Richard Teplick

Cardiovascular, pulmonary, and renal effects of massively increased intra-abdominal pressure in critically ill patients

Massive elevation of intra-abdominal pressure (IAP) causes cardiovascular, respiratory, and renal dysfunction. We managed eight patients with high IAP (mean 51 +/- 7 cm H2O), six of whom had hemodynamic measurements; a clinical syndrome, characterized by hemodynamic, respiratory, and renal dysfunction, then became apparent. We report a) a baseline cardiopulmonary profile and response to an acute vascular volume challenge in six patients and b) surgical decompression of the abdomen in four patients. The clinical impression of hypovolemia was confused by small to normal left ventricular end-diastolic volume (64 +/- 14 ml) and normal ejection fraction (55 +/- 6%) despite very high right and left atrial filling pressures. Complete ventilatory support was necessary to maintain oxygenation and ventilation; oliguria (urine output less than 10 ml/h) was present. Pericardial effusion was absent. After fluid challenge (10 ml/kg of colloid or crystalloid infused iv over 10 min), filling pressures, cardiac output, and stroke volume all increased significantly (p less than .025) while heart rate decreased. Surgical decompression of the abdomen improved oxygenation, ventilation, cardiac output, atrial filling pressures, and urine output within 15 min. The cardiovascular effects of massively elevated IAP compounded by the requisite supportive care may require surgical relief.

Transperitoneal versus retroperitoneal approach for aortic reconstruction: A randomized prospective study*

A prospective, randomized study was conducted to compare the retroperitoneal versus transperitoneal approach for elective aortic reconstruction. One hundred thirteen patients (transperitoneal = 59, retroperitoneal = 54) were randomized between March 1987 and October 1988. In addition, to assess the changing course of patients undergoing aortic reconstruction similar data were gathered retrospectively on a group of 56 patients undergoing aortic reconstruction by the same surgeons performed via a transperitoneal approach in 1984 to 1985. Randomized patients were identical in age, male to female ratio, smoking history, incidence and severity of cardiopulmonary disease, indication for operation, and use of epidural anesthetics. Details of operation including operative and aortic cross-clamp times, crystalloid and transfusion requirements, degree of hypothermia on arrival at the intensive care unit, and perioperative fluid and blood requirements did not differ significantly for patients undergoing transperitoneal versus retroperitoneal reconstruction. Respiratory morbidity, as assessed by percent of patients requiring postoperative ventilation, deterioration in pulmonary function tests, and the incidence of respiratory complications, was identical in randomized patients. Other aspects of postoperative recovery including recovery of gastrointestinal function, the requirement for narcotics, metabolic parameters of operative stress, the incidence of major and minor complications, and the duration of hospital stay were similar for randomized patients undergoing transperitoneal and retroperitoneal reconstruction. When compared to retrospectively reviewed patients having aortic reconstruction, randomized patients undergoing transperitoneal and retroperitoneal operations had highly significant (p less than 0.001) reductions in postoperative ventilation, transfusion requirements, and length of hospital stay. Such trends were all independent of transperitoneal versus retroperitoneal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative cardiovascular effects of midazolam and thiopental in healthy patients

Midazolam, a water-soluble benzodiazepine that is shorter-acting, more potent, and less irritating to veins than diazepam, has been suggested for use for induction of anesthesia. The cardiovascular effects of an induction-sized dose (0.25 mg/kg) of midazolam in A. S. A. class I or II surgical patients (N = 11) sedated with morphine and N2O-O2were compared in a double-blind fashion with a similar group of patients (N = 9) receiving thiopental (4.0 mg/kg). Consistent with earlier studies, patients given thiopental experienced downward trends from base line in mean arterial pressure, stroke volume, cardiac output, and heart rate; mean right a trial pressure increased slightly, whereas systemic vascular resistance did not change. Induction of anesthesia with midazolam was associated with more gradual and less pronounced hemodynamic alteration; the only significant changes from base line were decreases in mean arterial pressure 5 and 10 minutes after injection. When the two groups were compared, no significant differences were found. Midazolam is, then, as acceptable for induction of anesthesia as thiopental from a hemodynamic point of view in A. S. A. class I and II patients.

Effect of labetalol or lidocaine on the hemodynamic response to intubation: A controlled randomized double-blind study

Labetalol, a combined alpha 1- and nonselective beta-adrenergic blocking drug, was compared to lidocaine or saline to minimize the hypertensive and tachycardic response to intubation in a controlled randomized double-blind study in patients undergoing surgical procedures under general anesthesia. Forty adult patients were divided into four groups of 10 each: placebo (saline), lidocaine 100 mg, labetalol 5 mg, or labetalol 10 mg. The double-blind preparation was administered as an IV bolus just prior to induction and 2 min before the stimulus of laryngoscopy and intubation. Heart rate and blood pressure were measured at 1-min intervals for 2 min prior to induction of anesthesia and through 6 min following induction of anesthesia. Labetalol 10 mg prevented a rise in heart rate after intubation compared to patients who received placebo, lidocaine 100 mg, or labetalol 5 mg. The hypertensive response to intubation was similar in all four groups. Labetalol 10 mg IV just prior to induction of anesthesia is a safe and cost-effective means of preventing tachycardia but not hypertension in response to laryngoscopy and intubation.

Cardiovascular effects of midazolam and thiopentone for induction of anaesthesia in Ill surgical patients

The cardiovascular effects of midazolam (0.15 mg kg-) and thiopentone (3.0 mg kg1) were compared during induction of anaesthesia in 20 American Society of Anesthesiologists class HI patients. In patients given thiopentone (N = 11), cardiac output, mean arterial pressure, heart rate, and systemic vascular resistance all decreased significantly over the course of the study period; mean right atrial pressure rose slightly, and stroke volume remained the same. Patients receiving midazolam (N = 9) experienced similar haemodynamic changes which were significant relative to baseline only for the fall in mean arterial pressure and the rise in mean right atrial pressure at ten minutes. There were no significant differences between the two groups. Midazolam thus appears to be at least as acceptable an induction agent as thiopentone in ill patients, from a haemoaynamic point of view.RésuméOn a comparé les effets cardiovasculaires obtenus pendant I’administration de I’anesthésie avec le midazolam (0.15 mg kg-1) et le thiopentone (30 mg kg1) chez 20patients appartenant ä la Classe III (American Society of Anesthesiologists). Chez les patients recevant le thiopentone (N = 11), on a observé que le débit cardiaque, la fréquence cardiaque, la résistance vasculaire générale et la tension artérielle ont baissé sensiblement durant le cours de notre recherche. La pression moyenne de I’auriculaire cardiaque droite haussa faiblement tandis que le débit systolique resta le même. Les patients auxquels on administra le midazolam (N = 9) ont éprouvé des changements hémodynamiques significatifs par rapport à la valeur de base oi l’on observa settlement une baisse de la pression artérielle moyenne et une hausse à dix minutes de la pression moyenne de l’ auriculaire cardiaque droite. Il n’y a done pas áe différences significatives entre les deux groupes. Le midazolam apparaît être un agent d’induction aussi acceptable que le thiopentone chez les malades, au point de vue hémodynamique.

Benefit of Elective Intensive Care Admission After Certain Operations

To determine if patients who have undergone uneventful vascular surgery (VS), nonvascular intracranial surgery (ICS), or anterior cervical laminectomies (ACL) have enough serious postoperative problems to justify routine overnight observation in an intensive care unit (ICu), we recorded every problem and associated therapy administered to 263 such patients within 36 h of ICu admission. The severity of each treated problem was graded from 1 (safe to delay treatment for at least 2 h) to 4 (life-threatening, immediate treatment required). Defining patient benefit from the ICu as treatment for one grade 4 problem or more than one grade 3 problem, 44% of VS patients (N = 177), 14% of ICS patients (N = 73), and none of the ACL patients (N = 13) benefited. We conclude that these percentages justify an overnight ICu stay for all VS patients, especially as the occurrence of serious problems was unpredictable and most serious problems were still being treated 4 h postoperatively. Furthermore, routine ICu admission of all patients in the groups studied would reduce patient costs if only 13 of the 88 patients who benefited were prevented from becoming critically ill.

Pulmonary artery catheter redux: Physical findings in acute respiratory distress syndrome/acute lung injury

their efforts given the limitations of these studies. What can we conclude from this systematic review? The answer is that combining a variety of studies with different diagnostic criteria, variable quality, different designs (matched and unmatched), and high degree of heterogeneity does not produce results that we can be confident of. Furthermore, the finding that VAP was not associated with attributable mortality in the ARDS and trauma populations, in which there was little heterogeneity, should give rise to further thought. At the minimum, this systematic review should lead us to question accepted dogma and ask whether appropriately treated VAP does cause significant attributable mortality. In this respect, the debate continues (7). Because observational data in regard to the attributable mortality of VAP are all that we will ever have, studies of more methodological rigor are required if we are going to answer this important question. Case control studies need to be better matched for the prognostic factors of VAP outcome. No studies have conducted a propensity analysis of VAP mortality, and this may be useful in view of the large number of factors that may influence mortality (8). Furthermore, better definition of the groups being compared, along with better diagnostic modalities, are required. Without these, the controversy will continue without resolve. John Muscedere Queen’s University Kingston, Ontario, Canada