Perioperative pulmonary complications.

PURPOSE OF REVIEW: This article reviews current concepts in perioperative pulmonary management. RECENT FINDINGS: Preoperative risk assessment tools for perioperative pulmonary complications (POPCs) are evolving for both children and adults. Intraoperative management strategies have a demonstrable effect on outcomes. Late POPCs may be preceded by clinical signs. SUMMARY: POPCs are common and lead to significant resource utilization. Optimal POPC risk mitigation must span all phases of surgical care. Preoperative assessment may identify patients at risk and effectively lower their risk by identifying targeted interventions. Intra-operative strategies impact postoperative outcome. POPCs continue to be a concern for several days postoperatively. We review the current literature on this broad subject with a focus on implementable interventions for the clinician.

Fluids for prevention and management of acute kidney injury.

Fluids are the only known method of attenuating renal injury. Furthermore, whether for hydration, resuscitation or renal replacement therapy, fluid prescriptions must be tailored to the fluid and electrolyte, cardiovascular status and residual renal function of the patient. Different fluids have significantly different effects both on volume expansion as well as on the electrolyte and acid-base balance; while controversial, different fluids may even influence renal function differently. This systematic review focuses on fluids for prevention and management of acute kidney injury. We have reviewed the available evidence and have made recommendations for clinical practice and future studies.

On the location of the sulfhydryl group in bovine plasma albumin.

A series of spin labels has been empolyed to explore the environment of the sulfhydryl group in bovine plasma albumin. The spin labels consist of the nitroxide-free radical and a maleimide (or iodoacetamide)-attaching group separated by varying chain lenghths. Both sets of spin labels preferentially bind to the sulfhydryl group under appropriate conditions. From the change in the electron spin resonance spectra of these nitroxides as a function of chain length, we conclude that the sulfhydryl group is located in a crevice approx. 9.5 A in depth.

Disrupted latent inhibition in the rat with chronic amphetamine or haloperidol-induced supersensitivity: relationship to schizophrenic attention disorder.

Latent inhibition (LI) is an attentional process by which animals learn to ignore a stimulus that is repeatedly presented without reinforcement. This ability to tune out a motivationally irrelevant stimulus is disrupted by pharmacological manipulations producing hyperdopaminergic states. In Experiment I, LI was disrupted following five daily administrations of 4 mg/kg d-amphetamine. In Experiment II the disruptive effects of d-amphetamine were eliminated by concomitant administration of chlorpromazine. Experiment III showed that LI could also be disrupted with 1 mg/kg d-amphetamine coupled with dopamine receptor supersensitivity produced by prolonged pretreatment with haloperidol. These data suggest that pharmacological disruption of LI may provide an animal analogue of the defective stimulus filtering thought to characterize at least some forms of schizophrenia.

The phosphocreatine overshoot occurs independent of myocardial work.

Although the exact mechanism(s) responsible for the phosphocreatine/ATP overshoot have not been completely elucidated, our data demonstrate that the overshoot does not stem from reduced myocardial work, and consequently, reduced utilization of phosphocreatine (PCr). Additionally, we highlight a basic difference in the physiologic responses of skeletal and cardial muscle to work demands. By understanding the bioenergetic derangements which accompany reperfusion injury, one may hope to better salvage post-ischemic myocardium.

Synthesis of chiral and achiral pyranenamine derivatives. Potent agents with topical ocular antiallergic activity.

The SS, RR and meso stereoisomers of pyranenamine SK&F 84210 were synthesized stereospecifically starting from commercially available (R)-(-)- or (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol. In addition, two achiral pyranenamines 19 and 26 were also synthesized. When evaluated by intravenous and topical routes in the rat passive ocular anaphylaxis (POA) assay, (SS)- and meso-2 as well as achiral compounds 19 and 26 were found to be more potent antiallergic agents than (RR)-2.

Replacement of the carboxylic acid group of prostaglandin f(2alpha) with a hydroxyl or methoxy substituent provides biologically unique compounds.

Replacement of the carboxylic acid group of PGF(2alpha) with the non-acidic substituents hydroxyl (-OH) or methoxy (-OCH(3)) resulted in an unexpected activity profile. Although PGF(2alpha) 1-OH and PGF(2alpha) 1-OCH(3) exhibited potent contractile effects similar to 17-phenyl PGF(2alpha) in the cat lung parenchymal preparation, they were approximately 1000 times less potent than 17-phenyl PGF(2alpha) in stimulating recombinant feline and human FP receptors. In human dermal fibroblasts and Swiss 3T3 cells PGF(2alpha) 1-OH and PGF(2alpha) 1-OCH(3) produced no Ca(2+) signal until a 1 microM concentration was exceeded. Pretreatment of Swiss 3T3 cells with either 1 microM PGF(2alpha) 1-OH or PGF(2alpha) 1-OCH(3) did not attenuate Ca(2+) signal responses produced by PGF(2alpha) or fluprostenol. In the rat uterus, PGF(2alpha) 1-OH was about two orders of magnitude less potent than 17-phenyl PGF(2alpha) whereas PGF(2alpha) 1-OCH(3) produced only a minimal effect. Radioligand binding studies on cat lung parenchymal plasma membrane preparations suggested that the cat lung parenchyma does not contain a homogeneous population of receptors that equally respond to PGF(2alpha)1-OH, PGF(2alpha)1-OCH(3), and classical FP receptor agonists. Studies on smooth muscle preparations and cells containing DP, EP(1), EP(2), EP(3), EP(4), IP, and TP receptors indicated that the activity of PGF(2alpha) 1-OH and PGF(2alpha) 1-OCH(3) could not be ascribed to interaction with these receptors. The potent effects of PGF(2alpha) 1-OH and PGF(2alpha) 1-OCH(3) on the cat lung parenchyma are difficult to describe in terms of interaction with the FP or any other known prostanoid receptor.

Amiodarone keratopathy. Correlation to dosage and duration.

Amiodarone hydrochloride, a benzofurane derivative used for the treatment of cardiac arrhythmias, is known to cause a verticillate epithelial keratopathy, which has been classified into three stages. Patients receiving low dosages of 100 to 200 mg of amiodarone daily retain clear corneas or show stage 1 changes only, regardless of duration of treatment or total amount of substance ingested. Patients receiving higher dosages of 400 to 1,400 mg/day show stage 2 and 3 changes, depending on duration of treatment. This keratopathy progresses, even with reduced dosage; however, complete regression occurs once administration of medication is discontinued.

Increased mesolimbic dopamine binding following chronic haloperidol treatment.

It is well documented that chronic neuroleptic treatment creates a dopamine receptor supersensitivity in the striatum. The present study examined the effect of chronic neuroleptic treatment on mesolimbic dopamine receptor binding. Rats received either 0.5 mg/kg of haloperidol, 50 mg/kg of sodium phenobarbital, or 0.9% saline daily for 21 days. One week following the last injection, the rats were sacrificed and the septi were removed for the 3H-dopamine binding assay. Haloperidol treatment resulted in a 52% increase in 3H-dopamine binding in the septum, whereas phenobarbital treatment caused no significant change.

The pharmacology of bimatoprost (Lumigan).

Bimatoprost (Lumigan) is a pharmacologically unique and highly efficacious ocular hypotensive agent. It appears to mimic the activity of a newly discovered family of fatty acid amides, termed prostamides. One biosynthetic route to the prostamides involves anandamide as the precursor. Bimatoprost pharmacology has been extensively characterized by binding and functional studies at more than 100 drug targets, which comprise a diverse variety of receptors, ion channels, and transporters. Bimatoprost exhibited no meaningful activity at receptors known to include antiglaucoma drug targets as follows: adenosine (A(1-3)), adrenergic (alpha(1), alpha(2), beta(1), beta(2)), cannabinoid (CB(1), CB(2)), dopamine (D(1-5)), muscarinic (M(1-5)), prostanoid (DP, EP(1-4), FP, IP, TP), and serotonin (5HT(1-7)). Bimatoprost does, however, exhibit potent inherent pharmacological activity in the feline iris sphincter preparation, which is prostamide-sensitive. Bimatoprost also resembles the prostamides in that it is a potent and highly efficacious ocular hypotensive agent. A single dose of bimatoprost markedly reduces intraocular pressure in dogs and laser-induced ocular hypertensive monkeys. Decreases in intraocular pressure are well maintained for at least 24 hr post-dose. Human studies have demonstrated that systemic exposure to bimatoprost is low and that accumulation does not occur. The sclera is the preferred route of accession to the eye. The high scleral permeability coefficient Papp is a likely contributing factor to the rapid onset and long-acting ocular hypotensive profile of bimatoprost.

Safe intraaortic balloon pump placement through the ascending aorta using transesophageal ultrasound.

Intraaortic balloon pumping salvages a substantial number of patients who fail to be weaned from cardiopulmonary bypass after an open heart operation. Patients with severe peripheral vascular disease may require ascending aortic balloon pump insertion. We describe a simple method of direct aortic puncture for intraaortic balloon pump placement using transesophageal ultrasound as a means of avoiding complications during insertion and documenting correct balloon position.

Infected biatrial myxoma: transesophageal echocardiography-guided surgical resection.

We identified a biatrial myxoma using transesophageal echocardiography whose right atrial component was missed with conventional transthoracic techniques. Identifying the biatrial component directs a safer approach to right heart catheterization. Infected biatrial myxomas are both rare and successfully managed using prolonged intravenous antibiotic therapy followed by resection. Atrial septal defects created during the resection of an infected myxoma may be safely repaired using a prosthetic patch.

The American Academy of Dermatology's response to managed care and capitation.

Managed care is an important part of the health care delivery system; consequently, dermatologists are seeking information about various managed care plans and are joining them. Managed care can encompass a variety of different systems, including preferred provider organizations, health maintenance organizations, and individual practice associations. They all provide health care services to enrolled members through a defined network of providers who are given the responsibility to provide quality medical care while controlling use and access to specialists. Many members of the American Academy of Dermatology (AAD) respond in surveys that education in various aspects of managed care is an area of great importance to them.

Studies on a novel series of acyl ester prodrugs of prostaglandin F2 alpha.

A novel series of prostaglandin F2 alpha (PGF2 alpha) prodrugs, with acyl ester groups at the 9, 11, and 15 positions, was prepared in order to design clinically acceptable prostaglandins for treating glaucoma. Studies involving isolated esterases and ocular tissue homogenates indicated that 9-acyl esters cannot provide a prodrug since PGF2 alpha would not be formed as a product. In contrast, 11-mono, 15-mono, and 11, 15-diesters were converted to PGF2 alpha in ocular tissues and could, therefore, be considered as prodrugs of PGF2 alpha. Carboxylesterase (CE) appeared critically important for the hydrolytic conversion of those PGF2 alpha prodrugs where the 11 or 15-OH group was esterified and such prodrugs were not substrates for acetylcholinesterase (ACHE) or butyrylcholinesterase (BuCHE). The enzymatic hydrolysis of PGF2 alpha-1-isopropyl ester was also investigated for comparative purposes. This PGF2 alpha prodrug was a good substrate for CE, but was also hydrolysed by BuCHE, albeit at a much slower rate. The most striking feature of the enzymatic hydrolysis of PGF2 alpha-1-isopropyl ester in ocular tissue homogenates was that it was much faster than for prodrugs esterified at the 11 and/or 15 positions. In terms of ocular hypotensive activity, all prodrugs which showed detectable conversion to nascent PGF2 alpha were potent ocular hypotensives. Although no separation of ocular hypotensive and ocular surface hyperaemic effects was apparent for PGF2 alpha-1-isopropyl ester, a temporal separation of these effects was apparent for the novel PGF2 alpha ester series. This difference may reflect an unfavourably rapid conversion of PGF2 alpha-1-isopropyl ester in ocular surface tissues compared with anterior segment tissues.

Can preclinical medical students be integrated into the continuing medical education process by instructing prehospital care providers?

OBJECTIVE: To develop a model introducing medical students (MS) to the continuing medical education (CME) process while simultaneously developing a curriculum to enhance the relevant surgical anatomy knowledge base of the advanced prehospital care provider. METHODS: A CME curriculum for teaching human anatomy was developed and approved by the governing state agencies for prehospital education. The curriculum focused on structures relevant to the prehospital care of the trauma patient in a case based format using common scenarios presented by surgery and emergency medicine faculty. Five year-one medical students who completed gross anatomy served as teaching staff and were given a structures list one week prior to the CME course. Human cadavers were prosected by the medical students prior to the CME program under the guidance of the surgical faculty. Course attendees and medical student staff were anonymously surveyed at the end of the program (rating scale 1 = low to 5 = high). Prehospital providers were given a multiple-choice posttest and surveyed at 3 months after the course with regard to applicability to their current practice. Data are means +/- SD. RESULTS: Nineteen licensed practicing paramedics attended the course. All of the paramedics scored above the 85% passing cutoff on the posttest (95. 6% +/- 6.2%). Instructor qualities were rated highly (4.62 +/- 0.49) with no instructor rating less than a 3. MS believed themselves well prepared to teach (5 +/- 0), and spent 2 +/- 0.81 hours in preparation. They were only infrequently faced with questions they were not well prepared to answer (1.25 +/- 0.5) and would uniformly participate in CME offerings in the future (5 +/- 0). The CME program improved the MS view of CME (3 +/- 0), prehospital education (3 +/- 1.4), and the surgeon as educator (3.25 +/- 1.5). At 3 months, the paramedics felt that the CME program significantly impacted the care they rendered (4.37 +/- 0.76), and improved their understanding of injury complexes (4.53 +/- 0.61), and resuscitation (4.26 +/- 0. 73). The cadaver course was uniformly recommended to coworkers (5 +/- 0). CONCLUSIONS: This model provided prehospital care providers direct contact with clinically relevant human anatomy, enhanced their understanding of pertinent anatomy, and positively impacted their patient care. MS were introduced to the CME process and found it to be one with which they would become reinvolved. Furthermore, the MS felt prepared to present human anatomy, met the expectations of the course attendees, improved their understanding of prehospital education, and positively altered their perception of the surgeon as an educator. This process holds promise as both a model for prehospital education and as a tool for integrating MS into the role of allied health educator early in their career.

Technique of sacral hernia repair.

After sacrectomy, a hernial defect may develop through the pelvic floor at the reconstructed sacral bed. This complication has not previously been described. We describe a technique for repair of such a defect using a prosthetic patch. Accurate and safe repair of this hernia requires correct preoperative diagnosis and planning, including a thorough knowledge of pelvic floor anatomy.

Traumatic hematuria in patients with polycystic kidney disease.

Autosomal dominant polycystic kidney disease (PKD) is the most prevalent hereditary disorder in this country and a common cause of chronic renal failure. Patients frequently present with hematuria as the initial manifestation of PKD. We describe a patient with gross hematuria after blunt trauma who was found to have previously undiagnosed PKD. We review present diagnostic and treatment modalities and suggest potential management strategies for surgeons caring for patients presenting with traumatic hematuria and PKD.

Unilateral disk edema following tripod fracture repair necessitating optic nerve decompression.

Compression of the intracanalicular portion of the optic nerve as a complication of repair of a zygomaticomaxillary fracture is possible in the setting of multiple orbital fractures. This is a case report of optic canal compression of the optic nerve as a results of a delayed repair of a tripod fracture using the lateral approach. This occurred in the setting of a severely fractured orbit and resulted in florid unilateral disk edema, visual loss, and an afferent pupil defect. After optic canal decompression, vision was restored and the disk edema resolved. However, the afferent pupil defect has persisted. This is as yet an unreported complication of zygomaticomaxillary fracture repair.

Atlanto-occipital dislocation: an unusual lethal airbag injury.

Airbag-induced injury fatality is increasing in frequency. We present the case of a 6-year-old passenger who sustained a fatal atlanto-occipital dislocation associated with airbag deployment in a low-speed motor vehicle crash. The current literature regarding airbag fatalities and methods to ameliorate airbag-induced injury are reviewed.

Video recording trauma resuscitations: a guide to system set-up, personnel concerns, and legal issues.

Video recording trauma resuscitations has great merit with respect to healthcare-provider education, clinical research, and quality improvement. This paper addresses systems equipment problems, provider concerns, and legal issues that surround the implementation of a video recording system in the resuscitation suite.