OUTCOMES:
Post-Poliomyelitis Syndrome (PPS)

 

BACKGROUND

 

It has been estimated that from 1928 to 1962, 500,000 Americans were afflicted by poliomyelitis and 75,000 required ventilatory support, which was invariably by negative pressure body ventilators like the iron lung and abdominal displacement body ventilators like the rocking bed. Twelve-and-a-half percent of those who required ventilatory support never weaned, but almost all were eventually transitioned from body ventilator use to noninvasive ventilatory support (NVS/CNVS) (PPS1,JBCV35). Even though many had “bulbar polio” that caused them to aspirate food and saliva, be unable to effectively clear their airway secretions, and have tracheostomy tubes placed as a result, most of the severely affected post-poliomyelitis syndrome patients died acutely, and the others had their tubes decannulated and survived without severe bulbar-innervated muscle dysfunction (BIMD). As a result, there are few post-poliomyelitis syndrome patients with severe BIMD today, and even those who may have BIMD, no matter how severe, do not require tracheostomy tubes since, as for SMA type 1 (see outcomes for spinal muscular atrophy), positioning, and assisted coughing can eliminate need to resort to tracheotomy.

 

None of our over 200 post poliomyelitis syndrome patients have tracheostomy tubes nor are they ever likely to need them.

 

The normal rate of loss of vital capacity (VC) is 1% per year for males and 1.2% per year for females after age 19-20. While it has been reported that post-poliomyelitis syndrome patients, who never required ventilator use, lose VC at a normal rate; those who do eventually develop late-onset ventilatory insufficiency, lose VC at a mean of 1.9% per year (JBCV9).

 

 

OUTCOMES OF CONVENTIONAL MANAGEMENT

 

From 1991 to 1995, 672 ventilator users with neuromuscular conditions, but without gastrostomy tubes (to exclude severe bulbar muscle impairment as a confounding variable), including 371 post-poliomyelitis syndrome patients, were surveyed regarding their pneumonia and hospitalization rates during their 13,574 patient-years of mechanical ventilation. In total, 394 used noninvasive ventilation during daytime hours and 469 during sleep whereas 146 used CTMV and another 53 only sleep tracheostomy mechanical ventilation (TMV). The TMV users used it a mean of 18.4 hours per day compared to 19.9 hr/day for those using NVS.

  • Hospitalizations and pneumonia rates were significantly higher for the TMV/CTMV users and even for those with tracheostomy tubes, who did not use ventilators than for those managed noninvasively, whether by CNVS or part-time NVS (JBCV126).

  • Those treated by oxygen administration alone had pneumonia and hospitalization rates that were higher than the TMV and NVS users and even significantly higher than symptomatic patients not introduced to TMV or NVS.

 

We could find no studies that estimated life expectancy for post-poliomyelitis syndrome patients with tracheostomy tubes, and since none of our over 200 post-poliomyelitis syndrome patients had them (or if they did, they were decannulated), this information does not seem to be available. However, as early as 1993, we noted that of the 27 deaths of individuals, mostly with post-poliomyelitis syndrome and supported by CTMV, at least 14 and possibly 10 others were due to complications directly associated with the tube (JBCV54).

 

 

OUTCOMES OF NONINVASIVE RESPIRATORY MANAGEMENT

 

Centers for Noninvasive Respiratory Management

 

In 1991, it was reported that 88% of post-poliomyelitis syndrome patients using body ventilators weaned completely from  them, but again were requiring at least part-time ventilatory assistance, this time usually by NVS (JBCV35). Indeed, as the number of CNVS users from onset of acute poliomyelitis was declining by attrition, the number of new post-poliomyelitis syndrome ventilator users was increasing. However, some were placed on or were continuing to use body ventilators like the iron lung. Though, negative pressure body ventilators cause obstructive sleep apneas (OSA), and many users began to complain of symptoms of OSA.

 

In 1993, we reported 101 post-poliomyelitis day and night noninvasive ventilatory support users, who predominately used mouthpiece NVS for daytime support and lipseal NVS for sleep for a mean of 13.4 years and up to 39 and 29 years (mouthpiece and lipseal, respectively). The majority (61/101) used CNVS with little or no ventilator-free breathing ability since having had acute poliomyelitis. These 101 were among 257 mouthpiece NVS users with various neuromuscular conditions (JBCV54).

 

In 1994, it was demonstrated that, whereas post-poliomyelitis syndrome patients who used nasal NVS for sleep experienced O2 desaturations every 6 to 20 minutes, severely fragmented sleep, and often mean O2 sat less than 95%; 22 of 27 (82%) post-poliomyelitis syndrome mouthpiece lipseal users’ O2 sats remained normal (>94%) and they had better quality sleep (JBCV93). Eighty percent of the lipseal users also had maximum end-tidal carbon dioxide (ETCO2) less than 45 mmHg during sleep (JBCV78). Patients using mouthpiece NVS without lipseals, like nasal NVS users, demonstrated a “sawtooth” pattern of O2 desats, and their O2 sat often averaged less than 95% (JBCV15,PPS3). These NVS users’ O2 sats decreased because the ventilator delivered  air (insufflated air) leaked out of their noses and mouths. At the O2 sat nadir, they had arousals, of which they were usually unaware, resulting in reflexively triggered oropharyngeal muscle activity to cut off the leak, and their O2 sats returned to normal.

 

Sleep NVS users who were hypercapnic during daytime hours and those receiving sedative medications had greater insufflation leakage and decreases in O2 sats while using NVS during sleep than unsedated people whose CO2 remained normal during daytime hours (JBCV78). Also, administration of supplemental O2 resulted in greater insufflation leakage, higher sleep CO2, and less effective nasal NVS during sleep (JBCV15,JBCV93). Thus, it is very important to avoid sedatives and O2 administration for NVS users. When excessive leak using the open systems of nasal or mouthpiece ventilation causes symptoms such as brief arousals gasping for air (about 3% of the time or 5/168), NVS users can be switched to using oronasal interfaces for NVS delivery. The 5 (of 168) lipseal NVS users with excessive leak closed their ventilation delivery systems by sealing their nostrils. They placed cotton swabs in their nostrils and covered the nostrils with tape every night (JBCV78). As for all older adolescent and adult patients, volume-preset ventilation was used for most NVS users at volumes of 800 to, in this case, 2000 mL with physiologic backup rates (JBCV78).

 

By 1995, of the 145 post-poliomyelitis syndrome NVS/CNVS users with mean VC of 710 ± 568 mL, 73 were late-onset and 72 were CNVS-dependent since acute poliomyelitis (JBCV92). Post-poliomyelitis syndrome patients, who had required no ventilator use during the acute period, were also described (JBCV35,PPS4). The 73 late-onset NVS users began NVS a mean of 29 ± 12.1 years post-polio (range 3-59) and had been using NVS for 13 ± 9 years even at that time. Forty-one progressed to require CNVS including two who had not required ventilatory support acutely (JBCV92). The avoidance of tracheotomy permited 59 of the CNVS users overall to master glossopharyngeal breathing for ventilator free breathing. Their average VC was only 481 mL, but their average glossopharyngeal breathing maximum single breath capacity was 2133 mL (JBCV92). Twenty-four post-poliomyelitis syndrome CNVS users with no ventilator free breathing ability at all could use glossopharyngeal breathing for hours and, indeed, up to all day if necessary (JBCV92).

 

 

OUTCOMES OF POST-POLIO EXTUBATION

 

Because post-poliomyelitis syndrome patients generally have intact or nearly intact bulbar-innervated (throat) muscle function, they are almost invariably easy to extubate and decannulate to CNVS and mechanical insufflation-exsufflation (MIE) irrespective of the extent of their dependence on respiratory support. Forty-seven “unweanable” post-poliomyelitis syndrome patients NVS/CNVS users were intubated 118 times and successfully extubated to CNVS without a single one requiring tracheotomy (JBCV126). More recently, another 13 “unweanable” post-poliomyelitis syndrome patients were successfully extubated to CNVS and MIE (JBCV197,JBCV235).

 

 

OUTCOMES OF POST-POLIO DECANNULATION

 

One hundred fifty eight post poliomyelitis syndrome patients, including many who were CTMV dependent, were decannulated to CNVS. Their pneumonia and hospitalization rates decreased significantly, whereas the pneumonia and hospitalization rates of the NVS/CNVS users who agreed to and underwent tracheotomy increased significantly on TMV (JBCV126). In 1993, we reported having decannulated 32 post-poliomyelitis syndrome patients from TMV/CTMV to NVS/CNVS (JBCV54). Since all of these CNVS users had access to MIE, none were ever re-trached and only four died from complications associated with their requirement for CNVS (JBCV54). More recently, 4 additional PPS CTMV users were successfully decannulated to CNVS (JBCV232).