Determinants of re-operation for bleeding in head and neck cancer surgery.

OBJECTIVE: Post-operative bleeding in the head and neck area is potentially fatal. This 'real world' study sought to assess factors that increase the risk of re-operation for post-operative bleeding in head and neck cancer surgery. METHODS: A total of 456 patients underwent surgery for head and neck cancer (591 operations). The primary endpoint was re-operation for bleeding. RESULTS: The rate of re-operation for bleeding was 5 per cent of all operations. Re-operation for bleeding was an independent risk factor for 30-day mortality (odds ratio = 5.27, p = 0.014). Risk factors for re-operation because of bleeding included excessive (more than 4000 ml) fluid administration (over 24 hours) (p < 0.001), heavy alcohol consumption (p = 0.014), pre-operative oncological treatment (p = 0.017), advanced disease stage (p = 0.020) and higher tumour (T) classification (p = 0.034). Operations with more excessive bleeding (700 ml or more) were associated with an increased risk (p = 0.001) of re-operation for post-operative bleeding. Moreover, the risk of re-operation was significantly higher in patients undergoing microvascular surgery compared to those who had no oncological treatment pre-operatively (18 vs 6 per cent, p = 0.001). CONCLUSION: The 30-day mortality risk increased over 5-fold in patients undergoing re-operation for bleeding.

Incidence and predictors of 30-day cardiovascular complications in patients undergoing head and neck cancer surgery.

Incidence and predictors of peri-operative or post-operative cardiovascular complications in head and neck cancer surgery remain poorly elucidated. In this retrospective study, we investigated the rate and pre-operative risk factors for cardiovascular and cerebrovascular complications. This study included all patients (n = 456) operated for head and neck cancer between 1999 and 2008. Patients' medical records were reviewed and the adjudication of endpoints was performed by adjudication committee. The 30-day incidence of cardiovascular and cerebrovascular complications was 7.2 %. Cardiac mortality at 30 days was 1.0 %. Univariate predictors of MACCE (major adverse cardiac and cerebrovascular events) at the 30-day follow-up were history of myocardial infarction (OR 4.56, 95 % CI 1.73-11.97, p = 0.002); history of heart failure (OR 4.14, 95 % CI 1.32-13.02, p = 0.015); pre-existing coronary artery disease (OR 3.98, 95 % CI 1.75-9.06, p = 0.001); prior aspirin medication (OR 3.73, 95 % CI 1.81-7.71, p < 0.001); prior betablocker medication (OR 3.67, 95 % CI 1.79-7.51, p < 0.001); hypertension (OR 2.55, 95 % CI 1.25-5.19, p = 0.010); and increasing age (OR 1.08, 95 % CI 1.05-1.12, p < 0.001). In a multivariate model, independent predictors of MACCE were pre-existing coronary artery disease (OR 2.45, 95 % CI 1.03-5.80, p = 0.042) and increasing age (OR 1.08, 95 % CI 1.04-1.11, p < 0.001). Patients having surgery for head and neck cancer are at high (>5 %) risk of developing vascular complications. Prior coronary artery disease and increasing age are independent risk factors for MACCE.

White matter damage of the brain is associated with poor outcome in vascular surgery patients with claudication: a pilot study.

OBJECTIVE: Peripheral arterial disease (PAD) is a systemic atherosclerotic syndrome with high post-operative morbidity and mortality. Fractional anisotropy (FA), an index measured by magnetic resonance diffusion tensor imaging (DTI), has been shown to be exceedingly sensitive to microstructural damage in brain white matter tracts. It is hypothesized that pre-operative white matter damage is more extensive in PAD patients scheduled for vascular surgery who experience an adverse long-term outcome. METHODS: Preoperative FA values were obtained in 24 consecutive PAD patients (age >40 years) scheduled for elective infrainguinal revascularization surgery and in 15 healthy age matched participants. All patients had their clinical history taken and underwent physical examination and laboratory tests. After surgery, patients were followed for a median of 52 months (range 40-63) and major adverse cardiovascular and cerebrovascular events (MACCE) were recorded. RESULTS: There were no statistically significant differences in baseline demographic or clinical variables between the MACCE group and the non-MACCE group. During follow up, eight PAD patients suffered a MACCE and they had lower FA values than patients without MACCE or healthy controls (mean ± SD 0.370 ± 0.017 vs. 0.392 ± 0.023 vs. 0.412 ± 0.018, p = .036 and p = .00007, respectively). Voxelwise analysis of the FA data revealed diffuse spatial distribution of white matter damage in PAD patients. There was no statistically significant association between the FA values and other clinical variables. CONCLUSION: Microstructural white matter damage was associated with poor outcome in PAD patients with claudication requiring surgical revascularization, and its extent may have clinical value in risk stratification.

Heart rate dynamics during accentuated sympathovagal interaction.

Concomitant sympathetic and vagal activation can occur in various physiological conditions, but there is limited information on heart rate (HR) behavior during the accentuated sympathovagal antagonism. Beat-to-beat HR and blood pressure were recorded during intravenous infusion of incremental doses of norepinephrine in 18 healthy male volunteers (mean age 23 +/- 5 yr). HR and blood pressure spectra and two-dimensional Poincaré plots were generated from the baseline recordings and from the recordings at different doses of norepinephrine. The mean blood pressure increased (from 90 +/- 7 to 120 +/- 9 mmHg, P < 0.001), HR decreased (from 60 +/- 9 to 48 +/- 7 beats/min, P < 0.001), and the high-frequency spectral component of HR variability increased (P < 0.001) during the norepinephrine infusion as evidence of accentuated sympathovagal interaction. Abrupt aperiodic changes in sinus intervals that were not related to respiratory cycles or changes in blood pressure occurred in 14 of 18 subjects during the norepinephrine infusions. These fluctuations in sinus intervals resulted in a complex or parabola-shaped structure of the Poincaré plots of successive R-R intervals and a widening of the high-frequency spectral peak. In four subjects, the abrupt fluctuations in sinus intervals were followed by a sudden onset of fixed R-R interval dynamics with a loss of respiratory modulation of HR, resulting in a torpedo-shaped structure of the Poincaré plots. These data show that HR behavior becomes remarkably unstable during accentuated sympathovagal interaction, resembling stochastic dynamics or deterministic chaotic behavior. These features of HR dynamics can be better identified by dynamic analysis of beat-to-beat behavior of R-R intervals than by traditional analysis techniques of HR variability.

Echocardiographic evaluation of left ventricular response to isometric exercise in young insulin-dependent diabetics.

In order to evaluate the left ventricular (LV) response to isometric exercise in diabetics, 15 young insulin-dependent diabetic subjects and 12 control subjects of similar age and sex distribution performed a handgrip test during echocardiography. No base-line differences in hemodynamic or echocardiographic parameters were found between diabetic and control subjects. The heart rate and blood pressure responses to handgrip exercise were similar in the two groups, and LV dimensions, shortening fraction and velocity of circumferential fiber shortening remained unchanged in both groups. Three diabetic subjects had an impaired LV functional response to handgrip (a decrease of more than 5 percentage units in the shortening fraction). These 3 patients had high HbA1 values (17.6-18.2%) and modest correlations existed between decrease in the shortening fraction during handgrip and concentrations of HbA1 (r = 0.70, p less than 0.01) and fasting blood glucose (r = 0.62, p less than 0.01). Thus, most young insulin-dependent diabetic subjects appear to have a normal LV response to isometric exercise, but poor blood glucose control seems to be accompanied by a slight impairment of LV functional reserve.

Cardiovascular response to exercise in young women with insulin-dependent diabetes mellitus.

To evaluate the cardiovascular response to exercise in diabetes, a graded maximal exercise test was performed on 50 women with insulin-dependent diabetes mellitus, aged 15-40 years, and on 15 healthy women in the same age group. The diabetic subjects were divided into 3 groups according to the duration of disease: group 1: 0-5 years, group 2: 6-14 years, group 3: 15-29 years. The maximal work load was lower in the diabetic subjects than in the controls. The difference was most marked between the controls and group 3 (167 +/- 14 W vs 132 +/- 23 W, p less than 0.001). The maximal heart rate was lower in groups 2 and 3 than in the controls (173 +/- 16 vs 187 +/- 11, p less than 0.05). The diabetic women with long-standing disease had a slightly higher blood pressure response to exercise resulting in comparable rate-pressure products in the study groups. Two diabetic women in group 3 and one healthy woman had 1 mm ST depressions during the test without appearance of arrhythmias or chest pain. These studies suggest that exercise tolerance is reduced in young diabetic women, especially in patients with long-standing disease. The frequency of pathological exercise ECGs does not, however, seem to be increased.