Changes in mean systemic filling pressure as an estimate of hemodynamic response to anesthesia induction using propofol.

BACKGROUND: Even a small change in the pressure gradient between the venous system and the right atrium can have significant hemodynamic effects. Mean systemic filling pressure (MSFP) is the driving force of the venous system. As a result, MSFP has a significant effect on cardiac output. We aimed to test the hypothesis that the hemodynamic instability during induction of general anesthesia by intravenous propofol administration is caused by changes in MSFP. METHODS: We prospectively collected data from 15 patients undergoing major surgery requiring invasive hemodynamic monitoring. Hemodynamic parameters, including MSFP, were measured before and after propofol administration and following intubation, using venous return curves at a no-flow state induced by a pneumatic tourniquet. RESULTS: A significant decrease in MSFP was observed in all study patients after propofol administration (median (IQR) pressure 17 (9) mmHg compared with 25 (7) before propofol administration, p = 0.001). The pressure gradient for venous return (MSFP - central venous pressure; CVP) also decreased following propofol administration from 19 (8) to 12 (6) mmHg, p = 0.001. Central venous pressure did not change. CONCLUSIONS: These results support the hypothesis that induction of anesthesia with propofol causes a marked reduction in MSFP. A possible mechanism of propofol-induced hypotension is reduction in preload due to a decrease in the venous vasomotor tone.

Escort of older people into the operating room: A feasibility study.

BACKGROUND: While special care is given to perioperative risk assessment and management of older people undergoing surgery, psychological aspects have been largely neglected. Escort presence in the operating room (OR) is common practice in the surgical paediatric and obstetric populations and may be beneficial in older people. OBJECTIVES: This study explored the feasibility of family member escort of older people into the OR and their presence until induction of anaesthesia. METHODS: Prospective observational study of older people (>70 years) undergoing surgery, who were offered an escort into the OR. The primary end point was the proportion of relatives who completed the intervention without feeling dizzy or fainting. Secondary end points related to patient, escort and medical and nursing staff perception of the process. RESULTS: Forty-four sets of patients and escorts completed the process. The primary objective assessing feasibility was concluded successfully. Secondary objectives assessed (1) satisfaction, where 93% of escorts and 75% of patients would support a repeat of this process; (2) anxiolysis, where 61% of patients reported a reduced level of anxiety; (3) although 68% of anaesthesiologists agreed this process improved patients' well-being, most nurses and anaesthesiologists believed this should not become routine practice. Interestingly, most staff support parents escorting a paediatric patient into OR. CONCLUSIONS: This is the first study exploring the feasibility of escorting older people into the OR. It shows a unique insight into patient- and family-centred care of the surgical older person. Escort presence may help alleviate anxiety and increase satisfaction. The medical and nursing staff objections must be looked at further.

Cardiac Function and Hemodynamic Changes during Minimally Invasive Hysterectomy with Pneumoperitoneum and Steep Trendelenburg Position for Patients with Endometrial Cancer Who Are Obese.

STUDY OBJECTIVE: To assess the effect of carbon dioxide (CO2) pneumoperitoneum and steep Trendelenburg position on patients' cardiac function and hemodynamics during minimally invasive staging surgery for endometrial cancer. DESIGN: Single-center prospective longitudinal study. SETTING: University-affiliated tertiary hospital. PATIENTS: Patients with endometrial cancer undergoing minimally invasive surgery. INTERVENTIONS: After consent, the patients' hemodynamic parameters were assessed by the Non-Invasive Cardiac System (NI Medical, Petah Tikva, Israel) at 5 time points: before general anesthesia, after induction of general anesthesia, after CO2 insufflation of the peritoneum, after steep Trendelenburg position, and at the end of surgery. MEASUREMENTS AND MAIN RESULTS: Twenty-three women were recruited. The median age of the patients was 68 years (interquartile range [IQR] 62-75), with a median body mass index of 34.9 kg/m2 (IQR 31.2-39.5) and an American Society of Anesthesiologists score ≥2. The initial median mean arterial pressure was 108 mmHg (IQR 101-113), and the baseline median cardiac output was 7.2 L/min (IQR 5.6-8.7). The median mean arterial pressure significantly decreased by 18% after insufflation (p = .001), again after Trendelenburg position (p = .003), and did not fully recover at the end of surgery in comparison with the preanesthesia baseline (p = .001). The median stroke volume significantly decreased by 17% after insufflation compared with the baseline (p = .01) and then gradually recovered to the baseline levels by the end of surgery. The median cardiac power significantly decreased by 35% after insufflation (0.009), remained low during Trendelenburg position (p = .009), and recovered by the end of surgery to 18% below the baseline levels (p = .035). CONCLUSION: Significant hemodynamic changes occur during minimally invasive staging surgery for endometrial cancer. CO2 insufflation is accompanied by the most dramatic hemodynamic deterioration during surgery, and this does not get affected much with Trendelenburg. Knowledge of the hemodynamic values of women classified as high risk when using a noninvasive technique during surgery is obtainable and may assist both surgeon and anesthesiologist to ensure a safer procedure.