T. James Gallagher

Management of the agitated intensive care unit patient

Agitation: 1. Violent motion. 2. Strong or tumultuous emotion. Management of the agitated patient is fast becoming an area of major breakthroughs for critical care medicine. To illustrate, Figure 1 shows the total number of articles found on MEDLINE using a combination of search words related to sedation and critical care. This crude survey demonstrates an exponential rise in activity surrounding this topic and helps support the view that study of agitation in the critically ill patient is of rapidly expanding importance. Moreover, management of the agitated patient has developed into an economically powerful subject, both for pharmaceutical companies and for caregivers interested in improving the efficient use of intensive care unit (ICU) resources. It is increasingly apparent that outcomes are significantly influenced by the manner in which agitation is managed. The quantity of articles being published is only part of the picture. Investigations related to agitation in critical care are yielding a variety of intriguing observations including post-traumatic stress disorder and post-ICU depression, diagnosis of delirium, objective monitoring technology, sleep pattern changes, process/management strategies to enhance clinical and economic outcomes, scoring systems, tailorability of therapeutic approaches, and bronchodilatory, antioxidant, and immunosuppressive properties of sedative agents. Rather than simply discussing strategies for sedation, it is the deliberate intent of this continuing education program to focus on the specific topic of agitation (in the ICU patient). It is noteworthy that, although it is one of the most common issues facing critical care practitioners, agitation in the ICU has no clear and concise definition. The simple definition stated at the beginning of this article is from Funk and Wagnall’s 1982. This explanation of “agitation” has merit because it encompasses both physical and emotional distress. Under this characterization, either the nonsedated paralyzed patient or the comatose patient with patient-ventilator asynchrony can be considered agitated, even though the two may represent opposite ends of a spectrum. Accurate diagnosis of the cause of agitation frequently requires a careful analysis of the patient’s history and physical examination, review of laboratory and other diagnostic data, knowledge of the effectiveness of concomitant therapies, collaboration among members of the team and family, and a good deal of experience. The cause of agitation is often multifactorial (e.g., pain and confusion or delirium and withdrawal), and even with successful management it is difficult to be certain about precipitating factors in any single case. Anecdotes from patients and clinicians can serve as powerful tools for the critical care team’s armamentarium and help increase understanding from both sympathetic and empathetic perspectives. Pharmacologic management strategies for agitation include both prevention and treatment. Prevention commonly guides the hand of the critical care clinician when a patient is being stabilized and drips are ordered for analgesia and sedation in anticipation of agitation. Fine-tuning the therapy using agitation scales, daily awakening, and other strategies take on more of a treatment quality, as do pro re nata (PRN) agitation orders. Nonpharmacological approaches include a variety of environmental adjustments that are frequently underutilized. Yet, as obvious as these concepts for definition, diagnosis, and management may seem, it is difficult to consistently apply them to the literature (with the exception of short-term usage). There are a number of well-designed and wellexecuted studies in longer-duration agitation management but, excluding those in very focused populations (e.g., neurologic injury), most studies lump patients into groups for the purpose of assessing differing sedative regimens. Comparative pharmaceutical trials have been extraordinarily important to clinicians who deal regularly with agitation. These studies, as well as trials using innovative management techniques, are becoming increasingly sophisticated in the area of pharmacoeconomic assessment. There is still, however, a paucity of comprehensive studies evaluating the integration of economic, clinical, and humanistic outcomes of agitated ICU patients. Existing economic analyses include variables such as drug acquisition costs, ventilator duration, and ICU length of stay (LOS) to determine the “cost effectiveness” of one drug regimen over another; these are often only partial in their scope. Assigning or assuming costs for time in ICU or on a ventilator is fraught with the problems of evaluating the fixed and variable components. Opportunity costs are usually ignored, as they are exceedingly difficult to determine. And, failure to include post-ICU cost and outcome information ignores the post-ICU morbidity that appears linked to ICU sedation usage. These types of problems with economic analyses are widespread in the critically ill population and are not unique to the topic of agitation management. Notwithstanding, it can be said with a reasonable degree of confidence that the drug acquisition cost of various regimens is only one—often small—piece of the larger economic puzzle. Given the current tide of activity, it is conceivable that the approach to managing agitation in the critically ill patient will rise (or is rising) to a new level of sophistication. At this new level, pharmacologic and nonpharmacologic approaches will be highly selective and finetuned to more precisely address the Copyright

Craniotomy for Intracranial Aneurysm and Subarachnoid Hemorrhage Is Course, Cost, or Outcome Affected by Age?

BACKGROUND AND PURPOSE Age may influence cost or effectiveness of treatment for subarachnoid hemorrhage (SAH). This study examined the effect of age on both. METHODS Patients (n = 219) who underwent craniotomy for intracranial aneurysm and SAH over 6 years at one tertiary care center were divided in two ways by age: single advanced age (< 65 years and > or = 65 years) and decade of age (23 to 39, 40 to 49, 50 to 59, 60 to 69, and 70 to 81 years). Data recorded for each patient included numbers of procedures and complications in the surgical intensive care unit (SICU), number of days in the SICU and the hospital, costs for SICU and ward care, total cost (SICU plus ward costs), and the Acute Physiology and Chronic Health Evaluation (APACHE) II score at admission and discharge, the Hunt-Hess grade at admission and immediately preoperatively, and quality of life score, a measure of outcome. Mortality rates by age group were calculated. RESULTS The only variable significantly affected by decade of age was mortality rate, which increased as decade of age increased (3% to 17%). With the 65-year comparison, mortality rate, cost, APACHE II score at admission and discharge, days before operation, and days in the SICU were significantly higher for age > or = 65 years. CONCLUSIONS Whereas mortality is higher for the older age group, quality of life scores appear acceptable for those who survive. Even though the hospital costs of treating elderly patients for SAH may be higher than those for younger patients, this should not be used to justify withholding care from the elderly.

High-frequency percussive ventilation compared with conventional mechanical ventilation

In seven patients with severe respiratory distress, conventional mechanical ventilation and PEEP were used initially for respiratory support, which was changed to high-frequency percussive ventilation (HFPV) at the same level of airway pressure and FIO2. During both modes of ventilation, patients could breathe spontaneously via a low-threshold demand valve. With HFPV, PaO2 improved significantly (p < .01) compared with PaO2 during conventional methods. Cardiac output was unaffected by the change to HFPV.

A simplified method of independent lung ventilation

The authors have developed a new method for independent lung ventilation (ILV). After lung isolation with a double-lumen endotracheal tube, one ventilator with two subunits controls independent lung tidal volume (VT) and PEEP to each lung. A modified bird Mark 2 ventilator serves as a pneumatically powered timer activating two sets of parallel inspiratory-expiratory flow cartridges. Intermittent mandatory ventilation (IMV) with PEEP or controlled mechanical ventilation (CMV) with PEEP can be provided. This ventilator has been successfully used to treat patients with severe unilateral disease. Desirable qualities include simplicity of operation, availability of parts, and low cost.

Diltiazem to treat sinus tachycardia in critically ill patients: A four-year experience

ObjectivesTo determine whether an intravenous infusion of the calcium channel blocker diltiazem was effective and safe in treating sinus tachycardia in critically ill adult patients with contraindications to &bgr;-blockers or in whom &bgr;-blockers were ineffective. DesignRetrospective chart review. SettingUniversity medical center. PatientsThe records of 171 surgical intensive care unit patients with sinus tachycardia treated with intravenous diltiazem were evaluated. InterventionsIn all patients with sinus tachycardia (heart rate >100 beats/min), heart rate control with intravenous diltiazem was attempted after adequate intravascular volume expansion, pain, and anxiety control. In all patients, &bgr;-blockade either was contraindicated or (in 7%) had failed. Intravenous diltiazem was administered as a slow 10-mg bolus dose (0.1–0.2 mg/kg ideal body weight), and then an infusion was started at 5 or 10 mg/hr and increased up to 30 mg/hr, as needed, to decrease heart rate to <100 beats/min. Variables retrospectively collected included demographic data, preinfusion blood pressure, mean arterial pressure, heart rate, and preinfusion pressure-rate quotients (pressure-rate quotient = mean arterial pressure ÷ heart rate). Intravenous bolus dose, when given, and diltiazem infusion rate and time necessary to achieve the target heart rate also were recorded. The lowest heart rate recorded within 24 hrs from the initiation of the infusion and the time necessary to achieve the lowest heart rate after beginning the infusion were recorded. Measurements and Results Of 171 patients studied, 97 (56%) were classified as responders. Multiple linear regression suggested that response could be predicted by age, pressure-rate quotients, baseline mean arterial pressure, and central nervous system failure. In the responders, a heart rate <100 beats/min was achieved in an average of 2 hrs, at a mean diltiazem infusion of 13.3 mg/hr. The lowest rate reached by the responders in a 24-hr period averaged 86 beats/min and was achieved in 4.8 hrs with a mean infusion rate of 14.8 mg/hr. Both target and lowest rate values were statistically different from baseline heart rate. ConclusionDiltiazem was effective in achieving short-term control of heart rate in 56% of the patients, virtually without adverse effects, where &bgr;-blockade was contraindicated or ineffective.

Effects of hetastarch resuscitation on extravascular lung water and cardiopulmonary parameters in a sheep model of hemorrhagic shock

Eight sheep, weighing 29-71 kg, were used to evaluate the cardiopulmonary response to Hespan infusion following shock. Before shock was induced, mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAP), cardiac output (CO), extravascular lung water (EVLW), colloid oncotic pressure (COP), and hemoglobin were measured and shunt, arteriovenous oxygen content difference (C[a - v]O2) and COP-PCWP gradient were calculated. The animals were bled to a MAP of 50 mmHg and that level was maintained for 30 min. At the end of that time, the data were collected again. The animals were resuscitated back to baseline values of PCWP, MAP, and CO with a 6% hydroxyethylstarch solution. With shock, PCWP, MAP, CO, and arterial pH decreased and C(a - v)O2 increased significantly (P less than 0.05). With resuscitation, PAP, PCWP and CO were significantly greater than baseline. Arterial pH was less than the baseline value but was within normal range. MAP did not return to preshock levels. EVLW and venous admixture did not change at any time. C(a - v)O2 returned to baseline with resuscitation. Volume of hetastarch infused was 29.1 +/- 10 cm3/kg. We conclude that hetastarch is an effective resuscitation solution in a model of hemorrhagic shock and appears to have no adverse cardiopulmonary effects.

Medical Malpractice for Critical Care

RITICAL CARE malpractice means care that does not meet the standard expected by all practitioners of critical care, regardless of specialty. That care should not be judged differently regardless of the practitioners primary specialty. We obviously presume that the physicians involved willingly participated in the care of critically ill patients. Furthermore, such care does not necessarily have to be delivered in the intensive care unit (ICU) itself but at any location in the hospital where a patient may be critically ill The standard does not change by geographic location or hospital. Perhaps the only exceptions would be situations in which general practitioners or other non-critical care providers would find themselves caring for sick patients in isolated circumstances with no other competent medical help available. No doubt, the standards would be lowered in such cases.

Tolerability profile on continuous intravenous midazolam in critical care patients

This review summarizes the tolerability profile of midazolam administered as a continuous intravenous (IV) infusion to patients in the intensive care unit (ICU) who are receiving mechanical ventilation. Midazolam is a short-acting benzodiazepine indicated for intramuscular administration for preoperative sedation; for IV administration for conscious sedation prior to short diagnostic, therapeutic, or endoscopic procedures; and for IV administration for induction of general anesthesia. The drug can also be used for short surgical procedures as a component of IV supplementation. Because of its favorable properties (short half-life, ease of titration of infusion, and favorable tolerability profile), midazolam is used as a sedative agent for critically ill patients requiring mechanical ventilatory support. No clinically significant differences with respect to laboratory, hemodynamic, respiratory, neurologic, or monitoring variables have been reported between continuous IV midazolam and propofol, lorazepam, or diazepam. No adverse events were reported in association with the administration of midazolam by continuous infusion other than those previously identified in the short-term use of midazolam. Mortality rates for midazolam were no greater than those previously reported for critically ill patients receiving mechanical ventilation. The tolerability profile indicates that the continuous IV infusion of midazolam in critically ill patients who require mechanical ventilation in the ICU will not result in any significant clinical problems.

The Septic Patient: Future Directions

In order to provide some insights into potential new therapies for sepsis, we must contend with a new terminology proposed by a joint consensus conference of the Society of Critical Care Medicine and the American College of Chest Physicians. Systemic Inflammatory Response Syndrome (SIRS) describes the body’s widespread response to inflammation. Sepsis is a subcategory for those with documented infection. Multiple Organ Dysfunction Syndrome is the reflection of the degree of organ damage from the systemic inflammatory response syndrome.1 This can be direct or indirect injury.

Cardiac Anesthesia and Oxygen Delivery and Uptake in The Critically Ill

This chapter will include a discussion of anesthetic agents used in cardiac anesthesia, as well as a discussion on oxygen transport in the critically ill patient. Other specific aspects such as cardiopulmonary bypass will be found elsewhere.