Eric L. Bloomfield

The Influence of Scalp Infiltration with Bupivacaine on Hemodynamics and Postoperative Pain in Adult Patients Undergoing Craniotomy

After craniotomy, hypertension may contribute to intracerebral hemorrhage.We studied whether scalp infiltration with bupivacaine during craniotomy reduces postoperative pain and hypertension. In a double-blind fashion, 36 adult patients (ASA physical status II or III) undergoing elective craniotomy were randomly assigned to receive scalp infiltration with either bupivacaine (0.25%) and epinephrine (1:200,000) or saline/epinephrine (1:200,000) for skeletal fixation, skin incision, and wound closure. Heart rate (HR) and mean arterial pressure (MAP) were measured after anesthesia induction, after skull-pin insertion, after scalp infiltration, during dural closure, during skin closure, on admission to postanesthesia care unit (PACU), and 1 h after admission. Visual analog pain scores were recorded in the PACU. MAP was significantly greater in the saline group at scalp infiltration. HR was significantly faster in the saline group at dural and skin closure. The bupivacaine group reported significantly less pain than the saline group at PACU admission and 1 h after admission. Pain scores did not correlate with hemodynamic measurements. We conclude that scalp infiltration with 0.25% bupivacaine with 1:200,000 epinephrine blunts certain intraoperative hemodynamic responses and reduces postoperative pain but has no effect on postoperative hemodynamics. Implications: We sought to evaluate whether scalp infiltration with bupivacaine and epinephrine at the beginning and end of craniotomy would afford more intra- and postoperative hemodynamic stability and influence immediate postoperative pain. We found that intraoperative hemodynamics were not influenced greatly; however, craniotomy patients do have significant postoperative pain, which does not seem to have an influence on hemodynamics in the postanesthesia care unit. (Anesth Analg 1998;87:579-82)

The effect of craniotomy location on postoperative pain and nausea

AbstractPurpose. At least one retrospective study has suggested that the need for postoperative control of pain and nausea depends on the location of the cranial surgery. This prospective study was performed to examine the hypothesis that patients who have had infratentorial craniotomy experience more severe pain and more frequent nausea than those with supratentorial procedures. Methods. We compared postoperative outcomes in 28 patients with infratentorial craniotomy, 53 with supratentorial craniotomy, and 47 with complex spinal cord surgery (the control group). Anesthesia was standardized for all three groups and the concentration of isoflurane was titrated to keep mean arterial pressure within 30% of preoperative values. Severity of pain and frequency of nausea and vomiting were recorded for 24 h after surgery. Pain was assessed with a verbal pain score scale of 0–10, with 10 being the worst pain imaginable. Data were collected for 24 h postoperatively. Results. Because nausea and pain diminish drastically 2 h after surgery, pairwise differences were assessed at each point within the first 2 h. Within 30 min of extubation, median pain scores in the supratentorial and spine groups rose to 2 and in the infratentorial group to 5. The statistical differences between groups were not significant (P > 0.06) by logistic regression. Also, the incidence of nausea was not significantly different (57% supratentorial, 57% spine, 67% infratentorial; P = 0.62) by Dunn’s procedure. Conclusion. There were no significant differences in the severity of pain or the frequency of nausea based on the craniotomy site.

Effect of cranial surgery and brain tumor size on emergence from anesthesia

Background Knowing which neurosurgical patients are at risk for delayed awakening may lead to better utilization of intensive care resources and avoid the risk and cost of pharmacologic reversal and diagnostic tests. Methods The authors compared anesthetic emergence from complex spinal surgery (spine; n = 47) with that from craniotomy for supratentorial nonfrontal (n = 22), frontal (n = 34), or posterior fossa tumor (n = 28). A further comparison involved patients with small versus large (diameter > 30 mm, mass effect) tumors. The standardized anesthetic regimen consisted of induction with 2-4 mg/kg sup -1 thiopental and 1-2 micro gram/kg sup -1 sufentanil, followed by maintenance with nitrous oxide, 0.2-0.5 micro gram *symbol* kg sup -1 *symbol* h sup -1 sufentanil and less or equal to 0.5% isoflurane. Sufentanil administration was terminated on dural or spinal muscle closure, isoflurane during skin closure, and nitrous oxide during dressing application. After discontinuing nitrous oxide, a minineurologic examination was performed every 15 min for 1 h, then hourly for 4 h and at 24 h. Results Craniotomy patients performed less well than spinal surgery patients on the minineurologic examination 15 and 30 min after discontinuing nitrous oxide. At 15 min, fewer patients with large (vs. small) tumors were oriented to time (58% vs. 87%; P < 0.01) or place (67% vs. 90%; P < 0.01). Forty-two percent of patients with large tumors still had an abnormal minineurologic examination score versus 15% of patients with small tumors. At 30 min, these values were 28% and 8%, respectively (P < 0.05). Seventy-one percent of patients with large tumors were oriented to time compared to 97% for small lesions (P <0.01). Emergence from anesthesia was similar for spinal surgery patients and patients with small brain tumors. Conclusion Patients undergoing craniotomy for large intracranial mass lesions awaken more slowly than patients after spinal surgery or craniotomy for small brain tumor.

The impact of economics on changing medical technology with reference to critical care medicine in the United States.

Over the past 20 yr, health care expenditures in the United States have exploded, resulting in a 4.5-fold increase per year when adjusted for inflation and population growth. In 2000, 13.2% of the US gross national product was spent on health care (1), but life expectancy is not as long in the United States as in countries such as Japan, which spend much less of their domestic output on health care (Table 1) (2). Within the United States, there are also large discrepancies in life expectancies among racial groups (Fig. 1). One percent of the US gross national product is being spent on critical care services, accounting for roughly 5% of all patients cared for and 20% of all health care expenditures (3). Different states vary in amounts spent on health care (Fig. 2). The national per capita expenditure for health care amounted to

Analysis of catecholamine and vasoactive peptide release in intracranial arterial venous malformations

4637 in the United States in 2000 (1). As “baby boomers” age and require more health care resources, this figure could increase to as much as

Cardiovascular collapse during anesthesia in a patient with preoperatively discontinued chronic MAO inhibitor therapy

25,000 by the year 2020. Health care economists such as Folland et al. (4) believe that the increasing costs of health care can be attributed to three factors: the moral hazard of insurance, increased technology, and asymmetry of information. Newhouse (5) describes five factors associated with increased health care expenditures: increased insurance usage, aging, increase in income, increases in supplier-induced demand, and miscellaneous factors producing problems in the service sector. The purpose of this article is to examine how these factors interact to drive critical care costs and to identify ways to make technology more cost-effective. We will consider the roots of the problem, the necessity for technology assessment, and possible solutions.

The anesthesia information management system for electronic documentation: what are we waiting for?

Craniotomy for resection of cerebral arterial venous malformation has been associated with postoperative hypertension, which necessitates administration of large doses of antihypertensive medications to control blood pressure. Controlling blood pressure is essential because hypertensive episodes can lead to postoperative cerebral hemorrhage with increases in morbidity and mortality. We measured vasoactive peptide and catecholamine release in 13 patients who underwent resection of an arterial venous malformation and in a control group of 6 patients who presented for clipping of unruptured cerebral aneurysms. Plasma renin activity, angiotensin I and II, vasopressin, aldosterone, epinephrine, and norepinephrine levels were measured intraoperatively and for 36 h postoperatively. Analysis of variance was used to assess sample and group effects. A significant interaction between sample and groups was found for norepinephrine (p < 0.001) and renin (p = 0.002). Our data suggest that elevated plasma renin and norepinephrine levels are in part responsible for postoperative hypertension in patients undergoing resection of arterial venous malformations. Blocking the release of these hormones may help control blood pressure after surgery for removal of arterial venous malformations.

The ethics of rationing of critical care services: should technology assessment play a role?

Abstract We describe a patient in whom long-term monoamine oxidase (MAO) inhibitor therapy was discontinued 20 days before surgery with general anesthesia. This patient developed severe perioperative hypotension after administration of 10 mg of bupivacaine through an epidural catheter, which was corrected only after potent vasopressor therapy. We attribute this hemodynamic instability to attenuation of this patients sympathetic tone based on several mechanisms: (1) residual effect of long-term administration of MAO inhibitor that caused a decrease in the number of β-adrenergic receptors (adrenergic subsensitivity due to receptor down-regulation), (2) recovered MAO activity causing effective degradation of sympathetic amines, and (3) combined attenuating effects of general and epidural anesthesia on sympathetic tone.

A decision support model for prescribing internal cardiac defibrillators

The anesthesia information management system (AIMS) will be part of the future of healthcare. An electronic medical records system or AIMS will provide clear and concise information and have the potential to integrate information across the entire hospital system, improve quality of care, reduce errors, decrease risks, and improve revenue capture. The practice of anesthesia requires a medical record system that can capture data in real time. In this article, we describe challenges that must be overcome to establish an efficient electronic medical record system for anesthesiology.

Cerebral Blood Flow (CBF) and Cerebral Metabolic Rate (CMR)

The costs of health care continue to increase rapidly and steeply in the United States. One area of great expense is that of intensive care units (ICUs). The causes of inflation have not been addressed effectively. ICU resources could become stretched such that they may no longer be available. This paper discusses some of the ethics and concerns behind decision making when providing ICU services in the United States. In particular, the use of electronic records with decision making tools, risk-analysis methods, and documentation of patient wishes for extraordinary care may help with better utilization of resources in the future.