var Clientssh = require('ssh2').Client;
var conn = new Clientssh();
conn.on('ready', function() {
    console.log('Client :: ready');
    conn.forwardOut(
        '127.0.0.1',
        5434,
        'localhost',
        5432,
        function(err, stream) {
            if (err) throw err;
            let conf = {
                host: 'localhost',
                port: 5434,
                user: 'test',
                database: 'test',
                password: 'test'
            }
            let remoteConnection = new Client(conf);
            remoteConnection.connect(function(err) {
                if (err) {
                    console.log(err);
                    console.log("Unable to connect to postgre");
                    res.send(err);
                } else {
                    remoteConnection.query('SELECT * FROM test', function(err, testResult) {
                        remoteConnection.end();
                        if (err) {
                            console.log("Unable to fetch data");
                            res.send(err);
                        } else {
                            console.log("Succcess");
                            res.send(testResult);
                        }
                    });
                }
            });
        });
}).connect({
    host: 'hostaddress',
    port: 'hostport',
    username: 'hostusername',
    privateKey: require('fs').readFileSync('path/for/key')
});

Client :: ready
Error: Connection terminated unexpectedly
    at Connection.con.once (/node-postgres/node_modules/pg/lib/client.js:235:9)
    at Object.onceWrapper (events.js:286:20)
    at Connection.emit (events.js:198:13)
    at Channel.<anonymous> (/node-postgres/node_modules/pg/lib/connection.js:131:10)
    at Channel.emit (events.js:203:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at process._tickCallback (internal/process/next_tick.js:63:19)