Showing papers in "Critical Care Medicine in 1975"

Reduction in colloid osmotic pressure associated with fatal progression of cardiopulmonary failure

Abstract: The relationship between colloid osmotic pressure (COP) and the severity of cardiopulmonary failure was investigated in 99 consecutive patients admitted to our Shock Unit including 41 survivors and 58 fatal cases. The COP was significantly lower (p less than 0.001) in fatal cases in comparison to survivors. None of 21 patients in whom COP was less than 10.5 torr survived. A progressive increase in survival with typical S-shaped distribution was observed as COP increased from 10 to 19 torr, above which all patients survived. These preliminary observations demonstrated that reduction in COP in critically ill patients is associated with increases in mortality. The mechanisms by which lowering of COP may be related to fatal progression of cardiopulmonary failure is the subject of continuing study.

Influence of pH and hypoxia on the success of defibrillation.

Abstract: Clinical impressions about the problem of defibrillation during states of acid-base imbalance and hypoxia have been influenced by studies involving the effect of these derangements on the ventricular fibrillation threshold. Based on body weight, energy requirements for defibrillation in normal dogs were compared to requirements in dogs subjected to commonly encountered acid-base disturbances and severe hypoxemia. No significant differences were found. Seventy-five percent of all animals in the study were electrically converted with low-to-moderate levels of energy. The incidence of spontaneous resumption of circulation following defibrillation was lowest in animals subjected to metabolic acidosis and hypoxia. The results suggest that pH and blood gas alterations, previously shown to influence the normal ventricular fibrillation threshold, do not significantly affect the normal defibrillation threshold.

Errors in data derived from pulmonary artery blood gas values.

Abstract: Blood gas values were obtained from Swan-Ganz pulmonary artery catheters in 25 patients with acute pulmonary failure, with the objective of evaluating the possibility of contamination with "arterialized" blood and examining the mechanism by which this might happen. Blood oxygen content increased significantly from the main to a segmental pulmonary artery, proportional to the withdrawal rate of the sample. At 3 ml/min, distal contents ranged from 100 to 116% of proximal values (p less than 0.01). At 23 ml/min the range was 100-140% of proximal values (p less than 0.001). Sampling of blood from a Swan-Ganz catheter in the usual position for "wedge" pressure measurement, but with a balloon deflated, may lead to large errors in calculation of cardiac output by the Fick method and in calculation of intrapulmonary shunt fraction.

Second annual SCCM lecture. The role of hemodynamic monitoring in the management of the critically ill.

Abstract: Balloon flotation catheterization of the central circulation provides data which may be most meaningful and important to the management of critically ill patients. It allows the measurements of the filling pressures of the right and left ventricle as well as the cardiac output. These data combined with information concerning cardiac rhythm, heart rate, arterial pressure and other variables place the principal determinants of cardiac function at the disposal of the critical care personnel. In particular, the physician may optimize left ventricular filling pressure and then alter other functional determinants of cardiac performance so as to optimize the relationship of cardiac output to the metabolic needs of the body tissues and systems. Continued hemodynamic monitoring also provides prompt objective information as to success or failure of therapeutic interventions. It thereby allows for the most rational decision making and effective alteration in the therapy applied to the individual critically ill patient. Much still needs to be done to establish completely the impact of such monitoring techniques upon patient management. However, experience thus far has been most promising. Large numbers of physicians and health care personnel now rely on pressures provided by the pulmonary capillary wedge pressure in their decisions about fluid therapy. Others are rapidly assessing the importance of the cardiac output and other parameters of cardiac function on a semi-continuous basis. Thus, balloon flotation catheterization has allowed the application of sound physiological principles to the understanding of circulatory abnormalities characterizing important patient illnesses and provides a rational basis for the selection of therapy with objective quantitative assessment of responses. The procedures are simple; the complication rate is low, and the information provided is highly relevant to clinical practice.

A tongue stent for prevention of oral trauma in the comatose patient.

Abstract: This paper presents the need for and offers a solution to the problem of factitial tongue and other intra-oral injuries in comatose and decerebrate patients. The neurophysiology of jaw movement in the comatose patient is the basis for the design of an intraoral prosthesis which in two patients has prevented discoordinate mandibular chewing movements and facilitated healing of preexisting factitial lesions. The authors delineate in detail the fabrication, insertion, and maintenance of this protective prosthesis and emphasize the need for joint effort between the intensive care, neurosurgical, and oral surgical teams.

Management of subcutaneous emphysema, pneumomediastinum, and pneumothorax during respirator therapy.

Abstract: Pulmonary barotrauma developed in 18/430 patients receiving respirator support for longer than 12 hours. Pneumothorax occurred in 15 of these patients and was treated with tube thoracostomy and 15-20 cm H2O pleural suction. Full reexpansion of the lungs were achieved in all but three patients, two of whom had bronchopleural fistulae. Major complications occurred in 8/15 patients developing pneumothorax. We recommend extreme conservatism in clamping or removing tube thoracostomy. There should be no air leak and full lung expansion for 48 hours, followed by a trial of underwater seal drainage without recurrence of pneumothorax. Removal should be preceded by an additional trial of tube clamping.

The automated physiologic profile.

Abstract: The automated physiologic profile provides the critical care physician with hemodynamic, oxygen consumption and tissue utilization data at reasonable cost. A paramedical assistant performs all data acquisition, recordings and blood sampling procedures. Data reduction is performed through use of off-the-shelf desk-top calculator equipment and accessories and a standardized graphic display is provided for the physician in charge. The physiologic profile has been utilized in high-risk patients requiring medical and surgical interventions. It is routinely employed in postoperative monitoring of cardiac patients and patients undergoing major surgical procedures with associated cardiovascular decompensation. Diagnosis of cardiac and pulmonary deterioration and promptness of advanced support interventions represent additional areas of effective clinical application.

Thermodilution and Fick cardiac index determinations following cardiac surgery.

Abstract: With the thermodilution technique, repeated determination of cardiac index (CI) has become a rapid, easily accomplished, safe procedure. We paired 77 CI determinations measured by direct Fick and thermodilution techniques in 21 patients who underwent myocardial revascularization. Commercially available thermistor-tipped catheters and a cardiac output computer were used to determine CI according to the manufacturer's instructions. Oxygen consumption and arterial-venous oxygen content differences were measured directly to determine CI by the Fick method. Comparisons were made during mechanical ventilation with and without positive end-expiratory pressure (PEEP) and during spontaneous ventilation with and without PEEP. Cardiac indices measured by the two techniques were within +/- 0.5 L/min/m2 of each other only 76% of the time and within +/- 1.0 L/min/m2 96% of the time, if CI greater than or equal to 4.0 L/min/m2 were omitted. Ventilatory pattern had no apparent effect on results.

Pneumoperitoneum following tension pneumothorax. Report of two cases.

Abstract: Two cases of pneumoperitoneum following tension pneumothorax are described. Lungs in both patients had identifiable pathology and were ventilated with high inflation pressure and moderate positive end-expired pressure (PEEP). Laparotomy was performed in both patients with no evidence of intra-abdominal viscus perforations. A possible mechanism for the production of pneumoperitoneum is discussed.

Assessment of intra-aortic balloon counterpulsation in cardiogenic shock.

Abstract: Intra-aortic balloon pumping (IABP) has been shown to reverse the cardiogenic shock syndrome, but the long-term results (16 to 53% survival) have, in general, been disappointing. The most productive areas for the use of IABP are in the treatment of acute myocardial ischemia where in one report of 16 patients treated with IABP and surgery 15 survived and 13 were angina free, and in the open heart surgical setting where survival ranges from 42 to 70%. The implications of these treatment modalities are discussed.

Tissue Blood Flow and Oxygen Transport in Critically Ill Patients

Abstract: The expectation that oxygen might improve the ailing patient is nearly as old as the discovery of oxygen itself. The belief that his newly found “dephlogisticated air” would be of medical benefit was recorded by Joseph Priestly after the meager trial of being sampled by two mice and himself [35]. John Hunter proposed its use for resusciation in 1776 [21]. Since then, the desire to get more oxygen into patients has been pursued with great vigor, even though its pulmonary toxicity had been noted in the literature (albeit in mice) by 1796 [4]. Since then, the methodology, understanding, and limitations of getting more oxygen to the tissues have been, in large part, worked out. Now the problems of oxygen delivery have become so seemingly trivial that they are prematurely being treated with indifference by those who fund research programs. This will continue unless something dramatic is offered, such as extracorporeal oxygenation.

The therapeutic intervention scoring system. An application to acutely ill cancer patients.

Abstract: The Therapeutic Intervention Scoring System (TISS) has been introduced (Cullen DJ, Civetta JM, Briggs BA, et al: Therapeutic intervention scoring system: A method for quantitative comparison of patient care. Crit Care Med 2:57-60, 1974) at the Massachusetts General Hospital as a means of quantifying the medical and nursing care required by critically ill patients. The method has been instituted in the Intensive Care Unit of Memorial Cancer Center to evaluate its applicability to patients who develop life-threatening complications of their disease or its treatment. This is a preliminary report of the system's use in 55 consecutive patients who averaged 33.4 intervention points per day. This average compares closely with that of postcardiac surgery patients (31.8 points), the group that required the most care of all patients in the initial study. The results indicate the usefulness of this sytem in evaluating severity of illness, predicting survival, and assessing cost benefits. It has proven to be a simple and accurate method of assessment when simple and accurate method of assessment when applied to this patient population, but certain modifications seem warranted and have been suggested herein.

Hemodynamic patterns in shock and critically ill patients.

Abstract: Nine variables were studied in 56 patients to analyze hemodynamic patterns of critically ill and shock patients. The variables were central venous pressure, mean arterial pressure, heart rate, cardiac index, left ventricular stroke work, strok index, total peripheral resistance, arteriovenous oxygen difference, and oxygen consumption. We observed six patterns; three with low cardiac index (hypodynamic) and three with high cardiac index (hyperdynamic). Group IA: Low cardiac index with increased central venous pressure and arteriovenous oxygen differences associated with myocardial infarction, cardiac insufficiency, and postoperative cardiac surgery: Group IB: Low cardiac index with normal arteriovenous oxygen difference associated with myocardial infarction or hypovolemia. Group IC: Low cardiac index and decreased arteriovenous oxygen difference in patients with hypodynamic septic shock. Group IID: High cardiac index and increased arteriovenous oxygen difference in patients with sepsis and stable hemodynamic conditions. Groups IIE and IIF: Increased cardiac index and normal or increased arteriovenous oxygen difference in septic patients, who were hemodymamically unstable or in shock. These hemodynamic observations were found to be useful for understanding physiological compensations, for deciding on therapy, and in evaluating the effectiveness of therapy.

Effect of methylprednisolone on predicted myocardial infarction size in man.

Abstract: Therapeutic manipulations designed to conserve myocardium in patients with acute myocardial infarction appear to improve prognosis. To assess the role of glucocorticoids given in pharmacologic dosage in the early treatment of patients with acute myocardial infarction, serial serum creatine phosphokinase (CPK) were obtained every 1-2 hours in 39 consecutive patients admitted with acute myocardial infarction. Determination of completed infarction size (ISc) was made using all available CPK values (range 70-160 hours). Predicted infarct size (ILp) was based on early data following the rise in CPK from baseline values: projected CPK values were obtained over a 160 hour period using a curve fitting procedure based upon nonlinear Gauss-Newton stepwise iterations. In 13 uncomplicated control patients ISp was 43.2 +/- 11.6 (mean +/- SE) CPK-gram-equivalents (CPK-q-eq), based on data from the first 7 hours following the rise in serum CPK, while ISc was 44.7 +/- 11.4 CPK-geq (r = .99, n = 13). In 7 additional control patients whose hospitals courses were complicated by clinical extension ISp was 71.8 +/- 18.0 CPK-g-eq while ISc was 118.6 +/- 31.0 CPK-g-eq (p less than .03). In 19 patients treated with 3 grams of methylprednisolone 7-14 hours following the rise in serum CPK from baseline, data from early CPK determinations (7 hours) indicated an ISp of 118.5 +/- 24.1 CPK-g-eq while total CPK data indicate an ISc of 89.6 +/- 13.2 CPK-g-Eq (p less than .04). The exponential clearance of CPK (kd) was approximated in the controls (kd = .00095 +/- .00007 min-1) and glucocorticoid treated patients (kd = .00099 +/- .00006 min-1) and found to be similar. Thus, administration of a pharmacologic dose of methylprednisolone 7-14 hours following rise in serum CPK from baseline in a group of patients with acute myocardial infarctions has resulted in salvage of myocardium.

Studies of temperature balance after open-heart surgery.

Abstract: An analysis of postoperative records over a two-year period has shown that a mean rise in central body temperature greater than 2 degrees occurs in patients within 12 hours of return from the operating room following open-heart surgery. In some patients the central body temperature may rise to greater than 41 degrees C. despite an adequately warm peripheral temperature, and this is associated with a high mortality rate. An apparatus has been developed which enables the immediate enviroment of the patient to be controlled. A comparison of two groups of patients, in one of which the apparatus was used, demonstrated that it was possible to attenuate significantly the usual postoperative temperature rise seen in the control group. In a third group further cooling was employed: these patients were successfully held at subnormal temperatures. Using multiple temperature probes and heat balance formulas, it was shown that the rise in central body heat was due mainly to elevation of total body heat rather than the result of redistribution of heat from the surface.

Algorithm for resuscitation: a systematic plan for immediate care of the injured or postoperative patient.

Abstract: A systematic integrated approach to the diagnostic, monitoring and fluid volume therapy was developed for use in patients with accidental and elective surgical trauma. An algorithm (patient care protocol) is proposed for expeditious resuscitation in emergency situations using: (a) BP as the criteria for initiation of rapid fluid therapy, (b) hematocrit for the choice of blood transfusion or plasma expanders, and (c) CVP, urine output, arterial pressure and wedge pressure as criteria for slowing down or stopping the rate of volume therapy. History, physical examination, laboratory work, X-rays, monitoring and diagnostic procedures are interdigitated in a systematic fashion according to priorities of the most common life-threatening aspects of the total resuscitation problem. In chaotic emergency situations, it is impossible to plan for all possible contingencies; to try to do so results in an impossibly complex and unwiedly plan. However, we believe that almost any reasonable plan is better than no plan at all.

Cardiac function determined by echocardiogram.

Abstract: Echocardiographic analysis with a strip recorder gives an accurate assessment of cardiac function, easily obtainable at the bedside of the critically ill. Ejection fraction and velocity of circumferential fiber shortening (Vcf) are the two most accurate measurements of cardiac function. The diameter of the minor axis of the left ventricle is measured in systole (Ds) and diastole (Dd). Systolic volume is (Ds)-3, diastolic volume is (Dd)-3, ejection fraction is (Dd)-3-(Ds)-3 divided by (Dd)-3, Vcf is Dd-Ds divided by Dd times LVET.

Respirator weaning of the newborn: some practical considerations.

Abstract: Weaning of neonates from assisted ventilation or continous positive pressure breathing is a complex process. Unfortunately, at present we lack sensitive indices to measure the infant's ability to sustain spontaneous breathing. In the absence of such criteria we should rely heavily on clinical findings correlated with available biochemical data. Good clinical acumen and experience is necessary for successful weaning.