Capnography and Respiratory Depression

Abstract

In order to determine whether opioid-naive patients at risk for respiratory depression are better monitored with either capnography or pulse oximetry and respiratory-rate assessment, the authors conducted a randomized, prospective trial. In 54 opioid-naive postoperative orthopedic patients at one hospital, capnography resulted in greater detection of respiratory depression, and the authors conclude that capnography may be more appropriate for use with postsurgical high-risk patients taking opioids on the general care nursing unit. Capnography's sensitivity in the detection of pauses in breathing in the sedated patient may have the added advantage of indicating those patients who may be at risk for obstructive sleep apnea. Further research is needed to confirm these results.

Characterisation and monitoring of postoperative respiratory depression: current approaches and future considerations

“…106 This technique is a near-surrogate measure of ventilation and perfusion, 17 and is more sensitive than oximetry because it measures ventilation rather than oxygenation, serving as an early indicator of OIRD. 17,136e139 In a study of postoperative patients, Hutchison and Rodriguez 137 reported that respiratory depression was detected at a significantly higher rate with capnography than with pulse oximetry. In another study, capnography was shown to detect compromised respiratory status earlier than both oxygen desaturation and diminished chest excursion.…”

Time to Throw Away Your Stethoscope?

“…In fact, recent literature suggests ventilation assessment using capnography in nonintubated patients undergoing sedation may improve practice by providing an "early warning system" for impending respiratory compromise and hypoxemia (Cacho et al, 2010;Lightdale et al, 2006;Soto, Fu, Vila, & Miguel, 2004;Vargo, 2000;Vargo et al, 2002). Current practice generally has an increased emphasis on pulse oximetry for all patients receiving sedation, perhaps enabling a false sense of security while increased PetCO 2 levels go undetected (DeWitt, 2001;Fu, Downs, Schweiger, Miguel, & Smith, 2004;Hutchison & Rodriguez, 2008;Maddox, Williams, Oglesby, Butler, & Colclasure, 2006). However, pulse oximetry does not measure ventilation and decreased arterial saturation (SaO 2 ) is often a late sign of patient deterioration (American Academy of Pediatrics, Committee on Drugs, 2002; American Society of Anesthesiologists Task Force on Sedation and Analgesia by non- Anesthesiologists, 2002;Greensmith & Aker, 1998;Lightdale et al, 2006).…”

“…This is a reason why oxygen desaturation is considered a late sign of respiratory compromise in hypoventilating patients. Capnography monitors expired CO 2 levels and produces a waveform for each respiration, which reveals respiratory rate and depth, the presence of apnea, and efficiency of ventilation or gas exchange (Eisenbacher & Heard, 2005;Hutchison & Rodriguez, 2008). The addition of capnography can detect early signs of hypoventilation that pulse oximetry cannot detect.…”

Eco-Friendly Green Synthesis of Silver Nanoparticles from Egyptian Honey: Evaluating its Antibacterial Activities

“…The green synthesis of AgNPs involves three primary steps, that must be evaluated in accordance with green chemistry perspectives (Dahl et al, 2007) selection of the solvent medium (Hutchison & Rodriguez, 2008) selection of an environmentally benign reducing agent, and (Anastas & Warner, 2000;Raveendran et al, 2003) selection of non-toxic substances for AgNP stability. Based on this approach, we have reviewed green chemistry type AgNP synthesis processes.…”