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Biomedical subjects

M Licker

Publications and source records attributed to M Licker.

At least 19 recordsLinked to original sources
PubMed2004

Continuous haemodynamic monitoring using transoesophageal Doppler during acute normovolaemic haemodilution in patients with coronary artery disease.

Transoesophageal Doppler monitoring allows non-invasive assessment of stroke volume. We studied haemodynamic changes during acute normovolemic haemodilution (ANH) in anaesthetised patients with coronary artery disease. Twenty patients were randomly assigned to either ANH or a control group. During ANH, a mean (SD) blood volume of 15.3 (3.4) ml.kg(-1) was withdrawn decreasing systemic oxygen delivery from 12.7 (3.3) to 9.3 (1.8) ml.kg(-1).min(-1) (p < 0.001). In the control group, haemodynamic data remained unchanged, whereas in the ANH group, stroke volume and central venous pressure increased significantly (mean = +21 ml [95% CI: 18-25 ml.min(-1)]; mean = +2.5 mmHg [95% CI: 2.2-2.8 mmHg], respectively) and heart rate decreased (mean = -6 beat.min(-1)[95% CI: 6-8 beat.min(-1)], p < 0.05). According to the Frank-Starling relationship, individual changes in stroke volume compared with central venous pressure fitted a quadratic regression model (R2 > 0.91). A reduced viscosity associated with ANH resulted in improved venous return, higher cardiac preload and increased cardiac output. In summary, this study demonstrated that ANH to a haemoglobin value of 8.6 g.dl(-1) was well tolerated in patients with coronary artery disease.

Adult↗
PubMed2004

Cardiovascular response to acute normovolaemic haemodilution in patients with severe aortic stenosis: assessment with transoesophageal echocardiography.

Using multiplane transoesophageal echocardiography (TOE), we investigated the haemodynamic response to acute normovolaemic haemodilution (ANH) in anaesthetised patients with critical aortic stenosis. Twenty-eight patients were randomly assigned to ANH or control groups. In the control group, haemodynamic data remained unchanged over a 20-min period. In the ANH group, haemoglobin levels decreased from a mean (SD) of 134 (7) to 91 (9) g x l(-1) (p < 0.001) whereas stroke volume, central venous pressure and left ventricular (LV) end-diastolic area all increased significantly (mean (SD) +15 (6) ml; +2.0 (1.1) mmHg; +2.1 (0.8) cm2, respectively). During ANH, the accelerated blood flow through the stenotic valve caused an increased loss (SD) in LV stroke work: from 24 (8)% to 30 (10)%), (p < 0.01). Hence, lowering viscosity with ANH resulted in improved venous return, higher cardiac preload and increased stroke volume. However, this adaptive haemodynamic response was limited by less efficient LV stroke work due to dissipation of fluid kinetic energy.

Aged↗
PubMed2003

Influence of thoracic epidural analgesia on cardiovascular autonomic control after thoracic surgery.

BACKGROUND: Thoracic epidural analgesia (TEA) is effective in alleviating pain after major thoracoabdominal surgery and may also reduce postoperative mortality and morbidity. This study investigated cardiovascular autonomic control in patients undergoing elective thoracic surgery and its modulation by continuous TEA. METHODS: Thirty-eight patients were randomly assigned to receive patient-controlled analgesia (PCA group) or thoracic epidural analgesia (TEA group) with doses of bupivacaine (0.25% during operation, 0.125% after operation) and fentanyl (2 microg ml(-1)). Heart rate variability (HRV), baroreflex function and pressure response to nitroglycerine and phenylephrine were assessed before operation, 4 h after the end of surgery (POD 0) and on the first and second postoperative days (POD 1 and POD 2). RESULTS: Early after surgery, all HRV variables and baroreflex sensitivities were markedly decreased in both groups. In the TEA group, total HRV and its high-frequency components (HF) increased towards preoperative values at POD 1 and POD 2, whereas the ratio of low to high frequencies (LF/HF) was significantly reduced (mean (SD), -44 (15)% at POD 0, -38 (17)% at POD 1, -37 (18%) at POD 2) and associated with blunting of the postoperative increase in heart rate and blood pressure. In the PCA group, the ratio of LF/HF remained unchanged and the decrements in HRV variables persisted until POD 2. In the two groups, baroreflex sensitivities and pressure responses recovered preoperative values at POD 2. CONCLUSIONS: In contrast with PCA management, TEA using low concentrations of bupivacaine and fentanyl blunted cardiac sympathetic neural drive, resulting in vagal predominance, while HRV variables were better restored after surgery.

Adult↗
PubMed2001

Perioperative medical management and outcome following thymectomy for myasthenia gravis.

PURPOSE: To describe the evolution of the perioperative management of myasthenia gravis (MG) patients undergoing thymectomy and to question the need for systematic postoperative ventilation. CLINICAL FEATURES: We collected data retrospectively from 36 consecutive MG patients who underwent thymectomy over a 21-yr period, via transthoracic, -cervical or -sternal incisions (n=5, n=7, n=24, respectively). From 1980 to 1993, a balanced anesthetic technique (n=24) included various inhalational agents with opiates and myorelaxants (in eight cases); 22 patients were admitted to the intensive care unit (ICU). Since 1994, i.v. propofol was combined with epidural bupivacaine and sufentanil (n=12); all patients were admitted to the postanesthesia care unit. Short-term postoperative ventilation (median time four hours, range from three to 48 hr) was required in eight patients who had longer hospital stay (median stay=12 days, range (8-28) vs five days (4-15) for patients with early extubation, P <0.05) but similar clinical improvement six months after thymectomy. Postoperative ventilatory support was required more frequently when a balanced anesthetic technique was used (odds ratio=4.2 (1.1-9.7), P=0.03) and particularly when myorelaxants were given (odds ratio=13.9 (2.1-89.8), P=0.009). Leventhal's scoring system had low sensitivity (22.2%) and positive predictive values (25%). CONCLUSIONS: Our data show that the severity of MG failed to predict the need for postoperative ventilation. A combined anesthetic technique was a safe and cost-effective alternative to balanced anesthesia as it provided optimal operating conditions and resulted in fewer admissions in ICU and shorter hospital stays.

Adolescent↗
PubMed2001

Myocardial revascularization and bilateral lung transplantation without cardiopulmonary bypass.

Coronary artery disease is occasionally encountered in lung transplant recipients and is a risk factor for perioperative complications and poor survival. Besides combined heart-lung transplantation, various techniques of myocardial revascularization can be performed before, or at the time of lung transplantation. We report herein a patient with end-stage bronchoemphysema and two-vessel coronary disease who underwent 'off-pump' coronary artery bypass graft immediately followed by bilateral lung transplantation.

Coronary Artery Bypass↗
PubMed2001

Management and outcome of patients undergoing thoracic surgery in a regional chest medical centre.

BACKGROUND AND OBJECTIVE: The main objective of this study was to assess mortality and morbidity after thoracic surgery in a medical centre, without resident chest surgeons and anaesthesiologists, and to determine specific risk factors. METHODS: A prospective cohort study using a local database which includes patients' clinical characteristics, results of preoperative investigations, surgical and anaesthesia data and all postoperative complications was undertaken. Two hundred and seventy-three consecutive patients undergoing thoracic surgery from 1992 to 1999 were studied. The referral chest medical centre was without resident thoracic surgeons or anaesthesiologists; postoperative care was led by local chest physicians according to standardized protocols and in close collaboration with university-based surgeons and anaesthesiologists. RESULTS: The majority of patients had lung cancer (71%) and underwent resection of at least one lobe (62%). Thirty-day mortality rate was 2.2% and one or more complications occurred in 74 patients (27%). Three patients had to be transferred to a university hospital for further treatment. Univariate predictors of complications included age (> 70 years), history of smoking, body mass index, as well as the extent and duration of surgery. After multiple logistic regression analysis, smoking (current or past), prolonged surgery (>120 min) and major lung resection (pneumonectomy or bilobectomy) remained the only independent risk factors. CONCLUSIONS: Overall perioperative mortality and morbidity rates did not exceed those reported from large teaching hospitals. In selected patients, thoracic surgery can be safely performed in a specialized chest medical centre without on-site surgeons and anaesthesiologists.

Aged↗
PubMed2001

Factors influencing improvement and remission rates after thymectomy for myasthenia gravis.

BACKGROUND: Thymectomy has become an accepted option in the treatment of myasthenia gravis (MG). However, the optimal selection of patients for surgery remains controversial. OBJECTIVE: The objective of the study is to define factors influencing improvement and remission rates after thymectomy for MG. METHODS: We retrospectively reviewed our experience in the surgical management of patients with MG over the last 20 years, and analyzed if patient's age, sex, preoperative Osserman Stage, thymic histology, duration of symptoms, or radiological findings influenced outcome. RESULTS: There were 25 women and 10 men. Most of them presented with Osserman stage IIA (n = 12) and stage IIB (n = 17). Hyperplasia of the thymus was observed in 15 patients (43%), thymoma in 12 (34%), and atrophic or normal thymus in 8 (23%). Computed tomography (CT) had a positive predictive value of 91% in detecting thymoma and of 80% in detecting thymic hyperplasia. Over a mean follow-up of 96 months, MG improved markedly in 26 patients. Postoperative improvement was significantly greater in patients with advanced MG (stage IIB, III and IV), whereas a higher rate of remission occurred in patients with mild MG (stage I and IIA), and in those with thymic hyperplasia. No relation was observed between outcome and age, sex, duration of symptoms and abnormal CT findings. CONCLUSIONS: The beneficial effects of thymectomy are characterized by postoperative clinical improvement in most patients with moderate to severe preoperative myasthenic involvement and by a higher remission rate in patients with thymic hyperplasia and/or mild myasthenic symptoms.

Adolescent↗
PubMed2000

Hepatic haemodynamic changes following inhibition of endothelium-derived relaxing and hyperpolarising factors in anaesthetised miniature pigs.

The influence of endothelium-dependent vasodilatation in regulating the hepatic circulation has been investigated by intraportal infusion of inhibitors of either endothelium-derived relaxing factor (NG-nitro-L-arginine-methyl-ester [L-NAME]) or of endothelium-derived hyperpolarising factor (ATP-dependent K(+)-channel inhibitor, glybenclamide) in barbiturate anaesthetised miniature pigs. Intraportal infusion of acetylcholine (5.5 micrograms kg-1 min-1 over 2 min) produced a selective 3-fold increase in hepatic artery and coeliac trunk blood flow, while mesenteric, portal, systemic, and pulmonary vascular beds remained unchanged. Intraportal L-NAME or glybenclamide did not reduce the hepatic artery and coeliac trunk flows but increased systemic and mesenteric vascular resistances. The acetylcholine-induced hepatic artery vasodilatation was partially blocked by 59%, 76% and 66% by L-NAME, at 30, 100, and 300 mg/kg respectively. Glybenclamide pretreatment up to 3 mg/kg did not modify acetylcholine-induced vasodilatation of the hepatic artery and coeliac trunk. Furthermore, prior cyclooxygenase inhibition did not alter the hepatic vascular response to acetylcholine. These results suggest that, in contrast to what is observed in large vessels, the hepatic vascular tree may not be entirely regulated by nitric oxide under basal conditions, but nitric oxide is released readily upon stimulation with acetylcholine, a response that is largely but incompletely blocked by L-NAME pretreatment. Neither basal vascular tone nor acetylcholine-induced vasorelaxation are mediated by the opening of glybenclamide-sensitive K+ channels in the hepatic circulation in pigs.

Acetylcholine↗
PubMed2000

Cardiovascular responses to anesthetic induction in patients chronically treated with angiotensin-converting enzyme inhibitors.

PURPOSE: To investigate the effects of chronic ACE inhibition on cardiac neural function following induction of general anesthesia in patients with underlying coronary artery disease. METHOD: In a prospective case-control study, heart rate variability (HRV) and baroreflex control were compared preoperatively and 30 min after anesthesia induction in patients receiving, or not, ACEI (n=16, control group and n=16, ACEI group). All patients had normal cardiac function and anesthesia consisted of a fixed dose regimen of fentanyl and midazolam. Anesthesia-related hypotension was defined by systolic blood pressure < 90 mmHg. Spectral density of HRV was calculated for low frequency and high frequency bands (LF, from 0.05 to 0.15 Hz and HF, from > 0.15 to 0.6 Hz). Baroreflex sensitivity was estimated after blood pressure changes induced by injections of phenylephrine (PHE) and nitroglycerin (NTG). RESULTS: The HRV parameters and baroreflex sensitivity were not different between groups, during the awake and anesthesia periods. Anesthesia produced similar reduction in total HRV in the Control and ACEI groups (-93 +/- 28% vs -89 +/- 32%), and in baroreflex sensitivity during NTG (-64 +/- 21% vs -54 +/- 17%) or PHE tests (-74 +/- 25% vs -72 +/- 22%). Anesthesia-related hypotension occurred in nine patients in the ACEI group (vs two controls). Although the hypertensive response to phenylephrine was greater after anesthesia in both groups, the sensitivity to phenylephrine was attenuated in those patients experiencing hypotension in the ACEI group. CONCLUSIONS: Chronic preoperative treatment with ACEIs does not influence cardiac autonomic regulation and anesthetic-induced hypotensive episodes are mainly attributed to decreased alpha-adrenergic vasoconstrictive response.

Aged↗
PubMed2000

Near-fatal acute dissection of the thoracic aorta involving the right coronary artery.

Aortic dissection is the most common acute disease involving the ascending aorta and carries a high mortality rate if surgical therapy is not initiated rapidly following the onset of symptoms. Therefore, timely recognition of this disease entity coupled with urgent and appropriate management is the key to a successful outcome. We describe a patient with aortic dissection extending into the right coronary artery (RCA) who was successfully resuscitated and operated on following a cardiac arrest during transfer to the operating room.

Acute Disease↗
PubMed2000

Sex differences in presentation, management, and prognosis of patients with non-small cell lung carcinoma.

OBJECTIVE AND METHODS: To characterize gender differences in lung cancer, we conducted a retrospective analysis including all patients undergoing surgery for non-small cell lung carcinoma in a single institution over a 20-year period. RESULTS: Compared with men (n = 839), women (n = 198) were more likely to be asymptomatic (32% vs 20%, P =.006), nonsmokers (27% vs 2%, P <.001), or light smokers (31 pack-years vs 52 pack-years; P <.001). Squamous cell carcinoma predominated in men (65%), and adenocarcinoma predominated in women (54%). Preoperative bronchoscopy contributed more frequently to a histologic diagnosis in men (69% vs 49% in women, P <.001), and fewer pneumonectomies were performed in women (22% vs 32% in men, P =.01). After multivariate Cox regression analysis, women survived longer than men (hazard ratio, 0.72; 95% confidence interval, 0.56-0. 92; P =.009) independently of age, presence of symptoms, smoking habits, type of operation, histologic characteristics, and stage of disease. The protective effect linked to female sex was present in early-stage carcinoma (stage I and II) and absent in more advanced-stage carcinoma (stage III and IV). CONCLUSIONS: This study emphasizes strong sex differences in presentation, management, and prognosis of patients with non-small cell lung cancer.

Adult↗
PubMed2000

Postoperative fatal intestinal necrosis after enalapril treatment in a patient with rheumatoid arthritis.

The inappropriate use of antihypertensive medications may cause hypotensive responses associated with organ failure. We describe a patient who developed nonocclusive splanchnic ischemia leading to death following the administration of enalapril to treat postoperative hypertension. The mechanisms and consequences of refractory hypotension induced by angiotensin-converting enzyme inhibitors are discussed.

Aged↗
PubMed2000

Exercise capacity and extent of resection as predictors of surgical risk in lung cancer.

Lung resection remains the most effective treatment for non-small cell lung cancer (NSCLC). However, there is no consensus about reliable operative risk assessment in these patients. The aim of this study was to identify predictors of postoperative complications and death after lung resection for NSCLC. In this prospective trial, 125 of 142 (88%) consecutive NSCLC patients from 1990 to August 1997 had complete data sets. All underwent functional assessment including spirometry and cardiopulmonary exercise tests and lung resection via thoracotomy. Complications occurred in 31 of 125 (25%) patients including 2 (1.6%) deaths. On logistic regression analysis, only maximal oxygen uptake (V'O2,max) x kg body weight(-1) expressed as a percentage of the predicted value (p<0.0001) and the estimated extent of lung tissue resection (p=0.02) were independent predictors of postoperative complications. Six of seven patients with a V'O2,max x kg body weight(-1) of <60% pred, but only eight of 65 with values >90% pred, exhibited postoperative complications. Maximal oxygen uptake and the estimated extent of lung tissue resection are independent predictors of postoperative complications. These simple parameters should be integrated into the preoperative decision analysis for operability in patients undergoing lung resection for lung cancer.

Adult↗
PubMed2000

Near-fatal acute dissection of the thoracic aorta involving the right coronary artery.

We describe a patient with aortic dissection extending into the right coronary artery who was successfully resuscitated and operated upon after a cardiac arrest during transfer to the operating room. The use of transoesophageal echocardiography was particularly helpful for rapid diagnosis of aortic type A dissection and urgent surgical treatment.

Acute Disease↗
PubMed2000

Aprotinin does not impair renal haemodynamics and function after cardiac surgery.

Patients undergoing cardiac surgery with moderate hypothermic cardiopulmonary bypass (CPB) were allocated randomly to receive either saline (control group, n = 29) or a high-dose regimen of aprotinin (aprotinin group, n = 28). In both groups, CPB was associated with similar and transient increases in effective renal plasma flow (+54% in controls and +48% in aprotinin-treated patients) and in fractional excretion of sodium and potassium, but glomerular filtration rate remained unchanged. Plasma and urinary ratios of 6-keto-PGF1 alpha to thromboxane B2 (TxB2) increased significantly, indicating systemic and renal release of vasodilatory prostaglandins. Osmolar clearance correlated with urinary excretion of cyclic GMP (r = 0.79 and 0.86 in the control and aprotinin groups, respectively) and 6-keto-PGF1 alpha (r = 0.63 and 0.69 in the control and aprotinin groups, respectively). Compared with preoperative values, plasma atrial natriuretic peptide increased after weaning from CPB (+71% and +93% in the control and aprotinin groups, respectively). Aprotinin had no apparent adverse effect on renal function and it did not alter mechanisms involving prostanoids and atrial natriuretic peptide during cardiac surgery.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

[Experience of surgical treatment for primary lung cancer in Geneva 1977-1996].

INTRODUCTION: In Switzerland, primary lung carcinoma is the leading cause of cancer death among males and the third cause of cancer death after carcinomas of the breast and colon in females. Surgical resection is the only potentially curative treatment but only in 20-25% of the patients. METHODS: Between January 1, 1977 and December 31, 1996, 1079 consecutive patients (877 males, 202 females) underwent surgery for primary lung carcinoma at the University Hospital of Geneva. RESULTS: Lobectomy was performed in the majority of patients (n = 558, 51.7%), followed by pneumonectomy (n = 319, 29.6%), exploratory thoracotomy (n = 73, 6.8%), segmentectomy (n = 68, 6.3%), and bilobectomy (n = 61, 5.6%). Most tumours were squamous cell carcinomas (n = 613, 57%) and adenocarcinomas (n = 327, 30.3%). Small cell lung carcinomas were diagnosed in 33 patients (3%). The overall operative mortality rate was 6.6%. However, over the period studied, the operative mortality decreased from 9% in 1977-1980 to 4% in 1993-1996. Survival according to the new staging system was 61% at 5 years in stage IA, 43% in stage IB, 37% in stage IIA, 19% in stage IIB, 14% in stage IIIA, 0% in stage IIIB, and 4% in stage IV. CONCLUSIONS: In future, improvement in long-term survival will require earlier detection of lung carcinomas and better adjuvant and neoadjuvant therapies for advanced tumours.

Adenocarcinoma↗
PubMed1999

Chronic angiotensin converting inhibition does not influence renal hemodynamic and function during cardiac surgery.

PURPOSE: Treatment with angiotensin-converting enzyme (ACE) inhibitors affects the autoregulation of renal blood flow and glomerular filtration and provides renal protective effects. The purpose of this case-control study was to investigate the effects of chronic ACE inhibition on perioperative renal hemodynamics and function. METHOD: We prospectively studied renal function in two groups of patients, chronically treated or not, with ACE inhibitors (ACEI and control; n = 16, in each group) who underwent elective cardiac surgery under hypothermic cardiopulmonary bypass. Glomerular filtration rate, effective renal plasma flow, osmolar clearance and fractional excretion of sodium and potassium were determined before, during and after CPB. Additional measurements included plasma atrial natriuretic factor (ANF) as well as plasma and urinary cyclic GMP (cGMP), thromboxane B2 (TxB2) and 6-keto-PGF1. RESULTS: Renal functional and hemodynamic variables did not differ between the two groups, at any period. Cardiopulmonary bypass induced increases in urinary flow, osmolar clearance and fractional excretion of sodium and potassium in both groups. Plasma and urinary ratio of 6-keto-PGF to TxB2 increased markedly and reflected a predominant systemic and renal release of vasodilatory prostaglandins. Intraoperatively, ANF was higher in ACEIs than in control patients. CONCLUSIONS: Long term treatment with ACE inhibitors does not influence the perioperative changes in renal hemodynamics and function. During cardiopulmonary bypass, a transient impairment in solute reabsorption is associated with renal release of vasodilatory mediators (nitric oxide and prostacyclin).

Aged↗