Unrecognized severe postoperative hypercapnia: a case of apneic oxygenation.

Transcutaneous pulse oximetry is increasingly being used to supplant arterial blood gas measurement as a means to monitor oxygenation. Previous studies have demonstrated that, despite inadequate ventilation, oxygenation can be maintained during delivery of supplemental oxygen by a process known as diffusion respiration. In this setting, severe hypercapnia and acidosis rapidly develop. This case report demonstrates that pulse oximetry is an unreliable means to monitor adequacy of ventilation. A 75-year-old woman in good health suffered a fracture of the right hip that necessitated arthroplasty. During postoperative recovery, she remained unresponsive while receiving 100% oxygen through an endotracheal tube; mechanical ventilation was not used. Pulse oximetry indicated a blood oxygen saturation of 94 to 96%; however, results of blood gas studies 3 1/2 hours postoperatively revealed profound hypercapnia (arterial carbon dioxide tension, 265 mm Hg) and acidosis (pH, 6.65) but confirmed normal oxygen levels (arterial oxygen tension, 213 mm Hg). Assisted ventilation resulted in normalization of the blood gases and an improved level of consciousness. The patient was then transferred to Mayo Clinic Rochester and had an uneventful recovery.

Utilization and outcomes of surgical gastrostomies and jejunostomies in an era of percutaneous endoscopic gastrostomy: a population-based study.

OBJECTIVE: To determine the indications for use of surgical gastrostomy (SG) and surgical jejunostomy (SJ) as feeding tubes, the complications, and the trends in the use of SG and SJ after the introduction of percutaneous endoscopic gastrostomy (PEG) at our institution in 1981. DESIGN: We conducted a retrospective, population-based cohort study of residents of Olmsted County, Minnesota, who received surgically placed feeding tubes between 1976 and 1989. MATERIAL AND METHODS: The medical records of all Olmsted County residents with surgical placement of a feeding tube during the designated study period were reviewed, and underlying conditions, complications, and survival were analyzed. RESULTS: Of 77 adult patients (mean age, 66 years; 48% women), 54 underwent SG and 23 had SJ. General anesthesia was used in 42 patients (55%). The indications for SG or SJ were stroke in 23 patients, cancer in 19, other central nervous system-related conditions in 16, and other conditions in 19. Among the numerous comorbid conditions, pulmonary disease (N = 44) and cardiac disease (N = 32) were most frequent. The median duration of follow-up was 181 days. Complications occurred in 31 of 54 patients (57%) with SG and in 13 of 23 (57%) with SJ. Of the 117 complications, 15% were considered major. Twenty patients (26%) resumed eating. Survival at 1, 6, and 12 months was 79%, 49% and 36%, respectively. Most deaths were due to the disease for which the feeding tube had been placed. In a Cox proportional hazards regression analysis, only age and hypoxemia were found to be significantly associated with survival. Hypoxemia, type of tube, central nervous system disease as indication for procedure, and previous aspiration were associated with failure to resume eating (P < 0.05). Survival was similar to that for our patients with PEG during the same period. The overall incidence of feeding tube placement increased throughout the study period. CONCLUSION: Patients who require enteral feeding tubes have multiple comorbid conditions that have a major influence on the outcome. The overall incidence of feeding tube placement increased after the introduction of PEG. In patients who require long-term enteral nutrition and are unable to have a feeding tube placed percutaneously, surgically placed feeding tubes have outcomes similar to those reported for patients with PEG.

Predictors of outcome after percutaneous endoscopic gastrostomy: a community-based study.

Percutaneous endoscopic gastrostomy (PEG) is used to provide nutrition for patients who are unable to eat but have a functionally intact gut. Clinical guidelines for PEG are uncertain and have been derived mainly from referral practices. We performed a population-based cohort study in 97 residents of Olmsted County, Minnesota, referred for PEG between January 1982 and December 1988 to determine complications, duration of tube feeding, and survival. Follow-up continued until death or February 1990. Inpatient and outpatient records were reviewed to determine indications, comorbid conditions, level of consciousness, and limitations in activities of daily living. Outcomes determined after referral for PEG included type and number of complications, tube removal, and survival. Statistical methods used included Kaplan-Meier and proportional hazards regression analyses. PEG placement was successful in 94% of patients. Although complications occurred in 70% of patients, they usually were minor (88%) and most occurred within 3 months. In 24 patients, tubes were removed because eating was resumed. The probability of surviving 30 days, 1.5 years, and 4 years after referral for PEG was 78%, 35%, and 27%, respectively. The major causes of death within and after 30 days were pneumonia, heart disease, and vascular disease of the central nervous system. An increased risk of death after referral for PEG placement was associated with older age, male gender, diabetes, and specific indications for PEG. If validated in other population-based studies, these predictors of survival after referral for PEG placement could be used to identify patients with a low probability of survival who may not benefit from PEG.