Your fear for your husband's safety and health is natural, for the love between husband and wife is a bond ordained by God. Yet remember why the Holy Scriptures give us examples of trials. The Evangelist recounts prophecies of bonds and suffering "to show that these things were done for our salvation," and that "the death of Jesus was the salvation of the world." So too, the perils of travel and the uncertainty of health are not outside God's providence. They are reminders that safety is not found in a smooth road alone, but in the God who governs the road.
Consider the ancient law, "eye for eye, and tooth for tooth." This was not given to unleash vengeance, "but that men should check boldness in aggression, by fear of suffering in return, and thus should neither do any evil to others, nor suffer any evil from others themselves." The purpose was to bind the hands of harm, to preserve both your eyes and the eyes of another. Pray then that God would bind every potential accident and every sickness, not to make your husband suffer, but to restrain any aggression against his body and to preserve him whole. Pray that his journey becomes a testament to God's protective hand, a binding up of danger by the fear of His power.
But do not suppose that hearing of God's protection is sufficient for salvation. Christ warned against "the care of this world, and the deceitfulness of riches," and in these He set down all vices, vainglory, gluttony, envy, and the rest. The care that consumes you now, the anxiety over travel and medical results, can become such a thorn. It can choke the word of peace in your heart. Take up instead the easy yoke of Christ. He says, "Be not afraid, hearing of a yoke, for it is easy: fear not, because I said, 'a burden,' for it is light." Cast this specific worry upon Him. Ask not merely for a clean medical report, but for the grace to accept whatever the Lord permits, knowing that even a sickness discovered can be the means of drawing down God's grace, making your husband better, and finding him safe in the day of ultimate healing.
Do not neglect the state of your husband's soul for the sake of his body. The Scripture shows that when we are like guilty officers, God sometimes permits physical trials to strip us of our false security, that the sword of the Spirit might work deeply. Yet even then, remember the children in the temple who sang to Christ as God. Their simple, trusting praise confounded the wise. Let your prayer be a simple, trusting song, believing that Christ, who is meek and lowly in heart, hears your plea. Labor to enter into the rest of trusting God fully, lest you fall after the example of unbelief. Fix your mind, your hope, your expectation, not on a journey free from trouble or a body free from sickness, but on the eternal rest where all journeys end and every tear is wiped away. Let this trial, whatever its outcome, be the herald that drives you both closer to the Great Physician.