Cardiac function changes with switching from the supine to prone position: analysis by quantitative semiconductor gated single-photon emission computed tomography

Agreement between non-invasive and invasive arterial blood pressure during surgery in the prone position: an error grid analysis

PURPOSE

Prone position has recently gained renewed importance as a treatment for acute respiratory distress syndrome and spine and brain surgeries. Our study aimed to perform an error grid analysis to examine the clinical discrepancies between arterial blood pressure (ABP) and non-invasive blood pressure (NIBP) in the prone position and to investigate the risk factors influencing these differences.

METHODS

Error grid analysis was performed retrospectively on 1389 pairs of 100 consecutive prone positioning cases. This analysis classifies the difference between the two methods into five clinically relevant zones, from "no risk" to "dangerous risk". Additionally, multivariable ordinal logistic regression analysis was conducted to evaluate the relationship between the risk zones of mean blood pressure (MBP), as classified by error grid analysis and the covariate of interest.

RESULTS

Error grid analysis showed that the proportions of measurement pairs in risk zones A-E for systolic blood pressure were 96.8%, 3.2%, 0.1%, 0%, and 0%, respectively. In contrast, the MBP proportions were 74.0%, 25.1%, 0.9%, 0.1%, and 0%. Multivariable ordinal logistic regression analysis revealed that the position of arms (next to the head) was a significant factor (adjusted odds ratio: 4.35, 95% CI: 2.38-8.33, P < 0.001).

CONCLUSION

Error grid analysis revealed a clinically unacceptable discrepancy between ABP and NIBP for MBP during prone positioning surgery. The position of the arms next to the head was associated with increased clinical discrepancy between the two MBP measurement methods.

Vloga izvajalcev zdravstvene nege pri pronaciji in supinaciji intubiranega pacienta s hudim akutnim respiratornim sindromom koronavirus-2

Uvod: Hud akutni respiratorni sindrom koronavirus-2 je s svojo intenzivnostjo močno vplival na razmere in delo v enotah intenzivne terapije. Pri vse več intubiranih pacientih z akutnim respiratornim distresnim sindromom se je pokazala potreba po pronaciji (obrat na trebuh). Namen raziskave je bil preučiti vlogo izvajalcev zdravstvene nege pri pronaciji in supinaciji (obrat na hrbet) pacienta ter ugotoviti najpogostejše zaplete, ki se ob tem lahko pojavijo.Metode: Uporabljen je bil pregled znanstvene in strokovne literature. Iskanje literature je potekalo v podatkovnih bazah PubMed, Sage in ScienceDirect ter Google Scholar. Vključene so bile raziskave od januarja 2020 do decembra 2021. Izvedena je bila vsebinska analiza raziskav.Rezultati: Skupno je bilo identificiranih 993 člankov. Dodanih je bilo še deset člankov, najdenih s prostoročnim iskanjem v Google Scholar. Izmed 1.003 identificiranih zadetkov je bilo v končno analizo vključenih osem člankov. Izpostavljena so bila tri glavna vsebinska področja: (1) vloga izvajalcev zdravstvene nege pred pronacijo intubiranega pacienta; (2) vloga izvajalcev zdravstvene nege med pronacijo intubiranega pacienta in (3) vloga izvajalcev zdravstvene nege pri supinaciji intubiranega pacienta.Diskusija in zaključek: Pronacija in supinacija intubiranega pacienta predstavljata velik izziv za celoten zdravstveni tim, ki je v času epidemije okrnjen tako številčno kot tudi glede na stopnjo usposobljenosti. Izvajalec zdravstvene nege mora ob teh intervencijah zagotoviti hemodinamsko stabilnost, pravilno pozicioniranje pacienta, preprečiti ekstubacijo in izpade različnih katetrov, zaščititi kožo in vseskozi izvajati potrebne aktivnosti zdravstvene nege.

The Impact of Individualized Hemodynamic Management on Intraoperative Fluid Balance and Hemodynamic Interventions during Spine Surgery in the Prone Position: A Prospective Randomized Trial

Background and Objectives: The effect of individualized hemodynamic management on the intraoperative use of fluids and other hemodynamic interventions in patients undergoing spinal surgery in the prone position is controversial. This study aimed to evaluate how the use of individualized hemodynamic management based on extended continuous non-invasive hemodynamic monitoring modifies intraoperative hemodynamic interventions compared to conventional hemodynamic monitoring with intermittent non-invasive blood pressure measurements. Methods: Fifty adult patients (American Society of Anesthesiologists physical status I−III) who underwent spinal procedures in the prone position and were then managed with a restrictive fluid strategy were prospectively randomized into intervention and control groups. In the intervention group, individualized hemodynamic management followed a goal-directed protocol based on continuously non-invasively measured blood pressure, heart rate, cardiac output, systemic vascular resistance, and stroke volume variation. In the control group, patients were monitored using intermittent non-invasive blood pressure monitoring, and the choice of hemodynamic intervention was left to the discretion of the attending anesthesiologist. Results: In the intervention group, more hypotensive episodes (3 (2−4) vs. 1 (0−2), p = 0.0001), higher intraoperative dose of ephedrine (0 (0−10) vs. 0 (0−0) mg, p = 0.0008), and more positive fluid balance (680 (510−937) vs. 270 (196−377) ml, p < 0.0001) were recorded. Intraoperative norepinephrine dose and postoperative outcomes did not differ between the groups. Conclusions: Individualized hemodynamic management based on data from extended non-invasive hemodynamic monitoring significantly modified intraoperative hemodynamic management and was associated with a higher number of hemodynamic interventions and a more positive fluid balance.

Sudden arrhythmia in the prone position during spinal surgery: A case report

RATIONALE

The prone position is the most commonly required position during spinal surgery. Decreasing lumbar lordosis is necessary to facilitate the accessibility of the surgical field. And this can affect the hemodynamic circulation of the patients. The Jackson spine table is one of the most preferred methods, known to have minimal effects on cardiac function.

PATIENT CONCERNS

We report a case of sudden arrhythmia that developed during the prone position using a Jackson spine table. It occurred 30 minutes after the positional change.

DIAGNOSES

Arrhythmia showed bizarre P and QRS waves. Ectopic P, bundle branch block, or both was suspected.

INTERVENTIONS

Because it was difficult to define the exact type or cause of this sudden arrhythmia and considering that other vital signs remained stable, we decided to keep close observation during the operation rather than applying uncertain antiarrhythmic medication.

OUTCOMES

Arrhythmia spontaneously developed and subsided repeatedly. And it recovered to normal sinus rhythm immediately after the positional change to the supine position. Therefore, increased intrathoracic pressure caused by the prone position was highly suspected to be the cause of this event.

LESSONS

Although the Jackson spine table is known to have the least effect on cardiac function, the patient experienced arrhythmia in our case. Hence, to achieve better clinical outcomes, an understanding of physiological alterations and possible complications caused by the prone position is necessary for earlier diagnosis and management.

Graded Epidural Anesthesia for Non-cardiac Surgery in the Prone Position in a Patient With Low Ejection Fraction

Ischemic heart disease (IHD), also known as coronary artery disease, occurs due to the blockage of coronary arteries which reduces the blood supply of the myocardium. The main goal of the anesthetic management of IHD patients undergoing non-cardiac surgery is to maintain the balance between myocardial oxygen supply and demand. Here, we report the anesthetic management of an IHD patient with a low ejection fraction who was posted for percutaneous nephrolithotomy in the prone position. We opted for graded epidural anesthesia with a low dose of a local anesthetic drug and opioid. Graded epidural anesthesia is a safe alternative over general anesthesia for patients with IHD and low ejection fraction as it reduces stress response to surgery, provides good postoperative analgesia, and avoids myocardial depressant drugs and coagulation responses.

Deep learning-based attenuation map generation for myocardial perfusion SPECT

PURPOSE

Attenuation correction using CT transmission scanning increases the accuracy of single-photon emission computed tomography (SPECT) and enables quantitative analysis. Current existing SPECT-only systems normally do not support transmission scanning and therefore scans on these systems are susceptible to attenuation artifacts. Moreover, the use of CT scans also increases radiation dose to patients and significant artifacts can occur due to the misregistration between the SPECT and CT scans as a result of patient motion. The purpose of this study is to develop an approach to estimate attenuation maps directly from SPECT emission data using deep learning methods.

METHODS

Both photopeak window and scatter window SPECT images were used as inputs to better utilize the underlying attenuation information embedded in the emission data. The CT-based attenuation maps were used as labels with which cardiac SPECT/CT images of 65 patients were included for training and testing. We implemented and evaluated deep fully convolutional neural networks using both standard training and training using an adversarial strategy.

RESULTS

The synthetic attenuation maps were qualitatively and quantitatively consistent with the CT-based attenuation map. The globally normalized mean absolute error (NMAE) between the synthetic and CT-based attenuation maps were 3.60% ± 0.85% among the 25 testing subjects. The SPECT reconstructed images corrected using the CT-based attenuation map and synthetic attenuation map are highly consistent. The NMAE between the reconstructed SPECT images that were corrected using the synthetic and CT-based attenuation maps was 0.26% ± 0.15%, whereas the localized absolute percentage error was 1.33% ± 3.80% in the left ventricle (LV) myocardium and 1.07% ± 2.58% in the LV blood pool.

CONCLUSION

We developed a deep convolutional neural network to estimate attenuation maps for SPECT directly from the emission data. The proposed method is capable of generating highly reliable attenuation maps to facilitate attenuation correction for SPECT-only scanners for myocardial perfusion imaging.

Cardioprotective effect of transcutaneous electrical acupuncture point stimulation on perioperative elderly patients with coronary heart disease: a prospective, randomized, controlled clinical trial

Purpose

The purpose of this study was to evaluate the effects of transcutaneous electrical acupoint stimulation (TEAS) on postoperative autonomic nervous system function and serum biomarkers in the elderly.

Patients and methods

A total of 122 American Society of Anesthesiologists class II or III patients with coronary heart disease undergoing spinal surgery were randomly divided into two groups: TEAS (received TEAS at Neiguan [PC6] and Ximen [PC4] for 30 minutes before anesthesia induction until the end of surgery) and control (received electrode plate at the same acupuncture points without any electrical stimulation). Serum was isolated for the measurement of concentration of high-sensitive troponin T (hs-cTnT), CRP, and CK. Heart rate (HR) and heart rate variability (HRV) including: total power (TP), low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio were used to assess autonomic nervous system function. The primary outcome was to evaluate whether TEAS changed the postoperative serum hs-cTnT. The secondary outcomes were to observe the effects of TEAS on HRV, circulating CK and CRP after surgery.

Results

Hs-cTnT, CRP, and CK concentrations were significantly higher on first, third and fifth day after surgery than those before anesthesia induction in both groups. Hs-cTnT concentration was significantly lower on the first and third day after surgery in TEAS group than in control group. Compared with 1 day before surgery, TP, LF, and HF decreased significantly and HR, LF/HF increased significantly on first, third, and fifth day after surgery in control group. Compared with control group, HR was significantly lower on the first, third, and fifth day after surgery, LF/HF decreased and TP, LF, HF were significantly higher on the first day after surgery in TEAS group.

Conclusion

TEAS at PC6 and PC4 could reduce postoperative serum hs-cTnT concentration and change HRV index to improve autonomic nervous system activity.

Recent advances in cardiac SPECT instrumentation and imaging methods

Cardiac SPECT continues to play a critical role in detecting and managing cardiovascular disease, in particularly coronary artery disease (CAD) (Jaarsma et al 2012 J. Am. Coll. Cardiol. 59 1719-28), (Agostini et al 2016 Eur. J. Nucl. Med. Mol. Imaging 43 2423-32). While conventional dual-head SPECT scanners using parallel-hole collimators and scintillation crystals with photomultiplier tubes are still the workhorse of cardiac SPECT, they have the limitations of low photon sensitivity (~130 count s^-1 MBq^-1), poor image resolution (~15 mm) (Imbert et al 2012 J. Nucl. Med. 53 1897-903), relatively long acquisition time, inefficient use of the detector, high radiation dose, etc. Recently our field observed an exciting growth of new developments of dedicated cardiac scanners and collimators, as well as novel imaging algorithms for quantitative cardiac SPECT. These developments have opened doors to new applications with potential clinical impact, including ultra-low-dose imaging, absolute quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR), multi-radionuclide imaging, and improved image quality as a result of attenuation, scatter, motion, and partial volume corrections (PVCs). In this article, we review the recent advances in cardiac SPECT instrumentation and imaging methods. This review mainly focuses on the most recent developments published since 2012 and points to the future of cardiac SPECT from an imaging physics perspective.

Prone positioning for intramedullary nailing of subtrochanteric fractrures, the techniques of intraoperative fluoroscopy and reduction: A technique note

The treatment of subtrochanteric fractures is a challenge for orthopaedic trauma surgeons. Three positions have been described previously: supine on a fracture table, supine on a flat radiolucent table, and the lateral decubitus position on a flat radiolucent table. Each one has its advantages and limitations. In this article we describe a prone position for intramedullary nailing of subtrochanteric femoral fractures. This position has the advantages including: 1) an easy approach to reduce and maintain the reduction of fracture by adjusting only the leg plate on injured side, 2) perfect intraoperation fluoroscopic imaging on both anteroposterior view and lateral view, and 3) an easy approach to establish an appropriate entry point even in obese patients.