Preemptive volume therapy to prevent hemodynamic changes caused by the beach chair position: hydroxyethyl starch 130/0.4 versus Ringer's acetate-a controlled randomized trial

Postoperative cognitive dysfunction after beach chair positioning compared to supine position in orthopaedic surgery in the elderly

INTRODUCTION

Postoperative cognitive dysfunction (POCD) occurs in up to 26% of patients older than 60 years 1 week after non-cardiac surgery. Intraoperative beach chair positioning (BCP) is advantageous for some types of shoulder surgery. However, this kind of positioning leads to a downward bound redistribution of blood volume, with possible hypoperfusion of the brain. We hypothesized that patients > 60 years undergoing orthopaedic shoulder surgery in a BCP might experience more POCD than patients operated in the supine position (SP).

MATERIAL AND METHODS

A single-centre, prospective observational trial of 114 orthopaedic patients was performed. Study groups were established according to the type of intraoperative positioning. Anaesthesiological management was carried out similarly in both groups, including types of anaesthetics and blood pressure levels. POCD was evaluated using the Trail Making Test, the Letter-Number Span and the Regensburger Word Fluency Test. The frequency of POCD 1 week after surgery was considered primary outcome.

RESULTS

Baseline characteristics, including duration of surgery, were comparable in both groups. POCD after 1 week occurred in 10.5% of SP patients and in 21.1% of BCP patients (p = 0.123; hazard ratio 2.0 (CI 95% 0.794-5.038)). After 4 weeks, the incidence of POCD decreased (SP: 8.8% vs. BCP: 5.3%; p = 0.463). 12/18 patients with POCD showed changes in their Word Fluency Tests. Near-infrared spectroscopy (NIRS) values were not lower in patients with POCD compared to those without POCD (54% (50/61) vs. 57% (51/61); p = 0.671).

CONCLUSION

POCD at 1 week after surgery tended to occur more often in patients operated in beach chair position compared to patients in supine position without being statistically significant.

A Systolic Blood Pressure of 100 mm Hg Is Optimal for Optimal Visualization in Arthroscopic Rotator Cuff Repair in the Beach-Chair Position

Purpose

To investigate the relationship between visualization and blood pressure during arthroscopic rotator cuff repair (ARCR) in the beach-chair position and to clarify the optimal blood pressure to maintain good visualization during surgery.

Methods

One senior surgeon evaluated intraoperative visualization at the start of arthroscopy, at acromioplasty, at the refresh of the footprint on the greater tuberosity, at marrow vent creation in the footprint on the greater tuberosity, and at rotator cuff fixation. The evaluation grades were: 5, clear; 4, mild bleeding; 3, bleeding but operable; 2, poor visualization due to bleeding; and 1, inability to continue surgery due to massive bleeding. During ARCR, an arterial line was inserted, and blood pressure was measured continuously. The relationship between visualization and blood pressure was analyzed. Receiver operating characteristic analysis was performed with evaluation grades 5 and 4 as the good visualization group and the other evaluation grades as the poor visualization group.

Results

Visualization assessment and systolic/diastolic blood pressure were associated at the start of arthroscopy (P = .0257/.0057), at acromioplasty (P = .0023/.0399), and at the refresh of the footprint (P = .0201/.0272). The average blood pressure of evaluation grade 5 cases was 91/50 mm Hg. The cut-off values, based on the area under the curve on receiver operating characteristic analysis, were as follows: 104/60 mm Hg (0.91-0.95) at acromioplasty; 116/70 (0.94-0.96) at the refresh of the footprint; 116/70 mm Hg (0.94-0.96) at the refresh of the footprint; and 106/58 mm Hg (0.73-0.70) at marrow vent creation.

Conclusions

Good visualization during ARCR in the beach-chair position was significantly associated with blood pressure. An optimal blood pressure resulting in good visualization that would not cause excessive hypotension during ARCR surgery in the beach-chair position might be a systolic blood pressure of 100 mm Hg.

Level of Evidence

III, prospective, nonrandomized, observational study.

Fluid preloading before beach chair positioning for arthroscopic shoulder procedures: a randomized controlled trial

BACKGROUND AND OBJECTIVES

The Beach Chair Position (BCP) has many advantages such as less neurovascular injury and better intra-articular visualization, but it has also negative consequences, including hemodynamic instability. Although maintaining normal Mean Arterial Pressure (MAP) is important, fluid management is also a crucial concept for hemodynamic stability. The main objective of this study is whether preloading before positioning would be effective for less hemodynamic instability.

METHODS

This randomized, controlled study was conducted in a single center in the Istanbul University, Istanbul Faculty of Medicine. Forty-nine patients undergoing elective arthroscopic surgery in the BCP were recruited. In the study group, crystalloid fluid at 10 mL.kg^-1 of ideal body weight was administered intravenously 30 min before the BCP for preloading. The primary outcome measures were differences of hemodynamic variables as MAP, Stroke Volume (SV), Heart Rate (HR), and Cardiac Output (CO). The secondary outcome measures were Postoperative Nausea and Vomiting (PONV) rates in postoperative first day, surgical satisfaction scale, total ephedrine dose used during surgery, and total amount of fluid.

RESULTS

The MAP, CO, and SV measurements of the study group were higher than those of the control group in the 5th minute after the BCP (respectively, p = 0.001, p = 0.016, p = 0.01). The total amount of crystalloid and surgical satisfaction scales were higher in the study group (respectively, p = 0.016, p = 0.001). Total amount of colloid and ephedrine dose used in the intraoperative period, and PONV rates were lower in the study group (p = 0.003, p = 0.018, p = 0.019, respectively).

CONCLUSION

Consequently, preloading can be favorable approach to preserve hemodynamic stability.

Prophylactic measures to prevent cerebral oxygen desaturation events in elective beach-chair position shoulder surgeries; a systematic review and meta-analysis

Background

Prophylaxis for cerebral desaturation events (CDEs) during anesthesia in the beach chair position (BCP) for shoulder surgeries has not been evaluated. We systematically analyzed the effectiveness of various prophylactic measures used in this clinical setting.

Methods

We performed a meta-analysis (PROSPERO; no. CRD42020167285) of trials reporting CDEs and regional cerebral oxygen saturation (rSO₂) and jugular venous oxygen saturation (SjvO₂) values in anesthetized patients undergoing shoulder surgery in BCP. Considering the type of prophylactic measures used (pharmacological or non-pharmacological), a subgroup analysis was planned. Outcomes included (1) rSO₂ and SjvO₂ data with and without prophylactic measures for CDEs, recorded for different time intervals, and (2) the number of patients experiencing CDEs and hypotension.

Results

Twelve studies (786 patients) were included in the analysis. We observed lower absolute rSO₂ values for early and all-time periods for vasoactive agent prophylaxis. The lowest achieved rSO₂ values were also lower for vasoactive agent prophylaxis. Risk of CDEs was higher with vasoactive agent prophylaxis. Subgroup analysis identified targeted mild hypercarbia as effective in preserving cerebral oxygenation. Similarly, targeted mild hypercarbia prevented the fall in rSO₂ with position change. Meta-regressions revealed statistically significant highest estimates for vasoactive agent prophylaxis in contrast to targeted mild hypercarbia. Likelihood of not developing CDEs was higher for targeted mild hypercarbia. In contrast to rSO₂, most prophylactic methods reduced hypotensive episodes.

Conclusions

Targeted mild hypercarbia can reduce BCP-related CDEs. Evidence does not favor prophylactic use of vasoactive agents for the prevention of cerebral desaturations irrespective of whether their use interferes with cerebral oximetry readings.

Adverse heart rate responses during beach-chair position for shoulder surgeries - A systematic review and meta-analysis of their incidence, interpretations and associations

Background and Aims

Evaluations of adverse heart rate (HR)-responses and HR-variations during anaesthesia in beach-chair-position (BCP) for shoulder surgeries have not been done earlier. We analysed the incidence, associations, and interpretations of adverse HR-responses in this clinical setting.

Methods

We performed a meta-analysis of trials that reported HR-related data in anaesthetised subjects undergoing elective shoulder surgeries in BCP. Studies included prospective, randomised, quasi-randomised and non-randomised, controlled clinical trials as well as observational cohorts. Literature search was conducted in MEDLINE, EMBASE, CINHAL and the Cochrane Central Register of Controlled Trials of the 21^st century. In the first analysis, we studied the incidence and associations of bradycardia/hypotension-bradycardia episodes (HBE) with respect to the type of anaesthesia and different pharmacological agents. In the second, we evaluated anaesthetic influences, associations and inter-relationships between monitored parameters with respect to HR-behaviours.

Results

Among the trials designed with bradycardia/HBE as a primary end point, the observed incidence of bradycardia was 9.1% and that of HBE, 14.9% and 22.7% [(for Interscalene block (ISB) ± sedation) subjects and general anaesthesia (GA) + ISB, respectively]. There was evidence of higher observed risk of developing adverse HR-responses for GA subjects over ISB (Risk Difference, P < 0.05). Concomitant use of β-agonists did not increase risk of HBEs (P = 0.29, I ²= 11.4%) or with fentanyl (P = 0.45, I ²= 0%) for ISB subjects (subgroup analysis). Fentanyl significantly influenced the HR-drop over time [meta-regression, estimates (standard error), 14.9 (5.4), 9.8 (4.3) and 17 (2.6); P = 0.007, 0.024 and <0.001; for early, mid and delayed periods, respectively] in GA subjects. With respect to number of subjects experiencing cerebral desaturation events (CDEs), total intravenous anaesthesia (TIVA)- propofol had higher risk over inhalational anaesthesia (P = 0.006, I ² = 86.7%). Meta-correlation analysis showed relationships between the HR and rSO₂(regional cerebral oxygen saturation) or SjvO₂(jugular venous oxygen saturation) values (r = 0.608, 95%CI, 0.439 to 0.735, P < 0.001, I ²= 77.4% and r = 0.397, 95%CI, 0.151 to 0.597, P < 0.001, I ²= 64.3%, respectively).

Conclusions

There is not enough evidence to claim the associations of adverse HR-responses with any specific factor. HR-fall is maximal with fentanyl and its variability is associated with changes in rSO₂. Fall in rSO₂ could be the common link triggering adverse HR-responses in BCP.

The fragility of findings of randomized controlled trials in shoulder and elbow surgery

BACKGROUND

Considered the gold standard of study designs, randomized controlled trials' (RCTs) results shape clinical practice, effect policy, and influence reimbursement. The fragility index (FI) can be used to quantitate the relative robustness of RCT results, with higher scores indicating more stout results. Unfortunately, most RCTs in surgery have fragile results. The aim of this study was to report on the FI in addition to a qualitative assessment of recent RCTs within the field of shoulder and elbow surgery.

METHODS

A systematic review was performed identifying recently published shoulder/elbow RCTs that included 1:1 allocated parallel study arms, dichotomous primary outcome variables, and statistical significance. The FI was calculated by sequentially modifying outcome groups by exchanging a nonevent in one group to an event until the P value for the outcome comparison, as calculated by the Fisher exact test, was increased above the .05 threshold.

RESULTS

Thirty RCTs were included. The median FI was 4. Sixty percent trials had a FI of 2 or less. Fifty-three percent studies reported that participants were lost to follow-up. In 87.5% of these studies, the losses to follow-up exceeded their respective FIs. Only 53% of studies defined a primary outcome variable and 60% studies performed a prestudy power analysis.

CONCLUSIONS

The median FI reported in the recent shoulder/elbow literature is 4; however, a high proportion of included RCTs display significant methodological concerns. The FI is a useful adjunct to analyze RCT results, but careful analysis of trial methods should be employed in each circumstance before drawing conclusions.

[Cardiorespiratory effects of perioperative positioning techniques]

The supine position is still the most frequently used type of positioning during surgical procedures. Positions other than the supine position lead to physiological alterations that have a relevant influence on the course of anesthesia and surgery. As a matter of principle, hemodynamic stability is at risk because venous blood is pooled in the lower positioned body parts. In addition, head down positions (Trendelenburg position) may lead to an impairment of respiratory function by reducing lung volumes as well as lung compliance. Upright positions (beach chair position) are characterized by a relative hypovolemia accompanied by a reduction of mean arterial pressure, cardiac output and stroke volume, whereas pulmonary functions remain unchanged. Some severe adverse events have been described in the literature (e.g. intraoperative apoplexy, postoperative blindness). The pathophysiological principles and effects of hemodynamic alterations as well as potential strategies to avoid complications are presented and discussed in this lead article. Head down positions, especially the Trendelenburg position, cause a relative (intrathoracic) hypervolemia and an increase in cardiac preload that is usually well-tolerated in patients without heart problems; however, the Trendelenburg position, especially if combined with a capnoperitoneum, significantly impairs pulmonary function, can have a negative effect on intracerebral pressure and may reduce blood flow of intra-abdominal organs. The pathophysiological intraoperative changes caused by Trendelenburg positioning are described and approaches suitable for risk reduction are discussed. The prone position and lateral decubitus position have little influence on the intraoperative homeostasis. Nevertheless, there is an ongoing discussion concerning the efficacy of a 15° left lateral position during caesarean section, which is also discussed in a separate section of this review.

Cerebral Desaturation Events During Shoulder Arthroscopy in the Beach Chair Position

The beach chair position (BCP) is commonly used position in upper extremity surgery. Although there are many advantages to surgery in this position, there are also potential drawbacks and described complications including devastating neurologic outcomes. The etiology of these complications is postulated to be due to the gravitational effects of the seated position leading to cerebral hypoperfusion. We review the current literature on intraoperative cerebral monitoring and neurocognitive complications with shoulder surgery performed in the BCP. A previous systematic review estimated the incidence of neurocognitive complications after surgery in the BCP to be 0.004%. However, the true incidence is unknown and is likely much more common. Reports of neurologic complications have revealed a need for heightened vigilance, alternative anesthesia techniques, and improved monitoring. Methods for monitoring have included near-infrared spectroscopy, a measurement of cerebral oximetry shown to reliably detect cerebral hypoperfusion. In this literature review, we sought to update the incidence of intraoperative cerebral desaturation events (CDEs) to investigate the relationship of CDEs to neurocognitive complications and to review recent reported cases of neurocognitive complications. Existing literature suggest that accurate intraoperative monitoring of cerebral perfusion may improve patient safety.