Pulmonary venous air embolism following accidental patient laceration of a hemodialysis catheter

Vascular air embolism: A silent hazard to patient safety

PURPOSE

To narratively review published information on prevention, detection, pathophysiology, and appropriate treatment of vascular air embolism (VAE).

MATERIALS AND METHODS

MEDLINE, SCOPUS, Cochrane Central Register and Google Scholar databases were searched for data published through October 2016. The Manufacturer and User Facility Device Experience (MAUDE) database was queried for "air embolism" reports (years 2011-2016).

RESULTS

VAE may be introduced through disruption in the integrity of the venous circulation that occurs during insertion, maintenance, or removal of intravenous or central venous catheters. VAE impacts pulmonary circulation, respiratory and cardiac function, systemic inflammation and coagulation, often with serious or fatal consequences. When VAE enters arterial circulation, air emboli affect cerebral blood flow and the central nervous system. New medical devices remove air from intravenous infusions. Early recognition and treatment reduce the clinical sequelae of VAE. An organized team approach to treatment including clinical simulation can facilitate preparedness for VAE. The MAUDE database included 416 injuries and 95 fatalities from VAE. Data from the American Society of Anesthesiologists Closed Claims Project showed 100% of claims for VAE resulted in a median payment of $325,000.

CONCLUSIONS

VAE is an important and underappreciated complication of surgery, anesthesia and medical procedures.

Outcome of home haemodialysis patients: a case-cohort study

BACKGROUND

Randomized, controlled comparisons between home haemodialysis (HHD) and centre haemodialysis (CHD) have not been performed to date. Reported survival benefits of HHD as compared with CHD from uncontrolled studies have been attributed largely to patient selection.

METHODS

In order to minimize a selection bias, we have compared the outcome of our HHD and CHD patients with a nested case-cohort study. For each patient trained for HHD at our dialysis centre between 1970 and 1995 (n=103), a corresponding match was searched from the CHD patients by retrospective chart analysis. The pairs were matched for sex, age (+/-5 years), time of dialysis therapy onset (+/-2 years) and renal disease category. For 58 of the 103 HHD patients, a corresponding matched CHD patient was identified. Both treatment groups had the same mean age (50+/-13 years) at dialysis onset and were comparable with respect to the Khan comorbidity index, prevalence and duration of hypertension, smoking habits, history of myocardial infarction, stroke and peripheral vascular disease. In both groups, approximately 50% of the patients were transplanted during the observation period.

RESULTS

HHD patients were hospitalized less often and tended to have fewer operations as compared with CHD patients. Survival was significantly longer in HHD as compared with CHD. Five, 10 and 20 year survival rates were 93 (n=55 patients at risk), 72 (41) and 34% (11) with HHD and 64 (38), 48 (26) and 23% (4) with CHD, respectively. This survival difference persisted after adjusting for predictors of mortality, i.e. age at onset of dialysis, year of start of dialysis therapy and Khan comorbidity index.

CONCLUSIONS

HHD offers a cheap and valuable alternative to CHD, with no apparent disadvantages.

Air embolism during insertion of central venous catheters

PURPOSE

To determine the clinical consequences of air embolism occurring during insertion of central venous catheters.

MATERIALS AND METHODS

A computer search of our interventional radiology database revealed that 11,583 central venous catheters were inserted between January 1, 1995 and August 1, 2000: 7,178 were nontunneled and 4,404 were tunneled. Air embolism was reported to have occurred in 15 patients. Air embolization was recognized by audible air aspiration during catheter insertion or by fluoroscopic visualization of air within the right atrium or pulmonary artery. The radiology reports and medical records of these 15 patients were reviewed.

RESULTS

All 15 patients had an air embolism occur during insertion of a tunneled central venous catheter. These included eight Ash catheters, five chest wall ports, one Tesio catheter, and one Pheres-Flow catheter. Four patients remained asymptomatic. Six patients had mild symptoms that quickly resolved with supplemental oxygen. Four had moderate symptoms that also resolved with supplemental oxygen. One patient died acutely as a result of the air embolism.

CONCLUSION

Air embolism is a rare but potentially fatal complication of central venous catheter procedures. In our series, all occurred during insertion of a tunneled catheter through a peel-away sheath. The administration of supplemental oxygen was an effective treatment in the majority of patients.