Perioperative considerations for the patient on herbal medicines.

Herbal medicines have enormous presence in the United States health care system. There is an increasing trend towards reimbursement of herbal medicines by insurance companies, which further encourage their utilization. Herbs are listed under the "supplement" category by the Food and Drug Administration. The Dietary Supplement and Health Education Act signed into law in October 1994, requires no proof of efficacy, no demonstration of safety, and sets no standards for quality control for the products labeled as "supplements" thereby increasing the risk of adverse effects of these herbs. The United States has experienced an epidemic of over-the-counter "natural" products over the last two decades; but there is little motivation for the manufactures to conduct randomized, placebo-controlled, double-blinded clinical trials to unequivocally prove the safety and efficacy of these drugs. Physicians, irrespective of their specialty, should not underestimate the potential risks associated with the use of herbs as reports indicate that within the last two decades, more than 100 herbogenic deaths have occurred, many serious complications have been reported, patients have required renal dialysis, renal transplantation and hepatic transplantation after taking botanicals. Internists must inquire about the patient's use of herbal products. In addition, the education of each patient regarding the serious, potential drug-herb interactions should be a routine component of preoperative assessment. The American Society of Anesthesiologists (ASA) recommends that all herbal medications should be discontinued 2-3 weeks prior to an elective surgical procedure. If the patient is not sure of the content of the herbal medicine, he/she should be urged to bring the container so that an attempt can be made to review the contents of the preparation. While such an action holds some promise in the elective setting, emergency care should be based on a thorough drug-intake history from the patient or a relative, if possible. Medical research and medical literature in general has not addressed this new group of health supplements, despite the fact that many of these herbs have the potential to cause serious health problems and drug interations. There is a need to conduct scientific clinical trials to study the anesthetic drug responses to commonly used neutraceutical agents.

Effects of garlic extract (Allium sativum) on neutrophil migration at the cellular level.

Studies of the effects of garlic extract on oxidative and lipoprotein levels have yielded widely different findings. Leukocytes play an important role during many processes, including inflammation. They migrate from intravascular spaces into tissues and attack microorganisms. In a recent study, the inhibitory effects of the nonsteroidal antiinflammatory drug, ibuprofen, on leukocyte transmigration were demonstrated using an in vitro assay. Little is known about the cellular effects of garlic extracts (Allium sativum). The aim of the current study was to investigate the influence of garlic extract on leukocyte migration through endothelial cell monolayers and thereby evaluate a possible role in inflammatory processes. Human umbilical endothelial cells were cultured on microporous membranes to make an endothelial cell monolayer (ECM). Freshly isolated neutrophils were used in a recently described migration assay. The amount of untreated neutrophils migrating through the untreated ECM was used as control and set at 100%. Neutrophils and/or ECM were pretreated with garlic extract using moderate, higher, and lower concentrations. Moderate plasma concentrations of garlic extract inhibited neutrophil migration through ECM significantly (64 +/- 5.8% standard deviation [SD]; P < 0.05) when both cell types were treated, (a situation that may have clinical relevance). Treating either neutrophils or ECM alone showed significant reductions in migratory rate (neutrophils treated alone: 81 +/- 7.7% SD, P < 0.05; ECM alone: 70 +/- 6.7%, P < 0.05). Thus, garlic extract is identified as a potent inhibitor of leukocyte migration through endothelial cell monolayers. Treatment of both cell types has an additive effect. Endothelial cells seem to be more affected than neutrophils. Further investigations are necessary to understand the potential clinical consequences.

Perioperative considerations for the patient taking herbal medicines.

There has been a significant increase in the proliferation and use of dietary supplements known as neutraceuticals. Since 1994, herbal products have been regulated by the Dietary Supplement Health and Education Act (DSHEA), which does not require burden of proof to demonstrate premarketing safety and efficacy studies. Scientific literature and government policies have not adequately addressed this fast-emerging group of more than 20,000 health supplements. Lack of purity and standardization of these agents, combined with minimal education in traditional homeopathic medical education, has led to serious health-related problems including arrhythmias, cardiovascular compromise, strokes, and deaths. Even though 30% of our traditional medicines are derived from botanicals, most physicians are either unfamiliar or unwilling to develop any level of expertise with neutraceuticals. A review emphasizing perioperative considerations is provided of the history of herbal medicines, governmental policies, and specific herbal agent-drug interactions.

Garlic extract (allium sativum) reduces migration of neutrophils through endothelial cell monolayers.

Leukocytes play an important role during inflammation. They migrate from intravascular spaces into tissues and attack micro-organisms. In a recent study, the inhibitory effects of the non-steroidal anti-inflammatory drug, ibuprofen, on leukocyte transmigration were demonstrated using an in vitro assay. Little is know about the cellular effects of garlic extracts (allium sativum). The aim of the current study was to investigate the influence of garlic extract on leukocyte migration through endothelial cell monolayers and thereby evaluate a possible role in inflammatory processes. Human umbilical endothelial cells were cultured on microporous membranes to make an endothelial cell monolayer (ECM). Freshly isolated neutrophils were used in a recently described migration assay. The amount of untreated neutrophils migrating through the untreated ECM was used as control and set at 100%. Neutrophils and/or ECM were pre-treated with garlic extract using moderate, as well as higher and lower concentrations. Moderate plasma concentrations garlic extract inhibited neutrophil migration through ECM significantly (64 +/- 5.8% SD; P < 0.05), when both cell types were treated, (a situation that may have clinical relevance). Treating either neutrophils or ECM alone showed significant reductions in migratory rate (neutrophils treated alone: 81 +/- 7.7% SD, p < 0.05; ECM alone: 70 +/- 6.7%, p < 0.05). Thus, garlic extract is identified as a potent inhibitor of leukocyte migration through endothelial cell monolayers. Treatment of both cell types has an additive effect. Endothelial cells seem to be more affected than neutrophils. Further investigations are necessary to understand the potential clinical consequences. During inflammation, neutrophils play an important role. They migrate rapidly from the vascular space into tissues to destroy invading micro-organisms. During migration through endothelial cell monolayers (ECM), neutrophils undergo morphologic changes from rounded, relatively smooth cells to elongated, ruffled cells with pseudopodia. Recently, the influence of the non-steroidal anti-inflammatory drug, ibuprofen, on leukocyte function was investigated using an in vitro double chamber migration assay that includes ECM. Garlic extract (allium sativum) is a widely used "over the counter" herbal preparation. The effect of garlic on lipid metabolism is well documented. Previous studies have examined the influence of the extract on leukocyte function, e.g. respiratory burst. The effect of garlic on thrombocyte aggregation has also been recently described as has an anti-fungal effect. To our knowledge, nothing is known about the effect of garlic leukocyte transmigration. Therefore, we aimed to examine the effects of garlic extract on leukocyte transmigration through ECM in an in-vitro cell co-culture system.

Cardiac surgery in patients with protamine allergy.

Intravenous administration of protamine is associated with risk of severe anaphylactic and anaphylactoid reactions. In this review the incidence, pathophysiology, clinical management, and strategies for prevention of protamine reactions are addressed.

Assessment of right ventricular function by right ventricular systolic time intervals in acute respiratory failure.

OBJECTIVE: Whether right ventricular systolic time intervals accurately reflect right ventricular function in patients with acute respiratory failure was determined by assessing the correlation between right ventricular systolic time intervals and the right ventricular end-systolic pressure-volume relationship. DESIGN: A prospective study. SETTING: A surgical intensive care unit in a university hospital. PATIENTS: Twenty patients with acute respiratory failure. MEASUREMENTS AND MAIN RESULTS: Right ventricular systolic time intervals were determined by the simultaneous graphic display of the electrocardiogram, the phonocardiogram, and the pulmonary artery pressure curve and were expressed as a ratio of the pre-ejection period/right ventricular ejection time. The total electromechanical systole was measured from the onset of the electrocardiographic wave complex to the pulmonic component of the second heart sound. Right ventricular ejection time was measured from the rapid upstroke of the pulmonary artery pressure curve to the dicrotic notch. Right ventricular ejection fraction, from which right ventricular end-systolic volume was derived, was measured by the thermodilution technique. Pulmonary artery dicrotic notch pressure was used as an estimate of right ventricular end-systolic pressure. Data were collected at the baseline and after one or two alterations in preload, to define the right ventricular end-systolic pressure-volume relationship line. There was an inverse correlation between the pre-ejection period/right ventricular ejection time ratio and the slope of the right ventricular end-systolic pressure-volume relationship line (r2 = .67; p < .0001). When patients were divided into two groups, based on the pre-ejection period/right ventricular ejection time ratio, the slope of the right ventricular end-systolic pressure-volume relationship line was lower in the group with a high pre-ejection period/right ventricular ejection time ratio (p < .0001). No difference in other hemodynamic data, between the two groups, was noted. CONCLUSIONS: These data suggest that right ventricular systolic time intervals reflect right ventricular performance accurately in patients with acute respiratory failure.

Anaesthesia for the patient with acquired immune deficiency syndrome--a review.

Acquired immunodeficiency syndrome affects over 10 million persons worldwide. The disease represents an enormous cost to society in health care resources and in loss from the workforce. Although initially reported in 1980 as a disease affecting mainly homosexuals and intravenous drug abusers with a predominance in males, the male to female ratio was close to parity by 1992. The disease attacks all systems in the body. Preanaesthetic evaluation focuses on assessment of lung function and presence of infection, evaluation of endocarditis and treatment of congestive failure, rehydration and correction of electrolyte imbalances, transfusion and documentation of central nervous system manifestations. The Center for Disease Control and Prevention has produced guidelines to protect health care workers from transmission of the virus. Although the risk of infection is extremely low, these precautions should be routinely adopted.

Perioperative management of the head trauma patient.

Realizing that miracle drugs that can reverse severe brain damage have not yet been identified, studies in recent years have focused on identifying risk factors for head trauma and resuscitative events that might impede or improve outcome. Risk factors for poor outcome include advanced age, alcoholism, delay in transfer and operation, management errors and technical mistakes. Quality assurance programmes, now established in all United States hospitals, may be flawed in that assessments of preventable trauma deaths are often based on unsubstantiated subjective case review methods. Studies of the cerebral effects of anaesthetic agents have reconfirmed the detrimental effects of nitrous oxide in the trauma victim. Ketamine, a N-methyl D-aspartate receptor antagonist, has shown surprising cerebral protective effects in animal models. Appropriate fluid therapy after head injury requires avoidance of sugar-containing solutions, maintenance of normovolaemia and consideration of use of hypertonic solutions to maintain vascular volume. Although hypothermia continues to be an appealing means of affording brain protection after head injury, the degree and duration have still not been established. Establishment of the airway in the neck injured patient should be by careful endotracheal tube placement which causes less cervical movement than mask ventilation and less risk of infection or trauma than the nasotracheal route.

Extracorporeal shock wave lithotripsy of gall stones: an in vitro comparison between an electrohydraulic and a piezoceramic device.

A comparative study of the effectiveness of two types of lithotripter in fragmenting gall bladder stones is reported. The machines used were a Piezolith 2300, which generates shock waves by the piezoceramic principle, and a Dornier MPL 9000, which produces the shock waves by underwater spark discharge. With each machine, corresponding stones of 45 pairs of weight and volume matched calculi (median volume 0.5 cm3, median diameter 10.5 mm) obtained at cholecystectomy were treated. All stones were successfully disintegrated (fragments smaller than 2 mm) with up to 5400 (median 628) shocks with the Piezolith and 3450 (median 428) shocks with the MPL 9000 lithotripters. With the Piezolith, operating at the highest power setting, a 1.65 fold median higher number of shocks was required for stone fragmentation than with the MPL 9000 at a medium power setting. Stone volume seemed to be the only determinant which affected ease of fragmentation; composition and density of the stones as assessed by computed tomography did not seem to be governing factors.