Pulmonary complications after liver transplantation in children: risk factors and impact on early post-operative morbidity

Awake prone positioning in an infant following living donor liver transplantation

BACKGROUND

Prone position has been proven to improve ventilation and oxygenation in infants. Currently, there are few reports of early prone position ventilation after pediatric liver transplantation. Here, we present our experience with prone position in an infant following living donor liver transplantation, in an attempt to improve oxygenation.

CASE PRESENTATION

An 8-month-old boy, 7.5 kg, experienced two failed extubations that presented with Type II respiratory failure due to dyspnea, potentially caused by consolidation and airway secretions. To prevent the third failure of extubation, prone position ventilation was implemented after the third extubation on the 11th postoperative day. Oxygenation increased after each prone position session with no signs of transplant liver ischemia or other adverse outcomes. Following two days of continuous prone position, airway secretions decreased, and the infant was discharged from the ICU. The third extubation procedure was successful.

CONCLUSIONS

Prone position ventilation may be effective in this infant without adverse events, indicating that early prone position is not absolutely contraindicated after pediatric liver transplantation. Therefore, more reasonable prone position strategies should be sought in infants undergoing liver transplantation.

Respiratory problems associated with liver disease in children

Respiratory manifestations of chronic liver disease have a profound impact on patient clinical outcomes. Certain conditions within paediatric liver disease have an associated respiratory pathology. This overlap between liver and respiratory manifestations can result in complex challenges when managing patients and requires clinicians to be able to recognise when referral to specialists is required. While liver transplantation is at the centre of treatment, it opens up further potential for respiratory complications. It is established that these complications place patients at risk of longer stays in hospital and reduced survival. Additionally, late post-transplant complications can occur, including post-transplant lymphoproliferative disease and immunosuppression-induced interstitial lung disease. Although rare, it is important for clinicians to recognise these conditions to allow for prompt management. Finally, as liver disease progresses in children, respiratory complications can occur. Hepatopulmonary syndrome can occur in the context of portal hypertension, resulting in increased mortality and poorer quality of life for patients. Another consequence is portopulmonary hypertension, which can be associated with poor survival. Failure to recognise these complications in children may result in poorer outcomes and therefore it is vital that clinicians can establish when referral to a paediatric respiratory medicine specialist is required.

Estimating risk of prolonged mechanical ventilation after liver transplantation in children: PROVE-ALT score

BACKGROUND

Children at high risk for prolonged mechanical ventilation (PMV) after liver transplantation (LT) need to be identified early to optimize pulmonary support, allocate resources, and improve surgical outcomes. We aimed to develop and validate a metric that can estimate risk for Prolonged Ventilation After LT (PROVE-ALT).

METHODS

We identified preoperative risk factors for PMV by univariable analysis in a retrospective cohort of pediatric LT recipients between 2011 and 2017 (n = 205; derivation cohort). We created the PROVE-ALT score by mapping multivariable logistic regression coefficients as integers, with cutoff values using the Youden Index. We validated the score by C-statistic in a retrospectively collected separate cohort of pediatric LT recipients between 2018 and 2021 (n = 133, validation cohort).

RESULTS

Among total 338 patients, 21% (n = 72) were infants; 49% (n = 167) had cirrhosis; 8% (n = 27) required continuous renal replacement therapy (CRRT); and 32% (n = 111) required management in hospital (MIH) before LT. Incidence of PMV post-LT was 20% (n = 69) and 3% (n = 12) required tracheostomy. Independent risk factors (OR [95% CI]) for PMV were cirrhosis (3.8 [1-14], p = .04); age <1-year (8.2 [2-30], p = .001); need for preoperative CRRT (6.3 [1.2-32], p = .02); and MIH before LT (12.4 [2.1-71], p = .004). PROVE-ALT score ≥8 [Range = 0-21] accurately predicted PMV in the validation cohort with 73% sensitivity and 80% specificity (AUC: 0.81; 95% CI: 0.71-0.91).

CONCLUSION

PROVE-ALT can predict PMV after pediatric LT with a high degree of sensitivity and specificity. Once externally validated in other centers, PROVE-ALT will empower clinicians to plan patient-specific ventilation strategies, provide parental anticipatory guidance, and optimize hospital resources.

Pediatric living donor liver transplantation (LDLT): Short- and long-term outcomes during sixteen years period at a single centre- A retrospective cohort study

BACKGROUND AND OBJECTIVES

Pediatric living donor liver transplantation (LDLT) is an effective tool for managing pediatric patients with end-stage liver disease (ESLD) with good long-term graft and patient survival, especially after improvement in peri-operative care, surgical tools and techniques; however, the morbidity and mortality after such a procedure are still a challenging matter. The study aimed to analyze short-and long-term outcomes after pediatric LDLT in a single centre.

METHODS

We retrospectively analyzed 67 pediatric patients who underwent LDLT in the period from April 2003 to July 2018. The overall male/female ratio was 40/27.

RESULTS

Forty-one (61.2%) of patients had ≥1 early and/or late morbidities; the early (less than 3months) and late (≥3months) ones affected 36(53.7%) and 12(17.9%) of them respectively. The 16-year graft and patient survivals were 35(52.2%) while early and late mortalities were 23(34.3%) and 9(13.4%) respectively. Sepsis and chronic rejection were the most frequent causes of early and late mortalities respectively. Moreover, more packed RBCs transfusion units, bacterial infections, and pulmonary complications were independent predictors of poor patient survival.

CONCLUSIONS

More packed RBCs transfusion units intra-operatively, and post-liver transplant (LT) bacterial infection, sepsis, chronic rejection, as well as pulmonary complications had a negative insult on our patients' outcomes, so proper management of them is mandatory for improving outcomes after pediatric LDLT.

Reliable Detection of Intrapulmonary Shunts Using Contrast-Enhanced Echocardiography in Children With Portal Hypertension or Portosystemic Shunt

OBJECTIVES

The aim of this study was to analyze if contrast-enhanced echocardiography (CEE) is as reliable as lung perfusion scintigraphy (LPS) to detect intrapulmonary shunting (IPS) in children with portal hypertension (PHTN) or congenital/surgical portosystemic shunts (PSS) and to define the number of cardiac cycles required to exclude intrapulmonary shunting.

METHODS

Inclusion criteria for this cross-sectional study were: (1) presence of PHTN or PSS diagnosed on abdominal ultrasound, (2) technically valid saline contrast echocardiography, (3) lung perfusion scintigraphy within 6 months of CEE. The number of cardiac cycles between right atrial opacification and the arrival of contrast in the left atrium were counted. We analyzed our CEE data at three and five cardiac cycles and compared them with LPS results.

RESULTS

The study population was composed of 78 children (38 girls, 49%) ages 2.1-18.8 years (mean 9.8). Sixty-nine patients had PHTN (88%), and nine had a PSS (11%). Eleven subjects (14%) presented evidence of IPS on LPS. Peripheral oxygen saturation was lower in the subjects with IPS detected on LPS (95.3 ± 1.7% vs 99.0 ± 1.4%; P < 0.01). Comparison of LPS with CEE before three and five cardiac cycles showed that CEE is highly specific (95.7%) as early as three cardiac cycles with markedly better sensitivity (72.7%) when using five cardiac cycles. Furthermore, a negative study using five cardiac cycles ruled out IPS with a 95% negative predictive value. The cardiac cycle at which the bubbles appeared in the left atrium was inversely correlated to the shunt index measured using LPS (r = -0.563; P = 0.001).

CONCLUSION

CEE is sufficient for the screening of IPS in children with PHTN or congenital/surgical PSS, obviating the need for LPS.