Hemodynamic monitoring in thoracic surgical patients

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Perioperative Fluid Management

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the elderly are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the elderly. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

Esophagectomy-prevention of complications-tips and tricks for the preoperative, intraoperative and postoperative stage

Esophagectomy still remains the mainstay of treatment for localized esophageal cancer. Many progresses have been made in the technique of esophagectomy in the last decades but the overall morbidity for this operation remains formidable. Postoperative complication and mortality rate after esophagectomy are significant; anastomotic leak has an incidence of 11,4%. The occurrence of a complication is a significant negative prognostic factor for long term survival and is also linked to longer postoperative stay, a lower quality of life, increased hospital costs. Preventing the occurrence of postoperative morbidity and reducing associated postoperative mortality rate is a major goal for surgeons experienced in resective esophageal surgery. Many details of pre, intra and postoperative care for patients undergoing esophagectomy need to be shared among the professionals taking care of these patients (oncologists, dieticians, physiotherapists, surgeons, nurses, anesthesiologists, gastroenterologists) in order to improve the short and long term clinical results.

Restricted, optimized or liberal fluid strategy in thoracic surgery: A narrative review

Perioperative fluid balance has a major impact on clinical and functional outcome, regardless of the type of interventions. In thoracic surgery, patients are more vulnerable to intravenous fluid overload and to develop acute respiratory distress syndrome and other complications. New insight has been gained on the mechanisms causing pulmonary complications and the role of the endothelial glycocalix layer to control fluid transfer from the intravascular to the interstitial spaces and to promote tissue blood flow. With the implementation of standardized processes of care, the preoperative fasting period has become shorter, surgical approaches are less invasive and patients are allowed to resume oral intake shortly after surgery. Intraoperatively, body fluid homeostasis and adequate tissue oxygen delivery can be achieved using a normovolemic therapy targeting a “near-zero fluid balance” or a goal-directed hemodynamic therapy to maximize stroke volume and oxygen delivery according to the Franck–Starling relationship. In both fluid strategies, the use of cardiovascular drugs is advocated to counteract the anesthetic-induced vasorelaxation and maintain arterial pressure whereas fluid intake is limited to avoid cumulative fluid balance exceeding 1 liter and body weight gain (~1-1.5 kg). Modern hemodynamic monitors provide valuable physiological parameters to assess patient volume responsiveness and circulatory flow while guiding fluid administration and cardiovascular drug therapy. Given the lack of randomized clinical trials, controversial debate still surrounds the issues of the optimal fluid strategy and the type of fluids (crystalloids versus colloids). To avoid the risk of lung hydrostatic or inflammatory edema and to enhance the postoperative recovery process, fluid administration should be prescribed as any drug, adapted to the patient's requirement and the context of thoracic intervention.

Pulse Pressure Variation is a Valuable Marker for Predicting Fluid Responsiveness in Brain-Dead Donors

PURPOSE

Hemodynamic management in brain-dead donors (BDDs) is challenging due to hemodynamic instabilities. We compared functional parameters with traditional parameters for hemodynamic monitoring in BDDs.

MATERIALS AND METHODS

Seventeen BDDs with a positive balance of >500 mL for 8 hours were included. Functional hemodynamic monitoring, including pulse pressure variation (PPV), stroke volume variation (SVV), cardiac output, and systemic vascular resistance index (SVRI) was performed in the setting of tidal volume of 6 mL/kg to 8 mL/kg and minimal positive end-expiratory pressure of 5 cm to 8 cm H2O. Responders were defined by a cardiac output increase of >15% after fluid therapy.

RESULTS

Among the 17 BDDs (mean age, 46.80±13.91 years), 15 were male. Seven responders out of 17 (41.1%) had a significantly higher PPV (22.8±8.4 vs 13.4±5.9%, P = .038) and serum albumin level (3.2±0.6 vs 2.6±0.5 g/L, P = .040) at baseline than nonresponders. However, other hemodynamic markers such as SVV and SVRI were similar between groups. Traditional markers of volume status, such as heart rate, central venous pressure, hemoglobin, and serum uric acid level were also similar between the 2 groups. Hemodynamic markers including PPV, SVV, and SVRI were significantly reduced in responders.

CONCLUSIONS

PPV was the most valuable hemodynamic marker for predicting volume responsiveness in BDDs.

A Survey of the Practice of Thoracic Anesthesia in India

OBJECTIVE

The aim of the survey was to understand the contemporary thoracic anesthesia practice in India.

DESIGN

A prospective questionnaire-based survey.

SETTINGS

The survey was conducted at the Annual Conference of the Indian Association of Cardiovascular and Thoracic Anesthesiologists 2018 (IACTACON-2018). After the conference, the questionnaire was distributed again to the conference participants electronically to increase the response rate.

PARTICIPANTS

Anesthesiologists from India attending IACTACON-2018.

INTERVENTIONS

Hard copies of a validated questionnaire (n = 430) were distributed among Indian anesthesiologists attending IACTACON 2018. The questionnaire included 17 questions pertaining to preanesthesia checkup, lung isolation devices, intraoperative management, postoperative analgesia, and infrastructure available at their institutions. Following the conference, the survey was continued online by sending the link of the online survey to all registered participants (n = 421) from India, taking care to avoid duplication of responses. Collected data were analyzed using frequency distributions and chi-square tests.

MEASUREMENTS AND MAIN RESULTS

Total responses were 166 (110 hardcopies and 56 online responses) of 430, with the response rate being 38.6%. A double-lumen tube (DLT) was the most commonly preferred for lung isolation (160/166: 96.4%). Nearly 55% of anesthesiologists preferred auscultation for confirmation of DLT, as 38% of anesthesiologists reported unavailability of the pediatric bronchoscope. Nearly 80% of anesthesiologists were compliant with the principles of protective one-lung ventilation. Preference for inhalation anesthetic agents during one-lung ventilation, use of restrictive intravenous fluids, and regional blocks for postoperative analgesia commonly were followed by the Indian anesthesiologists.

CONCLUSION

Despite the challenges offered by limited resources, the practice of thoracic anesthesia in India is at par with the standards followed across the world.

[Unexpected increase in extravascular lung water after acute lung injury]

HISTORY AND CLINICAL FINDING

We report on a 27-year-old female patient presenting with pneumonia and developing acute respiratory distress syndrome. Using transpulmonary thermodilution, an elevated extravascular lung water was detected (17 ml/kg). Patient required lung-protective mechanical ventilation and received antibiotic therapy. Negative fluid balance was targeted. Under this treatment, respiratory function improved, inflammation parameters declined, and extravascular lung water was recurrent (10 ml/kg). Subsequently, extravascular lung water increased to 29 ml/kg.

DIAGNOSIS

In a chest x-ray, the central venous catheter tip was dislocated into the right internal jugular vein. 7 days before, the catheter was shown to be in projection of the Vena cava superior in a previous chest x-ray.

THERAPY AND COURSE

After insertion of a new central venous catheter, extravascular lung water was quantified at 10 ml/kg again. After 10 days of mechanical ventilation the patient was successfully extubated.

CONCLUSION

As mechanism for this catheter dislocation, we propose a Valsalva maneuver or spontaneous movements of the upper body of the patient. Sudden increase in extravascular lung water may reflect central venous catheter tip dislocation and chest x-ray should be considered to verify catheter tip position.

Validation study of the dynamic parameters of pulse wave in pulmonary resection surgery

INTRODUCTION

In lung resection surgery, restrictive fluid therapy is recommended due to the risk of acute lung injury. In contrast, this recommendation increases the risk of hypoperfusion. Guided fluid therapy allows individualization of fluid intake. The use of dynamic volume response parameters is not validated during one-lung ventilation. The main objective is the validation of dynamic parameters, stroke volume variation (SVV) and pulse pressure variation (PPV), during lung resection surgery as fluid response predictors, after the administration of 250ml crystalloid volume loads, if IC<2.5ml/min/m² and if SVV≥8% and/or PPV≥10%.

MATERIAL AND METHODS

Pilot, prospective, observational and single centre study. Twenty-five patients monitored with the PiCCO system were included during open lung resection surgery with the patient in a lateral position, one lung ventilation with tidal volume (TV): 6ml/kg and open chest. Hemodynamic variables were collected before and after volume loading. The results were classified into two groups: volume responders (increase IC≥10% and/or VSI≥10% after volume loading) and non-responders (no increase or increase IC<10% and/or VSI<10% after volume loading). We assess the diagnostic efficacy of SVV and PPV by analyzing the AUC (area under curve) in the ROC curves.

RESULTS

In the analysis of ROC curves, SVV and PPV did not reach a discriminative value (AUCSVV: 0.47; AUCPPV: 0.50), despite the decrease in the threshold value of SVV and PPV to initiate an overload of volume during one-lung ventilation, in lateral position and open chest.

CONCLUSIONS

The results obtained show that the values of the dynamic parameters of volume response (SVV≥8% and PPV≥10%) do not discriminate against responders patients and non-responders during open lung resection surgery.

Precise anesthesia in thoracoscopic operations

Purpose of review

The current review focuses on precise anesthesia for video-assisted thoracoscopic surgery (VATS) with the goal of enhanced recovery.

Recent findings

VATS has become an established and widely used minimally invasive approach with broad implementation on a variety of thoracic operations. In the current environment of enhanced recovery protocols and cost containment, minimally invasive VATS operations suggest adoption of individualized tailored, precise anesthesia. In addition to a perfect lung collapse for surgical interventions with adequate oxygenation during one lung ventilation, anesthesia goals include a rapid, complete recovery with adequate postoperative analgesia leading to early discharge and minimized costs related to postoperative inpatient services. The components and decisions related to precise anesthesia are reviewed and discussed including: letting patients remain awake versus general anesthesia, whether the patient should be intubated or not, operating with or without muscle relaxation, whether to use different separation devises, operating with different local and regional blocks and monitors.

Conclusion

The determining factors in designing a precise anesthesic for VATS operations involve consensus on patients’ tolerance of the associated side effects, the best practice or techniques for surgery and anesthesia, the required postoperative support, and the care team's experience.

Phenylephrine does not improve oxygenation during one-lung ventilation: A randomized, double-blind, cross-over study

Background

Phenylephrine is an α₁ adrenergic receptor agonist that causes pulmonary vasoconstriction, and so may effectively enhance hypoxic pulmonary vasoconstriction (HPV). However, there is little evidence that phenylephrine augments HPV in clinical situations. This study aimed to evaluate the clinical effects of phenylephrine infusion on oxygenation during one-lung ventilation (OLV) in patients undergoing thoracic surgery.

Methods

This was a prospective, randomized, double-blind, cross-over study. Included patients were those undergoing elective thoracic surgery in the lateral decubitus position with OLV. Patients were randomly allocated to two groups. The N-P group initially had OLV with normal saline infusion for 30 minutes; after a 10 minute interval, OLV was then maintained with phenylephrine infusion for 30 minutes. The P-N group had the drug-infusion in the reverse order. The primary outcome was arterial partial pressure of oxygen. Secondary outcomes were mean arterial pressure, heart rate, pulse pressure variation, perfusion index, and difference between bladder and skin temperature. Statistical analysis was performed using the student t-test, Fisher's exact test, and ANOVA for Cross-over design. P < 0.05 was considered statistically significant.

Results

Twenty-nine patients were analyzed. Although phenylephrine infusion significantly increased mean arterial pressure (P < 0.001), arterial partial pressure of oxygen did not differ between the two timepoints (P = 0.19). There was no carryover effect in arterial partial pressure of oxygen (P = 0.14). Phenylephrine infusion significantly decreased heart rate (P = 0.02) and pulse pressure variation (P < 0.001).

Conclusions

Phenylephrine infusion did not improve oxygenation during OLV. The present results indicate that phenylephrine does not have clinically meaningful effects on HPV.

Trial registration

University Hospital Medical Information Network 000024317

Validity of Pulse Pressure Variation (PPV) Compared with Stroke Volume Variation (SVV) in Predicting Fluid Responsiveness

OBJECTIVE

Static monitors for assessing the fluid status during major surgeries and in critically ill patients have been gradually replaced by more accurate dynamic monitors in modern-day anaesthesia practice. Pulse pressure variation (PPV) and systolic pressure variation (SPV) are the two commonly used dynamic indices for assessing fluid responsiveness.

METHODS

In this prospective observational study, 50 patients undergoing major surgeries were monitored for PPV and SPV: after the induction of anaesthesia and after the administration of 500 mL of isotonic crystalloid bolus. Following the fluid bolus, patients with a cardiac output increase of more than 15% were classified as responders and those with an increase of less than 15% were classified as non-responders.

RESULTS

There were no significant differences in the heart rate (HR), mean arterial pressure (MAP), PPV, SVV, central venous pressure (CVP) and cardiac index (CI) between responders and non-responders. Before fluid bolus, the stroke volume was significantly lower in responders (p=0.030). After fluid bolus, MAP was significantly higher in responders but there were no significant changes in HR, CVP, CI, PPV and SVV. In both responders and non-responders, PPV strongly correlated with SVV before and after fluid bolus.

CONCLUSION

Both PPV and SVV are useful to predict cardiac response to fluid loading. In both responders and non-responders, PPV has a greater association with fluid responsiveness than SVV.