Improvement of peri-operative patient management to enable outpatient colectomy.

AIM OF THE STUDY: Outpatient left colectomy has been described in several small series or case reports. We conducted a prospective study to determine whether an optimized management approach could allow performance of this procedure in a broader patient population. PATIENTS AND METHODS: Between December 2014 and December 2015, all eligible patients were prospectively and consecutively included in this study. They all underwent surgery following the same outpatient management protocol. After discharge, patients were followed by home health nurses with surgeon follow-up visits on days 10 and 21 (D10, D21) or earlier, if necessary. RESULTS: During this period, 56 patients underwent a left colectomy, 47 of whom met the inclusion criteria. Seven patients refused the outpatient care approach, leaving a total of 40 patients included (8 ASA 3 [American Society of Anesthesiologists], 24 ASA 2, 8 ASA 1). All but one of the patients were able to return home the same evening. Bowel motility was restored on D1 for most patients. Two patients had abdominal pain that required a follow-up visit before D10 but their subsequent course was uneventful. No patient was re-hospitalized. An uncomplicated post-operative course was confirmed at follow-up visits on D10 and D21. CONCLUSION: Our study confirms that outpatient left colectomy is feasible for most patients, including fragile patients and/or those undergoing more complex procedures. Communication and close coordination by all stakeholders as well AS optimal organization of downstream patient care are essential to guarantee quality and safety.

Evaluation of transesophageal echocardiography for diagnosis of traumatic aortic injury.

BACKGROUND: Traumatic aortic injury is a frequent cause of death after blunt trauma, but few patients survive to reach a trauma center. The role of transesophageal echocardiography (TEE) in the diagnosis of traumatic aortic injury remains debated. METHODS: Over a 9-yr period, 209 blunt trauma patients (mean age, 34 +/- 13 yr) were suspected of having traumatic aortic injury because of enlarged mediastinum and/or sudden deceleration, and underwent TEE and angiography (aortography and/or contrast-enhanced computed tomography. RESULTS: Traumatic aortic injury was diagnosed in 42 patients (20%). Angiography (aortography and/or contrast-enhanced computed tomography) was less accurate (sensitivity, 83%; specificity, 100%) than TEE (sensitivity, 98%; specificity, 100%) for the diagnosis of aortic injury because it failed to diagnose most minor injuries (intramural hematoma or limited intimal flap, n = 7). However, when considering only patients with major aortic injury (n = 33; i.e., those who might need surgery), angiography (sensitivity, 97%; specificity, 100%) and TEE (sensitivity, 97%; specificity, 100%) were equivalent. CONCLUSION: Transesophageal echocardiography is an accurate method for diagnosis of traumatic aortic injury. Nevertheless, the clinical implications of limited aortic injuries diagnosed by the technique have yet to be determined.

Evaluation of the effects of mivacurium chloride on hemodynamics and left ventricular function in patients with coronary artery disease undergoing abdominal aortic surgery.

OBJECTIVE: To determine the effects of two doses of mivacurium chloride on hemodynamics and left ventricular function in patients with documented coronary artery disease undergoing aortic surgery. DESIGN: A prospective study with the dose of mivacurium determined by randomization. SETTING: Induction area at a university hospital. PARTICIPANTS: Twenty consecutive patients undergoing aortic surgery with clinically and/or angiographically documented coronary artery disease. INTERVENTIONS: Intravenous administration of mivacurium chloride. MEASUREMENTS AND MAIN RESULTS: Induction of anesthesia was performed with midazolam and fentanyl. Two different doses of mivacurium chloride, 0.15 mg/kg (n = 10) and 0.2 mg/kg (n = 10; 2 and 2.5 ED95; respectively), were administered as a single bolus injection over a 60-second period in the absence of any surgical stimulation. In addition to standard hemodynamic monitoring, pulmonary artery catheterization and transesophageal echocardiography were used. The occurrence of myocardial ischemia was monitored using both a computerized three-lead ST-segment analysis system and the echocardiographic assessment of regional wall motion. No change in heart rate, mean arterial pressure, pulmonary capillary wedge pressure, cardiac output, and global left ventricular function was noted after administration of mivacurium with the two doses studied. No ST-segment change or new segmental wall motion abnormality was noted in either group. CONCLUSION: Mivacurium chloride, when injected over a 60-second period, preserves global and regional myocardial function in patients with documented coronary artery disease undergoing noncardiac surgery.

Another application of two-dimensional transesophageal echocardiography: spinal cord imaging. A preliminary report.

This prospective study was performed in 17 consecutive patients continuously monitored intraoperatively and postoperatively for cardiac function with two-dimensional (2D) TEE. Prior to systematic evaluation of spinal cord imaging by 2D TEE, the aims of this study were to determine: (1) the feasibility of such imaging, and (2) the relationship between spinal cord images and fixed structures (like vertebral bodies); 7.5 +/- 2.3 spinal segments were identified in the patients. There is a close relationship between the distance of the probe from the teeth and the intervertebral disc. Successful imaging of the spinal cord was achieved in all 17 patients with visualization of discs, spinous processes, spinal canal, and a pulsating spinal cord. Further studies are needed to better define the potential applications of this new technique: detection of spinal cord trauma, visualization of a thoracic epidural catheter, and successful preservation of spinal cord vascularization during thoracic aortic surgery.

Evaluation of the effects of rocuronium bromide on haemodynamics and left ventricular function in patients undergoing abdominal aortic surgery.

In an open study of 26 patients undergoing abdominal aortic surgery, the effects of rocuronium 0.6 mg kg-1 (eight patients) and 0.9 mg kg-1 (nine patients) were compared with those of pancuronium 0.085 mg kg-1 (eight patients) on haemodynamic parameters and transoesophageal echocardiography. The anaesthetic technique was based on a benzodiazepine and low dose fentanyl (6 micrograms kg-1). Pancuronium was associated with a significant increase in mean arterial pressure, end-diastolic area and heart rate, none of which were seen after rocuronium at either dose level.

[Value of thallium-dipyridamole myocardial scintigraphy in coronary patients in non cardiac surgery]. / Intérêt de la scintigraphie myocardique au thallium-dipyridamole chez le coronarien en chirurgie non cardiaque.

Cardiac assessment is of particular importance in patients with documented or suspected coronary artery disease (CAD) as well as in all those patients undergoing vascular surgery. Use of dipyridamole thallium scintigraphy (DTS) in this population could help to detect significant coronary artery narrowing, together with the location and quantification of the areas of myocardium in jeopardy. Such information might lead to changing the surgical procedure, or to starting other treatment, such as coronary angioplasty or bypass graft surgery, thereby diminishing the morbidity and mortality associated with surgery in these high-risk patients. The ability of DTS to predict acute postoperative ischaemic events has been suggested by several studies. Various shortcomings of DTS used as a preoperative screening test have been pointed out in some recent papers. Therefore it is concluded that: 1) DTS should not be used as a routine preoperative test in vascular surgical patients. DTS is not accurate enough when used in patients without any clinical findings suggestive of CAD, 2) DTS may prove more useful in stratifying patients with an intermediate probability of developing cardiac complications. In such patients, the test will not provide a linear "all or nothing" result, but, when taken together with the clinical findings and the nature of the surgical procedure, a complex stratification, 3) Because of progress in the perioperative management of high-risk patients, positive findings on preoperative DTS may not correlate perfectly with perioperative cardiac events, 4) As several factors influence thallium uptake after dipyridamole, DTS does not have a perfect specificity, thus leading to order an excessive number of coronary angiographies. Some patients will be seen as having a false-positive DTS, 5) Preoperative screening DTS leads to cardiac catheterization and hence to revascularisation, independently of symtomatology. Further studies must be undertaken to determine whether this approach will improve short and long term patient survival.

Transesophageal echocardiographic assessment of left ventricular function in response to labetalol for control of postoperative hypertension.

Although labetalol (LAB), the combination of an alpha- and beta-adrenergic blocking agent, is thought to be effective and safe for the control of postoperative hypertension, no study has focused on changes in left ventricular (LV) function when this drug was used to control postoperative hypertension. Therefore, this study determined the effects of LAB on hemodynamics and LV function assessed by 2D transesophageal echocardiography (TEE) in 17 patients undergoing abdominal aortic surgery who experienced a postoperative hypertensive episode. Postoperatively, patients were transferred while still intubated and under fentanyl sedation to the postanesthesia care unit where a TEE probe was inserted to provide a short-axis view of the LV. When their systolic blood pressure increased above 165 mmHg for more than 4 minutes, LAB was given in a dose of 0.75 mg/kg IV, over 2 minutes. If the blood pressure was not lowered to within 10% of the preoperative values, additional doses of LAB were given. Control of hypertension was obtained in all patients and was associated with a significant decrease in heart rate (90 +/- 19 to 70 + 13 bpm), cardiac index (4.52 +/- 1.65 to 3.36 +/- 1.55 L/min/m2), and mixed venous oxygen saturation (73 +/- 10 to 63 +/- 10%). With the lower blood pressure, end-diastolic area increased, indicating myocardial depression. In conclusion, LAB can be used to effectively control hypertension during the early postoperative period after abdominal aortic surgery. However, the reduction of blood pressure is achieved principally by the negative inotropic effect of LAB, which predominates over its vasodilator action.

[Flow-dependent vasodilation. Pharmacology and physiopathology]. / La dilatation débit-dépendante. Aspects pharmacologiques et physiopathologiques.

The phenomenon of flow-dependent vasodilatation is characterised by the variations of vascular tone to changes in regional blood flow. Initially considered to be a purely myogenic reaction of a vessel to a change in blood flow in the microcirculation, it is now generally accepted that "flow-dependent" vasodilatation is closely related to the modulating properties of the vascular endothelium. Local chemical or mechanical destruction of the vascular endothelium abolishes any vasomotor response in that particular region to increased blood flow in that vessel (for example during a hyperemic response or after injection of papaverine), whereas the response to a substance directly relaxing the smooth muscle of the large arteries (such as nitroglycerine) remains unchanged. Bioassay methods have shown that the fundamental mechanism of flow dependence is the liberation of one or more relaxing factors (EDRF) from endothelial cells sensitive to variations in shear stress which accompany all changes in regional blood flow. From the pharmacological point of view, flow-dependent vasodilatation enables identification of several types of vasodilator drugs depending on whether the relaxation of vascular smooth muscle which follows their administration remains the same or not in the absence of concomitant changes in regional blood flow. The vasodilatation caused by calcium antagonists and potassium agonists is largely related to the phenomenon of flow-dependency whilst that induced by nitroglycerin is totally independent. Finally, from the physiopathological view-point, the clinical studies published in this domain show that blood pressure has little influence on flow-dependent vasodilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Compared peripheral vascular responses to intravenous and intra-arterial administrations of positive inotropic agents in conscious dogs.

In addition to their direct effects on cardiac contractility, a number of positive inotropic agents also induce, through direct peripheral vasodilation, a reduction in afterload which is of major importance in their beneficial effects in the treatment of congestive heart failure. However, the induced increase in cardiac output can indirectly improve perfusion of peripheral vessels through a flow-mediated mechanism. Thus, the goal of the present study was to compare the direct peripheral vasomotor effects assessed in the iliac vascular bed of four positive inotropic agents: DPI 201-106, ouabain, milrinone and dobutamine, in the presence and absence of simultaneous changes in cardiac function. These drugs were administered either through intravenous or intra-arterial (aorto-iliac catheter) routes in 6 conscious dogs, chronically instrumented for the measurement of heart rate, arterial pressure, left ventricular dP/dt, iliac artery blood flow and iliac artery diameter (sonomicrometry). Intravenous doses were selected as those inducing equipotent positive inotropic responses whereas intra-arterial doses were below those required to induce any significant change in systemic hemodynamics. Ouabain decreased and milrinone increased both iliac blood flow and diameter after either intravenous or intra-arterial administrations. In contrast, iliac blood flow did not change after intra-arterial administration of DPI 201-106 and dobutamine whereas iliac diameter was not modified by DPI 201-106 and even decreased with dobutamine. After intravenous administration, DPI 201-106 but not dobutamine, increased both iliac blood flow and diameter. Thus, this experimental preparation can differentiate inotropic agents with direct vasodilating (milrinone) or constricting (ouabain) properties and those (DPI 201-106 and dobutamine) with indirect vasodilating effects most likely mediated by the improvement in cardiac function.

The L-arginine-nitric oxide pathway in the canine femoral vascular bed: in vitro and in vivo experiments.

Vascular endothelial cells synthesize nitric oxide from L-arginine, and this pathway can be inhibited by various analogues of L-arginine, including NG-nitro L-arginine methyl ester (L-NAME). To investigate the role of this pathway in the regulation of femoral arterial tone, the effect of L-NAME was studied in vitro in isolated canine femoral arteries suspended in organ chambers for isometric tension recording, and in vivo in conscious dogs chronically instrumented for the measurement of iliac blood flow and iliac artery diameter. In vitro, L-NAME induced an endothelium-dependent contraction, inhibited the endothelium-dependent relaxations to acetylcholine or bradykinin, and potentiated the relaxation evoked by the nitric oxide donor SIN-1. In vivo, locally administered L-NAME induced a decrease in iliac artery diameter and an increase in iliac resistance, potentiated the iliac responses to the organic nitrate nitroglycerin, but did not affect the iliac responses to the endothelium dependent vasodilator acetylcholine. Thus, in the canine femoral vascular bed: a) basal release of nitric oxide contributes in vivo to the maintenance of a permanent vasodilator tone at the level of both large conductance and small resistance vessels; b) the endothelium-dependent relaxations to acetylcholine and bradykinin in vitro are mostly mediated through the release of nitric oxide from L-arginine; c) the endothelium-dependent relaxations to acetylcholine in vivo are probably mediated by a relaxing factor distinct from nitric oxide, or by a nitric oxide-like molecule released from endothelial pools; and d) removal of the NO-mediated vasodilator tone by L-NAME leads to a supersensitivity to nitrovasodilators, both in vitro and in vivo.