Full bladder on a Plane - What would you do?

Full bladder on a Plane

Long plane flights are generally not very comfortable, especially with a full bladder.  As the urine from the minor calyces flows to the major calyces, coalesce at the renal pelvis and drain down the ureters (bilaterally), to accumulate into the bladder, the detrusor (smooth) muscle (composed of transitional epithelium) begins to stretch. Stretch receptors send signals to the nervous system to stimulate special receptors located on the detrusor muscle (DM) of the bladder to contract and urethral sphincters to relax, but there are times when something goes awry resulting in no urine output. How can this be? is perhaps a question an unnamed man asked himself in the first 4 hours of a 10-hour flight from New York to China on China Southern Airlines (Cole, 2019). 

In normal circumstances, for urine to exit the bladder and into the outside world (by bladder contraction and sphincters relaxation) several neurological pathways must function properly: sympathetic, parasympathetic, and somatic. Before we journey through these pathways, keep in mind the following: Which pathway innervates the DM, external and internal urethral sphincters (EUS and IUS, respectively)? 

In sympathetic innervation (involuntary), preganglionic sympathetic neurons send acetylcholine (ACh) (a neurotransmitter) signal to bind to a nicotinic receptor (aka cholinergic receptor) on the sympathetic postganglionic neuron located in the pre-aortic plexus (Morton, 2015). The signal is sent down the postganglionic neuron, releases norepinephrine (NE) to bind beta (DM) and alpha (IUS) adrenergic receptors on 1) DM (to relax and expand) and 2) IUS (to close so that urine can accumulate) (Morton, 2015). See Figure 1. Side note, the IUS can be thought as the initial gate keeper of the flood gate. Summary: NE binds beta-adrenergic receptor and bladder expands and NE binds alpha-adrenergic receptor and IUS closes. 

In parasympathetic innervation (involuntary), preganglionic parasympathetic neuron sends ACh to bind to a nicotinic receptor (aka cholinergic receptor) on the parasympathetic postganglionic neuron (Morton, 2015). The ACh signal is sent down the parasympathetic postganglionic neuron which binds to muscarinic receptors on 1) BM (contracts) and 2) IUS (opens for urine to flow into the urethra) (Morton, 2015). See Figure 2. Important note, the IUS is before the prostate. Summary: ACh binds to muscarinic receptors on DM (bladder contact) and IUS (open).

All the while, the EUS is closed because ACh is bound to its nicotinic receptor. In order for the EUS to remain closed, it received constant innervation by a special nerve (pudendal n.) (Morton, 2015). During somatic innervation (voluntary), as action potentials travel down this specialized somatic nerve, the pre-bound ACh on nicotinic receptor of EUS is broken down (by an enzyme) and a new ACh (released by the action potential) binds to the same nicotinic receptor to maintain a closed state (Morton, 2015). However, when a person is ready to void, the innervation (by the specialized n.) stops, ACh is no longer sent to “reinforce” the closed state, and the EUS opens (Morton, 2015). See Figure 3. Summary: Somatic innervation relies on constant ACh release to maintain a closed EUS, if the signal is interrupted, an enzyme will break down the ACh bound to EUS muscle and the urine will flow out. 

So, now we know about bladder voiding. In the cause of the full bladder on a plane, the “pension” aged man had a history of prostate enlargement (remember the location of the IUS?). This is particularly troublesome because the prostatic urethra (channel passing from the bladder through the prostate, to penile urethral, out to the outside world) is constricted. Luckily (medically, not socially) on the plane were 2 quick-thinking surgeons who assessed that his bladder could rupture (Cole, 2019). 

So, surgeons punctured the gentleman’s bladder, made a catheter with a plastic oxygen tube from the plane, used a first-aid syringe, “a plastic straw from a milk carton and some tape” to drain the urine (Cole, 2019). But the syringe was too thin to be effective… so the surgeon used his mouth to suck the urine out and spit it “into an empty wine bottle” (Cole, 2019). About 30 minutes later, they were able to drain 800 mL of urine (Frishberg, 2019). These doctors were in the right biomedical ethic mindset: beneficence (doing what is best for the patient), justice (showed no discrimination throughout their task), and non-maleficence (do no harm by preventing further agonizing pain the patient felt [and I hope, achieved sterility of equipment by using the wine from the empty wine bottle to disinfect]). 

Figure 1 (Morton, 2015)

Figure 2 (Morton, 2015)

Figure 3 (Morton, 2015)

References: 

Cole, B. (2019, November 22). Surgeon on New York-bound flight sucks urine from blocked bladder of elderly passenger in life-saving procedure. Retrieved from https://www.newsweek.com/china-southern-airlines-doctor-passenger-saved-1473278.

Morton, D. (2015, October 5). Autonomic innervation of the Bladder. Retrieved from https://www.youtube.com/watch?v=x5Lv4M998Go.

Frishberg, H. (2019, November 22). Doctor saves life by sucking urine from man's bladder mid-flight to NYC. Retrieved from https://nypost.com/2019/11/22/doctor-saves-life-by-sucking-urine-from-mans-bladder-mid-flight-to-nyc/.