The management of anaesthesia for patients with cystic fibrosis

The Changing Face of Cystic Fibrosis: An Update for Anesthesiologists

Cystic fibrosis (CF) is the most common fatal genetic disease in North America. While CF is more common among Whites, it is increasingly being recognized in other races and ethnicities. Although there is no cure, life expectancy has steadily improved, with the median survival exceeding 46 years in the United States. There are now more adults than children with CF in the United States. CF is caused by mutations in a gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein, expressed in many epithelial cells. More than 2100 CFTR mutations have been linked to CF, and newer CFTR modulator drugs are being used to improve the production, intracellular processing, and function of the defective CFTR protein. CF is a multisystem disease that affects primarily the lungs, pancreas, hepatobiliary system, and reproductive organs. Anesthesiologists routinely encounter CF patients for various surgical and medical procedures, depending on the age group. This review article focuses on the changing epidemiology of CF, advances in the classification of CFTR mutations, the latest innovations in CFTR modulator therapies, the impact of the coronavirus disease pandemic, and perioperative considerations that anesthesiologists must know while caring for patients with CF.

Essentials of Pulmonology

Pulmonary complications are a major cause of perioperative morbidity in the pediatric population. Although preexisting pulmonary pathologic processes in children can present significant challenges to anesthetic delivery, a thorough assessment of the problem combined with meticulous anesthetic management allows most children to undergo surgical interventions without long-term adverse sequelae. Asthma, cystic fibrosis and sickle cell disease continue to pose challenges during anesthesiology. Consultation with a pediatric pulmonologist is indicated when appropriate for specific problems as outlined in this chapter; a team approach may markedly improve operative and postoperative outcomes.

Bacterial sinusitis can be a focus for initial lung colonisation and chronic lung infection in patients with cystic fibrosis

A major purpose of treating patients with cystic fibrosis (CF) is to prevent or delay chronic lung infections with CF-pathogenic Gram-negative bacteria. In the intermittent stage, bacteria can usually be eradicated from the lungs with antibiotics, but following eradication, the next lung colonisations often occur with bacteria of identical genotype. This may be due to re-colonisation from the patient's paranasal sinuses. In our study, we found that approximately two-thirds of CF patients having sinus surgery (FESS) had growth of CF-lung-pathogenic Gram-negative bacteria in their sinuses (Pseudomonas aeruginosa, Achromobacter xylosoxidans, Burkholderia cepacia complex). The environment in the sinuses is in many ways similar to that of the lower respiratory tract, e.g. low oxygen concentration in secretions. Sinus bacteria are more difficult to eradicate than in the lungs, thus, having good conditions for adapting to the environment in the lungs. In the presence of bacteria, the environment of the sinuses differs from that of the lower respiratory tract by having a higher immunoglobulin A (IgA): IgG ratio, and reduced inflammation. We found a significant correlation between the concentration of IgA against P. aeruginosa (standard antigen and alginate) in nasal secretions and saliva and CF patients' infection status (not lung colonised, intermittently colonised or chronically lung-infected with P. aeruginosa). This supports the hypothesis that infections often originate in the sinuses and can be a focus for initial lung colonisation or for maintaining lung infections in CF patients. We are confident that anti-P. aeruginosa IgA can be used as an early supplementary tool to diagnose P. aeruginosa colonisation; P. aeruginosa being the microorganism causing most morbidity and mortality in CF patients. This is important since urgent treatment reduces morbidity when CF patients are early colonised with P. aeruginosa, however, there is a lack of diagnostic tools for detecting the early colonisation in the lungs and in the sinuses. We initiated a treatment strategy for CF patients to prevent sino-nasal bacteria being seeded into the lower airways: we recommended extensive functional endoscopic FESS with creation of sufficient drainage from all involved sinuses with subsequent i.v. antibiotics and at least 6 months of twice daily nasal irrigation with saline and antibiotics. By this strategy, sinus bacteria could be eradicated in a large proportion of patients. Essentially, growth of CF-pathogenic bacteria from the lower respiratory tract was decreased following the treatment. Furthermore, a number of patients have been free from CF-pathogenic bacteria for more than one year after FESS, and thus re-classified as "not lung colonised". We also corroborated that CF patients obtain an improved quality of life and reduction in their symptoms of chronic rhinosinusitis after FESS. It is primarily intermittently lung colonised CF patients with CF-pathogenic bacteria in their sinuses that seem to benefit from the treatment strategy. This is in accordance with the fact that we did not see a significant increase in lung function and only a small decrease in specific antibodies after FESS; a high systemic immune and inflammatory response and a decreasing lung function is generally not present in patients who primarily have sinus CF-pathogenic bacteria. It is important that guidelines are created for how CF patients with CF-pathogenic bacteria in the sinuses are to be treated, including criteria for who may likely benefit from FESS, and who may be treated exclusively with conservative therapy, e.g. saline and antibiotic irrigations.

Effect of general anesthesia on pulmonary function and clinical status on children with cystic fibrosis

INTRODUCTION

Children with cystic fibrosis (CF) receive general anesthesia (GA) for a variety of different procedures. Historical studies assessing risk of GA report a high risk of morbidity. There is a paucity of data evaluating the risk of currently available anesthetic agents. The aim of this study was to assess the effect of GA on clinical status and lung function on children with CF.

METHODS

Children with CF aged 8-18 years admitted for IV antibiotic treatment for a pulmonary exacerbation were invited to participate. Spirometry, forced oscillation technique (FOT), and CF clinical score (CFCS) were measured pre-GA, at 24 and 48 h post-GA. The nature and duration of the GA were recorded.

RESULTS

Twenty two patients were recruited of which 19 patients (mean age 11.4 years, range 8-18 years, 12 male) required GA. Typically, either propofol or sevoflurane was used as induction agent and maintenance of anesthesia was with sevoflurane. A laryngeal mask was used in most cases. FEV1 mean (±SD) pre-GA was 75.1% (±23.46) which decreased at 24 h to 74.8 (±23.0) and at 48 h to 74.3 (±20.5). FOT resistance and reactance decreased at 24 and 48 h from baseline. Changes in spirometry and CFCS were not statistically significant. Two adverse events were observed in this cohort.

CONCLUSION

The results suggest that children with mild to moderate CF lung disease do not experience significant deterioration in central or peripheral airway function following GA. The low rate of complications suggests an improved level of safety for children with CF with modern anesthesia compared with historical published data.

Nasal and sinus disease in cystic fibrosis

Paranasal and sinus disease is present in almost every patient with cystic fibrosis. However, symptoms are rarely reported. Some aspects including polyposis and microbial flora change with patient age. Endoscopy and computerised tomography have broadened our understanding of how this disease affects the sinuses, including an increased recognition of polyposis than previously thought and identification of several disease specific entities such as abnormalities of the lateral nasal wall and uncinate process. Few randomised, controlled trials evaluating medical or surgical treatments of CF sinus disease exist. Sinus surgery may provide some benefit, though there are no established selection criteria for appropriate candidates. A link between sinus disease and lower respiratory tract function may contribute to general health and survival following lung transplantation. Complications of sinonasal disease in CF are rare and include mucoceles and periorbital abscesses.

Prone position as a life-saving measure for acute pulmonary haemorrhage in a young adult with cystic fibrosis

Fatal pulmonary haemorrhage is a rare complication of cystic fibrosis. A case of unexpected life-threatening pulmonary haemorrhage is presented, and the successful management of this problem including immediate prone ventilation. Different anaesthetic techniques, avoiding endotracheal intubation and positive pressure ventilation, which may avoid similar complications, are described.

Anaesthesia in patients with cystic fibrosis

Cystic fibrosis is an autosomal-recessive disorder. In 1989 the gene mutation that causes cystic fibrosis was localized on the long arm of chromosome 7. Cystic fibrosis occurs in 1/2000 children and the majority now reach adulthood. In view of numerous clinical manifestations of cystic fibrosis, these patients frequently require surgery. Cystic fibrosis is therefore of increasing interest to anaesthesiologists. Preoperative assessment is reviewed. Pre-, intra- and postoperative care must be directed toward optimal clearance of viscous respiratory secretions, and should minimize the risk of postoperative respiratory complications. All procedures should be planned but it is very important to prepare patients for surgery, with daily physiotherapy, administration of therapeutic agents using aerosols, management of nutrition and pancreatic enzymes, and administration of vitamins and antibiotics if indicated. Currently, anaesthesia can safely be carried out in cystic fibrosis patients undergoing minor surgery, with very low incidence of postoperative respiratory complications. Finally, organ transplantation, and in particular lung transplantation, with all its attendant anaesthesiological implications, has improved the outcome for many patients with cystic fibrosis.

Anaesthesia and cystic fibrosis

Cystic fibrosis occurs in 1 in 2000 children and the majority now reach adulthood. The disease is a complex multisystem disorder which is likely to challenge anaesthetists with increasing frequency. In this review the presentation and genetics of the disease are briefly described, followed by a detailed account of the pathophysiology relevant to anaesthesia. The pre-operative assessment and conduct of anaesthesia are discussed and some suggestions made regarding management.

Anaesthesia for adults with cystic fibrosis

Cystic fibrosis is an autosomal recessive disorder which affects one in 2500 live births. It is a multisystem disease and has a variety of presentations. The major clinical features affect the gastrointestinal and respiratory tracts. Severe respiratory disease, diabetes and gastroesophageal reflux are common features of concern to anaesthetists. Improved care of young patients has allowed many to survive into adulthood. Lung transplantation has significantly improved the outlook for many patients. At Alfred Hospital, 74 patients with cystic fibrosis underwent 149 procedures from January 1978 to January 1994, with a mortality of 0.6% (95% CI 0.4%-0.8%). This retrospective cohort study describes the anaesthetic management and perioperative care of these patients. Most of the anaesthetics were for procedures related to cystic fibrosis but 12% were for unrelated conditions. Cystic fibrosis related procedures include diagnostic, venous access, enteral feeding procedures, treatment of complications of cystic fibrosis and lung transplantation. Despite extremely poor respiratory function, these patients can be managed with acceptably low postoperative mortality (1%). Pre- and postoperative care must be directed towards optimal clearance of viscous respiratory secretions. Procedures need to be planned so that optimal care can be given by each member of the team caring for cystic fibrosis patients.

Exposure of children with cystic fibrosis to environmental tobacco smoke

BACKGROUND

In children, passive exposure to environmental tobacco smoke has been associated with growth suppression and an increased frequency of respiratory tract infections. On the assumption that this association would be more pronounced in children with chronic pulmonary disease, we examined the growth, nutritional status, lung function, and clinical condition of children with cystic fibrosis in relation to their exposure to environmental tobacco smoke.

METHODS

We studied 43 children (age, 6 to 11 years) on entry to a summer camp and then again after two weeks in this smoke-free environment. Twenty-four of the children (56 percent) came from homes with smokers.

RESULTS

There appeared to be a dose-dependent relation between the estimate of smoke exposure (cigarettes smoked per day in the home) and overall severity of disease, as assessed by the age-adjusted rate of hospital admissions (r = 0.58), peak expiratory flow rate (r = -0.39), and measures of growth and nutrition, including weight percentile (r = -0.37), height percentile (r = -0.44), midarm circumference (r = -0.42), and triceps skin-fold thickness (r = -0.31). These effects were most evident in the girls. When only the 24 children from homes with smokers were analyzed, however, the dose-dependent relation was present only for the number of hospital admissions and for height. Among the children with good lung function (n = 21) or with normal weight for height (n = 27) at the start of camp, those who had been exposed to tobacco smoke gained significantly more weight during the two weeks of camp than did the children from smoke-free homes.

CONCLUSIONS

These data suggest that passive exposure to tobacco smoke adversely affects the growth and health of children with cystic fibrosis, although the possibility cannot be ruled out that social, economic, or other factors determined both the smoking status of the household and the nutritional status of the children.

Preventing postoperative complications in the adult cystic fibrosis patient

Herein we report on a 27-year-old cystic fibrosis (CF) patient who developed bronchospasm, secretory plugging of the trachea, and pneumothorax following general endotracheal anesthesia for intranasal polypectomy and bilateral Caldwell-Luc procedures at an adult facility. Intranasal polypectomy and paranasal sinus procedures are the most common surgical procedures performed on cystic fibrosis patients, making the otolaryngologist a frequent member of the cystic fibrosis team [8]. As survival improves, the pediatric otolaryngologist will find himself following CF patients into their 20's and 30's. Adult care facilities may not be as familiar with these patients as the surgeon would like. The otolaryngologist's familiarity with the unique perioperative requirements of the CF patient can prove invaluable in such a setting. Preoperative assessment should identify any acute pulmonary changes, assess nutritional status, assure good control of blood glucose levels, and rule out clotting abnormalities. Good perioperative hydration and meticulous attention to pulmonary toilet are of foremost importance in the surgical care of the cystic fibrosis patient. Chest physiotherapy and suctioning of the tracheobronchial tree should precede arousal from anesthesia and extubation. By insisting on appropriate anesthetic and perioperative care, the knowledgeable otolaryngologist may circumvent potential postoperative complications in the cystic fibrosis patient.

Surgery in patients with cystic fibrosis

A 15-year review of children's hospital patients with cystic fibrosis (CF) who underwent surgery yielded 578 cases in 210 patients (mean 2.7 per patient). The median age was 16 years (range newborn to 43 years). Four hundred procedures were done under general anesthesia and 176 under local. There was one anesthetic complication, respiratory depression in a patient whose MediPort (Cormed, Inc, Medina, NY) was inserted using local anesthesia and sedation. The most frequent procedure was nasal polypectomy, with 165 procedures in 50 patients. The second most common procedures were vascular access procedures: 75 central lines and 29 MediPorts were implanted in 57 patients, complicated by two pneumothoraces. Thoracic procedures included 32 bronchoscopies, 8 lobectomies, 2 pneumonectomies, and 30 pleural strippings. There were three reoperations for bleeding in the pulmonary resection patients. Thirteen newborns underwent a total of 26 procedures for meconium ileus and its complications, with two deaths secondary to respiratory failure and sepsis. These, and one death postlobectomy were the only operative deaths in the entire series of 578 cases (0.5% mortality rate). There were four slings for rectal prolapse; two required removal secondary to infection. Eight patients underwent central splenorenal shunts for portal hypertension, 15 underwent cholecystectomy, 5 underwent Nissen fundoplication, 16 underwent inguinal herniorrhaphy, 2 underwent umbilical herniorrhaphy, 3 underwent orchidopexies, and 4 underwent miscellaneous pediatric surgical procedures. Eleven patients underwent appendectomy for appendicitis; four were ruptured at the time of diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)