Relax, it's just laparoscopy! A prospective randomized trial on heart rate variability of the surgeon in robot-assisted versus conventional laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic surgery might be beneficial for the patient, but it imposes increased physical and mental strain on the surgeon. Robot-assisted laparoscopic surgery addresses some of the laparoscopic drawbacks and may potentially reduce mental strain. This could reduce the risk of surgeon's fatigue, mishaps and strain-induced illnesses, which may eventually improve the safety of laparoscopic surgical procedures. METHODS: To test this hypothesis, a randomized study was performed, comparing both heart rate and heart rate variability (HRV) of the surgeon as a measure of total and mental strain, respectively, during conventional and robot-assisted laparoscopic cholecystectomy. RESULTS: Both heart rate and HRV (the low-frequency band/high-frequency band ratio) were significantly decreased when using robotic assistance. CONCLUSIONS: These data suggest the use of the daVinci® Surgical System leads to less physical and mental strain of the surgeon during surgery. However, assessing mental strain by means of HRV is cumbersome since there is no clear cutoff point or scale for maximum tolerated strain levels and its related effects on surgeon's health.

Level of agreement between heart rate variability and pulse rate variability in healthy individuals.

BACKGROUND AND OBJECTIVE: According to international standards, autonomic function is assessed by heart rate variability (HRV) calculated from R-R intervals obtained with an electrocardiogram (ECG). However, intra-operative movement artefacts and electrical interference may complicate R-wave detection. Pulse rate variability (PRV) derived from continuous blood pressure measurements may provide a feasible alternative for HRV. We aimed to investigate the level of agreement between PRV and traditional HRV using a novel beat-to-beat non-invasive blood pressure monitoring device. METHODS: In this prospective observational study, R-R intervals and non-invasive blood pressure waveforms were recorded simultaneously from 20 healthy male individuals at rest. HRV and PRV were analysed offline by spectral analysis, which divides the signal into its composing frequencies. Spearman's correlation coefficient, intra-class correlation coefficients and Bland-Altman analysis were used to study the level of agreement between HRV and PRV. RESULTS: The correlation coefficient between HRV and PRV was 0.99 (P < 0.001). Level of agreement was excellent with a mean difference of 1% in the very low frequency and low-frequency band and 14% in the high-frequency band. Reliability of both HRV and PRV was moderate to high. CONCLUSION: Our data show that PRV derived from non-invasive blood pressure waveforms corresponds well with traditional HRV derived from ECG. These results indicate that under standard conditions, blood pressure waveforms may replace HRV in healthy individuals and that the use of PRV in the peri-operative setting should be further evaluated.

Peripheral Insulin Extraction in Non-Diabetic Subjects and Type 2 Diabetes Mellitus Patients.

BACKGROUND: Insulin has to be transported across the capillary endothelium to stimulate muscle glucose uptake. We investigated insulin uptake from the peripheral circulation in non-diabetic (ND) individuals and in type 2 diabetes (T2D) patients. METHODS: Single-center cross-sectional study involving 40 ND (age 65±11 years) and 30 T2D patients (age 67±8 years). Thirty-six participants were studied in the fasted state (22 ND subjects and 14 T2D patients termed NDF and T2DF) and 34 participants 1-h following a glucose challenge (18 ND subjects and 16 T2D patients indicated as NDG and T2DG). Main outcome measure was fractional extraction (FE) of insulin (FEins) and glucose using the forearm balance method. RESULTS: In NDF, FEins was 18 (10-26) % at lower insulin levels (63 51-80] pmol/l), while in NDG at higher insulin levels (776 [543-1176] pmol/l), FEins was 9 (4-16) % (p = 0.01 vs. NDF). In NDF only, a negative correlation was observed between FEins and arterial plasma insulin load (rho = - 0.575;p = 0.006) and fasting plasma glucose levels (rho = - 0.551;p = 0.01). In T2DF FEins was 6 (1-19) % and not different from FEins in T2DG (10 2-14) %), and was not associated to fasting glucose. FEins tended to be higher in NDF compared to T2DF (p = 0.07). DISCUSSION: We propose that in ND individuals, besides passive diffusion, an active high-affinity pathway with limited capacity around lower physiologic insulin levels exists for insulin transendothelial transport, contributing to glycemic control. In T2D patients, this mechanism of peripheral insulin uptake is diminished or even absent. Modulation of insulin extraction from the circulation may be a novel target to improve glucose metabolism in T2D.

Health risk factors in the anesthesia population.

STUDY OBJECTIVE: We investigated the prevalence of lifestyle risk factors in patients admitted to our preoperative assessment outpatient clinic, and compared patient self-reports and anesthetist reports of health risk factors to evaluate the patient self-image of preoperative health status. DESIGN: Cross-sectional survey. SETTING: The study was performed in an academic teaching hospital in Amsterdam, the Netherlands, during 3 consecutive months at the preoperative screening clinic. PATIENTS: A total of 1227 adult patients scheduled for surgery were screened, and 1111 were included (patients being excluded where data were incomplete). INTERVENTIONS AND MEASUREMENTS: Before health risk screening by an anesthetist, patients filled out a lifestyle risk factor questionnaire including overweight, hypertension, diabetes mellitus, smoking, physical activity, and alcohol use. These were compared with risk factors stated in the preoperative assessment report of the anesthetist. MAIN RESULTS: The study population was aged 51 ± 17 years with a body mass index of 25.6 ± 4.7 kg/m(2). The most frequent lifestyle risk factors reported by the anesthetist were overweight and obesity (47.5%), smoking (25.3%), and hypertension (23.7%). The prevalence of no, 1, or 2 lifestyle risk factors in the preoperative assessment outpatient clinic population was, respectively, 30.1%, 35.6%, and 18.5% reported by the anesthetist and 36.4%, 36.7%, and 18.6% reported by the patients. Patients with more lifestyle risk factors were older with a higher body mass index and American Society of Anesthesiologists classification. Differences in reporting of lifestyle risk factors between patients and anesthetist occurred especially with overweight (26.5% vs 47.5%). CONCLUSIONS: The prevalence of lifestyle risk factors in perioperative patients is high, and differences in reporting between patients and anesthetists may suggest that patients are unaware of or ignore their unhealthy state. Further studies are warranted to investigate the association between the lifestyle risk factors and outcome in the anesthesiology setting.