Ankle-brachial blood pressure differences in the beach-chair position of the shoulder surgery

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.

Anesthesia and Analgesia in the Patient with an Unstable Shoulder

Introduction:

The patient with an unstable shoulder represents a challenge for the anesthesiologist. Most patients will be young individuals in good health but both shoulder dislocation reduction, a procedure that is usually performed under specific analgesia in an urgent setting, and instability surgery anesthesia and postoperative management present certain peculiarities.

Material and Methods:

For the purpose of the article, 78 references including clinical trials and reviews were included. The review was organized considering the patient that presents an acute shoulder dislocation and the patient with chronic shoulder instability that requires surgery. In both cases the aspects like general or regional anesthesia, surgical positions and postoperative pain management were analyzed.

Conclusion:

The patient with an acutely dislocated shoulder is usually managed in the emergency room. Although reduction without analgesia is often performed in non-medical settings, an appropriate level of analgesia will ease the reduction procedure avoiding further complications. Intravenous analgesia and sedation is considered the gold standard but requires appropriate monitorization and airway control. Intraarticular local analgesic injection is considered also a safe and effective procedure. General anesthesia or nerve blocks can also be considered. The surgical management of the patient with shoulder instability requires a proper anesthetic management. This should start with an exhaustive preoperative evaluation that should be focused in identifying potential respiratory problems that might be complicated by local nerve blocks. Intraoperative management can be challenging, especially for patients operated in beach chair position, for the relationship with problems related to cerebral hypoperfusion, a situation related to hypotension events directly linked to patient positioning. Different nerve blocks will help attaining excellent analgesia both during and after the surgical procedure. An interescalene nerve block should be considered the best technique, but in certain cases, other blocks can be considered.

Blood pressure response to combined general anaesthesia/interscalene brachial plexus block for outpatient shoulder arthroscopy

BACKGROUND

Shoulder surgery is often performed in the beach-chair position, a position associated with arterial hypotension and subsequent risk of cerebral ischaemia. It can be performed under general anaesthesia or with an interscalene brachial plexus block, each of which has specific advantages but also specific negative effects on blood pressure control. It would be worthwhile to combine the advantages of the two, but the effects of the combination on the circulation are not well investigated. We studied blood pressure, heart rate, and incidence of adverse circulatory events in patients undergoing shoulder surgery in general anaesthesia with or without an interscalene block.

METHODS

Prospective, randomised, blinded study in outpatients (age 18 to 80 years) undergoing shoulder arthroscopy. General anaesthesia was with propofol/opioid, interscalene block with 40 ml 1% mepivacaine. Hypotension requiring treatment was defined as a mean arterial pressure <60 mmHg or a systolic pressure <80% of baseline; relevant bradycardia was a heart rate <50 bpm with a decrease in blood pressure.

RESULTS

Forty-two patients had general anaesthesia alone, 41 had general anaesthesia plus interscalene block. The average systolic blood pressure under anaesthesia in the beach-chair position was 114 ± 7.3 vs. 116 ± 8.3 mmHg (p = 0.09; all comparisons General vs. General-Regional). The incidence of a mean arterial pressure under 60 mmHg or a decrease in systolic pressure of more than 20% from baseline was 64% vs. 76% (p = 0.45). The number of patients with a heart rate lower than 50 and a concomitant blood pressure decrease was 8 vs. 5 (p = 0.30).

CONCLUSION

One can safely combine interscalene block with general anaesthesia for surgery in the beach-chair position in ASA I and II patients.

CLINICAL TRIAL NUMBER

DRKS00005295.