Indian Journal of Critical Care Medicine January 2015 Vol 19 Issue 1

The remaining 25% considered replacement only on Access this article online signs of infection. Routine prophylactic antibiotics was Quick Response Code: advocated by 36%. Website: www.ijccm.org

Results show that awareness on the use of chlorhexidine, ultrasound, correct management of arterial punctures DOI: 10.4103/0972-5229.148653 and protocol for CVC inserted in emergency departments needs to be increased. Regular training programs with the nursing staff on bundles of care related to insertion and maintenance of CVC are needed.[1-3]

American Society of Anesthesiologists guidelines[4] Permissive hypercapnia: are focused on elective insertions of CVC’s performed by anesthesiologists, but the Centers for Disease Is there any upper limit? Control and Prevention guidelines[5] also address emergency placements, peripherally inserted central catheters, pulmonary artery catheter and tunneled Sir, central lines. Safety or effi cacy of chlorhexidine in We read the article by Garg SK “Permissive hypercapnia: [1] neonates and infants aged <2 months remains an Is there any upper limit?” with great interest. The author has rightly focused on a current protective lung unresolved issue. Fluid administration sets need to ventilation strategy. Though there are several reports of be changed at 96 h intervals and tubings for blood extreme levels of hypercapnia tolerated by patients no products and lipid emulsions every 24 h. Routine safe upper limit has been described. We would like to replacement of CVCs on the basis of fever alone and add following facts. prophylactic administration of systemic antimicrobial agents is discouraged. Mandatory replacement is to Permissive hypercapnia allows for low-tidal volume be done within 48 h for all catheters inserted in an ventilation and hence minimizes ventilator associated emergency without aseptic precautions. lung injury. It also reduces infl ammatory response in lungs by attenuating free radical formation, nuclear Arushi Gupta, Tanvir Samra1, Neerja Banerjee, factor kappa- activation and increased tumor necrosis Rajesh Sood factor-, interleukin-1, 6, 8 production. On the contrary, Departments of Anaesthesia and Critical Care, Dr. Ram Manohar Lohia it impairs plasma membrane wound healing in injured Hospital, New Delhi, 1PGIMER, lungs in a pH dependent fashion[2] and also prevents Chandigarh, India alveolar fl uid resorption by inhibiting Na-K ATPase Correspondence: of alveolar epithelial cells. Sustained hypercapnia in Dr. Tanvir Samra, cases of pulmonary infection increases bacterial load C-II/77, Moti Bagh 1, New Delhi - 110 021, India. and may further aggravate lung injury. Hence in E-mail: [email protected] conditions of sepsis associated lung injury permissive

hypercarbia would be benefi cial. Elevated CO2 level also References induces mitochondrial dysfunction and impairs alveolar 1. Hewlett AL, Rupp ME. New developments in the prevention of epithelial cell proliferation. Hypercapnic acidosis intravascular catheter associated infections. Infect Dis Clin North Am increases ventilatory drive and if patient is not properly 2012;26:1-11. sedated and paralyzed, patient-ventilator dyssynchrony 2. Smith M. A care bundle for management of central venous catheters. may occur and result in increased transpulmonary Paediatr Nurs 2007;19:39-44. 3. Gullatte MM. Nursing management of external central venous catheters pressure. Previous animal studies have reported (CVCs). Adv Clin Care 1990;5:12-7. vasogenic cerebral edema in hypercapnic acidosis and 4. American Society of Anesthesiologists Task Force on Central Venous in human beings cerebral edema have been reported in Access, Rupp SM, Apfelbaum JL, Blitt C, Caplan RA, Connis RT, et al. severe respiratory acidosis associated with asthma.[3] Practice guidelines for central venous access: A report by the American Hypercapnia has a benefi cial effect on brain in an optimal Society of Anesthesiologists Task Force on Central Venous Access. Anesthesiology 2012;116:539-73. range. Lowering CO2 causes cerebral vasoconstriction 5. CDC. Guidelines for the Prevention of Intravascular Catheter-Related whereas increased CO2 results in cerebral edema. Hence, Infections. Available from: http://www.cdc.gov/hicpac/BSI/01-BSI- like any other drug “permissive hypercapnia” should guidelines-2011. [Last acessed on 2013 Dec 12].

5566 Indian Journal of Critical Care Medicine January 2015 Vol 19 Issue 1 be used judiciously and under strict hemodynamic 5. Weber T, Tschernich H, Sitzwohl C, Ullrich R, Germann P, Zimpfer M, monitoring. et al. Tromethamine buffer modifies the depressant effect of permissive hypercapnia on myocardial contractility in patients with acute respiratory distress syndrome. Am J Respir Crit Care Med Hypotension in this patient may not be attributed to 2000;162:1361-5. 6. Hotchkiss JR Jr, Blanch L, Murias G, Adams AB, Olson DA, hypercapnic acidosis. Though hypercapnic acidosis has a Wangensteen OD, et al. Effects of decreased respiratory frequency negative inotropic effect it increases net cardiac output by on ventilator-induced lung injury. Am J Respir Crit Care Med sympatho-adrenal stimulation and reduction in systemic 2000;161:463-8. vascular resistance.[4]

Usually hypercapnic metabolic acidosis doesn’t require Access this article online buffering as it has less effect on the cardiovascular Quick Response Code: Website: system. In situations where hemodynamic compromise www.ijccm.org occurs buffering should ideally be done by tris-hydroxy-amino-methane (THAM/Tromethamine), DOI: 10.4103/0972-5229.148655 as it does not release CO2 and more effective in the correction of pH. Weber et al. have also found that THAM attenuates the reversible myocardial depressant action of permissive hypercapnia in patients with acute respiratory distress syndrome.[5]

Last but not the least, it is not clear from the case whether the author tried recruitment maneuvers or A rare survival after how did they achieve optimum positive end-expiratory 2,4-D (ethyl ester) pressure as a strategy for open lung ventilation and preventing atelectrauma. Moreover, managing poisoning: Role of forced elevated PaCO2 by increasing tidal volume is now known to be unacceptable; however, management by alkaline diuresis increasing the respiratory rate, although common is of uncertain impact. For example, increasing respiratory rate frequency from 17 to 35/min adds over 25,000 Sir, additional opening and closing cycles per day to an We report a rare case of 2-4 D (ethyl ester) poisoning already injured lung, and laboratory data suggest that survived after treatment. This is probably the that this approach is associated with additional lung injury.[6] second case reported from India, who has survived after intentional poisoning with ethyl ester form of 2,4-D, Snehamayee Nayak, Atul Jindal marketed as a weed killer. Department of Pediatrics, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India A 19-year-old male patient was brought to the Correspondence: emergency department with alleged history of ingestion Dr. Atul Jindal, Deparment of Pediatrics, All India Institute of Medical Sciences, Raipur, of a liquid poison. Upon telephonic enquiry, the container Chhattisgarh - 492 099, India. had a brand name of Hit 44. Hit-44 is a weedicide with E-mail: [email protected] 2,4-D (ethyl ester) being the active ingredient. Re ferences 1. Garg SK. Permissive hypercapnia: Is there any upper limit? Indian J The patient had dissolved 3 teaspoons of Hit-44 in Crit Care Med 2014;18:612-4. a glass of water and consumed it at around 3:00 pm. 2. Caples SM, Rasmussen DL, Lee WY, Wolfert MZ, Hubmayr RD. Impact of buffering hypercapnic acidosis on cell wounding in The patient had a history of repeated vomiting of ventilator-injured rat lungs. Am J Physiol Lung Cell Mol Physiol gastric contents after its consumption. He also had 2009;296:L140-4. had a single generalized tonic-clonic seizure (GTCS) 3. Joyce RR, McGee WT. Hypercapnic cerebral edema presenting in a woman with asthma: A case report. J Med Case Rep 2011;5:192. after which he became drowsy. Patient was taken to a 4. Stengl M, Ledvinova L, Chvojka J, Benes J, Jarkovska D, Holas J, local hospital where gastric lavage was done around et al. Effects of clinically relevant acute hypercapnic and metabolic acidosis on the cardiovascular system: An experimental porcine study. 5:00 pm. He was then referred and received by us Crit Care 2013;17:R303. around 8:00 pm.

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