Use of transesophageal echocardiography in burns:a retrospective review

Current status of point of care ultrasonography for the perioperative care of trauma patients

PURPOSE OF REVIEW

The incorporation of point of care ultrasound into the field of anesthesiology and perioperative medicine is growing at rapid pace. The benefits of this modality align with the acuity of patient care and decision-making in anesthetic care of a trauma patient.

RECENT FINDINGS

Cardiac ultrasound can be used to diagnose cardiac tamponade or investigate the inferior vena cava to assess volume status in patients who may suffer from hemorrhagic shock. Thoracic ultrasound may be used to rapidly identify pneumothorax or hemothorax in a patient suffering chest wall trauma. In addition, investigators are exploring the utility of ultrasonography in traumatic airway management and elevated intracranial pressure. In addition, the utility of gastric ultrasound on trauma patients is briefly discussed.

SUMMARY

Incorporation of point of care ultrasound techniques into the practice of trauma anesthesiology is important for noninvasive, mobile and expeditious assessment of trauma patients. In addition, further large-scale studies are needed to investigate how point of care ultrasound impacts outcomes in trauma patients.

Indications, Clinical Impact, and Complications of Critical Care Transesophageal Echocardiography: A Scoping Review

BACKGROUND

Critical care transesophageal echocardiography (ccTEE) is an increasingly popular tool used by intensivists to characterize and manage hemodynamics at the bedside. Its usage appears to be driven by expanded diagnostic scope as well as the limitations of transthoracic echocardiography (TTE) - lack of acoustic windows, patient positioning, and competing clinical interests (eg, the need to perform chest compressions). The objectives of this scoping review were to determine the indications, clinical impact, and complications of ccTEE.

METHODS

MEDLINE, EMBASE, Cochrane, and six major conferences were searched without a time or language restriction on March 31^st, 2021. Studies were included if they assessed TEE performed for adult critically ill patients by intensivists, emergency physicians, or anesthesiologists. Intraoperative or post-cardiac surgical TEE studies were excluded. Study demographics, indication for TEE, main results, and complications were extracted in duplicate.

RESULTS

Of the 4403 abstracts screened, 289 studies underwent full-text review, with 108 studies (6739 patients) included. Most studies were retrospective (66%), performed in academic centers (84%), in the intensive care unit (73%), and were observational (55%). The most common indications for ccTEE were hemodynamic instability, trauma, cardiac arrest, respiratory failure, and procedural guidance. Across multiple indications, ccTEE was reported to change the diagnosis in 52% to 78% of patients and change management in 32% to79% patients. During cardiac arrest, ccTEE identified the cause of arrest in 25% to 35% of cases. Complications of ccTEE included two cases of significant gastrointestinal bleeding requiring intervention, but no other major complications (death or esophageal perforation) reported.

CONCLUSIONS

The use of ccTEE has been described for the diagnosis and management of a broad range of clinical problems. Overall, ccTEE was commonly reported to offer additional diagnostic yield beyond TTE with a low observed complication rate. Additional high quality ccTEE studies will permit stronger conclusions and a more precise understanding of the trends observed in this scoping review.

Is There a Role for Transesophageal Echocardiography in the Perioperative Trauma Patient?

Purpose of Review

This review article summarizes the advantages and potential uses of focused transesophageal echocardiography (TEE) in the perioperative period for trauma patients. We suggest a locally developed TEE protocol for trauma and provide strategies to achieve widespread use of TEE in the anesthesia care of trauma patients.

Recent Findings

In recent years, TEE has gained interest as an additional modality as point-of-care ultrasound (POCUS) for the resuscitation of acutely ill patients in whom transthoracic echocardiography is not feasible or non-diagnostic. Nevertheless, its use among non-cardiac anesthesiologists is still limited compared to the more traditional POCUS applications.

Summary

A goal-directed, focused TEE can be performed at the bedside in different locations and mechanically ventilated patients. TEE provides relevant diagnostic information to guide the resuscitation of acutely injured patients, particularly to identify life-threatening hidden thoracic injuries in the scenario of patients with multi-system trauma.

Fluid resuscitation management in patients with burns: update

Since 1968, when Baxter and Shires developed the Parkland formula, little progress has been made in the field of fluid therapy for burn resuscitation, despite advances in haemodynamic monitoring, establishment of the 'goal-directed therapy' concept, and the development of new colloid and crystalloid solutions. Burn patients receive a larger amount of fluids in the first hours than any other trauma patients. Initial resuscitation is based on crystalloids because of the increased capillary permeability occurring during the first 24 h. After that time, some colloids, but not all, are accepted. Since the emergence of the Pharmacovigilance Risk Assessment Committee alert from the European Medicines Agency concerning hydroxyethyl starches, solutions containing this component are not recommended for burns. But the question is: what do we really know about fluid resuscitation in burns? To provide an answer, we carried out a non-systematic review to clarify how to quantify the amount of fluids needed, what the current evidence says about the available solutions, and which solution is the most appropriate for burn patients based on the available knowledge.

Burn resuscitation--hourly urine output versus alternative endpoints: a systematic review

Controversy remains over appropriate endpoints of resuscitation during fluid resuscitation in early burns management. We reviewed the evidence as to whether utilizing alternative endpoints to hourly urine output produces improved outcomes. MEDLINE, CINAHL, EMBASE, Cochrane Library, Web of Science, and full-text clinicians' health journals at OVID, from 1990 to January 2014, were searched with no language restrictions. The keywords burns AND fluid resuscitation AND monitoring and related synonyms were used. Outcomes of interest included all-cause mortality, organ dysfunction, length of stay (hospital, intensive care), time on mechanical ventilation, and complications such as incidence of pulmonary edema, compartment syndromes, and infection. From 482 screened, eight empirical articles, 11 descriptive studies, and one systematic review met the criteria. Utilization of hemodynamic monitoring compared with hourly urine output as an endpoint to guide resuscitation found an increased survival (risk ratio [RR], 0.58; 95% confidence interval, 0.42-0.85; P < 0.004), with no effect on renal failure (RR, 0.77; 95% confidence interval, 0.39-1.43; P = 0.38). However, inclusion of the randomized controlled trials only found no survival advantage of hemodynamic monitoring over hourly urine output (RR, 0.72; 95% confidence interval, 0.43-1.19; P = 0.19) for mortality. There were conflicting findings between studies for the volume of resuscitation fluid, incidence of sepsis, and length of stay. There is limited evidence of increased benefit with utilization of hemodynamic monitoring, however, all studies lacked assessor blinding. A large multicenter study with a priori-determined subgroup analysis investigating alternative endpoints of resuscitation is warranted.

A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: a 3-year prospective cohort study

Introduction

The use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion.

Methods

We conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m² and an intrathoracic blood volume index (ITBVI) >600 ml/m², and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test.

Results

A total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m²) and the ITBVI (709 ± 254 mL/m²). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m²). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels.

Conclusions

Initial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An adequate CI and tissue perfusion can be achieved with below-normal levels of preload. Early resuscitation guided by lactate levels and below-normal preload volume targets appears safe and avoids unnecessary fluid input.