A145 High flow nasal cannula and diaphragmatic function after video-assisted thoracic surgery. A randomized, open-labeled, controlled trialA. Fogagnolo 1, G. De Paoli 1, F. Dalla Corte 2, A. Andalò 1, G. Benetto 1, M. Riccardo 1, C.A. Volta 1, S. Spadaro1 1Azienda Ospedaliero Universitaria di Ferrara, Ferrara, Italy; 2 IRCCS Humanitas, Rozzano, Italy Correspondence: A. Fogagnolo

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A145

Background

Data on high-flow nasal cannula (HFNC) after thoracic surgery are limited and the heterogeneity of the studies increases the uncertainty. We hypothesized that among patients undergoing video-assisted lobectomy, early postoperative support with HFNC may reduce the incidence of diaphragmatic dysfunction. We also compared the incidence of PPCs between HFNC and conventional oxygen therapy (COT).

Methods

This is a single center randomized trial including patients undergoing VATS lobectomy. Informed consent was taken from each patient before the surgery. After two hours from extubation, patients were randomized 1:1 to HFNC or COT; the intervention was maintained for at least 24 h. FiO2 was titrated to maintained SpO2 > 93%. In HFNC, oxygen flow was initially set at 60 L/min. In case of patient discomfort, oxygen flow was lowered to 50 L/min. In patients with SpO2 > 93% when breathing on room air, HFNC was still applied 24 h with FIO2 set at 24%. In COT group, low-oxygen flow was delivered through nasal cannula until a maximum of 4 L/m. In case of SpO2 < 94% with 4 L/m of oxygen, higher FIO2 were delivered by a Venturi face mask. In patients with SpO2 > 93% when breathing on room air, no supplemental respiratory support was given. After 24 h, ultrasound evaluation of diaphragmatic displacement (DD) and thickening fraction (TF%) was performed. The primary outcome was the incidence of diaphragmatic dysfunction defined as DD < 11 mm. The secondary outcome was the rate of PPCs, which were categorized as mild (hypoxemia, actelectasis, pleural effusion) or severe (pneumonia, new onset of respiratory failure).

Results

One-hundred-sixteen patients were randomized (58 in HFNC and 58 in COT group). Diaphragmatic dysfunction occurred in 38/116 (32%) of patients. Clinical characteristics are shown in Table 1. Density distribution of DD and TF% in the two groups are shown in Fig. 1.

Incidence of diaphragmatic dysfunction did not differ between groups (29% [17/58] in HFNC vs 36% [21/58]; = 0.55). PPCs occurred in 59% of the patients (54% in HFNC vs 64% in COT;p = 0.45). Incidence severe PPCs was 5% in HFNC and 19% in COT group; p = 0.04. HFNC did not reduced the occurrence of PPCs (HR 0.86,95% CI [0.54–1.38] p = 0.54). In a mixed model, the application of HFNC in patients with diaphragmatic dysfunction seems able to prevent the occurrence of PPCs (OR 0.16, [95% CI 0.02–0.83];p = 0.035). Incidence of severe PPCs was 14/116 (12%), being lower in HFNC patients (3/58 (5%) vs 11/58 (19%); p = 0.043; OR = 0.03 95% CI [0.61–0.89]). Accordingly, length of hospital stay was significantly lower in HFNC vs COT (4 [4–5] vs 5 [4–7]; p = 0.004).

Discussion

The main findings of our study are that early application of HFNC in after thoracoscopy lobectomy did not reduce the incidence of diaphragmatic dysfunction or postoperative pulmonary complication. Nonetheless, HFNC seems to reduce the incidence of PPCs in patients with postoperative diaphragmatic dysfunction; finally, patients in HFNC group had less rate of severe PPCs and less length of hospital stay.

Fig. 1

(abstract A145). See text for description

Table 1 (abstract A145). Preoperative characteristics of the patients.A146 Effect of different peep strategies on reduction of atelectasis determined by lung ultrasound in patients undergoing robot-assisted radical prostatectomy: a prospective study at a single centerA. Lanotte, P. RaimondoASL Lecce, Lecce, Italy Correspondence: A. Lanotte

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A146

The pneumoperitoneum and the steep Trendelenburg position, in patients undergoing robot-assisted prostatectomy, are both elements that could worsen intraoperative respiratory mechanics and induce postoperative atelectasis. We investigated the effects of two different PEEP (positive end-expiratory pressure) in particular low PEEP (5 cmH2O) and high PEEP (10 cmH2O) on reduction of postoperative atelectasis, evaluated with the use of lung ultrasonography. After obtaining informed consent, 22 male patients undergoing robot-assisted prostatectomy were recruited and were randomly allocated into two groups (low PEEP or high PEEP). All patients underwent monitoring vital sign and depth of anesthesia using bispectral index (BIS), subarachnoid analgesia with 150 mcg of morphine and subsequent balanced general anesthesia. Restrictive fluid therapy with 4 ml/kg/h of crystalloids is applied. All patients were ventilated protectively with tidal volume of 6–8 ml/kg PBW (predicted body weight), FiO2 35–40%, I:E ratio 1:2 and respiratory rate adjusted in order to maintain EtCO2 between 33–40 mmHg. Ultrasound examination was performed on 12 sections of thorax and at three times: T0 ten minutes before oro-tracheal intubation, T1 at the end of surgery in mechanically ventilated patients, T2 fifteen minutes after extubation. For each section was measured a lung ultrasound score from 0 to 3 according to the number of B lines or the presence of subpleural consolidation. The aim of the study was the impact of two different PEEP levels on lung aeration determined by lung ultrasound score. An increase of the difference of LUS score at T2 between group L and group H means the development of atelectasis. According to the demographic analysis of the two groups it emerged that there are no differences regarding age, eight, BMI, prostate volume, duration of surgery and main comorbidities; only the smoking habit is more expressed in L group. The analysis of the trend of LUS scores shows that in both groups there is an increase in LUS going from T0 to T2 which is more marked in L group. Comparing the average LUS scores of the two groups shows how the average LUS score at T2 is significantly higher in group L. Only for the L group was observed an inverse correlation between P/F ratio and LUS score. High PEEP (10 CmH2O) during the pneumoperitoneum and steep Trendelenburg position significantly reduced postoperative atelectasis, evaluated using lung ultrasonography. However, the clinical significance should be evaluated by a larger clinical trial.

A147 Postoperative continuous monitoring in surgical ward with wearable devicesM. Panizzi, V. Bellini, F. Bezzi, M. Mion, M. Bagnoli, E.G. BignamiAnesthesiology, Intensive Care and Pain Medicine Division, Department of Medicine and Surgery, University of Parma, Parma, Italy Correspondence: M. Bagnoli

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A147

Background

Postoperative deterioration is often preceded by abnormalities in vital parameters [1, 2]. Nevertheless, limited resources generally preclude continuous monitoring in ICU/SICU for all patients. The development of new technologies recently allowed the introduction of wearable devices (WDs) and wireless data-transmission protocols such as LoRa: these tools are potentially capable of extending access possibilities to more intense monitoring regimes for a larger patient population, especially in general hospital wards [3]. The aim of this review was to investigate the state of the art of the use of WDs as remote early warning systems in the postoperative period.

Materials and Methods

This review was conducted according to PRISMA-ScR guidelines. PICO framework was used before the search to define the review protocol. A systematic literature research has been performed on PubMed, MeSH, MEDLINE, and Embase, considering a period between 2018 and February 2024. Both retrospective and prospective studies were eligible for inclusion and no automated tools were used.

Results

10 articles were included in the review, with a total of 11 different CE/FDA wearable devices used in the analyzed studies. Devices information and monitored parameters are summarized in (Fig. 1). In all the studies considered, devices were applied on surgery day upon patient arrival to recovery room or surgical ward. Mean monitoring duration was 6.7 days, ranging from 72 h to 14 days. Globally, both beyond-threshold alarms and trend analysis protocols were used to set up reactive or proactive intervention on patients, although in some studies the output was blinded to medical staff.

Conclusions

The use of WDs in clinical practice as an integral part of post-operative monitoring systems is feasible and safe, and soon its potential could be enhanced by the implementation of LoRa data transmission protocol and artificial intelligence. Assessing the trend in vital signs with such systems could help to identify post-operative complications earlier, shorten the length of hospital stay, reduce the likelihood of unplanned ICU/clinical admissions and, despite a high initial investment, reduce healthcare costs. However, further studies are needed to clarify the potential role of these devices in perioperative medicine.

References

1.

Breteler MJM, KleinJan E, Numan L et al. Are current wireless monitoring systems capable of detecting adverse events in high-risk surgical patients? A descriptive study. Injury. 2020;51 Suppl 2:S97-S105.

2.

Hillman KM, Bristow PJ, Chey T et al. Duration of life-threatening antecedents prior to intensive care admission. Intensive Care Med. 2002;28(11):1629–1634.

3.

Churpek MM, Yuen TC, Park SY et al. Using electronic health record data to develop and validate a prediction model for adverse outcomes in the wards*. Crit Care Med. 2014;42(4):841–848.

Fig. 1

(abstract A147). Devices overwiev. IntelliVue GS = Guardian Solution; Isansys PSE = Patient Status Engine (3 devices system); HR = Heart Rate; RR = Respiratory Rate; NIBP = Non-Invasive Blood Pressure; Temp = Temperature; Icons credits: Freepik from Flaticon.com; Karyative from Flaticon.com; Flaticon.com.

A148 Lung ultrasound score profile in obese patients undergoing laparoscopic-robotic surgery: a secondary analysis of peep lap studyF. Verdina 1,2, G. Furlan 2, D. Rosalba 1,2, L. Carrera 2, F. Santangelo 2, A. Rivolta 2, A. Guzzo 2, f. Vietti 2, a. Migliavacca 2, S. Gentilli 2,3, R. Romito 4, L. Portigliotti 4, D. Surico 2,5, M. Giana 5, A. Vigone 5, A. Volpe 2,6, M. Billia 6, R. Vaschetto 1,2, G. Cammarota 2,7 1 Anestesia e Terapia Intensiva, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 2 Dipartimento di Medicina Traslazionale, Università del Piemonte Orientale, Novara, Italy; 3 Clinica Chirurgica, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 4 Chirurgia Generale 2 Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 5 Ginecologia e Ostetricia, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 6 Urologia, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 7 Azienda Ospedaliero Universitaria di Alessandria SS. Antonio e Biagio e Cesare Arrigo, Alessandria, Italy Correspondence: D. Rosalba

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A148

Background

Laparoscopic surgery and General Anesthesia are known to cause atelectasis. Additionally, elevated FiO2 levels, can exacerbate alveolar collapse. Positive end-expiratory pressure (PEEP) can be used to mitigate this risk. In obese patients the risk of atelectasis is even higher. While higher PEEP values may seem necessary in these patients to keep airways open and improve lung mechanics [1], the impact of elevated PEEP on postoperative respiratory complications remains unclear [2]. Furthermore, the optimization of PEEP levels is still under evaluation.

Materials and Methods

After informed consent, we recruited adult obese patients (BMI > 30 kg/m2) who underwent laparoscopic or robotic abdominal/pelvic surgery. Prior to anesthesia induction, a twelve-point Lung Ultrasound Score (LUSS) examination was conducted (T0). Volume-controlled ventilation was administered during surgery, with a tidal volume of 6 ml/kg. Respiratory rate and FiO2 were adjusted to maintain normocapnia and normal blood oxygenation levels. PEEP was set based on lung reclutability assessed with Recruitment-to-Inflation Ratio (RIR). At the conclusion of the procedure, LUSS was reassessed (T1). Data are reported as median and 25-75th interquartile range.

Results

Between January and April 2024, we included 10 patients (5 males) with a median age of 59 years (48–66) and a median body mass index of 36 kg/m2 (34–39). Higher PEEP levels (median 15, 13–17) were set in case of high lung recruitability (RIR >  = 0.5), whereas lower PEEP levels (median 7, 6–9) were administered in instances of low lung recruitability (RIR < 0.5). During surgery FiO2 remained unchanged in both groups 0.49 (0.46–0.5) vs. 0.5 (0.4–0.63). Oxygenation was maintained with SpO2/FiO2 at 457 (442–467) postoperatively compared to 471 (463–475) preoperatively, despite a slight increase of LUSS from 0 (0–2) at baseline to 3 (2–4) after surgery. If RIR was >  = 0.5, LUSS increased from 0 (0–1) at T0 to 2(2–3) at T1. Conversely, in the RIR < 0.5 subgroup, LUSS increased from 0(0–1) at T0 to 4(2–6) at T1. Analyzing regional differences, significant effects were observed in the dorsal parts of the lung compared to the anterior regions: 2 (1–3) vs 0 (0–0) in patients with high potential for lung recruitment, and 4 (3–4) vs 0 (0–0) in patients with low potential for lung recruitment. In one patient, a LUSS > 10 was recorded, with an increase of 11 points from baseline (13 vs 2), yet this did not result in major effects on oxygenation (SpO2/FiO2: 461).

Conclusions

In obese patients undergoing laparoscopic or robotic surgery, despite adequate PEEP setting according to RIR, a slight worsening of LUSS was observed postoperatively. This effect is more pronounced in patients with low potential for lung recruitment and especially in the dorsal parts of the lungs.

References

1.

Nestler C, et al. Individualized positive end-expiratory pressure in obese patients during general anaesthesia: a randomized controlled clinical trial using electrical impedance tomography. Br J Anaesth. 2017

2.

PROBESE Collaborative Group, Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients: A Randomized Clinical Trial. JAMA. 2019

A149 Recruitment-to-inflation ratio in obese patients undergoing laparoscopic/robotic surgeryF. Verdina 1,2, G. Furlan 2, D. Rosalba 1,2, S. Spadaro 3,4, G. Scaramuzzo 3,4, D.L. Grieco 5, S.M. Maggiore 6, L. Ball 7, C. Gregoretti 8, A. Cortegiani 8, M. Carron 9, P. Navalesi 9, S. Gentilli 2,10, R. Romito 11, D. Surico 2,12, A. Volpe 2,13, E. DE Robertis 14, R. Vaschetto 1,2, R. Simonte 14, G. Cammarota2,15 1 Anestesia e Terapia Intensiva, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 2 Dipartimento di Medicina Traslazionale, Università del Piemonte Orientale, Novara, Italy; 3 Dipartimento di Medicina Traslazionale, Università degli Studi di Ferrara, Ferrara, Italy; 4 Anestesia e Terapia Intensiva, Azienda Ospedaliero Universitaria di Ferrara, Ferrara, Italy; 5 Dipartimento di Emergenze, Terapia Intensiva e Anestesia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy; 6 Dipartimento di Anestesia e Terapia Intensiva, Ospedale SS Annunziata e Dipartimento di Tecnologie innovative in Medici, Chieti, Italy; 7 Dipartimento di Scienze chirurgiche e Diagnostiche integrate, Università di Genova, Genova, Italy; 8 Dipertimenti di Scienze Chirurgiche, Oncologiche e Stomatologiche, Università di Palermo, Palermo, Italy, 9 Dipartimento di Medicina (DIMED), Policlinico Universitario di Padova e Istituto di Anestesia e Terapia, Padova, Italy; 10 Clinica Chirurgica, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italy; 11 Chirurgia Generale 2 Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italia, Novara, Italy; 12 Ginecologia e Ostetricia, Azienda Ospedaliero Universitaria Maggiore della Carità, Novara, Italia, Novara, Italy; 13 Urologia, Azienda Ospedaliero Universitaria Maggiore della Carità,, Novara, Italy; 14 Dipartimento di Medicina e Chirurgia, Università degli Studi di Perugia, Perugia, Novara, Italy; 15 Anestesia e Rianimazione, Azienda Ospedaliero Universitaria di Alessandria SS.Antonio e Biagio e Cesare Arrigo, Alessandria, Italy Correspondence: F. Verdina

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A149

Background

Setting positive end-expiratory pressure (PEEP) in obese patients undergoing surgery could be challenging. Recruitment-to-inflation ratio (RIR) allows to assess lung recruitability [1], but its application in surgery has not been explored yet. The present study sought at investigating the feasibility of RIR maneuver to assess lung recruitability in obese patients undergoing laparoscopic/robotic surgery with application of pneumoperitoneum (PNP).

Materials and Methods

Adult obese patients (body mass index > 30 kg/m2) undergoing laparoscopic or robotic abdominal/pelvic surgery were prospectively enrolled after informed consent collection. Exclusion criteria were severe chronic respiratory or impaired cardiac conditions. With intubated patients undergoing general anesthesia and protective mechanical ventilation, PNP was applied and definitive body position was achieved. Afterwards, a low-flow insufflation maneuver to assess airway opening pressure (AOP) was performed and two different RIR assessment were performed: after a 5-min high-PEEP test and, subsequently, after a 30-min high-PEEP test. RIR was assessed through a simplified one-breath derecruitment maneuver with prolonged exhalation from PEEP = 15 cmH2O to PEEP = 5 cmH2O. In case AOP > 5 cmH2O, high PEEP was AOP + 10 cmH2O (1). RIR >  = 0.5 indicated high potential for lung recruitment; RIR < 0.5 low potential for lung recruitment. SpO2/FiO2 was computed and data regarding ventilatory setting and vital parameters were collected after intubation (baseline), following PNP application, and after RIR maneuvers. Data are reported as median and 25-75th interquartile range.

Results

From January to April 2024, 10 patients (5 male) with a median age of 59 (48–66) years and a median body mass index of 36 (34–39) kg/m2 were included. Two patients were excluded for severe comorbidities and laparotomic conversion during surgery.

AOP was observed in 50% of the cases with a median value of 8 (8–10) cmH2O. When assessed after the 5-min high-PEEP test, median RIR was 0.16 (0.06–0.43); when assessed after the 30-min high-PEEP test, RIR was 0.51 (0.14–0.59). In one patient, the RIR after 30 min at high PEEP was not computed due to the early ending of the surgery. Two patients vs. five patients were considered having high potential for lung recruitment with RIR assessed after 5 or 30 min, respectively. Overall, at 30 vs. 5 min, the potential for lung recruitment changed in three patients (30%).

Conclusions

In obese patients undergoing laparoscopic/robotic surgery with application of PNP, RIR maneuver was feasible to assess potential for lung recruitment. The present study indicates that exposure lasting at least 30 min is needed to properly exploit PEEP effects on lung recruitment [2], also in the intraoperative setting.

References

1.

Chen L et al. Potential for Lung Recruitment Estimated by the Recruitment-to-Inflation Ratio in Acute Respiratory Distress Syndrome. A Clinical Trial AJRCCM 2020

2.

Cammarota G et al. PEEP-induced alveolar recruitment in patients with COVID-19 pneumonia: take the right time! Crit Care 2021

3.

Collaborative group for PEEP LAP study: Laura Carrera, Francesca Santangelo, Alessio Rivolta, Alessia Guzzo, Filippo Vietti, Alberto Migliavacca, Luca Portigliotti, Michele Giana, Alessandro Vigone, Michele Billia, Giovanni Misseri;

A150 Neuromuscular monitoring and incidence of postoperative residual curarization: a prospective observational study (Porc Trial)A. Piersanti, R. Garra, F. Sbaraglia, R. Lamacchia, C. Cuomo, M. Gozza, G. Bernardi, F. Maiellare, D. Posa, M. RossiFondazione Policlinico Agostino Gemelli IRCCS. Università Cattolica del Sacro Cuore, Rome, Italy Correspondence: D. Posa

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A150

Background

Non-depolarizing neuromuscular blocking (NMB) agents are commonly used in anesthesia practice to facilitate tracheal intubation and allow muscle relaxation during surgery.

An incomplete postoperative recovery of neuromuscular function potentially expose the patient to adverse respiratory events.

Anesthesiologist's subjective qualitative assessment of the patient's recovery of muscle strength before extubation based solely on clinical signs is not predictive of adequate neuromuscular recovery. An expert consensus statement in 2018 suggested that a quantitative and objective assessment of neuromuscular function using the train-of-four ratio (TOFR) acceleromyographic method at the level of the adductor muscle of the thumb represents the best way to minimize this risk.

Aim of this study was the evaluation of the incidence of residual curarization upon arrival in the PACU in a cohort of surgical patients receiving NMB agents.

Methods

This single-center observational cohort study was approved by the Internal Ethic Committee (ID Number: 5991, Protocol Number 0000494/23) on 23/11/2023. The study was registered at ClinicalTrials.gov (NCT06193213, on 05/01/2024) and the protocol conforms to the Declaration of Hensinki.

The study was performed at the IRCCS Fondazione Policlinico Universitario Agostino Gemelli of Rome, Italy between February and April 2024 according to STROBE guidelines for observational studies. Informed consent was obtained from all participants included in the study.

Primary outcome was the incidence of postoperative residual neuromuscular blockade upon arrival at the PACU, defined as a TOFR < 0.9 by acceleromyographic method in 90 patients who received NMB agents for tracheal intubation and/or for maintaining paralysis during surgery. We performed 2 TOFR measurements 30 s apart. If their difference was < 10%, we considered the average value while in case of a difference > 10%, a third measurement was taken and we considered the average of the two closest results.

Secondary outcomes were the number of any respiratory adverse events (defined as episodes of SpO2 < 92% requiring O2 supplementation or the finding of atelectasis, pneumonia or non-cardiac pleural effusion on imaging tests) occurred in the PACU and before hospital discharge, as well as residual neuromuscular blockade estimated risk factors by logistic regression model.

Preliminary results. In our cohort of 90 patients (median age 57 (41, 72) years), the incidence of residual neuromuscular blockade was 4% at arrival at the PACU (Table 1). Rocuronium was the only agent used. Five (5%) patients received > 1 dose of rocuronium during surgery and in 11 (12%) patients neuromuscular blockade was reversed with sugammadex before extubation. Of note, only 41 (45%) anesthesiologists reported any form of neuromuscular transmission monitoring on anesthesia sheets. One (1%) patient with residual curarization received O2 supplementation during PACU stay. Among patients with no residual neuromuscular blockade 9 (10%) of them received O2 for episodes of SpO2 < 92% during PACU stay and 3 (3%) of them also during hospitalization (Table 2).

Conclusions

Residual neuromuscular blockade frequently occurs even when a single NMB dose is administered and represents a relevant cause of preventable desaturation during postoperative care. Efforts to improve awareness of the problem among anesthesiologists increasing routine monitoring of neuromuscular function is warranted.

Table 1 (abstract A150). See text for descriptionTable 2 (abstract A150). See text for descriptionA151 Anesthetic management of a giant inferior vena cava leiomyosarcoma: a case reportG. Torregiani 1, P. Papa 2, G. Gazzè 2, V. Ceccarelli 2, S. Orlando 2, F. Sardellitti 1, E. Venti 1, C. Coccia 1, E.M.A. Forastiere1 1Department of Anesthesia, Intensive Care and Pain Therapy, IRCCS—Regina Elena National Cancer Institute, Roma, Italy; 2Department of Anesthesia, Intensive Care and Pain Therapy, Policlinico Umberto I, Sapienza University of Rome, Roma, Italy Correspondence: P. Papa

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A151

Background

Leiomyosarcoma (LMS) of the inferior vena cava (IVC) is a rare malignant retroperitoneal tumor emerging from the smooth muscle cells of the venous vassels. It presents as intra- or extra-luminal growth and often involves vital retroperitoneal organs and vascular structures [1].

Case Report

Our case involves a 62-year-old man (83 kg, BMI 25.6 kg/m2), ASA 3, diagnosed with a rare LMS of IVC. He presented with hypertension, anemia (Hb 10.6 g/dL), pyelonephritis, and AKI due to tumor infiltration of the right kidney and ureter, managed with antibiotics and percutaneous nephrostomy.

CT-scan revealed an occlusive lesion of the infrarenal IVC measuring 24 × 20x16 cm by-passed by retroperitoneal collateral circles (Fig. 1). The lesion infiltrated the kidney, right ureter and established contiguous relationships with the abdominal aorta, which appeared modestly compressed, the left renal vein, and the right renal artery, necessitating en bloc excision.

Surgery was performed under general endotracheal anesthesia. Three PVC and one CVC were placed.

Hemodynamic management was guided by continuous monitoring of SVV, CI, IBP, ECG, HR, PetCO2, BIS, temperature by esophageal and bladder probe and SpO2 at left upper limb and lower limb bilaterally.

Intraoperatively, careful monitoring of blood count and coagulation status was conducted through serial arterial blood gas analyses and laboratory tests. The system for intraoperative hemorecovery was arranged.

The most critical moment occurred during the tangential clamping of the subrenal aorta, coupled with complete clamping of the IVC to facilitate excision of the subrenal IVC segment, tumor mass, kidney, adrenal gland, and right ureter. In that circumstance, monitoring revealed values of: PAM 48 mmHg, SVV 24%, CI 1.6L/min/m2 and HR 112 bpm. In addition, the minimum Hb level reached 5.3 g/dL.

Therefore, we positioned the patient in Trendelemburg at 30-degrees angle, administered norepinephrine and adrenaline at maximum dose of 0.08mcg/kg/min and 0.18mcg/kg/min, respectively, and promptly infused 1000 mL of Gelofusine and 100 mL of Albumin20%, achieving improvement in hemodynamic parameters (PAM 68 mmHg, SVV 16%, CI 2.9L/min/m2 and HR 105 bpm).

Throughout the procedure, a total of eight units of packed red blood cells, two units of fresh frozen plasma, and one unit of platelets were administered.

Renal function was maintained by correcting metabolic acidosis with bicarbonates (340 mEq) and administering Furosemide in refractory boluses (40 mg).

The doses of vasopressors were gradually reduced until adrenaline was discontinued entirely and norepinephrine was maintained at 0.03mcg/kg/min.

Subsequently, the patient, intubated, was admitted to the ICU with an hemoglobin level of 8.9 g/dL, INR 1.27 and aPTTratio 1.34. The patient was discharged from the hospital on the sixth day after the surgery.

Conclusions

The management of patients with retroperitoneal LMS of the IVC presents unique challenges. Effective intraoperative management requires meticulous planning, vigilant monitoring, and prompt intervention to optimize outcomes and minimize perioperative complications. Collaboration among surgical, anesthesia, and critical care teams is essential for achieving favorable outcomes in these complex cases.

Informed consent to publish had been obtained.

Reference

1.

Kapoor R, Bansal A, Sharma SC. Leiomyosarcoma of inferior vena cava: Case series of four patients. J Cancer Res Ther. 2015;11(3):650-650

Fig. 1

(abstract A151). CT-scan revealed an occlusive lesion of the infrarenal IVC measuring 24 × 20x16 cm by-passed by retroperitoneal collateral circles

A152 The dual use of smote and ghost algorithms: handling class imbalance in ai-driven post-operative acute kidney failure prediction in the isaki (Intelligent Score for AKI) projectV. Bellini 1, D. Azzolina 2,3, M. Panizzi 1, F. Bezzi 1, M. Mion 1, E. Bignami1 1 Anesthesiology, Critical Care and Pain Medicine Division, Department of Medicine and Surgery, University of Parma, Parma, Italy; 2 Department of Environmental and Preventive Science, University of Ferrara, Ferrara, Italy, 3 Clinical Trial and Biostatistics, Research and Development Unit, University Hospital of Ferrara, Ferrara, Italy Correspondence: M. Panizzi

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A152

Background and Objectives

Post-operative acute kidney injury (PO-AKI) remains a common complication, affecting approximately one-fifth of patients after major surgery [1]. Although several PO-AKI prediction models already exist, they contain many biases [2]. The ISAKI study aims to create a dynamic and patient-tailored risk model for the development of PO-AKI using Artificial Intelligence (AI) and Machine Learning (ML). The model will be able to predict the onset of PO-AKI at three distinct times: preoperatively, postoperatively and at ward discharge.

Methods

ISAKI is a retrospective-prospective, observational, single-center study (ethics-committee-registration-number:803/2022 /OSS/AOUPR).

After obtaining informed consent, patients undergoing major non-cardiac surgery were enrolled. Once the dataset has been created, several ML algorithms (Random Forest, Gradient Boosting Machine, Neural Network, and Generalized Linear Model) were trained by considering 100 bootstrap internal validation runs.

This study applies a dual strategy to tackle the classification imbalance in PO-AKI prediction: the employment of the synthetic minority oversampling technique (SMOTE) and the innovative generalized tHreshOld ShifTing (GHOST) procedure. SMOTE addresses this imbalance by augmenting the minority class through synthetic data generation, directly influencing the composition of the training dataset. Complementarily, GHOST optimizes the decision threshold based on the distribution of prediction scores, effectively adjusting the bias towards the majority class typically seen in imbalanced datasets [3].

Results

Preliminary data from retrospective patients and the first prospectively enrolled patients are presented. Patient’s charateristics are summarized in Table 1. The model performed reasonably well considering our limited sample size and the outcome imbalance (25 events of PO-AKI among 313 healthy patients). The internal validation balanced accuracy on internal testing was 0.7, achieved by the Random Forest trained with the SMOTE and GHOST procedures (Fig. 1). After the training phase, which exploited the automated GHOST procedure, the training balanced accuracy was 0.82.

Regarding the preoperative variables impact on the onset of PO-AKI it emerges that preoperative creatinine level and the presence of cardiovascular disease are the most impactful.

Discussion and Conclusion

Even though the results obtained are still partial, this preliminary model we created showed a satisfying performance. This encourages us to continue the study to further enhance the model's performance and reliability. Furthermore, our work provides an example of how it is possible to use synthetic data in preliminary analyses when only an unbalanced dataset it’s available.

References

1.

Vaara ST, Bellomo R. Postoperative renal dysfunction after noncardiac surgery. Curr Opin Crit Care. 2017 Oct;23(5):440–446.

2.

Bell S, Prowle J. Is postoperative AKI-prevention Better than Cure? J Am Soc Nephrol. 2019 Jan;30(1):4–6. https://doi.org/10.1681/ASN.2018111127.

3.

Esposito C, Landrum GA, Schneider N, et al. GHOST: Adjusting the Decision Threshold to Handle Imbalanced Data in Machine Learning. J Chem Inf Model. 2021 Jun 28;61(6):2623–2640. https://doi.org/10.1021/acs.jcim.1c00160. Epub 2021 Jun 8. PMID: 34100609.

Fig. 1

(abstract A152). Balanced accuracy GHOST Plot and models with and without SMOTE. (RF = Random Forest, GBM = Gradient Boosting Machine, NNET = Neural Network, GLM = Generalized Liner Model)

Table 1 (abstract A152). The first 313 enrolled patients charateristics are presented using descriptive statisticsA153 Efficacy of post-operative oxygen therapy using High-Flow Nasal Cannulas (HFNC) in the prevention of immediate post-operative respiratory complicationsG. Paladini, A. Di Filippo, L. Foti, G. Villa, T. Del Santo, S. RomagnoliDepartment of Anesthesia and Critical Care Azienda Ospedaliera-Universitaria Careggi, University of Florence, Firenze, Italy Correspondence: G. Paladini

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A153

Background

The widespread diffusion of the HFNC oxygenation method during the period of the Sars-Cov-2 pandemic for the treatment of respiratory insufficiency has aroused growing interest in its use as an alternative to standard oxygen therapy[1,2,3]. Although many papers have dealt with the effectiveness of its post-operative use in reducing the incidence of post-operative complications [4,5,6,7,8], it is still not clear what its role is in reducing immediate post-operative respiratory complications. The aim of this pilot study is therefore to evaluate the efficacy of oxygen therapy using HFNC, administered in the first 2 post-operative hours, in the prevention of immediate post-operative respiratory complications in major surgery. Informed consent was collected for each patient who participated in this pilot study.

Materials and methods

Two groups of 22 patients were selected: the study group (H) and the control group (C). The groups were not different in ASA class, BMI, gender, age, preexisting respiratory pathologies and types of surgery. Once patients arrived in the Recovery Room, those in group H were administered HFNC for a duration of 2 h at 60 L/min, patients in group C received a standard protocol of O2 administration with facial mask or nasal cannulae; the FiO2 in the two group, was modulated according to the patient's SpO2 (for SpO2 greater than or equal to 94%, the FiO2 was set at 21%). SpO2, HR, RR and ROX index [9,10,11,12,13] were detected at the following times: T0 (5 min from the start of the administration of HFNC), T1 (1 h after), T2 (10 min after removal of high flow, discontinued 1 h after T1) and on day 1 (G1). In group H also the PaO2 was collected.

Results

The two groups were not statistically different for SpO2, HR, RR detected at T0, T1, T2 and G1. ROX index was statistically higher in group H (Group H vs Group C = 31.5 ± 6.9 vs 25,3 ± 7,8 p < 0.05) at T2; SpO2 in the two groups was not different, but FiO2 was higher at T2 in group C vs group H (Group H vs Group C = 21 ± 0 vs 29,95 ± 12,81 p < 0.05). PaO2/FiO2 calculated at T1 in group H exceeds the value of 400 indicating a very effective state of oxygenation.

Conclusions

These preliminary data indicate the achievement, at the end of recovery in recovery room, of a better oxygenation status in the HFNC treated patients with no need of supplemental Oxygen administration. This finding is assumed to be due to the HFNC mechanism of action resulting in an improvement in the ventilation/perfusion ratio, that is so effective to indicate an increasing diffusion of HFNC application in the immediate post-operative period to preventing post-operative immediate respiratory complications.

References

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Effect of High-Flow Oxygen Therapy vs Conventional Oxygen Therapy on Invasive Mechanical Ventilation and Clinical Recovery in Patients With Severe COVID-19: A Randomized Clinical Trial. Ospina-Tascón G.A., Calderón-Tapia L.E., García A.F. JAMA, 2021.

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Wang Y, Ni Y, Sun J, Liang Z. Use of High-Flow Nasal Cannula for Immunocompromise and Acute Respiratory Failure: A Systematic Review and Meta-Analysis. J Emerg Med. 2020 Mar.

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Guo K, Liu G, Wang W, Guo G, Liu Q. Effects of high-flow nasal oxygen cannula versus other noninvasive ventilation in extubated patients: a systematic review and meta-analysis of randomized controlled trials. Expert Rev Respir Med. 2021 Aug 17.

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Gaspari R, Spinazzola G, Ferrone G, Soave P-M, Pintaudi G, Cutuli S-L, Avolio A-W, Conti G, and Antonelli M. High-Flow Nasal Cannula Versus Standard Oxygen Therapy After Extubation in Liver Transplantation: A Matched Controlled Study. Respiratory Care. 2020, January.

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Huang H-W, Sun X-M, Shi Z-H, Chen G-Q, Chen L, Friedrich J-O, and Zhou J-X. Effect of High-Flow Nasal Cannula Oxygen Therapy Versus Conventional Oxygen Therapy and Noninvasive Ventilation on Reintubation Rate in Adult Patients After Extubation. A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Intensive Care Med. 2018 Nov.

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Xiang GL, Wu QH, Xie L, Song JQ, Wu X, Hao SY, Zhong M, Li SQ. High flow nasal cannula versus conventional oxygen therapy in postoperative patients at high risk for pulmonary complications: A systematic review and meta-analysis. Int J Clin Pract. 2021 Mar.

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Lu Z, Chang W, Meng S–S, et al. Effect of high-flow nasal cannula oxygen therapy compared with conventional oxygen therapy in postoperative patiens: a systematic review and meta-analysis. BMJ Open 2019.

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Wang Y, Zhu J, Wang X, Liu N, Yang Q, Luan G, Ma X and Liu J. Comparison of High-Flow Nasal Cannula (HFNC) and Conventional Oxygen Therapy in Obese Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis. In Vivo 2021 July.

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Reyes LF, Bastidas Goyes A, Tuta Quintero EA, Pedreros KD, Mantilla YF, Herrera M, Carmona GA, Saza LD, Bello LE, Muñoz CA, Chaves JC, Arias JC, Alcaraz PM, Hernández MD, Nonzoque AP, Trujillo N, Pineda AF, Montaño GS. Validity of the ROX index in predicting invasive mechanical ventilation requirement in pneumonia. BMJ Open Respir Res. 2022 Sep.

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Zhou X, Liu J, Pan J, Xu Z, Xu J. The ROX index as a predictor of high-flow nasal cannula outcome in pneumonia patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis. BMC Pulm Med. 2022 Apr 1.

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Roca O, Caralt B, Messika J, Samper M, Sztrymf B, Hernández G, García-de-Acilu M, Frat JP, Masclans JR, Ricard JD. An Index Combining Respiratory Rate and Oxygenation to Predict Outcome of Nasal High-Flow Therapy. Am J Respir Crit Care Med. 2019 Jun 1.

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Chandel A, Patolia S, Brown AW, Collins AC, Sahjwani D, Khangoora V, Cameron PC, Desai M, Kasarabada A, Kilcullen JK, Nathan SD, King CS. High-Flow Nasal Cannula Therapy in COVID-19: Using the ROX Index to Predict Success. Respir Care. 2021 Jun.

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Yu PT, Chen CH, Wang CJ, Kuo KC, Wu JC, Chung HP, Chen YT, Tang YH, Chang WK, Lin CY, Wu CL. Predicting the successful application of high-flow nasal oxygen cannula in patients with COVID-19 respiratory failure: a retrospective analysis. Expert Rev Respir Med. 2023 Apr.

A154 Preoperative infusion of levosimendan in heart failure patient undergoing robotic cystectomy: a case reportG. Torregiani 2, S. Orlando 1, G. Gazzè 1, P. Papa 1, V. Ceccarelli 1, H. Matteucci 1, M. Covotta 2, M.E. Marcelli 2, E. Forastiere2 1Università di Roma La Sapienza, Roma, Italy; 2 IRCCS Regina Elena National Cancer Institute, Roma, Italy Correspondence: S. Orlando

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A154

Background

Heart failure is an important risk factor for mortality and cardiovascular complications after noncardiac surgery [1,2]. Levosimendan is a calcium sensitizer. Levosimendan administration is associated with a reduction in preload and afterload and an increase in coronary blood flow, plus an energetically favorable type of increase in myocardial contractility. Improved myocardial tissue perfusion might contribute to cardioprotective effect of levosimendan [3]. Levosimendan may be safe and effective for the perioperative optimization of patients with heart failure undergoing elective non-cardiac surgery [4]. There are few clinical studies on levosimendan in non-cardiac surgery [5].

Case Report

71 year-old man, BMI 21.60 kg/m2, post-chemotherapy dilated cardiomyopathy with ejection fraction 38%, previous Hodgkin's lymphoma, diabetes mellitus, 25 pack-year smoker, coronary angiography without stenosis. Home therapy: antiaggregant, SGLT2 inhibitors, ACE inhibitor, beta blocker. Denies angor, dyspnea, heart palpitations or lipothymia, reported good functional capacity. Increased cardiac surgical risk. He is admitted to the intensive care unit the day before the scheduled cystectomy + orthotopic neobladder surgery. Basal vital parameters were heart rate (HR) 61 bpm, mean arterial pressure (MAP) 98 mmHg, SpO2 99%, P/F ratio 419. Central venous catheter and arterial cannula were positioned, advanced hemodynamic monitoring is started with cardiac index (CI) 4.1 L/min/m2, global ejection fraction (GEF) 21%. Levosimendan started at 0.1 mcg/kg/min and continued for 24 h. After we proceeded with surgery. Intraoperative monitoring: electrocardiography, HR, SpO2, advanced hemodynamic monitoring, BIS, mioresolution, EtCO2. During the entire duration of the operation, the patient was hemodynamically stable without drugs. CI was between 3.5 and 3.9 L/min/m2, good respiratory exchanges. Fluids administered 2500 ml. Operation duration approximately 275 min, anesthesia duration approximately 300 min. At the end of the surgery, the patient is extubated and transferred to intensive care unit. The patient was alert and cooperative, in valid spontaneous breathing, stable hemodynamics with good hemodynamic indices (CI 3.9 L/min/m2, GEF 20%, HR 61 bpm, MAP 89 mmHg), diuresis valid (100 ml/h). During the first postoperative day the patient remains stable, good hemodynamic indices (CI 3.9 L/min/m2, GEF 23%, HR 58 bpm, MAP 75 mmHg) (Table 1) without infusion of vasoconstrictors or cardiokinetics. Respiratory exchanges were good (SpO2 98%, P/F ratio 279). Diuresis present with bolus diuretic stimulus. Resumes home therapy. On the second postoperative day, the patient was transferred to the urology department. The patient remained stable for the entire duration of the hospital stay and was discharged on the ninth postoperative day.

Conclusion

During robotic cystectomy, carbon dioxide insufflation, high abdominal pressure, steep Trendelenburg position and prolongation of the surgical time result in hemodynamic and homeostatic alterations involving increases in arterial pressure and systemic vascular resistance [6]. In a patient with reduced ejection fraction and increased cardiac surgical risk, it is desirable to optimize cardiac performance preoperatively. Levosimendan could be safely administered in patients with chronic heart failure and reduced ejection fraction undergoing major oncological abdominal surgery, but preoperative prophylactic treatment with levosimendan in these patients deserves further study.

Informed consent to publish had been obtained.

Table 1 (abstract A154). Trend of hemodynamic indices after Levosimendan infusionA155 Impact of midazolam premedication on propofol concentrations: comparing schnider and eleveld models in TCI general anesthesia—a prospective observational studyF. Linassi 1, P. Zanatta 2, L. Spanò 3, C. Rizzetto 2, M. Carron3 1Dipartimento di Scienze del Farmaco UNIPD, Padova, Italy; 2 ULSS2 Marca Trevigiana, Treviso, Italy; 3 Istituto di Anestesia e Rianimazione, Padova, Italy Correspondence: F. Linassi

Journal of Anesthesia, Analgesia and Critical Care 2024, 4(1):A155

Background

Midazolam is frequently used as premedication for general anesthesia due to its sedative, anxiolytic, and amnestic effects. 1,2 It significantly influences Bispectral Index (BIS) scores, reduces the required propofol dose for anesthesia induction, and impacts the estimated concentration at the effector site of Propofol (CeP) with the Diprifusor Pump. 3 However, no studies have assessed midazolam’s effects on CeP using the Schnider or Eleveld PK/PD models in Total Intravenous Anesthesia with Target Controlled Infusion (TIVA-TCI), nor their outcomes. 4

Methods

Following approval from the Institutional Ethical Committee (registered as NCT05800288), a prospective observational study was conducted at Treviso Regional Hospital, Italy. This study evaluated the impact of midazolam premedication on CeP values at Loss of Responsiveness (LoR), during Maintenance of Anesthesia (MA), and at Return of Responsiveness (RoR) in adult female patients undergoing breast cancer surgery with TIVA-TCI using the Schnider and Eleveld models. It also explored the incidence of unwanted spontaneous responsiveness events (USRE), burst suppression events (BSuppE), and post-operative delirium (POD).

Results

Eighty patients were enrolled. Significant differences in CeP values were noted across three time points (LoR, MA, RoR) for different age groups and both model groups (p < 0.001). Unwanted anesthesia events occurred in 36.3% of patients, with USRE in 10% and BSuppE in 26.3%; POD was experienced by 1.2% of patients. CeP values at RoR significantly differed between adults and elders.

General Population: No significant demographic or anesthesia duration differences were.

observed between the group receiving compared with the group not receiving midazolam premedication. The total dose of propofol was significantly higher in patients not receiving midazolam, with increased BIS, CeP at LoR, CeP during MA, CeR during MA, and.

Schnider Model: Similar to the general population, propofol dosage was significantly higher without midazolam, with increased values of CeP at LoR, CeP during MA, CeR during MA, and δCeP at RoR (Img 1).

Eleveld Model: No demographic differences or differences in anesthesia duration were noted. While propofol doses did not differ significantly, BIS and CeP at LoR, CeP during MA, CeR during MA, and δCeP at RoR were significantly higher in the non-premedicated grou