Remote wireless vital signs monitoring on the ward for early detection of deteriorating patients: A case series.

INTRODUCTION: Remote wireless monitoring is a new technology that allows the continuous recording of ward patients' vital signs, supporting nurses by measuring vital signs frequently and accurately. A case series is presented to illustrate how these systems might contribute to improved patient surveillance. METHODS AND RESULTS: Five hospitals in three European countries installed a remote wireless vital signs monitoring system on medical or surgical wards. Heart rate, respiratory rate and temperature were measured by the system every 2 min. Four cases of (paroxysmal) atrial fibrillation are presented, two cases of sepsis and one case each of pyrexia, cardiogenic pulmonary edema and pulmonary embolisms. All cases show that the remote monitoring system revealed the first signs of ventilatory and circulatory deterioration before a change in the trends of the respective values became obvious by manual vital signs measurement. DISCUSSION: This case series illustrates that a wireless remote vital signs monitoring system on medical and surgical wards has the potential to reduce time to detect deteriorating patients.

Cytochrome P450 1D1: a novel CYP1A-related gene that is not transcriptionally activated by PCB126 or TCDD.

Enzymes in the cytochrome P450 1 family oxidize many common environmental toxicants. We identified a new CYP1, termed CYP1D1, in zebrafish. Phylogenetically, CYP1D1 is paralogous to CYP1A and the two share 45% amino acid identity and similar gene structure. In adult zebrafish, CYP1D1 is most highly expressed in liver and is relatively highly expressed in brain. CYP1D1 transcript levels were higher at 9h post-fertilization than at later developmental times. Treatment of zebrafish with potent aryl hydrocarbon receptor (AHR) agonists (3,3',4,4',5-pentachlorobiphenyl or 2,3,7,8-tetrachlorodibenzo-p-dioxin) did not induce CYP1D1 transcript expression. Morpholino oligonucleotide knockdown of AHR2, which mediates induction of other CYP1s, did not affect CYP1D1 expression. Zebrafish CYP1D1 heterologously expressed in yeast exhibited ethoxyresorufin- and methoxyresorufin-O-dealkylase activities. Antibodies against a CYP1D1 peptide specifically detected a single electrophoretically-resolved protein band in zebrafish liver microsomes, distinct from CYP1A. CYP1D1 in zebrafish is a CYP1A-like gene that could have metabolic functions targeting endogenous compounds.

A quantum adiabatic evolution algorithm applied to random instances of an NP-complete problem.

A quantum system will stay near its instantaneous ground state if the Hamiltonian that governs its evolution varies slowly enough. This quantum adiabatic behavior is the basis of a new class of algorithms for quantum computing. We tested one such algorithm by applying it to randomly generated hard instances of an NP-complete problem. For the small examples that we could simulate, the quantum adiabatic algorithm worked well, providing evidence that quantum computers (if large ones can be built) may be able to outperform ordinary computers on hard sets of instances of NP-complete problems.

Environmental sensing and response genes in cnidaria: the chemical defensome in the sea anemone Nematostella vectensis.

The starlet sea anemone Nematostella vectensis has been recently established as a new model system for the study of the evolution of developmental processes, as cnidaria occupy a key evolutionary position at the base of the bilateria. Cnidaria play important roles in estuarine and reef communities, but are exposed to many environmental stressors. Here, I describe the genetic components of a "chemical defensome" in the genome of N. vectensis and review cnidarian molecular toxicology. Gene families that defend against chemical stressors and the transcription factors that regulate these genes have been termed a chemical defensome and include the cytochromes P450 and other oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters, oxidative detoxification proteins, as well as various transcription factors. These genes account for about 1% (266/27,200) of the predicted genes in the sea anemone genome, similar to the proportion observed in tunicates and humans, but lower than that observed in sea urchins. While there are comparable numbers of stress-response genes, the stress sensor genes appear to be reduced in N. vectensis relative to many model protostomes and deuterostomes. Cnidarian toxicology is understudied, especially given the important ecological roles of many cnidarian species. New genomic resources should stimulate the study of chemical stress sensing and response mechanisms in cnidaria and allow us to further illuminate the evolution of chemical defense gene networks.

Esophageal-directed pressure support ventilation in normal volunteers.

STUDY OBJECTIVES: To ascertain whether inspiratory pressure support (IPS) can be triggered reliably from and targeted at esophageal pressures (Pes), and to compare the work of breathing and time delay to initiation of inspiratory flow between conventional pressure support and esophageal-directed pressure support (EDPS). DESIGN: Prospective laboratory study. SETTING: University medical school. PATIENTS OR PARTICIPANTS: Five normal volunteers. INTERVENTIONS: IPS at a level to achieve tidal volume of 10 mL/kg, and EDPS with a target Pes of 0 cm H2O via full facemask. MEASUREMENTS AND RESULTS: Pes, airway pressure, and inspiratory flow were measured during spontaneous breathing. Peak Pes and pressure time product (PTP) of Pes were calculated during spontaneous breathing and through linear resistances. Measurements were repeated during IPS and EDPS ventilation. At rest, PTP was 7.56 (+/- 3.6) and peak Pes was -5.8 cm H2O (+/- 1.44). When subjects were breathing through the resistors, PTP increased to 12.4 (+/- 8.1) and 30.3 (+/- 8.9) and peak Pes decreased to -7.2 and -15.3 cm H2O respectively. With facemask IPS, unloaded PTP fell to 1.7 (+/- 1.3) and peak Pes fell to -3.3 cm H2O (+/- 1.3). When ventilated through the highest resistance with IPS, mean PTP increased to 21.9 and peak Pes increased to -11.9 (+/- 4.2) cm H2O relative to baseline. During EDPS with the resistor, PTP fell to 1.5+/-1.1 (p < 0.007) and peak Pes fell to -1.9+/-1.1 cm H2O (p < 0.0001). CONCLUSIONS: It was possible to initiate supported breathing from Pes values. The work performed, as measured by PTP, was lower during EDPS than during either unsupported breathing or conventional IPS.

Preoperative and intraoperative factors associated with prolonged mechanical ventilation. A study in patients following major abdominal vascular surgery.

A study of 51 patients undergoing elective major abdominal surgery was carried out to determine the incidence of postoperative respiratory failure requiring mechanical ventilation for more than 24 h and which preoperative and intraoperative factors are associated with this respiratory complication. Mechanical ventilation for more than 24 h was required in 12 of the 51 patients. These 12 patients had a significantly longer stay in the intensive care unit and in the hospital than the patients who were successfully extubated in the postoperative period. Also, there was a trend for a higher mortality in the ventilated group compared to the group of patients who did not require postoperative ventilation. Preoperative abnormalities in FEV1 did not identify which patients were destined to require postoperative ventilation. Significant differences for the ventilated versus the nonventilated patients included a longer history of cigarette smoking, a lower preoperative PaO2, and a large intraoperative blood loss.

The use of medical audits in surgical education.

Quality of medical care audits conducted in the form of a conference attended by surgical residents, faculty, and medical students accomplish the following: (1) provide an excellent educational experience for all participants; (2) are enthusiastically received by all concerned; (3) accomplish considerably more than audits performed in the manner prescribed by the Joint Commission on Accreditation of Hospitals (JCAH); and (4) fulfill JCAH/Professional Standards Review Organization (PSRO) requirements. This modified type of audit can be used successfully as a variant of a teaching seminar in which learning is more predictable because of the active participation of all concerned. Criteria sets which include simple and complex criteria must be developed if audits are to alter patterns of care for complex surgical problems.

Life expectancy following aortofemoral arterial grafting.

The existence of symptomatic aortoiliofemoral occlusive vascular disease would appear to result in approximately a 10 year decrease in life expectancy compared to that of the "normal" population. However, a significant proportion of the cumulative mortality rate appears to be due to both coronary artery disease and diabetes mellitus, as patients with peripheral vascular disease had a near "normal" life expectancy in the absence of either coronary artery disease or diabetes mellitus. Neither the presence nor the anatomical location of occlusive disease distal to the comon femoral bifurication by itself decreased life expectancy compared to those patients with aortoliofemoral disease but without similar distal occusive disease. Low operative mortality rate, excellent long-term patency, and potentially "normal" life expectancy all encourage an aggressive operative approach in patients with symptoms of peripheral vascular disease but without either diabetes mellitus or coronary artery disease. Revascularization in those patients with diabetes mellitus should be directed at limb salvage rather than at relief of minor symptoms of ischemia.

The aortofemoral graft: detection and identification of healing complications by ultrasonography.

Although accepted as an accurate method for determining the size of abdominal aortic aneurysms, the value of gray-scale ultrasound in other aspects of peripheral vascular disease is less well defined. Therefore, we studied 87 patients with are aortofemoral grafts using B-scan and real-time scanners to determine the efficacy of these techniques in the detection of healing complications. Sonography delineated the proximal anastomosis in 84%, the iliac graft limbs in 88% to 91%, and the distal anastomosis in all but one instance. Sixty-six abnormalities, most clinically unsuspected, were identified. Of these, anastomotic femoral and aortic false aneurysms were most common. Ultrasound also identified perigraft fluid collections secondary to hematoma, seroma, and infection that were not detected by angiography. Ultrasound is relatively inexpensive, atraumatic, and without radiation hazard. It is recommended as the initial method for evaluating suspected healing complications of arterial grafting and as a means of long-term follow-up of patients with aortofemoral grafts.

The use of ophthalmosonometry in the diagnosis of carotid artery stenosis.

One hundred and fifty-two patients underwent supraorbital Doppler studies of 304 carotid arteries to determine the presence or absence of hemodynamically significant lesions. Subsequent carotid arteriography was used to validate the accuracy of the test. Of 124 patients having abnormal Doppler examinations, 107 (86%) were angiographically proved to have lesions of the internal carotid artery that produced a stenosis of 50% or more. In the last 80 patients, the accuracy was increased to 94%. Of 115 proved stenoses or occlusions, the supraorbital Doppler examination correctly identified 99, for a diagnostic accuracy of 86%. In the last 50 patients, this accuracy was increased to 93%. Since only 58% of the patients with lesions had a bruit, the Doppler study was of particular value in identifying the patients with significant lesions in the absence of a bruit. Likewise, since only 61% of carotid arteries with bruits had lesions of hemodynamic significance, a normal Doppler examination could have been used to avoid angiographic screening of those arteries with bruits in the absence of major lesions, providing those hemodynamically insignificant lesions were not producing symptoms related to emboli. The technique of ophthalmosonometry and the significance of the test in clinical evaluation is discussed.

Digital video subtraction angiography: screening technique for renovascular hypertension.

Significant deterrents to the detection of renovascular hypertension are the unreliability of current screening methods and the widespread belief that the incidence of renal artery stenosis is too low to justify the expense and morbidity of routine angiography. We have developed a new imaging method, digital video subtraction angiography, suitable for screening outpatients for renal artery lesions. It involves injecting a 45 cc bolus of contrast medium through a venous catheter. Instead of exposing x-ray film, images are recorded directly on an image intensifier, digitized, and stored in a computer that electronically subtracts, reconstructs, enhances, and magnifies the images on a video screen. Renal parenchymal vessels less than 1 mm in diameter can be seen. So far, 45 studies have been performed in 39 hypertensive patients. Images of diagnostic quality were obtained in all except one. Renal artery stenosis was revealed in 15 patients, renal artery occlusion in two, diffuse intrarenal arterial narrowing in two, atrophic kidney with small renal arteries in two, and normal renal vessels in 23. Digital video subtraction angiography is an inexpensive, cost-effective, safe, and accurate method for renovascular hypertension screening and for evaluating patients after surgical correction of renal artery stenosis.

Intraoperative anticoagulation in cardiovascular surgery.

The optimal heparin dose to prevent intraoperative thrombosis or excessive bleeding during the occlusive phase of cardiovascular operations has not been determined. Therefore, we studied the kinetics of heparin effect in 28 patient undergoing peripheral vascular and cardiac operations. The activated clotting time (ACT) was measured in seconds by an electronic clot timer. The maximum ACT after initial heparin administration, the time to reach maximum ACT, and the half-time of heparin effect (t1/2) were determined. The anticoagulant effect of a given dose of heparin varies greatly among patients. No correlation was found between the t1/2 and the dosage of heparin administered. Despite higher doses of heparin administered to cardiac patients, the t1/2 in cardiac and vascular patients was not significantly different. Four patients received the same dose of heparin preoperatively and intraoperatively in an effort to predict the intraoperative effect. The times to maximum effect were the same but t1/2 intraoperatively was longer. These results indicate: (1) maximum heparin effect occurs later than previously believed and is different for cardiac and peripheral vascular patients; (2) the recommendation to give more heparin based on the 5-minute ACT is not valid; (3) individual response to a standard dose of heparin is unpredictable, both in duration and maximum effect; and (4) intraoperative monitoring of the heparin effect is practical and is the only way that any consistent, specific and point of heparin can be achieved.

Carotid endarterectomy in a metropolitan community: comparison of results from three institutions.

The hospitalizations of 300 patients who had carotid endarterectomies (CEA) in three different kinds of hospital were analyzed. 100 patients had CEA performed by experienced vascular surgeons in a university hospital (UH), 100 patients had CEA performed by experienced vascular surgeons in private community hospitals (PCH), and 100 patients had CEA performed by senior general surgery residents (GSR) assisted by experienced vascular surgeons in a university-affiliated Veterans Administration hospital (VA). Analysis of patient characteristics revealed that, compared with the other groups, VA patients were (1) younger (62 +/- 7 years; p less than 0.001); (2) had a higher frequency of peripheral vascular operations (51%; p less than 0.01; (3) were more often cigarette smokers (84%; p less than 0.001); and (4) had more contralateral carotid occlusions (19%) and ulcerated lesions (73%) (p less than 0.01). GSR had longer operating room times and cerebral ischemia times during shunt insertion and removal (6 +/- 2.8 minutes) and during the CEA (30 +/- 27 minutes) (p less than 0.001). Postoperative hypertension and neck hematomas were less common in PCH patients (p less than 0.001) than in the other groups. Although their duration of hospitalization (17 +/- 12 days) was longer, the VA patients experienced no increased morbidity. There was a high rate of cranial nerve injury in all groups (27%, 15%, 17%) but symptoms were not often permanent (9%, 6%, 6%). Our data indicate that results of vascular operations performed by well-supervised residents are comparable in all important respects to those performed by fully trained surgeons.

Prostacyclin production in regions of arterial stenosis.

The effect of abnormal flow dynamics on prostacyclin (PGI2) production by intact endothelium is unknown. To investigate this we studied the effects of graded stenoses on vessel wall PGI2 production in dogs (n = 8) whose femoral and carotid arteries (n = 32) were narrowed by machine-milled clips, producing 1.0 cm segmental stenoses of 25%, 50%, 75%, and 90% diameter reduction. Three dogs were injected with Indium 111-labeled platelets and 12 vessels were scanned for platelet deposition. All stenotic vessels were excised at 6 weeks for histologic study (hematoxylin-eosin section and immunohistochemistry for factor VIII) and PGI2 radioimmunoassay (as the metabolite 6-keto PGF1 alpha). All vessels remained patent with no thrombus formation in any segment. Vessel imaging in platelet-labeled animals showed no significant deposition. Histologic analysis demonstrated an intact endothelial surface in the stenotic segments, confirmed by the demonstration of factor VIII production by these cells. PGI2 production (per unit surface area) by the arterial segments with greater than or equal to 50% stenosis markedly exceeded the PGI2 production by the normal proximal and distal segments (p less than 0.0002) and showed further significantly increased production with increasing degrees of stenosis (p less than 0.00001). The data indicate increased PGI2 production by normal endothelium in regions of arterial stenosis. The mechanism of this increase is unknown, but this endothelial "turn on" effect may serve to inhibit deposition of platelets and thrombus formation in the presence of disordered flow patterns.

Emergency carotid artery surgery in neurologically unstable patients.

Although angiography and carotid artery surgery are illadvised in patients with acute, profound stroke, there is no consensus on the management of patients with stroke in evolution, waxing and waning neurologic deficits, or crescendo transient ischemic attacks. This type of clinical picture was associated with a critical, unstable lesion of the internal carotid artery in each of 12 patients. Emergency angiography permitted identification of the lesions responsible for the varying neurologic manifestations, and emergency carotid thromboendarterectomy produced prompt, complete recovery in all but one patient, who had a total carotid occlusion, received no operation, and died of a cerebral infarction. Based on our experience with these 12 patients, an aggressive diagnostic and therapeutic approach is recommended for patients with acute unstable cerebrovascular disease.

The natural history of bilateral aortofemoral bypass grafts for ischemia of the lower extremities.

Analysis of the immediate and long-term results in 180 patients undergoing aortofemoral bypass grafts for occlusive disease of the lower extremities showed the immediate graft limb patency in 360 graft limbs to be 99.2%. The cumulative ten-year graft limb patency was 66%. Factors associated with thrombosis of the graft limb revealed correlations for localized atherosclerotic disease of either the profunda femoris artery or the tibial trifurcation vessels. The highest correlation for graft limb thrombosis was with simultaneous lesions involving both the profunda femoris artery and tibial trifurcation vessels. The acute lower extremity salvage rate was 94%, and the ten-year cumulative extremity salvage for legs at risk of amputation was 85%. Postoperative symtpoms correlated well with patency. Overall operative mortality was five patients out of 180 (2.5%).

Guillotine amputation in the treatment of nonsalvageable lower-extremity infections.

Primary definitive amputation performed in the presence of distal-extremity infection carries the risk of wound infection and additional limb loss. We reviewed 75 below-knee amputations performed for nonsalvageable foot infections. Patients were retrospectively divided into two groups: group 1 underwent open ankle guillotine amputation followed by definitive below-knee amputation, and group 2 underwent primary definitive below-knee amputation. In group 1, 97% of patients achieved primary healing after revision, and none required amputation at a higher level. In group 2, 78% of patients achieved primary healing, but 11% required revision of the amputation to the above-knee level. These data supported the following conclusion: guillotine ankle amputation followed by below-knee amputation for the nonsalvageable, infected lower extremity is associated with a significantly lower amputation failure rate than primary definitive amputation.

Natural history of nonstenotic, asymptomatic ulcerative lesions of the carotid artery.

To define the natural history of the asymptomatic, nonstenotic, ulcerative lesion involving the carotid artery bifurcation, the arteriograms and clinical course of 67 patients with 72 asymptomatic ulcerative lesions of the carotid artery were reviewed. The angiographic appearance of ulceration was classified into three groups: minimal (group A), large (group B), and compound (group C). Using life-table methods, the clinical course of these patients was compared between groups and was also compared to a nonrandomized surgically treated group of patients with nonstenotic ulcerative lesions in whom operation was performed for hemispheric or monocular symptoms. There were no significant (P greater than .1) differences in mortality, but the differences in stroke incidence was highly significant (P less than .001). The annual stroke rate, averaged over seven years, was 0.4% per year for group A, 1.47% per year for the surgically treated group, and 12.5% per year for groups B and C. The data indicate that group A ulcers have a benign prognosis, in noticeable contrast to group B and C ulcers which incur a high risk for subsequent stroke.

Saphenous vein bypass to pedal arteries. An aggressive strategy for foot salvage.

Patients with forefoot ischemia and severe tibial artery disease present a major challenge to revascularization and foot preservation. Encouraged by the success of saphenous vein bypass to the more proximal arteries of the lower leg, we extended this technique to the pedal arteries. Between February 1986 and September 1988, we performed 26 bypasses in 24 men (mean age, 66 years) with critical foot ischemia. Sixty-three percent of the patients had diabetes mellitus, 50% had hypertension, and 71% were actively smoking. Angiography invariably revealed multiple tibial artery occlusions with reconstitution of the pedal arteries. The foot salvage rate was 83% (mean survival, 14 months), primary patency was 83% (mean survival, 9 months), and survival was 86% (mean, 12 months). There were 11 wound complications (42%); two resulted in disruptions of the distal anastomosis and eventual graft failure. Bypass to the pedal arteries yields a high rate of foot salvage and is comparable with more proximal bypass procedures; however, wound complications are common and require special technical considerations.

Splenectomy for massive splenomegaly.

Removal of a massively enlarged spleen is a challenging surgical problem that is associated with higher death and complication rates than the removal of smaller spleens. Older age, serious and chronic primary diseases, and associated cardiopulmonary abnormalities contribute to the morbidity and mortality. Most patients with massive splenomegaly have been treated with corticosteroid and/or antineoplastic drugs, which impair wound healing, hemostatic function, and host resistance. Precise surgical technic is especially important in these cases because of the susceptibility to postoperative hemorrhage. Ligation of the splenic artery via the lesser peritoneal sac before mobilization of the spleen is associated with lower intraoperative transfusion requirements than when the spleen is mobilized before the splenic artery is ligated.