ETCO2 over 10 mm Hg is associated with effective CPR. A rapid rise in ETCO2 during CPR heralds recovery of spontaneous circulation. In conclusion, the use of prognostic indicators as predictors of outcome is supported as an important adjunct to the management of critically ill patients. These indicators serve as useful monitors to evaluate treatment and guide clinical management. Understanding the underlying pathophysiologic mechanisms responsible for the wide variety of illnesses associated with circulatory failure is crucial in our concerted effort to reduce mortality in these patients. As knowledge is gained, we hopefully will be able to develop more accurate and specific predictors of outcome to prudently select patients most likely to benefit.     

Cardiac tamponade during transesophageal echocardiography in the patient of circumferential aortic dissection

A 43-year-old woman, whose physical findings were consistent with Marfan's syndrome, presented with acute chest pain. Transthoracic two-dimensional echocardiography demonstrated dilated ascending aorta with a circular shape intimal flap at the root level. Subsequently, the patient required transesophageal echocardiography (TEE), but during esophageal intubation, the patient developed acute pericardial tamponade which resulted in death in spite of cardiopulmonary resuscitation. Although, some investigators recommend TEE as the first choice of diagnostic method of aortic dissection, hemodynamic stability is very important during TEE study. Therefore, aggressive sedation may be required in the case of circumferential dissection of the ascending aorta to prevent the increases of the blood pressure and the heart rate which suggested an extensive tear of the aortic intima during TEE procedure.     

Combined surgery for coronary artery disease and thoracic aortic disease

Combined surgery in 6 cases who had coronary artery disease and thoracic aortic disease simultaneously was analyzed. Case # 1 had ascending aortic replacement under deep hypothermic circulatory arrest because of iatrogenic aortic dissection caused by aortic clamp during the routine coronary artery bypass grafting (CABG). Case # 2 had DeBakey type II chronic dissection. Case # 3 had type I aortic dissection 4 years after the initial CABG. Both case # 2 and # 3 had ascending aortic replacement under retrograde cerebral perfusion along with CABG. Transverse aortic replacement was performed in case # 4, # 5 and # 6 under selective cerebral perfusion along with CABG. Case # 4 was associated with ascending-transverse aortic aneurysm. Case # 5 had aortitis syndrome complicated with severe coronary ostial stenosis and cervical branch stenosis. Case # 6 also had aortitis syndrome, severe coronary ostial stenosis, heavily calcified ascending-transverse aorta, and mitral and aortic regurgitation. This case had mitral and aortic valve replacement additionally. Case # 2 died of low cardiac output syndrome and multi-organ failure postoperatively. Case # 4 did not recover from profound shock that followed the preoperative acute myocardial infarction. The problems of low cardiac output syndrome caused by long interval of ischemic cardiac arrest, and also the problems of proximal anastomotic site of saphenous vein grafts were discussed.