Severe hypoxemia and intrapulmonary shunting resulting from cirrhosis reversed by liver transplantation in a pediatric patient

Cryptogenic Cirrhosis and Hepatopulmonary Syndrome in a Boy with Hepatic Hemangioma in Botswana: A Case Report and Review of the Literature

Hepatic hemangiomas are considered to be the most common benign tumors of the liver. They are often found incidentally while investigating for other causes of liver disease. Hemangiomas that are less than 10 cm are not expected to cause any problems. Typically, they do not enlarge and, apart from regular follow-up, no definitive treatment is indicated. This is a posthumous case report of a male child with a medium-sized hemangioma from infancy, complicated by cryptogenic cirrhosis and hepatopulmonary syndrome. It demonstrates the challenges of managing a child with such complicated conditions in a resource-limited setting.

Defining and characterizing severe hypoxemia after liver transplantation in hepatopulmonary syndrome

Hepatopulmonary syndrome is defined as a triad of liver disease, intrapulmonary vascular dilatations, and abnormal gas exchange, and it carries a poor prognosis. Liver transplantation is the only known cure for this syndrome. Severe hypoxemia in the early postoperative period has been reported to be a major complication and often leads to death in this population, but it has been poorly characterized. We sought to propose an objective definition for this complication and to describe its risk factors, incidence, and outcomes. We performed a systematic literature search and reviewed our single-center experience to characterize this complication. On the basis of the most commonly applied definition in 27 identified studies, we objectively defined severe postoperative hypoxemia as hypoxemia requiring a 100% fraction of inhaled oxygen to maintain a saturation ≥ 85% and out of proportion to any concurrent lung process. Nineteen of the 27 reports (70%) fulfilled this definition, as did 4 of the 21 patients (19%) at our center. We determined the prevalence and mortality of this complication from reports including 10 or more consecutive patients and providing sufficient postoperative details to determine whether this complication had occurred. In these reports, the prevalence of this complication was 12% (25/209). For the 11 cases with reported outcomes, the posttransplant mortality rate was 45% (5/11). There was a trend toward an increased risk of developing this complication in patients with very severe preoperative hypoxemia, defined as a partial pressure of arterial oxygen ≤ 50 mm Hg (8/41 with very severe hypoxemia versus 3/49 without severe hypoxemia, P = 0.053), and there was a significantly increased risk for patients with anatomic shunting ≥ 20% (7/25 with anatomic shunting ≥ 20% versus 1/25 without anatomic shunting ≥ 20%, P = 0.049). In conclusion, increased preoperative vigilance for this common complication is required among high-risk patients, and further research is required to identify the best management strategies.

The role of garlic in hepatopulmonary syndrome: a randomized controlled trial

BACKGROUND

Increased nitric oxide production in cirrhosis has been commonly implicated in the genesis of hepatopulmonary syndrome (HPS). Initial studies suggested that garlic, a constituent of the daily diet, may have a role in the treatment of HPS by altering nitric oxide production.

OBJECTIVE

To evaluate the effects of oral garlic supplementation on arterial blood gas parameters, and overall morbidity and mortality in patients with HPS.

METHODS

Twenty-one and 20 HPS patients were randomly assigned to receive either oral garlic supplementation or placebo, respectively, and were evaluated monthly over a period of nine to 18 months.

RESULTS

After nine months, garlic supplementation was associated with a 24.66% increase in baseline arterial oxygen levels (83.05 mmHg versus 66.62 mmHg; P<0.001), compared with only a 7.37% increase (68.75 mmHg versus 64.05 mmHg; P=0.02) among subjects in the placebo group. There was also a 28.35% decrease in alveolar-arterial oxygen gradient (21.35 mmHg versus 29.77 mmHg; P<0.001) among patients with HPS who received garlic, in contrast with only a 10.73% decrease (29.11 mmHg versus 32.61 mmHg; P=0.12) among those in the placebo group. After nine months, the arterial oxygen level was significantly higher (83.05 mmHg versus 68.75 mmHg; P<0.001) and the alveolar-arterial oxygen gradient was significantly lower (21.35 mmHg versus 29.11 mmHg; P<0.001) among patients receiving garlic compared with those receiving placebo. Reversal of HPS was observed in 14 of 21 patients (66.67%) on garlic supplementation (intent-to-treat analysis) and in one of 20 patients (5%) on placebo. Two of 21 patients undergoing garlic supplementation died during follow-up in contrast to seven of 20 patients who were on placebo.

CONCLUSIONS

Garlic supplementation may be beneficial in patients with HPS for the reversal of intrapulmonary shunts as well as reducing hypoxemia and mortality.

Impact of Mild and Moderate Intrapulmonary Shunting in Children with End-Stage Liver Disease Undergoing Liver Transplantation

AIM

The aim of this study was to evaluate the impact of mild and moderate intrapulmonary shunting (IPS) in children with end-stage liver disease (ESLD) undergoing liver transplantation.

MATERIALS AND METHODS

A total of 73 patients (38 male, 35 female; mean age 31.5 +/- 35.2 months, range 6-180 months) with ESLD and subsequent liver transplantation were enrolled. Based on contrast echocardiography, patients without IPS were assigned to group 1 (n = 57), and patients with mild or moderate IPS were assigned to group 2 (n = 17). The preoperative age, body weight, O(2) saturation, length of hospital stay, duration of mechanical ventilation, postoperative complications, and 1-year survival rate were compared between groups.

RESULTS

The overall incidence of IPS and 1-year survival rate were 23.3% (17/73) and 96% (70/73), respectively. There were significant differences between group 1 and group 2 patients regarding age at transplant (35.9 vs. 16.6 months, p = 0.002) and body weight (12.6 vs. 8.5 kg, p = 0.002). There were no other statistically significant differences between the two groups.

CONCLUSION

Although children with mild and moderate IPS were younger at the time of transplantation and had significantly lower body weight than those without IPS, the presence of mild and moderate IPS in children with ESLD did not affect the overall outcome of liver transplantation.

Anesthetic management of the pediatric patient undergoing solid organ transplantation

Solid organ transplantation is now routinely performed at many institutions. Pediatric organ recipients present difficult challenges to pediatric anesthesiologists. Physiologic, anatomic, and pharmacologic derangements in this population may make both the surgical procedure and the anesthetic management complicated. This article presents an overview of the unique problems and the strategies to solve them in this population.

The choice of inhalation anaesthetic for major abdominal surgery in children with liver disease

Many children with liver disease undergo major abdominal surgery. Maintenance of anaesthesia is thus an important consideration in this surgical population. Despite a comprehensive and painstaking review of the literature, a sound evidence base, on which a choice of inhalation anaesthetic may be made, is lacking due to limited research in these patients. Differences between the more recent agents such as isoflurane, sevoflurane and desflurane are minor. Sevoflurane is favoured in paediatric practice for gaseous induction, but desflurane or isoflurane are marginally the preferred agents for maintenance of anaesthesia in children with liver disease undergoing major abdominal surgery. However, on the evidence that exists, much of it admittedly in animals and in adults, all three are preferable to halothane in this group of patients. More work is needed in this area before sound conclusions can be drawn and one agent proved to be definitely superior to the others.

The hepatopulmonary syndrome

The hepatopulmonary syndrome is a triad of liver disease, increased alveolar-arterial oxygen gradient and intrapulmonary vascular dilatations. Manifestations include orthodeoxia, platypnoea and hyperdynamic circulation. Intrapulmonary vascular abnormalities, perhaps mediated by nitric oxide, cause hypoxaemia by shunting, a perfusion-diffusion defect, and ventilation-perfusion mismatching. Contrast-enhanced echocardiography is the method of choice for demonstrating pulmonary vascular abnormalities, although perfusion lung scanning is a more specific and sensitive test. Angiography is best reserved for patients with poor response to 100% oxygen and defines whether vascular dilatations are of the diffuse 'spongy' type or, less commonly, discrete arteriovenous communications amenable to embolization. About 80% of patients with the hepatopulmonary syndrome eventually have improved oxygenation after liver transplantation, thereby making worsening hypoxaemia the primary indication for transplantation in many instances. Nevertheless, severe hypoxaemia carries a peri-operative mortality of 30% and reliable predictors of successful outcome after transplantation remain to be determined.

Intrapulmonary arteriovenous shunting may be a universal phenomenon in patients with the superior cavopulmonary anastomosis: a radionuclide study

OBJECTIVE

To evaluate the extent of intrapulmonary right to left shunting in children after bidirectional cavopulmonary anastomosis (BCPA).

DESIGN

Prospective study of patients who underwent BCPA in a single centre.

PATIENTS

17 patients with complex cyanotic congenital cardiac malformations who underwent BCPA at 1-45 months of age (median 21 months) were evaluated 15-64 months postoperatively (median 32 months). Five children between 1 and 10 years (median 5 years) with normal or surgically corrected intracardiac anatomy and peripheral pulmonary circulation who required V/Q scanning for other reasons were used as controls.

INTERVENTIONS

All patients underwent cardiac catheterisation to exclude angiographically demonstrable venovenous collaterals followed by pulmonary perfusion scanning using (99m)technetium ((99m)Tc) labelled albumen microspheres to quantify the intrapulmonary right to left shunt.

MAIN OUTCOME MEASURE

Percentage of intrapulmonary right to left shunt.

RESULTS

The mean (SD) level of physiological right to left shunting found in the control group was 5.4 (2.3)%. All patients with BCPA showed the presence of a significantly higher level of intrapulmonary shunting (26.8 (16.9)%, p < 0.001). The degree of shunting was significantly increased in the subgroup of 11 patients with BCPA as the only source of pulmonary blood flow (34.9 (15.8)%), when compared to the six remaining patients with an additional source of pulmonary blood supply (12.0 (2.6)%, p < 0.001). There was a negative correlation between age at BCPA and the shunt percentage found in the patients with a competitive source of pulmonary blood flow (r = -0.63, p < 0. 01).

CONCLUSIONS

Intrapulmonary right to left shunting develops in all patients following BCPA. This may be caused by a sustained and inappropriate vasodilatation resulting from absence or decreased levels of a substance that inhibits pulmonary vasodilatation. Augmenting BCPA with an additional source of blood flow containing hepatic factor limits the degree of intrapulmonary arteriovenous shunting and may help provide successful longer term palliation.

Hepatopulmonary syndrome in inferior vena cava obstruction responding to cavoplasty

Reports show that hepatopulmonary syndrome mostly occurs in the setting of advanced hepatic dysfunction, with the associated vasoactive substance imbalance believed to be responsible for its pathogenesis. However, hepatopulmonary syndrome has also been reported in cases of mild hepatic dysfunction or noncirrhotic portal hypertension, indicating that portal hypertension also plays a part in the pathogenesis. Liver transplantation remains the only therapeutic option of proven benefit. We describe 2 cases of hepatopulmonary syndrome in the setting of inferior vena cava (suprahepatic) obstruction, but with minimal hepatic dysfunction. After balloon cavoplasty, 1 patient showed, in addition to improvement of the features of hepatic outflow obstruction, significant reduction of dyspnea, cyanosis, and hypoxemia with arterial blood gas normalization within 2 weeks and intrapulmonary shunt reversal within 8 weeks. This implies that hemodynamic alterations (such as portal hypertension) independently contribute to the pathogenesis of hepatopulmonary syndrome in at least some of the cases. Therapies aimed at correcting these abnormal hemodynamics may be important in the treatment of this condition, especially when the hepatic functional status by itself does not warrant a liver transplant.

[Hepatopulmonary syndrome]

ANAMNESIS

We report about a 60-year-old woman with hepatopulmonary syndrome. The patient suffered from progressive dyspnea and liver cirrhosis following viral hepatitis C, acquired through blood transfusion 30 years ago.

EXAMINATION RESULTS

Remarkable were clinical signs of chronic liver disease (cutaneous spider naevi, palmar erythema) and signs of chronic respiratory failure (clubbing) with platypnea. Arterial pO2 was 33 mm Hg under 41 O2/min nasal oxygen supplement and improved to 74 mm Hg under 81 O2/min. Arterial pO2 deteriorated in upright position (orthodeoxia). Contrast enhanced two-dimensional transthoracic echocardiography showed a delayed microbubble opacification in the left heart chambers (without atrial or ventricular septal defect), suggesting pulmonary vascular dilatations. Perfusion scan with macroaggregated albumin labelled with technetium-99m showed uptake over thyroid, kidneys, liver, and spleen suggesting an abnormal passage through the pulmonary vascular bed. The radiological examination with chest radiography and high resolution computer tomography revealed no signs of interstitial lung disease. The pulmonary artery angiography showed neither anatomical shunts nor malformations.

DIAGNOSIS

The final diagnosis was hepatopulmonary syndrome Type 1. TREATMENT/FOLLOW-UP: The patient underwent liver transplantation with following good function of the liver graft. After 6 months the patient presented in a much better general condition, but with persisting severe hypoxemia whereas the spider naevi disappeared completely. One year after the liver transplantation in the perfusion scan the uptake over thyroid, kidneys, liver, and spleen was absent. The orthodeoxia and hypoxemia improved evidently. From that we conclude that the pulmonary vascular dilatations diminished after liver transplantation.

The hepatopulmonary syndrome

The hepatopulmonary syndrome occurs in subjects with chronic liver disease and/or portal hypertension who develop intrapulmonary vasodilation resulting in arterial deoxygenation. Clinical and basic science studies investigating the pathophysiology of HPS are presented. A diagnostic algorithm is provided using contrast echocardiography, the lung perfusion scan, and pulmonary angiography. Medical therapy and experience with liver transplantation are reviewed.

Effects of hypoxemia on early postoperative course of liver transplantation in pediatric patients with intrapulmonary shunting

Nine pediatric patients (mean age, 10 years) with biliary atresia, who had hypoxemia related to intrapulmonary shunting, underwent living related liver transplantation. The effects of hypoxemia during the early postoperative period after liver transplantation on cardiopulmonary and renal function, as well as on transplanted liver, were analyzed. Based on the degree of shunt ratio calculated by technetium-99m macroaggregated albumin scintigraphy, the nine patients were included in the moderate group (shunt ratio under 40%, n=4) or the severe group (shunt ratio over 40%, n=5). Partial pressure of arterial oxygen was maintained at normal range in the moderate group, while that in the severe group persistently had very low values (<50 mmHg), in spite of a high degree of oxygen supply. However, all patients in the severe group maintained stable cardiopulmonary vital signs, including systemic blood pressure, heart rate, respiratory rate, and cardiac index. They also demonstrated stable renal function. None of the patients died of cardiopulmonary or renal insufficiency after transplantation, but three patients died of portal vein thrombosis, sepsis, and intracranial hemorrhage (one each). The minimal adverse effect of hypoxemia on the transplanted liver was confirmed by a rapid increase of arterial ketone body ratio, low peak values (under 200 IU/L) of aspartate aminotransferase, and a steady decrease of serum total bilirubin. Four patients encountered surgical complications, including two bile leaks from the cut liver surface, two leaks from bilioenteric anastomosis, and one intestinal perforation. Six patients suffered from bacterial infections, including four wound infections, three right subphrenic abscesses, one cholangitis, and two systemic sepses. All patients in the moderate group recovered from hypoxemia, but four of five patients in the severe group have not recovered during the follow-up period between 4 and 9 months. It was concluded that the adverse effects of hypoxemia on cardiopulmonary and renal function and transplanted liver were minimal, so that patients with severe hypoxemia could tolerate the stress of liver transplantation without special management. However, the high incidence of surgical complication and infection suggested the adverse effects of hypoxemia on wound healing and resistance to bacteria infection.

Hepatopulmonary syndrome with progressive hypoxemia as an indication for liver transplantation: case reports and literature review

In the hepatopulmonary syndrome (HPS), a pulmonary vascular complication of liver disease, severe hypoxemia due to pulmonary vascular dilatation can be extremely debilitating. Determining whether patients with advanced liver disease and HPS should be considered for liver transplantation is difficult. We describe three patients with progressive and severe hypoxemia who underwent successful liver transplantation and had resolution of their arterial hypoxemia. In these patients, the progressive pulmonary deterioration accelerated the need and was considered an indication for liver transplantation rather than being considered an absolute or relative contraindication. In addition, we review the literature on 81 pediatric and adult patients with HPS who underwent liver transplantation and specifically highlight mortality, morbidity, syndrome resolution, and prognostic factors. Posttransplantation mortality (16%) was associated with the severity of hypoxemia (mean arterial oxygen tension [PaO2] in 68 survivors was 54.2 +/- 13.2 mm Hg and in 13 nonsurvivors was 44.7 +/- 7.7 mm Hg; P<0.03). Patients with a pretransplantation PaO2 of 50 mm Hg or lower had significantly more frequent mortality (30%) in comparison with those with a PaO2 greater than 50 mm Hg (4%; P<0.02). Pulmonary recommendations that address the severity of hypoxemia and candidacy for liver transplantation are discussed.

Scenario number one: hepatopulmonary syndrome

HPS is an increasingly recognized clinical entity resulting from intrapulmonary vasodilatation in patients with liver disease and/or portal hypertension. The pathogenesis of alterations in the pulmonary vascular bed in affected patients is poorly understood and the subject of ongoing investigation. The differential diagnosis of pulmonary symptoms and gas-exchange abnormalities in patients with liver disease being evaluated for transplantation is broad and should be focused on differentiating pulmonary causes that significantly increase the risk for transplantation from HPS where transplantation has emerged as a useful treatment. Specific contraindications to transplantation in patients with HPS have not been identified, though unique postoperative complications have been observed and may be treatable during the frequently prolonged resolution of intrapulmonary vasodilatation. The development of a database of information on patients with HPS undergoing transplantation will provide insight into potential contraindications, prognostic features, and postoperative complications unique to these patients.

Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.

Hepatopulmonary syndrome. A pulmonary vascular complication of liver disease

Hepatopulmonary syndrome is part of the spectrum of pulmonary vascular disorders seen in advanced liver disease. The pathophysiology of these entities likely is dependent on the degree of pulmonary vasoconstriction or vasodilation that occurs. Our understanding of hepatopulmonary syndrome has helped further our knowledge of the interaction of the liver and the lung. Advances in the management of this disorder, especially liver transplantation, finally have allowed us to offer some hope to patients with this disease.

Mechanisms of gas exchange impairment in patients with liver cirrhosis

This article reviews the basic pathophysiologic mechanisms underlying the abnormal pulmonary gas exchange often seen in patients with cirrhosis. To summarize, the following keypoints seem appropriate: (1) Patients with cirrhosis have a low pulmonary vascular tone characterized by a poor or absent hypoxic pressor response. This results in a marked dilation of the pulmonary vasculature. (2) This abnormal pulmonary vascular tone, independently of airway disease, causes VA/Q mismatch and mild to moderate hypoxemia. Yet, as liver disease progresses and hepatocellular function deteriorates, more severe degrees of intrapulmonary shunt emerge and, probably, O2 diffusion limitation ensues, causing severe respiratory failure (see Table 1). (3) At rest, the high cardiac output and minute ventilation of cirrhosis minimize the degree of arterial hypoxemia that otherwise would be expected from the observed degree of both VA/Q inequality and intrapulmonary shunt. During exercise, the relative "normalization' (with respect to metabolic demands) of the hemodynamic and ventilatory status of the patient explains the fall in PaO2. (4) A clear pathogenic mechanism of these pathophysiologic abnormalities is still lacking, although available evidence suggests that both the liver and the endothelial cells may play a pivotal role in the regulation of the pulmonary vascular tone in these patients. (5) To date, no pharmacologic intervention has been effective in treating hypoxemia in these patients. Yet liver transplantation helps in most of them. This observation reinforces the functional nature of the gas exchange abnormalities of cirrhosis.

The hepatopulmonary syndrome. Effect of liver transplantation

The role of liver transplantation as a treatment for the hepatopulmonary syndrome (HPS) has had an evolving and controversial history. Although early experience was disappointing, more recent experience has documented resolution of HPS-associated hypoxemia after liver transplantation. This article reviews the history of liver transplantation for patients with the hepatopulmonary syndrome. In addition, we discuss the clinical features that have been considered to predict successful reversibility and the time frame over which reversal occurs. Despite this evolution of thought, many basic questions still remain.

Diagnostic utility of contrast echocardiography and lung perfusion scan in patients with hepatopulmonary syndrome

BACKGROUND & AIMS

Two modalities, contrast echocardiography and lung perfusion scan, are used to identify intrapulmonary vascular dilatation and diagnose hepatopulmonary syndrome (HPS), but a comparison of these two procedures has not been performed. The aim of this study was to compare the use of these diagnostic modalities in detecting intrapulmonary vascular dilatation and diagnosing HPS.

METHODS

Forty consecutive outpatients with biopsy-proven cirrhosis had contrast echocardiography, a lung perfusion scan, and arterial blood gases analyzed.

RESULTS

Fifteen of 40 cirrhotics (38%) had positive contrast echocardiogram results. Seven patients with positive echocardiogram results had gas exchange abnormalities and could be considered to have HPS (7 of 40 [17.5%]). Three of these patients were hypoxemic and had no concurrent cardiopulmonary disease, and each had positive contrast echocardiogram and lung perfusion scan results and were readily diagnosed as having HPS. The other 4 patients (3 hypoxemic and 1 normoxemic with an elevated alveolar-arterial gradient) had coexisting intrinsic lung disease and/or chest radiograph abnormalities complicating the diagnosis of HPS, and each had positive echocardiogram and negative lung scan results. The remaining 8 patients with positive echocardiogram results had normal lung scan and normal gas exchange results. No patient had positive lung scan and negative contrast echocardiogram results.

CONCLUSIONS

Contrast echocardiography is the most useful screening test for intrapulmonary vasodilatation and may be positive more frequently than lung perfusion scans in patients with HPS.

Hepatopulmonary syndrome: what are we learning from interventional radiology, liver transplantation, and other disorders?

Interventional radiology (pulmonary angiography, coil embolotherapy, and TIPS) in patients with HPS seems to provide both diagnostic data and therapeutic results of clinical importance. The case report by Riegler et al. is instructive and emphasizes the need for further prospective study to analyze the successes and failures in terms of measurable clinical variable in a procedure such as TIPS. The resolution of hypoxemia following liver transplantation and careful patient selection offers hope to patients with severe, debilitating oxygenation abnormalities caused by HPS.

Pulmonary arteriovenous shunting in children with liver disease

Pulmonary arteriovenous shunting (PAVS) with hypoxemia is a severe complication of cirrhosis that may regress after liver transplantation. We report PAVS in 25 children with cirrhosis and in 1 with portal vein obstruction; proof of shunting was obtained by technetium Tc 99m microaggregated albumin pulmonary scanning or a high alveoloarterial O2 gradient or both. Cyanosis or dyspnea or both occurred at ages ranging from 6 months to 14 years, earlier in children with biliary atresia and polysplenia syndrome (p < 0.01). Mean arterial oxygen tension (PaO2) was 57 mm Hg (range, 42 to 81 mm Hg) during breathing of 21% O2 and 367 mm Hg (range, 179 to 535 mm Hg) in 100% O2. Cardiac index was always raised, significantly more in children with biliary atresia and polysplenia syndrome (p < 0.01). Seven untreated children died 3 months to 8 years after the diagnosis of PAVS. Eleven underwent liver transplantation: seven are alive (follow-up, 1 to 4 years) and have no signs of PAVS. The PaO2 value during breathing of 100% O2 was > 300 mm Hg in the survivors and < 200 mm Hg in the four nonsurvivors (p < 0.01). These results indicate (1) that PAVS can occur at any age in children with portal hypertension, and that the risk is highest and earliest in children with biliary atresia and polysplenia syndrome, (2) that early liver transplantation allows regression of PAVS, and (3) that the prognosis may in part be related to the level of PaO2 while the patient is breathing 100% O2. The results indicate that systematic screening for PAVS should be part of the examination of these children.

A prospective study of pulmonary function and gas exchange following liver transplantation

Pulmonary function and gas exchange were prospectively studied in 95 patients before and 9 to 15 months following liver transplantation. Pretransplant, the most common PF abnormality was impaired efficiency of gas exchange as measured by Dss. As a group, the mean Dss was 78.0 +/- 16.6 percent predicted and was found to be less than 80 percent predicted in 50 patients. As a group, patients with the most severe liver diseases clinically (Child's C classification) had the lowest mean Dss pretransplant. Posttransplant, three findings were of clinical importance: PaCO2 significantly improved posttransplantation, suggesting a resolution of pretransplant respiratory alkalosis. Expiratory airflow obstruction, measured by a change in the FEV1/FVC, was extremely uncommon posttransplant. Mean Dss improved significantly in patients with Child's C severity of liver disease. The most frequent deteriorations in Dss statistically were associated with posttransplant thoracotomy, ARDS, nonspecific pneumonitis, significant pleural effusions and hepatic retransplantation.